Protective PLCG2 variants associate with a delayed onset of Alzheimer’s disease among heterozygous APOE ε4 carriers

Probably not a substantial claim: may not pass S3 (load-bearing).

TREM2-R62H (AF = 0.0078) is more common in the Finnish population than the TREM2-R47H (AF = 0.00045) AD risk variant.

“The TREM2-R62H (AF = 0.0078) is more common in the Finnish population than the more widely known TREM2-R47H (AF = 0.00045) AD risk variant [15, 25].”

• cites [15] Guerreiro R, Wojtas A, Bras J, Carrasquillo M, Rogaeva E, Majounie E, et al. TREM2 Variants in Alzheimer’s disease. N Engl J Med. 2013;368(2):117–27. sourcePartly supported

  The Results section identifies TREM2-R47H as an Alzheimer’s disease risk variant. The Methods section reports an R47H minor allele frequency of 0.003 from the 1000 Genomes Project, but the copy does not report R62H or either stated frequency in the Finnish population. It therefore does not support the claimed Finnish frequency comparison. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [25] Jonsson T, Stefansson H, Steinberg S, Jonsdottir I, Jonsson PV, Snaedal J, et al. Variant of TREM2 associated with the risk of Alzheimer’s disease. N Engl J Med. 2013;368(2):107–16. sourcePartly supported

  The Results section identifies TREM2-R47H as an Alzheimer’s disease risk variant. It reports an allele frequency for Iceland, not Finland; our copy does not establish the Finnish frequencies, discuss R62H, or compare the two variants there (searched: R62H, Finnish, and the stated frequencies). (LLM, conf=0.88)

  Experimental — accuracy not yet measured

May combine two claims.

PLCG2-P522R potentiates PLCγ2 function and mediates several beneficial effects on microglia function in in vivo and in vitro models.

“PLCG2-P522R, which potentiates PLCγ2 function, mediates several beneficial effects on microglia function in in vivo and in vitro models [5–10].”

• cites [5] Coulon A, Rabiller F, Takalo M, Roy A, Martiskainen H, Siedlecki-Wullich D, et al. Neuronal downregulation of PLCG2 impairs synaptic function and elicits Alzheimer disease hallmarks. bioRxiv; 2024. p. 2024.04.29.591575. https://doi.org/10.1101/2024.04.29.591575v1. Cited 2025 June 6 sourcePartly supported

  The Discussion (page unavailable) describes PLCG2-P522R as a functionally hypermorphic variant, supporting the claim that it potentiates PLCγ2 function. It also reports improved synaptic function and behavior in a mouse model, but does not establish the claimed beneficial effects on microglial function across both in vivo and in vitro models. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [6] Solomon S, Sampathkumar NK, Carre I, Mondal M, Chennell G, Vernon AC, et al. Heterozygous expression of the Alzheimer’s disease-protective PLCγ2 P522R variant enhances Aβ clearance while preserving synapses. Cell Mol Life Sci. 2022;79(8):453. sourcePartly supported

  The Background describes P522R as a mild hypermorph that may potentiate PLCγ2 enzymatic activity. The Results report beneficial effects in cultured microglia, including increased Aβ uptake and reduced synaptosome uptake. This paper does not report those effects in an in vivo model, so the in vivo portion is not supported by this source. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [7] Staley HA, Jernigan JE, Bolen ML, Titus AM, Neighbarger N, Cole C, et al. Alzheimer’s disease-associated protective variant Plcg2-P522R modulates peripheral macrophage function in a sex-dimorphic manner. J Neuroinflammation. 2024;1(21):280. sourceSupported
• cites [8] Takalo M, Wittrahm R, Wefers B, Parhizkar S, Jokivarsi K, Kuulasmaa T, et al. The Alzheimer’s disease-associated protective Plcγ2-P522R variant promotes immune functions. Mol Neurodegener. 2020;15(1):52. sourceSupported
• cites [9] Takalo M, Jeskanen H, Rolova T, Kervinen I, Hellén M, Heikkinen S, et al. The protective PLCγ2-P522R variant mitigates Alzheimer’s disease-associated pathologies by enhancing beneficial microglial functions. J Neuroinflammation. 2025;22(1):64. sourceSupported
• cites [10] Tsai AP, Dong C, Lin PBC, Oblak AL, Viana Di Prisco G, Wang N, et al. Genetic variants of phospholipase C-γ2 alter the phenotype and function of microglia and confer differential risk for Alzheimer’s disease. Immunity. 2023;56(9):2121-2136.e6. sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

PLCγ2 works downstream of TREM2.

“PLCγ2 works downstream of triggering receptor expressed on myeloid cells 2 (TREM2) [11].”

• cites [11] Keren-Shaul H, Spinrad A, Weiner A, Matcovitch-Natan O, Dvir-Szternfeld R, Ulland TK, et al. A unique microglia type associated with restricting development of Alzheimer’s disease. Cell. 2017;169(7):1276-1290.e17. sourceCould not verify

  The Results and Discussion describe a TREM2–TYROBP signaling complex and a TREM2-dependent phase of microglial activation, but they do not establish that PLCγ2 acts downstream of TREM2. Searches for PLCγ2, Plcg2, and phospholipase C gamma 2 did not locate a passage addressing that relationship. (LLM, conf=0.74)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Several AD risk-increasing variants in TREM2, such as R47H and R62H, have been recognized.

“In TREM2 gene, several AD associated risk increasing variants have been recognized, such as R47H and R62H [1, 13–15].”

• cites [1] Bellenguez C, Küçükali F, Jansen IE, Kleineidam L, Moreno-Grau S, Amin N, et al. New insights into the genetic etiology of Alzheimer’s disease and related dementias. Nat Genet. 2022;54(4):412–36. sourcePartly supported

  Table 1 in the GWAS meta-analysis lists two TREM2 variants associated with increased Alzheimer’s disease risk (odds ratios 1.41 and 2.39). The paper’s text does not identify those variants as R47H and R62H, so the named examples are not verified by our copy. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [13] Dijkstra JIR, Vermunt L, Venkatraghavan V, Ozhegov G, Coomans EM, Ossenkoppele R, et al. TREM2 risk variants and associated endophenotypes in alzheimer’s disease. Alzheimer’s Res Ther. 2025;17(1):57. sourceSupported
• cites [14] Lu Y, Liu W, Wang X. TREM2 variants and risk of Alzheimer’s disease: a meta-analysis. Neurol Sci. 2015;36(10):1881–8. sourceNot checked — no full text of the source
• cites [15] Guerreiro R, Wojtas A, Bras J, Carrasquillo M, Rogaeva E, Majounie E, et al. TREM2 Variants in Alzheimer’s disease. N Engl J Med. 2013;368(2):117–27. sourcePartly supported

  The Results report that several TREM2 variants are associated with Alzheimer’s disease and identify R47H as the most strongly associated. A search for R62H found no passage addressing that variant, so this source does not support the R62H example. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

TREM2 is selectively expressed in microglia and plays a key role in modulating cell survival, phagocytosis, and inflammatory responses.

“TREM2 is selectively expressed in microglia and it plays a key role in modulating the cell survival, phagocytosis, and inflammatory responses [3, 11, 12].”

• cites [3] Sims R, ARUK Consortium, GERAD/PERADES, CHARGE, ADGC, EADI, et al. Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer’s disease. Nat Genet. 2017;49(9):1373–84. sourcePartly supported

  The TREM2 discussion (section labeled Abstract; page not provided) reports high expression in microglia, with limited expression in other brain cell types. It also describes TREM2-DAP12-mediated immune activation, recognition of debris and amyloid deposits, and microglial proliferation. It does not specifically establish a role in cell survival or phagocytosis; recognition of debris alone does not establish phagocytosis. (LLM, conf=0.83)

  Experimental — accuracy not yet measured
• cites [11] Keren-Shaul H, Spinrad A, Weiner A, Matcovitch-Natan O, Dvir-Szternfeld R, Ulland TK, et al. A unique microglia type associated with restricting development of Alzheimer’s disease. Cell. 2017;169(7):1276-1290.e17. sourcePartly supported

  The Discussion reports that TREM2 is required for the phagocytic phase of disease-associated microglial activation. It does not establish that TREM2 is selectively expressed in microglia or that it modulates cell survival and inflammatory responses; the inflammatory-gene pattern noted in the Discussion is treated as a possible tissue-processing artifact. No page numbers are available in our copy. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites [12] Andreone BJ, Przybyla L, Llapashtica C, Rana A, Davis SS, Van Lengerich B, et al. Alzheimer’s-associated PLCγ2 is a signaling node required for both TREM2 function and the inflammatory response in human microglia. Nat Neurosci. 2020;23(8):927–38. sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

TREM2 risk variants impair TREM2 functions leading to reduced microglial activation and clearance of β-amyloid, which exacerbates disease pathology.

“These variants impair TREM2 functions leading to reduced microglial activation and clearance of β-amyloid, which exacerbates the disease pathology [3, 11, 12].”

• cites [3] Sims R, ARUK Consortium, GERAD/PERADES, CHARGE, ADGC, EADI, et al. Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer’s disease. Nat Genet. 2017;49(9):1373–84. sourcePartly supported

  The paper’s Abstract says TREM2 participates in recognition of amyloid deposits and microglial activation, and reports fewer plaque-associated microglia in TREM2 knockout mice. It says risk variants may reduce TREM2 signaling, but does not establish that these variants reduce β-amyloid clearance or thereby exacerbate pathology. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [11] Keren-Shaul H, Spinrad A, Weiner A, Matcovitch-Natan O, Dvir-Szternfeld R, Ulland TK, et al. A unique microglia type associated with restricting development of Alzheimer’s disease. Cell. 2017;169(7):1276-1290.e17. sourcePartly supported

  The Discussion (page unavailable) reports that full DAM activation and induction of phagocytic pathways depend on Trem2; it also says that absence of Trem2 at a late, but not early, stage of AD exacerbates disease manifestations. The study used Trem2-knockout mice, however, and does not establish that AD risk variants impair TREM2 function or directly show reduced clearance of β-amyloid caused by those variants. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [12] Andreone BJ, Przybyla L, Llapashtica C, Rana A, Davis SS, Van Lengerich B, et al. Alzheimer’s-associated PLCγ2 is a signaling node required for both TREM2 function and the inflammatory response in human microglia. Nat Neurosci. 2020;23(8):927–38. sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Neuronal downregulation of PLCG2 impairs synaptic function and triggers AD-related alterations.

“recent findings have revealed that neuronal downregulation of PLCG2 impairs synaptic function and triggers AD-related alterations, suggesting that changes in PLCγ2 levels and subsequent functions also within neurons are significant in the context of AD [5].”

• cites [5] Coulon A, Rabiller F, Takalo M, Roy A, Martiskainen H, Siedlecki-Wullich D, et al. Neuronal downregulation of PLCG2 impairs synaptic function and elicits Alzheimer disease hallmarks. bioRxiv; 2024. p. 2024.04.29.591575. https://doi.org/10.1101/2024.04.29.591575v1. Cited 2025 June 6 sourceSupported

Classified as probably not a substantial claim.

FinnGen is a biobank-scale cohort integrating genotype data from approximately 500,000 Finnish participants with longitudinal health information derived from national registries.

“FinnGen is a biobank-scale cohort integrating genotype data from approximately 500,000 Finnish participants with longitudinal health information derived from national registries.”

• cites [16] Kurki MI, Karjalainen J, Palta P, Sipilä TP, Kristiansson K, Donner KM, et al. FinnGen provides genetic insights from a well-phenotyped isolated population. Nature. 2023;613(7944):508–18. sourcePartly supported

  The Main section and Methods > Biobank samples confirm that FinnGen links genotype data from Finnish biobanks to longitudinal national health-register data. But the paper describes 500,000 participants as a goal, not the size of the genotyped cohort reported here: 412,000 samples had been collected and 224,737 participants were included in the study. (LLM, conf=0.91)

  Experimental — accuracy not yet measured

May combine two claims.

The PLCG2-P522R variant decreases the risk of Alzheimer's disease and increases longevity.

“Genetic studies have identified a protective P522R variant in the PLCG2 gene (PLCG2-P522R; rs72824905 C > G), which decreases the risk of Alzheimer’s disease (AD) and increases longevity [1–4].”

• Also stated in: § Background · plain

  “The PLCG2-P522R variant, which encodes a mildly hyperactive form of the PLCγ2 enzyme, has been identified as a protective genetic factor against Alzheimer’s disease (AD).”

• cites [1] Bellenguez C, Küçükali F, Jansen IE, Kleineidam L, Moreno-Grau S, Amin N, et al. New insights into the genetic etiology of Alzheimer’s disease and related dementias. Nat Genet. 2022;54(4):412–36. sourcePartly supported

  The GWAS meta-analysis table lists rs72824905 in PLCG2 with the G minor allele associated with lower Alzheimer’s disease odds (OR 0.74, 95% CI 0.68–0.81). Our copy does not report that this variant increases longevity; searches for P522R and longevity found no supporting passage. The paper reports an association with disease risk, not a demonstrated causal effect. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [2] Conway OJ, Carrasquillo MM, Wang X, Bredenberg JM, Reddy JS, Strickland SL, et al. ABI3 and PLCG2 missense variants as risk factors for neurodegenerative diseases in Caucasians and African Americans. Mol Neurodegener. 2018;11(13):53. sourcePartly supported

  The Results (Association of rs616338 and rs72824905 with AD; page unavailable) report an association between PLCG2-P522R and lower AD risk in the complete Caucasian cohort, though the non-overlapping replication cohort's result was not statistically significant. The paper does not report that the variant increases longevity (searched: longevity, lifespan, survival). (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [3] Sims R, ARUK Consortium, GERAD/PERADES, CHARGE, ADGC, EADI, et al. Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer’s disease. Nat Genet. 2017;49(9):1373–84. sourcePartly supported

  The paper’s Abstract identifies PLCG2-P522R (rs72824905) as a protective variant associated with decreased risk of late-onset Alzheimer’s disease (OR=0.68). The passages do not report that the variant increases longevity; a search for longevity found no supporting passage in our copy. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [4] Van Der Lee SJ, DESGESCO (Dementia Genetics Spanish Consortium), EADB (Alzheimer Disease European DNA biobank), EADB (Alzheimer Disease European DNA biobank), IFGC (International FTD-Genomics Consortium), IPDGC (The International Parkinson Disease Genomics Consortium), et al. A nonsynonymous mutation in PLCG2 reduces the risk of Alzheimer’s disease, dementia with Lewy bodies and frontotemporal dementia, and increases the likelihood of longevity. Acta Neuropathol. 2019;138(2):237–50. sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Ghrelin is a neuroprotective hormone secreted by cells in the stomach.

“Ghrelin, a neuroprotective hormone secreted by cells in the stomach, plays a key role in regulating the appetite and energy balance of the body [20, 29, 44].”

• cites [20] Thomas AS, Sassi M, Angelini R, Morgan AH, Davies JS. Acylation, a conductor of ghrelin function in brain health and disease. Front Physiol. 2022;30(13):831641. sourcePartly supported

  The Introduction describes ghrelin as a stomach peptide that stimulates hunger during low energy balance. It attributes beneficial effects in neurodegenerative disorders to acyl-ghrelin specifically, while reporting that unacylated ghrelin impairs neurogenesis and memory. Calling ghrelin generally neuroprotective therefore omits a distinction central to this review. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [29] Espinoza García AS, Martínez Moreno AG, Reyes CZ. The role of ghrelin and leptin in feeding behavior: Genetic and molecular evidence. Endocrinología, Diabetes y Nutrición (English ed). 2021;68(9):654–63. sourceNot checked — no full text of the source
• cites [44] Cowley MA, Smith RG, Diano S, Tschöp M, Pronchuk N, Grove KL, et al. The distribution and mechanism of action of ghrelin in the CNS demonstrates a novel hypothalamic circuit regulating energy homeostasis. Neuron. 2003;37(4):649–61. sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

TREM2 is one of the key receptors modulating PLCγ2 activity.

“TREM2 is one of the key receptors modulating PLCγ2 activity [12, 36, 37].”

• cites [12] Andreone BJ, Przybyla L, Llapashtica C, Rana A, Davis SS, Van Lengerich B, et al. Alzheimer’s-associated PLCγ2 is a signaling node required for both TREM2 function and the inflammatory response in human microglia. Nat Neurosci. 2020;23(8):927–38. sourceNot checked — no full text of the source
• cites [36] Ulland TK, Colonna M. TREM2 — a key player in microglial biology and Alzheimer disease. Nat Rev Neurol. 2018;14(11):667–75. sourceNot checked — no full text of the source
• cites [37] Krasemann S, Madore C, Cialic R, Baufeld C, Calcagno N, Fatimy RE, et al. The TREM2-APOE pathway drives the transcriptional phenotype of dysfunctional microglia in neurodegenerative diseases. Immunity. 2017;47(3):566. sourceCould not verify

  The Results section describes TREM2-dependent APOE signaling and changes in microglial gene expression, but does not address PLCγ2 activity. Searches for “PLCγ2 activity” and “Plcg2 phospholipase C gamma 2 TREM2 signaling” found no passage in our copy establishing the claimed modulation. (LLM, conf=0.72)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Ghrelin plays a key role in regulating appetite and energy balance.

“Ghrelin, a neuroprotective hormone secreted by cells in the stomach, plays a key role in regulating the appetite and energy balance of the body [20, 29, 44].”

• cites [20] Thomas AS, Sassi M, Angelini R, Morgan AH, Davies JS. Acylation, a conductor of ghrelin function in brain health and disease. Front Physiol. 2022;30(13):831641. sourceSupported
• cites [29] Espinoza García AS, Martínez Moreno AG, Reyes CZ. The role of ghrelin and leptin in feeding behavior: Genetic and molecular evidence. Endocrinología, Diabetes y Nutrición (English ed). 2021;68(9):654–63. sourceNot checked — no full text of the source
• cites [44] Cowley MA, Smith RG, Diano S, Tschöp M, Pronchuk N, Grove KL, et al. The distribution and mechanism of action of ghrelin in the CNS demonstrates a novel hypothalamic circuit regulating energy homeostasis. Neuron. 2003;37(4):649–61. sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

TREM2 variants associate with an increased risk of AD.

“Importantly, TREM2 variants associate with an increased risk of AD [15, 25, 38–40].”

• cites [15] Guerreiro R, Wojtas A, Bras J, Carrasquillo M, Rogaeva E, Majounie E, et al. TREM2 Variants in Alzheimer’s disease. N Engl J Med. 2013;368(2):117–27. sourceSupported
• cites [25] Jonsson T, Stefansson H, Steinberg S, Jonsdottir I, Jonsson PV, Snaedal J, et al. Variant of TREM2 associated with the risk of Alzheimer’s disease. N Engl J Med. 2013;368(2):107–16. sourceSupported
• cites [38] Huang M, Wang D, Xu Z, Xu Y, Xu X, Ma Y, et al. Lack of genetic association between TREM2 and Alzheimer’s disease in East Asian population. Am J Alzheimers Dis Other Demen. 2015;30(6):541–6. sourceNot checked — no full text of the source
• cites [39] Jiang T, Tan L, Chen Q, Tan MS, Zhou JS, Zhu XC, et al. A rare coding variant in TREM2 increases risk for Alzheimer’s disease in Han Chinese. Neurobiol Aging. 2016;1(42):217.e1-217.e3. sourceNot checked — no full text of the source
• cites [40] Jin SC, Benitez BA, Karch CM, Cooper B, Skorupa T, Carrell D, et al. Coding variants in TREM2 increase risk for Alzheimer’s disease. Hum Mol Genet. 2014;23(21):5838–46. sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

APOE ε4 disrupts lipid homeostasis and immune response and causes mitochondrial dysfunction.

“APOE ε4 is known to disrupt lipid homeostasis and immune response and to cause mitochondrial dysfunction [31–34]”

• cites [31] Hansen DV, Hanson JE, Sheng M. Microglia in Alzheimer’s disease. J Cell Biol. 2018;217(2):459–72. sourcePartly supported

  The section on microglia and tau pathology reports heightened microglial response with apoE4 in a mouse model and suggests apoE4 may exacerbate neuroinflammation. The human-genetics section describes ApoE’s lipid-transport role, but does not establish that ε4 disrupts lipid homeostasis; neither passage establishes that ε4 causes mitochondrial dysfunction. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [32] Lin YT, Seo J, Gao F, Feldman HM, Wen HL, Penney J, et al. APOE4 causes widespread molecular and cellular alterations associated with Alzheimer’s disease phenotypes in human iPSC-derived brain cell types. Neuron. 2018;98(6):1141-1154.e7. sourceSupported
• cites [33] Pires M, Rego AC. Apoe4 and Alzheimer’s disease pathogenesis—mitochondrial deregulation and targeted therapeutic strategies. Int J Mol Sci. 2023;24(1):778. sourceSupported
• cites [34] Sienski G, Narayan P, Bonner JM, Kory N, Boland S, Arczewska AA, et al. APOE4 disrupts intracellular lipid homeostasis in human iPSC-derived glia. Sci Transl Med. 2021;13(583):eaaz4564. sourcePartly supported

  The Abstract reports that APOE4 disrupted lipid homeostasis in human iPSC-derived astrocytes and yeast, supporting that part of the claim. The passages retrieved for immune response and mitochondrial dysfunction do not report either effect; the References mention a study of mitochondria-associated membranes, but that does not establish mitochondrial dysfunction in this paper. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

TREM2 deficiency leads to impaired microglial response to β-amyloid plaques, accumulation of lipid droplets, and increased β-amyloid load in the brain.

“TREM2 deficiency leads to impaired microglial response to β-amyloid plaques, accumulation of the lipid droplets, and increased β-amyloid load in the brain [11, 41].”

• cites [11] Keren-Shaul H, Spinrad A, Weiner A, Matcovitch-Natan O, Dvir-Szternfeld R, Ulland TK, et al. A unique microglia type associated with restricting development of Alzheimer’s disease. Cell. 2017;169(7):1276-1290.e17. sourcePartly supported

  The Results and Discussion (page numbers unavailable in our copy) show that Trem2-deficient 5XFAD mice fail to develop fully activated disease-associated microglia, whose program includes phagocytic and lipid-metabolism pathways. This supports an impaired microglial response, but the paper does not report lipid-droplet accumulation or an increased brain β-amyloid load caused by TREM2 deficiency. (LLM, conf=0.88)

  Experimental — accuracy not yet measured
• cites [41] McQuade A, Coburn M, Tu CH, Hasselmann J, Davtyan H, Blurton-Jones M. Development and validation of a simplified method to generate human microglia from pluripotent stem cells. Mol Neurodegener. 2018;13(1):67. sourceCould not verify

  The Results section on IDE1-treated microglia reports TREM2 expression, and the functional-validation Results report uptake of beta-amyloid fibrils by cells made using two differentiation methods (page numbers unavailable). Neither passage addresses TREM2 deficiency, responses to plaques, lipid droplets, or brain amyloid load. Searches for the claimed deficiency and those outcomes found no passage that does. (LLM, conf=0.76)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Ghrelin reduces the number of inflammatory M1 type microglia in cerebral ischemic injury.

“and reduce the number of inflammatory M1 type microglia in cerebral ischemic injury [52].”

• cites [52] Tian R, Mao G. Ghrelin reduces cerebral ischemic injury in rats by reducing M1 microglia/macrophages. Eur J Histochem. 2022;66(1):3350. sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Ghrelin treatment suppresses inflammatory response and reduces reactive oxygen species production in microglial cells.

“Yet, ghrelin treatment has been shown to suppress inflammatory response and reduce reactive oxygen species production in microglial cells [53, 54].”

• cites [53] Lee JY, Yune TY. Ghrelin inhibits oligodendrocyte cell death by attenuating microglial activation. Endocrinol Metab. 2014;29(3):371–8. sourceSupported
• cites [54] Moon M, Kim HG, Hwang L, Seo JH, Kim S, Hwang S, et al. Neuroprotective effect of Ghrelin in the 1-Methyl-4-Phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson’s disease by blocking microglial activation. Neurotox Res. 2009;15(4):332–47. sourceNot checked — no full text of the source

Classified as probably not a substantial claim. May combine two claims.

Ghrelin can pass through the blood-brain barrier, directly affecting brain cells.

“It has been shown that ghrelin can pass through the blood–brain barrier, directly affecting brain cells [46, 48–50].”

• cites [46] Rhea EM, Salameh TS, Gray S, Niu J, Banks WA, Tong J. Ghrelin transport across the blood–brain barrier can occur independently of the growth hormone secretagogue receptor. Mol Metab. 2018;18:88–96. sourceSupported
• cites [48] Russo C, Valle MS, Russo A, Malaguarnera L. The interplay between ghrelin and microglia in neuroinflammation: implications for obesity and neurodegenerative diseases. Int J Mol Sci. 2022;23(21):13432. sourceSupported
• cites [49] Banks WA, Tschöp M, Robinson SM, Heiman ML. Extent and direction of ghrelin transport across the blood-brain barrier is determined by its unique primary structure. J Pharmacol Exp Ther. 2002;302(2):822–7. sourceNot checked — no full text of the source
• cites [50] Diano S, Farr SA, Benoit SC, McNay EC, da Silva I, Horvath B, et al. Ghrelin controls hippocampal spine synapse density and memory performance. Nat Neurosci. 2006;9(3):381–8. sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Ghrelin reduces tau phosphorylation.

“It binds to growth hormone secretagogue receptor (GHSR), and it has been shown to protect neurons from β-amyloid-induced toxicity, reduce tau phosphorylation, and enhance synaptic plasticity [20, 44–46].”

• cites [20] Thomas AS, Sassi M, Angelini R, Morgan AH, Davies JS. Acylation, a conductor of ghrelin function in brain health and disease. Front Physiol. 2022;30(13):831641. sourceCould not verify

  The Introduction (page unavailable) describes acyl-ghrelin’s effects on neurogenesis and memory, and the acylation section discusses its association with dementia. Neither addresses tau phosphorylation. Searches for “tau phosphorylation” and “tau protein hyperphosphorylation” found no passage in our copy saying that ghrelin reduces it. (LLM, conf=0.72)

  Experimental — accuracy not yet measured
• cites [44] Cowley MA, Smith RG, Diano S, Tschöp M, Pronchuk N, Grove KL, et al. The distribution and mechanism of action of ghrelin in the CNS demonstrates a novel hypothalamic circuit regulating energy homeostasis. Neuron. 2003;37(4):649–61. sourceNot checked — no full text of the source
• cites [45] Kent BA, Beynon AL, Hornsby AKE, Bekinschtein P, Bussey TJ, Davies JS, et al. The orexigenic hormone acyl-ghrelin increases adult hippocampal neurogenesis and enhances pattern separation. Psychoneuroendocrinology. 2015;51:431–9. sourceCould not verify

  The Introduction discusses ghrelin’s effects on cognition and hippocampal plasticity, while the Results report increased neurogenesis in treated rats. Neither those passages nor searches for “tau phosphorylation” and phosphorylated tau address whether ghrelin reduces tau phosphorylation. (LLM, conf=0.76)

  Experimental — accuracy not yet measured
• cites [46] Rhea EM, Salameh TS, Gray S, Niu J, Banks WA, Tong J. Ghrelin transport across the blood–brain barrier can occur independently of the growth hormone secretagogue receptor. Mol Metab. 2018;18:88–96. sourceCould not verify

  The Introduction discusses ghrelin’s receptor binding and a protective effect in cortical neuronal injury, while the Discussion addresses transport across the blood–brain barrier. Neither passage addresses tau phosphorylation; searches for “tau phosphorylation” and related terms found no such finding in our copy. (LLM, conf=0.75)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Ghrelin could affect microglia functions indirectly by modulating other brain cell types that do express GHSR, such as neurons and astrocytes.

“Hence, ghrelin could affect microglia functions indirectly by modulating other brain cell types that do express the GHSR, such as neurons [53, 54, 57] and astrocytes [58].”

• cites [53] Lee JY, Yune TY. Ghrelin inhibits oligodendrocyte cell death by attenuating microglial activation. Endocrinol Metab. 2014;29(3):371–8. sourcePartly supported

  The Discussion reports that microglia and BV-2 cells lack GHS-R1a and that ghrelin inhibits microglial activation. It does not say that ghrelin acts indirectly through GHSR-expressing neurons or astrocytes; instead, it proposes a receptor-independent pathway in BV-2 cells and says the mechanism needs further study. (LLM, conf=0.85)

  Experimental — accuracy not yet measured
• cites [54] Moon M, Kim HG, Hwang L, Seo JH, Kim S, Hwang S, et al. Neuroprotective effect of Ghrelin in the 1-Methyl-4-Phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson’s disease by blocking microglial activation. Neurotox Res. 2009;15(4):332–47. sourceNot checked — no full text of the source
• cites [57] Xu H, Li Y, Liu R, Wu L, Zhang C, Ding N, et al. Protective effects of ghrelin on brain mitochondria after cardiac arrest and resuscitation. Neuropeptides. 2019;1(76):101936. sourceNot checked — no full text of the source
• cites [58] Fuente-Martín E, García-Cáceres C, Argente-Arizón P, Díaz F, Granado M, Freire-Regatillo A, et al. Ghrelin regulates glucose and glutamate transporters in hypothalamic astrocytes. Sci Rep. 2016;30(6):23673. sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

Ghrelin binds to growth hormone secretagogue receptor (GHSR).

“It binds to growth hormone secretagogue receptor (GHSR), and it has been shown to protect neurons from β-amyloid-induced toxicity, reduce tau phosphorylation, and enhance synaptic plasticity [20, 44–46].”

• cites [20] Thomas AS, Sassi M, Angelini R, Morgan AH, Davies JS. Acylation, a conductor of ghrelin function in brain health and disease. Front Physiol. 2022;30(13):831641. sourceSupported
• cites [44] Cowley MA, Smith RG, Diano S, Tschöp M, Pronchuk N, Grove KL, et al. The distribution and mechanism of action of ghrelin in the CNS demonstrates a novel hypothalamic circuit regulating energy homeostasis. Neuron. 2003;37(4):649–61. sourceNot checked — no full text of the source
• cites [45] Kent BA, Beynon AL, Hornsby AKE, Bekinschtein P, Bussey TJ, Davies JS, et al. The orexigenic hormone acyl-ghrelin increases adult hippocampal neurogenesis and enhances pattern separation. Psychoneuroendocrinology. 2015;51:431–9. sourceSupported
• cites [46] Rhea EM, Salameh TS, Gray S, Niu J, Banks WA, Tong J. Ghrelin transport across the blood–brain barrier can occur independently of the growth hormone secretagogue receptor. Mol Metab. 2018;18:88–96. sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

Ghrelin protects neurons from β-amyloid-induced toxicity.

“It binds to growth hormone secretagogue receptor (GHSR), and it has been shown to protect neurons from β-amyloid-induced toxicity, reduce tau phosphorylation, and enhance synaptic plasticity [20, 44–46].”

• cites [20] Thomas AS, Sassi M, Angelini R, Morgan AH, Davies JS. Acylation, a conductor of ghrelin function in brain health and disease. Front Physiol. 2022;30(13):831641. sourceCould not verify

  The Introduction discusses acyl-ghrelin’s effects on neurogenesis and memory, and the section on ghrelin acylation discusses dementia, but neither reports protection from β-amyloid-induced neuronal toxicity. Searches for β-amyloid, amyloid-beta-induced neuronal death, and Aβ toxicity found no passage addressing that specific claim. (LLM, conf=0.72)

  Experimental — accuracy not yet measured
• cites [44] Cowley MA, Smith RG, Diano S, Tschöp M, Pronchuk N, Grove KL, et al. The distribution and mechanism of action of ghrelin in the CNS demonstrates a novel hypothalamic circuit regulating energy homeostasis. Neuron. 2003;37(4):649–61. sourceNot checked — no full text of the source
• cites [45] Kent BA, Beynon AL, Hornsby AKE, Bekinschtein P, Bussey TJ, Davies JS, et al. The orexigenic hormone acyl-ghrelin increases adult hippocampal neurogenesis and enhances pattern separation. Psychoneuroendocrinology. 2015;51:431–9. sourcePartly supported

  The Introduction describes ghrelin as having neuroprotective properties, supporting the general idea of neuronal protection. It does not identify β-amyloid-induced toxicity as a condition against which ghrelin protects neurons; searches for amyloid-related toxicity found no such passage in our copy. (LLM, conf=0.78)

  Experimental — accuracy not yet measured
• cites [46] Rhea EM, Salameh TS, Gray S, Niu J, Banks WA, Tong J. Ghrelin transport across the blood–brain barrier can occur independently of the growth hormone secretagogue receptor. Mol Metab. 2018;18:88–96. sourcePartly supported

  The Introduction (page unavailable) says protective effects against cortical neuronal injury have been ascribed to desacyl ghrelin. It does not identify β-amyloid-induced toxicity as the cause of that injury, so it supports only the broader neuroprotection claim. (LLM, conf=0.82)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Microglia lack GHSR, the primary receptor for ghrelin.

“Moreover, microglia lack the GHSR, the primary receptor for ghrelin [53–55].”

• cites [53] Lee JY, Yune TY. Ghrelin inhibits oligodendrocyte cell death by attenuating microglial activation. Endocrinol Metab. 2014;29(3):371–8. sourceSupported
• cites [54] Moon M, Kim HG, Hwang L, Seo JH, Kim S, Hwang S, et al. Neuroprotective effect of Ghrelin in the 1-Methyl-4-Phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson’s disease by blocking microglial activation. Neurotox Res. 2009;15(4):332–47. sourceNot checked — no full text of the source
• cites [55] Kojima M, Hosoda H, Date Y, Nakazato M, Matsuo H, Kangawa K. Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature. 1999;402(6762):656–60. sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Elevated ghrelin levels exert anti-inflammatory effects, metabolic regulation, and promote cognitive enhancement.

“This is an interesting finding, as elevated ghrelin levels are known to exert anti-inflammatory effects, metabolic regulation, and promote cognitive enhancement [20, 45, 47].”

• cites [20] Thomas AS, Sassi M, Angelini R, Morgan AH, Davies JS. Acylation, a conductor of ghrelin function in brain health and disease. Front Physiol. 2022;30(13):831641. sourcePartly supported

  The Abstract (page unavailable) says acyl-ghrelin regulates energy homeostasis and enhances memory function, supporting the metabolic and cognitive parts of the claim. It distinguishes acyl-ghrelin from unacylated ghrelin, which it says inhibits memory-related processes. The passages found for “anti-inflammatory effects” and “inflammation” do not establish an anti-inflammatory effect, so the claim is not fully supported. (LLM, conf=0.86)

  Experimental — accuracy not yet measured
• cites [45] Kent BA, Beynon AL, Hornsby AKE, Bekinschtein P, Bussey TJ, Davies JS, et al. The orexigenic hormone acyl-ghrelin increases adult hippocampal neurogenesis and enhances pattern separation. Psychoneuroendocrinology. 2015;51:431–9. sourcePartly supported

  The Introduction says ghrelin regulates energy homeostasis, appetite, body weight, and adiposity, and describes pro-cognitive effects. The Discussion reports enhanced pattern-separation memory after elevated systemic acyl-ghrelin treatment. Neither section supports the attributed anti-inflammatory effect; a search of our copy for inflammation found no such passage. Page numbers were unavailable. (LLM, conf=0.87)

  Experimental — accuracy not yet measured
• cites [47] Walker A, Rivera P, Wang Q, Chuang JC, Tran S, Osborne-Lawrence S, et al. The P7C3 class of neuroprotective compounds exerts antidepressant efficacy in mice by increasing hippocampal neurogenesis. Mol Psychiatry. 2015;20(4):500–8. sourcePartly supported

  The Introduction (page not provided) describes ghrelin’s role in feeding and metabolic responses to stress, and says ghrelin signaling enhances memory retention. It does not state that elevated ghrelin levels exert anti-inflammatory effects; a References entry mentions a study of blocked microglial activation, but that does not establish the broader claim. (LLM, conf=0.84)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Ghrelin enhances synaptic plasticity.

“It binds to growth hormone secretagogue receptor (GHSR), and it has been shown to protect neurons from β-amyloid-induced toxicity, reduce tau phosphorylation, and enhance synaptic plasticity [20, 44–46].”

• cites [20] Thomas AS, Sassi M, Angelini R, Morgan AH, Davies JS. Acylation, a conductor of ghrelin function in brain health and disease. Front Physiol. 2022;30(13):831641. sourcePartly supported

  The Introduction (page unavailable) says ghrelin regulates brain plasticity, and the Abstract (page unavailable) says acyl-ghrelin promotes hippocampal neurogenesis and enhances memory. Those passages support a positive role in brain plasticity, but they do not specifically state that ghrelin enhances synaptic plasticity. (LLM, conf=0.76)

  Experimental — accuracy not yet measured
• cites [44] Cowley MA, Smith RG, Diano S, Tschöp M, Pronchuk N, Grove KL, et al. The distribution and mechanism of action of ghrelin in the CNS demonstrates a novel hypothalamic circuit regulating energy homeostasis. Neuron. 2003;37(4):649–61. sourceNot checked — no full text of the source
• cites [45] Kent BA, Beynon AL, Hornsby AKE, Bekinschtein P, Bussey TJ, Davies JS, et al. The orexigenic hormone acyl-ghrelin increases adult hippocampal neurogenesis and enhances pattern separation. Psychoneuroendocrinology. 2015;51:431–9. sourcePartly supported

  The Introduction says ghrelin treatments have been shown to affect measures of hippocampal synaptic plasticity, but does not say whether those measures increased. The Results report enhanced neurogenesis in adult rats, which the Introduction describes as a form of plasticity; that does not establish enhanced synaptic plasticity specifically. (LLM, conf=0.82)

  Experimental — accuracy not yet measured
• cites [46] Rhea EM, Salameh TS, Gray S, Niu J, Banks WA, Tong J. Ghrelin transport across the blood–brain barrier can occur independently of the growth hormone secretagogue receptor. Mol Metab. 2018;18:88–96. sourceCould not verify

  The Introduction describes ghrelin’s effects on olfaction and other functions, but does not address synaptic plasticity. A References entry names a study of hippocampal spine synapse density; our copy does not report its findings or state that ghrelin enhances synaptic plasticity. Searches for “synaptic plasticity” and hippocampal spine synapse density found no decisive passage in the paper’s text. (LLM, conf=0.72)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

The beneficial role of ghrelin in the central nervous system has been widely discussed, including enhanced cognition.

“Moreover, the beneficial role of ghrelin in the central nervous system has been widely discussed, including enhanced cognition [48, 59–61].”

• cites [48] Russo C, Valle MS, Russo A, Malaguarnera L. The interplay between ghrelin and microglia in neuroinflammation: implications for obesity and neurodegenerative diseases. Int J Mol Sci. 2022;23(21):13432. sourceSupported
• cites [59] Poher AL, Tschöp MH, Müller TD. Ghrelin regulation of glucose metabolism. Peptides. 2018;100:236–42. sourcePartly supported

  The section “Ghrelin’s effects beyond the stimulation of food intake” (page unavailable) discusses ghrelin’s effects on hypothalamic circuits and reports possible anxiolytic and antidepressant-like effects in mice. It does not report enhanced cognition; searches for cognition, memory, and learning found no supporting passage. (LLM, conf=0.84)

  Experimental — accuracy not yet measured
• cites [60] Reich N, Hölscher C. Acylated Ghrelin as a multi-targeted therapy for Alzheimer’s and Parkinson’s Disease. Front Neurosci. 2020;14(14):614828. sourceSupported
• cites [61] Stark R, Ashley SE, Andrews ZB. AMPK and the neuroendocrine regulation of appetite and energy expenditure. Mol Cell Endocrinol. 2013;366(2):215–23. sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Aged knock-in mice homozygous for Plcg2-P522R weighed less compared to their wild-type counterparts.

“Supporting this observation, we previously demonstrated that aged knock-in mice homozygous for the Plcg2-P522R weighed less compared to their wild-type counterparts [9].”

• cites [9] Takalo M, Jeskanen H, Rolova T, Kervinen I, Hellén M, Heikkinen S, et al. The protective PLCγ2-P522R variant mitigates Alzheimer’s disease-associated pathologies by enhancing beneficial microglial functions. J Neuroinflammation. 2025;22(1):64. sourcePartly supported

  The Results section (Fig. 7A; page unavailable) reports that homozygous PLCγ2-P522R knock-in mice weighed less than wild-type littermates, but only among females on the APP/PS1-negative background. It did not find the same difference among APP/PS1-hemizygous mice, so the unqualified claim is broader than the result. (LLM, conf=0.88)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Males showed lower leptin levels than females.

“However, males showed lower leptin levels than females (Supp. Figure 8 F).”

• AssumptionRests on an assumption: The plasma ghrelin levels measured in the FINGER cohort are representative of PLCG2-P522R carriers in the general population.

May combine two claims.

Within the APOE ε4/ε4 group, PLCG2-P522R variant or sex did not significantly affect AD onset age as compared to non-carrier AD patients.

“Within the APOE ε4/ε4 group, the PLCG2-P522R variant or sex did not significantly affect the AD onset age as compared to non-carrier AD patients (Fig. 1B and Supp. Figure 2C-D).”

• AssumptionRests on an assumption: The FinnGen AD endpoint based on ICD codes accurately identifies Alzheimer's disease cases.

May combine two claims.

PLCG2−3'UTR acts as a splice QTL across multiple tissues, driving a shift in splice acceptor site usage: the G allele is strongly associated with increased utilization of the annotated acceptor site at chr16:81,937,758 (e.g., Whole Blood, p = 3.7 × 10−11) and decreased use of a cryptic, unannotated site at chr16:81,937,823 (e.g., Whole Blood, p = 9.7 × 10−12).

“This analysis revealed that PLCG2−3’UTR acts as a splice QTL across multiple tissues, driving a shift in splice acceptor site usage: the G allele is strongly associated with increased utilization of the annotated acceptor site at chr16:81,937,758 (e.g., Whole Blood, p = 3.7 × 10⁻11) and decreased use of a cryptic, unannotated site at chr16:81,937,823 (e.g., Whole Blood, p = 9.7 × 10⁻12).”

Probably not a substantial claim: may not pass S3 (load-bearing).

There were no significant differences between sexes with respect to PLCG2-3'UTR.

“There were no significant differences between sexes with respect to PLCG2-3’UTR (Supp. Table 1, Supp. Figure 3A-B).”

• AssumptionRests on an assumption: The FinnGen AD endpoint based on ICD codes accurately identifies Alzheimer's disease cases.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

APOE genotype nor sex affected the levels of ghrelin or visfatin.

“APOE genotype nor sex affected the levels of ghrelin or visfatin (Supp. Figure 8A-E).”

• AssumptionRests on an assumption: The plasma ghrelin levels measured in the FINGER cohort are representative of PLCG2-P522R carriers in the general population.

May combine two claims.

The delayed anxiety onset effect was observed in female but not male PLCG2-P522R carriers.

“Notably, this effect was observed in female but not in male PLCG2-P522R carriers (Fig. 3C-E).”

• AssumptionRests on an assumption: The FinnGen AD endpoint based on ICD codes accurately identifies Alzheimer's disease cases.

Probably not a substantial claim: may not pass S3 (load-bearing).

There was no difference in ghrelin levels between PLCG2-P522R and PLCG2-3'UTR variant carriers.

“There was no difference between PLCG2-P522R and PLCG2-3’UTR variant carriers (Fig. 4A-B).”

• AssumptionRests on an assumption: The plasma ghrelin levels measured in the FINGER cohort are representative of PLCG2-P522R carriers in the general population.

May combine two claims.

In UK Biobank, PLCG2-P522R and PLCG2-3'UTR variants were not significantly associated with delayed onset of AD, except among individuals homozygous for PLCG2-3'UTR who also carried APOE ε3/ε4 (HR = 0.81, 95% CI: 0.66-0.98, p = 0.03).

“PLCG2-P522R and PLCG2-3'UTR variants were not significantly associated with delayed onset of AD, except among individuals homozygous for the PLCG2-3’UTR variant who also carried APOE ε3/ε4 (HR = 0.81, 95% CI: 0.66–0.98, p = 0.03) (Supp. Tables 4–7, Supp. Figure 5).”

• AssumptionRests on an assumption: The FinnGen AD endpoint based on ICD codes accurately identifies Alzheimer's disease cases.

May combine two claims.

There were no differences in APOE genotype-stratified analysis nor between sexes for 'Any Death' endpoint.

“Also, there were no differences in APOE genotype-stratified analysis nor between sexes (Fig. 3B, Supp. Figure 7A-D).”

Probably not a substantial claim: may not pass S3 (load-bearing).

There was a nominally significant difference in visfatin (p = 0.0056 before Bonferroni correction and p = 0.224 after correction).

“and a nominally significant difference in visfatin (p = 0.0056 before Bonferroni correction and p = 0.224 after correction).”

• AssumptionRests on an assumption: The plasma ghrelin levels measured in the FINGER cohort are representative of PLCG2-P522R carriers in the general population.

Probably not a substantial claim: may not pass S3 (load-bearing).

In similar analysis, there were no statistically significant differences in the levels of visfatin or leptin.

“In a similar analysis, there were no statistically significant differences in the levels of visfatin or leptin (Supp. Table 11–12).”

• AssumptionRests on an assumption: The plasma ghrelin levels measured in the FINGER cohort are representative of PLCG2-P522R carriers in the general population.

May combine two claims.

In FinnGen, both the PLCG2-P522R and PLCG2-3'UTR variants associated independently with a delayed age of AD onset, including among heterozygous APOE ε4 carriers.

“In FinnGen, both the PLCG2-P522R and PLCG2-3’UTR variants associated independently with a delayed age of AD onset, including among heterozygous APOE ε4 carriers.”

• AssumptionRests on an assumption: The FinnGen AD endpoint based on ICD codes accurately identifies Alzheimer's disease cases.

May combine two claims.

PLCG2-3'UTR variant is associated with a delayed onset of Alzheimer's disease, including among carriers of one APOE ε4 allele, with a weaker but significant effect.

“Both PLCG2 variants were associated with a delayed AD onset, also among carriers of one APOE ε4 allele, with the PLCG2-3’UTR variant showing a weaker, yet significant, effect.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Levels of plasma C-reactive protein (CRP) remained unaffected at baseline and during seven-year follow-up measurements between the carriers and controls.

“Furthermore, levels of plasma C-reactive protein (CRP), an indicator of inflammation, remained unaffected at baseline and during seven-year follow-up measurements between the carriers and controls (Supp. Figure 9).”

• AssumptionRests on an assumption: The plasma ghrelin levels measured in the FINGER cohort are representative of PLCG2-P522R carriers in the general population.

May combine two claims.

PLCG2-P522R is significantly associated with decreased onset age of type 2 diabetes (T2D), but only in males.

“Interestingly, when screening metabolism-associated endpoints in FinnGen, PLCG2-P522R was found to significantly associate with decreased onset age of type 2 diabetes (T2D), but only in males (Fig. 5A-C).”

• AssumptionRests on an assumption: The FinnGen AD endpoint based on ICD codes accurately identifies Alzheimer's disease cases.

May combine two claims.

No significant differences in waist circumference, BMI, and waist-to-height ratio between the genotypes were observed.

“No significant differences in these parameters between the genotypes were observed (Fig. 4D-F).”

• AssumptionRests on an assumption: The plasma ghrelin levels measured in the FINGER cohort are representative of PLCG2-P522R carriers in the general population.

May combine two claims.

The TREM2-R62H variant decreases the onset age of AD, especially in APOE ε4 carriers, both in FinnGen and UK Biobank.

“We found that the TREM2-R62H variant decreases the onset age of AD, especially in the APOE ε4 carriers, both in FinnGen and UK Biobank.”

May combine two claims.

In FinnGen, PLCG2-P522R variant is associated with delayed AD onset age in APOE ε3/ε4 carriers but not in APOE ε4/ε4 carriers, compared to non-carriers.

“In FinnGen, the protective PLCG2-P522R and PLCG2-3’UTR variants were associated with delayed AD onset age in APOE ε3/ε4, but not in APOE ε4/ε4 carriers, compared to non-carriers.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Carriers of the PLCG2-P522R variant showed significantly elevated plasma levels of ghrelin.

“Also, carriers of the PLCG2-P522R variant showed significantly elevated plasma levels of ghrelin.”

• AssumptionRests on an assumption: The plasma ghrelin levels measured in the FINGER cohort are representative of PLCG2-P522R carriers in the general population.

May combine two claims.

In FinnGen, PLCG2-3'UTR variant is associated with delayed AD onset age in APOE ε3/ε4 carriers but not in APOE ε4/ε4 carriers, compared to non-carriers.

“In FinnGen, the protective PLCG2-P522R and PLCG2-3’UTR variants were associated with delayed AD onset age in APOE ε3/ε4, but not in APOE ε4/ε4 carriers, compared to non-carriers.”

Probably not a substantial claim: may not pass S3 (load-bearing).

There was a slight trend towards a decrease in waist circumference among PLCG2-P522R-carrying females compared to PLCG2-3'UTR or TREM2-R62H variant carriers and non-carriers.

“although a slight trend towards a decrease was detected in the waist circumference among the PLCG2-P522R-carrying females as compared to PLCG2-3’UTR or TREM2-R62H variant carriers and non-carriers.”

May combine two claims.

Thomassen et al. reported that male APOE ε4/ε4 individuals with the TREM2-R62H variant had higher risk of AD compared to females, suggesting TREM2-R62H has a sex-dependent effect.

“However, in line with our findings, also Thomassen et al. [42] reported that male APOE ε4/ε4 individuals with the TREM2-R62H variant had higher risk of having AD as compared to females, suggesting that TREM2-R62H has sex-dependent effect.”

• cites [42] Thomassen JQ, Hampton L, Ulms B, Grenier-Boley B, Heikkinen S, Garcia P, et al. APOE stratified genome-wide association studies provide novel insights into the genetic etiology of Alzheimers’s disease. medRxiv; 2025. p. 2025.05.07.25327065. https://doi.org/10.1101/2025.05.07.25327065v1. Cited 2025 June 9 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

The low number of variant carriers limited the analysis of interaction between the PLCG2 and TREM2 variants.

“Unfortunately, the low number of variant carriers limited the analysis of interaction between the PLCG2 and TREM2 variants.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The observed association of male sex with increased risk for certain variants may reflect FinnGen-specific effects.

“Likewise, the observed association of male sex with increased risk for certain variants may reflect FinnGen-specific effects.”

May combine two claims.

Elevated plasma ghrelin levels observed in carriers of the PLCG2-P522R variant suggest a potential connection between this metabolic hormone and beneficial anti-inflammatory or cognitive effects, although its specific role in AD remains uncertain.

“Moreover, the elevated plasma ghrelin levels observed in the carriers of the PLCG2-P522R variant suggest a potential connection between this metabolic hormone and beneficial anti-inflammatory or cognitive effects, although its specific role in AD remains uncertain.”

• AssumptionRests on an assumption: The plasma ghrelin levels measured in the FINGER cohort are representative of PLCG2-P522R carriers in the general population.

Classified as probably not a substantial claim.

Separate APOE ε3/3, ε3/4, and ε4/4 groups were created to analyze effects of APOE ε4 because the cox models nor the extended cox models proportional hazard assumption were met.

“Separate APOE ε3/3, ε3/4, and ε4/4 groups were created to analyze the effects of APOE ε4 because the cox models nor the extended cox models proportional hazard assumption were met.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Our findings for TREM2-R62H may reflect characteristics specific to FinnGen rather than the entire Finnish population.

“Our findings for TREM2-R62H may reflect characteristics specific to FinnGen rather than the entire Finnish population, despite FinnGen representing ~ 10% of Finnish population.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Multiple regression analyses of ghrelin, leptin, and visfatin were done in SPSS adjusting for age, sex, and APOE ε4 carrier status.

“Multiple regression analyses of ghrelin, leptin, and visfatin were done in SPSS (v 29.0.0.0) adjusting for age, sex, and APOE ε4 carrier status.”

Probably not a substantial claim: may not pass S3 (load-bearing).

CRP levels > 10 were considered as a sign of acute inflammation and were excluded.

“CRP levels > 10 were considered as a sign of acute inflammation and were excluded.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Outliers from the data were identified using ROUT (Q = 1%) and excluded from the analysis and figures.

“Outliers from the data were identified using ROUT (Q = 1%) and excluded from the analysis and figures.”

Classified as probably not a substantial claim. May combine two claims.

Replication of the FinnGen AD onset age and cox regression model analyses were done in UK Biobank.

“Replication of the FinnGen AD onset age and cox regression model analyses were done in UK Biobank, which are described in Supplementary Methods.”

Classified as probably not a substantial claim.

APOE ε3/3 and APOE ε3/4 groups were analyzed using the cox model, including sex as covariate.

“APOE ε3/3 and APOE ε3/4 groups were analyzed using the cox model, including sex as covariate.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Model fit was tested using Schoenfeld residuals.

“Model fit was tested using Schoenfeld residuals.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Thomassen et al. showed that the TREM2-R62H variant significantly increases the risk of AD also in APOE ε3/3 carriers.

“This differs from Thomassen et al. [42] results, which showed that the TREM2-R62H variant significantly increases the risk of AD also in APOE ε3/3 carriers.”

• cites [42] Thomassen JQ, Hampton L, Ulms B, Grenier-Boley B, Heikkinen S, Garcia P, et al. APOE stratified genome-wide association studies provide novel insights into the genetic etiology of Alzheimers’s disease. medRxiv; 2025. p. 2025.05.07.25327065. https://doi.org/10.1101/2025.05.07.25327065v1. Cited 2025 June 9 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The PLCG2-3'UTR A allele, but not the G allele, associates with reduction of full-length PLCγ2 levels by introducing a premature stop codon.

“The PLCG2-3’UTR A allele, but not the G allele, associates with the reduction of the full-length PLCγ2 levels by introducing a premature stop codon”

Probably not a substantial claim: may not pass S3 (load-bearing).

Bonferroni correction was applied for the p-values to correct for multiple testing.

“Bonferroni correction was applied for the p-values to correct for multiple testing.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Ghrelin acts as a mitochondrial mediator and enhances mitochondrial fitness upon inflammation in macrophages.

“Furthermore, ghrelin has also been shown to act as a mitochondrional mediator and enhance mitochondrial fitness upon inflammation in macrophages [56].”

• cites [56] Corrêa da Silva F, Aguiar C, Pereira JAS, de Monteiro Brito L, Davanzo GG, Codo AC, et al. Ghrelin effects on mitochondrial fitness modulates macrophage function. Free Rad Biol Med. 2019;145:61–6. sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

The absence of mechanistic data related to plasma ghrelin findings in PLCG2-P522R carriers adds complexity to the interpretation of the obtained results.

“Finally, the absence of mechanistic data related to plasma ghrelin findings in PLCG2-P522R carriers add complexity to the interpretation of the obtained results”

Probably not a substantial claim: may not pass S3 (load-bearing).

Ghrelin affects microglia polarization to an anti-inflammatory M2 type.

“Interestingly, ghrelin has been observed to affect microglia polarization to an anti-inflammatory M2 type [51]”

• cites [51] Guo Y, Zhao J, Liu X, Lu P, Liang F, Wang X, et al. Ghrelin induces ferroptosis resistance and M2 polarization of microglia to alleviate neuroinflammation and cognitive impairment in Alzheimer’s Disease. J Neuroimmune Pharmacol. 2025;20(1):6. sourceNot checked — no full text of the source

May combine two claims.

The low frequency of the rare protective PLCG2-P522R variant reduces statistical power and prevents evaluation of its combined effects with rare TREM2 risk variants, either independently or among APOE ε4 carriers.

“First, the low frequency of the rare protective PLCG2-P522R variant reduces statistical power and prevents evaluation of its combined effects with rare TREM2 risk variants, either independently or among APOE ε4 carriers.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Genetic drift and lifestyle could influence variant frequencies and effect sizes, which may explain why replication in the UK Biobank revealed similar trends but not identical results with PLCG2 and TREM2 variants.

“Factors, such as genetic drift and lifestyle could influence variant frequencies and effect sizes, which may explain why replication in the UK Biobank revealed similar trends but not identical results with PLCG2 and TREM2 variants.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The observed association of male sex with increased AD risk could partly reflect biobank selection bias compared to purely population-based recruitment.

“For example, the observed association of male sex with increased AD risk could partly reflect biobank selection bias compared to purely population-based recruitment.”