Minimal residual disease (MRD) detection using quantification of clone-specific Ig or TCR rearrangements before and after transplantation in children with high-risk ALL is an important predictor of outcome. The method and guidelines for its interpretation are very precise to avoid both false-negative and -positive results. In a group of 21 patients following transplantation, we observed detectable MRD positivities in Ig/TCR-based real-time quantitative PCR (RQ-PCR) leading to no further progression of the disease (11 of 100 (11%) total samples). We hypothesized that these positivities were mostly the result of nonspecific amplification despite the application of strict internationally agreed-upon measures. We applied two non-self-specific Ig heavy chain assays and received a similar number of positivities (20 and 15%). Nonspecific products amplified in these RQ-PCR systems differed from specific products in length and sequence. Statistical analysis proved that there was an excellent correlation of this phenomenon with B-cell regeneration in BM as measured by flow cytometry and Ig light chain-kappa excision circle quantification. We conclude that although Ig/TCR quantification is a reliable method for post transplant MRD detection, isolated positivities in Ig-based RQ-PCR systems at the time of intense B-cell regeneration must be viewed with caution to avoid the wrong indication of treatment.

Department of Paediatric Haematology Oncology 2nd Medical School Charles University and University Hospital Motol Prague Czech Republic

Citace poskytuje Crossref.org

The gray area of RQ-PCR-based measurable residual disease: subdividing the "positive, below quantitative range" category

Analysis of measurable residual disease by IG/TR gene rearrangements: quality assurance and updated EuroMRD guidelines

Quality Control for IG /TR Marker Identification and MRD Analysis

Patient specific real-time PCR in precision medicine - Validation of IG/TR based MRD assessment in lymphoid leukemia

Dynamics of tumor-specific cfDNA in response to therapy in multiple myeloma patients

Is Next-Generation Sequencing the way to go for Residual Disease Monitoring in Acute Lymphoblastic Leukemia?

Next-generation sequencing indicates false-positive MRD results and better predicts prognosis after SCT in patients with childhood ALL

Standardized flow cytometry for highly sensitive MRD measurements in B-cell acute lymphoblastic leukemia

Loss of B cells and their precursors is the most constant feature of GATA-2 deficiency in childhood myelodysplastic syndrome

The TREC/KREC assay for the diagnosis and monitoring of patients with DiGeorge syndrome