Objective: Minimal residual disease (MRD) is considered the greatest prognostic factor in acute lymphoblastic leukemia (ALL). MRD is a valuable tool for anticipating impending relapse and treatment response assessment. The objective of the present study was to investigate whether the detection of IgH gene rearrangement using polymerase chain reaction (PCR)-based GeneScan analysis could be a complementary method to monitor MRD along with the quantitative realtime PCR (qPCR).
Materials and methods: In this cross-sectional study, we valued the MRD levels, based on the GeneScanning analysis (GSA), and then compared the data with quantitative real-time polymerase chain reaction at different time points in peripheral blood (PB) samples of adult B-lineage ALL patients (n=35). The specific polymerase chain reaction (PCR) primers for IGH gene FR-1 and fluorescence-labeled J-primer were used and analyzed by capillary gel electrophoresis on a sequencer. The results of this study were compared with the previously reported MRD results obtained by the IGH rearrangements allele-specific oligonucleotide (ASO) -qPCR methods.
Results: The total concordance rate was 86.7%, with a P<0.001. MRD results obtained by GSA and ASO-qPCR methods were concordant in all diagnostic samples and samples on the 14th and 28th days of induction therapy. The results of these 2.5 years' follow-ups demonstrated a significant correlation between the two techniques (r=0.892, P<0.001).
Conclusion: It seems that the PCR-based GeneScan analysis of IGH gene rearrangement detection may be a valuable molecular technique to distinguish monoclonality from polyclonality. And also, it may be a precise tool to detect the residual leukemic DNA in the PB follow-up samples of patients.
Keywords: Acute lymphoblastic leukemia; Capillary Gel Electrophoresis; GeneScanning; Immunoglobulin Heavy Chain; Minimal Residual Disease.