Original Article Real-Time Quantitative PCR: Standardized Detection of Minimal Residual Disease in Pediatric Acute

Purpose: To develop a standardized real-time polymerase chain reaction (PCR) method of quantifying minimal residual disease (MRD) in patients with pre-B acute lymphoblastic leukemia (ALL). Patients and Methods: In a series of 24 follow-up bone marrow (BM) samples in 11 patients (14 clonal markers), we performed real-time PCR assays using one consensus and one clone-specific primer for each marker. The markers analyzed included immuno-globulin heavy chain (IgH), T-cell receptor (TCR) and TEL-AML1 rearrangements. Results: We achieved a detection limit of 3.3 × 10−5 ± 1.2 × 10−5 and an accurate quantitation (r −0.99) limit of 2.0 × 10−4 ± 8.8 × 10−5 blasts. Both inter- and intra-assay reproducibility were exceptional. Additionally, we found comparable results to those of a “gold standard ” limiting-dilution PCR assay (r 0.62)