Eight-color multiparameter flow cytometry (EuroFlow-NGF) is as sensitive as next-generation sequencing in detecting minimal/measurable residual disease in autografts of patients with multiple myeloma.

Abstract

The prognostic value of minimal/measurable residual disease (MRD) detection in autografts of patients with multiple myeloma (MM) in an autologous stem-cell transplantation setting has been reported. Next-generation flow (NGF) cytometry has lower sensitivity (2×10-6) to detect MRD than next-generation sequencing (NGS) (<10-6). We compared the clinical value of high-sensitivity NGF (cutoff: <10-6) and NGS (cutoff: 10-6) for the detection of MRD in the cryopreserved autografts of 49 patients with newly diagnosed MM. The sensitivity test using frozen/thawed autografts revealed a strong correlation among MRD levels of 5×10-7 and 1×10-4 (r=0.9997, p<0.0001) when an adequate number of cells were analyzed. Autograft MRD levels determined using NGF and NGS were highly correlated (r=0.811, p<0.0001). MRD-negative patients identified with NGF (cutoff: <10-6) showed significantly longer progression-free survival (PFS) than MRD-positive patients (p=0.026). The PFS of MRD-negative patients determined by NGS (cutoff: 10-6) was similar to that determined by NGF. These results show that the high-sensitivity NGF method can assess MRD in frozen/thawed autografts, and its prognostic value is comparable to that of NGS.