Consensus strategy to quantitate malignant cells in myeloma patients is validated in a multicenter study. Belgium-Dutch Hematology-Oncology Group

• Published in: Blood 2000-07, Vol.96 (1), p.63-70
• Main Authors: Willems, P, Verhagen, O, Segeren, C, Veenhuizen, P, Guikema, J, Wiemer, E, Groothuis, L, Jong, T B, Kok, H, Bloem, A, Bos, N, Vellenga, E, Mensink, E, Sonneveld, P, Lokhorst, H, van Der Schoot, E, Raymakers, R
• Format: Article
• Language: English
• Subjects: Base Sequence; Belgium; Bone Marrow Cells - immunology; Bone Marrow Cells - pathology; Calibration; Combined Modality Therapy; DNA Primers; Genes, Immunoglobulin; Hematopoietic Stem Cell Transplantation; Humans; Immunoglobulin Heavy Chains - analysis; Immunoglobulin Heavy Chains - genetics; Molecular Sequence Data; Multiple Myeloma - immunology; Multiple Myeloma - pathology; Multiple Myeloma - therapy; Neoplasm Staging; Netherlands; Polymerase Chain Reaction - methods; Reproducibility of Results; Sensitivity and Specificity
• ISSN: 0006-4971

Recently the Belgium-Dutch Hematology-Oncology group initiated a multicenter study to evaluate whether myeloma patients treated with intensive chemotherapy benefit from additional peripheral stem cell transplantation. To determine treatment response accurately, we decided to quantitate malignant cells. To test a consensus quantitation strategy, 5 centers independently determined the immunoglobulin heavy chain sequences of patient tumor cells and developed allele-specific oligonucleotides (ASO) and ASO-polymerase chain reaction (PCR). We compared the reproducibility of real-time quantitation with quantitation using limiting dilutions. We distributed DNA samples with a 4-log range of tumor cell concentrations and found average quantitation values deviating 74% and 42% from the input values with real-time PCR (1 center) and limiting dilutions (4 centers), respectively. Within single centers we found an average variation coefficient of 0.74, with limiting dilutions not significantly different from the average 0.82 center-to-center variation coefficient. Within a single center, real-time quantitation proved more reproducible (average variation coefficient, 0.36). Quantification was confirmed in 3 patients during treatment in the protocol. This report shows that real-time PCR or limiting dilution assays can be used for quantitation in a single multicenter trial. We present a consensus strategy that allows an accurate comparison of quantitation data generated in independent centers.