A Real-Time Quantitative PCR Targeting the Viral Vector for the Monitoring of Patients Treated with Axicabtagene Ciloleucel
Open accessAbstract
Axicabtagene ciloleucel or axi-cel [CD19 chimeric antigen receptor (CAR) T cell] has been recently approved for refractory/relapsed diffuse large B-cell lymphoma and primary mediastinal B-cell lymphoma. Proliferation of CAR T cells after infusion and their persistence have been reported as important factors. Laboratory tools are needed for the monitoring of patients. We developed a vector-based, simple, and accurate real-time quantitative PCR (qPCR) to measure axi-cel vector copy number in peripheral blood samples. Primers and probe targeting the 5'LTR region of the gammaretroviral vector (mouse stem cell virus) were designed for amplification. To generate standard curves, mouse stem cell virus plasmid was subcultured and quantified using droplet digital PCR. The method was applied to quantify vector copy number in blood samples from patients treated with axi-cel. The limit of quantification of the qPCR assay was established at 2.2 copies/μL in DNA eluate. The qPCR method was well correlated with flow cytometry findings; however, the assay appeared to be more sensitive than flow cytometry. The kinetics observed in blood samples from treated patients were in agreement with previously reported findings. In conclusion, we developed a sensitive and accurate qPCR assay for the quantification of transgenic CAR T cells, which can be a useful additional tool for the monitoring of patients treated with axi-cel.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
An insufficient number of vector copies may result in low or absent CAR receptor expression, compromising product efficacy.
“Therapeutic Efficacy: an insufficient number of vector copies may result in low or absent CAR receptor expression, compromising product efficacy [27–30].”
From Harmonisation of quality control tests for academic production of CAR-T cells: a position paper from the WP-bioproduction of the UNITC consortium (2025) · cites this paper as [28]
The Introduction and Discussion (page unavailable) describe vector-copy quantification as a way to monitor CAR T cells and report that their persistence is a marker of long-term clinical efficacy. They do not establish that an insufficient number of vector copies causes low or absent CAR receptor expression, or that this mechanism compromises product efficacy. (LLM, conf=0.78)
Experimental — accuracy not yet measuredA high vector copy number raises the risk of insertional mutagenesis, where the vector integrates into genomic regions that could activate proto-oncogenes or disable tumor suppressor genes.
“Additionally, a high copy number raises the risk of insertional mutagenesis, where the vector integrates into genomic regions that could activate proto-oncogenes or disable tumor suppressor genes [28–31].”
From Harmonisation of quality control tests for academic production of CAR-T cells: a position paper from the WP-bioproduction of the UNITC consortium (2025) · cites this paper as [28]
The Introduction describes an integrated CAR transgene, and the Discussion describes measuring axi-cel vector copy numbers, but neither connects a high copy number to insertional mutagenesis. Searches for insertional mutagenesis, oncogene activation, tumor-suppressor disruption, and integration-related risk found no passage addressing that claim. Page numbers were unavailable in our copy. (LLM, conf=0.78)
Experimental — accuracy not yet measuredAn excessive number of vector copies can lead to CAR overexpression, increasing toxicity risks.
“Safety: an excessive number of vector copies can lead to CAR overexpression, increasing toxicity risks.”
From Harmonisation of quality control tests for academic production of CAR-T cells: a position paper from the WP-bioproduction of the UNITC consortium (2025) · cites this paper as [28]
The Introduction (page unavailable) says monitoring CAR T-cell kinetics could help assess associations with adverse events, and the Discussion (page unavailable) describes measuring axi-cel vector copies. Neither passage, nor the additional passages searched for overexpression and toxicity, says that excessive vector copies cause CAR overexpression or increase toxicity risk. (LLM, conf=0.76)
Experimental — accuracy not yet measured
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
The citation lists haven’t been fetched yet
References 27 · Cited by 14
Research works printed but not linked: 3
- Catros V. [Next generation engineered T cells for cell therapy: from lymphoma to solid tumors]. Med Sci MS, 2019, 35:316-26
- Kochenderfer JN, Feldman SA, Zhao Y, Xu H, Black MA, Morgan RA, Wilson WH, Rosenberg SA. Construction and preclinical evaluation of an anti-CD19 chimeric antigen receptor. J Immunother Hagerstown Md 1997, 2009, 32:689-702
- Avettand-Fènoël V, Chaix M-L, Blanche S, Burgard M, Floch C, Toure K, Allemon M-C, Warszawski J, Rouzioux C, French Pediatric Cohort Study ANRS-CO 01 Group. LTR real-time PCR for HIV-1 DNA quantitation in blood cells for early diagnosis in infants born to seropositive mothers treated in HAART area (ANRS CO 01). J Med Virol, 2009, 81:217-23
- Authors
- Baras, A., Bocket, L., Beauvais, D., Hallaert, C., Varlet, P., Yakoub-Agha, I., Hober, D., & Alidjinou, E. K.
- Affiliations
- Université de Lille (FR)
- Inserm (FR)
- Corresponding author
- Alidjinou, Enagnon Kazali
- Venue
- The Journal of Molecular Diagnostics
- Publisher
- Elsevier BV
- Published
- 2021-04
- Volume
- 23
- Issue
- 4
- Pages
- 447-454
- ISSN
- 1525-1578 (ISSN-L)
- OpenAlex
- W3116468903
- Cited by
- 14
- References
- 27
- Citations by year
- 2026: 2 · 2025: 2 · 2024: 1 · 2023: 1 · 2022: 3 · 2021: 5
- FWCI
- 0.82
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Licence
- Locations
- Journal of Molecular Diagnostics (publishedVersion)
- PubMed (publishedVersion)
- HAL (submittedVersion, cc-by-nc)
- Topics
- Health Sciences › Medicine › Oncology › CAR-T cell therapy research
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Virus-based gene therapy research
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › CRISPR and Genetic Engineering
- Keywords
- axicabtagene ciloleucel, CAR T-cell therapy, gammaretroviral vectors, diffuse large B-cell lymphoma, primary mediastinal B-cell lymphoma, CAR T cell persistence, real-time quantitative PCR assay, patient monitoring
- MeSH terms
- Data Accuracy, Antineoplastic Agents, Immunological, Receptors, Chimeric Antigen, Aged, Biological Products, Female, Genetic Vectors, Humans, Male, Middle Aged, Monitoring, Physiologic, Sensitivity and Specificity, Immunotherapy, Adoptive, Lymphoma, Large B-Cell, Diffuse, Treatment Outcome, Gammaretrovirus, Transgenes, Real-Time Polymerase Chain Reaction
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
