Ig Gene Clonality Analysis Using Next-Generation Sequencing for Improved Minimal Residual Disease Detection with Significant Prognostic Value in Multiple Myeloma Patients

Next-generation sequencing (NGS) of rearranged Ig genes is an effective technology for identifying pathologic clonal cells in multiple myeloma (MM) and tracking minimal residual disease. The clinical effect of implementing NGS in Ig gene clonality analysis was evaluated via a retrospective chart review. A total of 312 patients diagnosed with MM were enrolled in the study. Ig gene clonality was determined by fragment analysis using BIOMED-2 multiplex PCR assays and by NGS using the LymphoTrack IGH FR1 Assay and LymphoTrack IGK Assay. The clonality detection rates in diagnostic samples obtained using fragment analysis and NGS were 96.7% and 95.4%, respectively (statistically nonsignificant difference; P = 0.772). Among samples of patients in complete remission, the clonality detection rates obtained using fragment analysis and NGS were 33.3% and 60.3%, respectively (statistically significant difference; P = 0.034). Progression-free survival was significantly longer in negative than positive patients by NGS analysis (P = 0.03). Clonality detection by NGS-based methods using IGH FR1 and IGK assays in routine clinical practice is feasible, provides good clonality detection rates in diagnostic samples, and allows monitoring of samples in MM patients with significant prognostic value.