Application of “cell sorting” for genetic risk factors identification in patients with multiple myeloma: a real life study

Abstract

Cytogenetic alterations (CA) represent significant prognostic factors for multiple myeloma (MM) and divide patients into two main risk groups (intermediate-risk and high-risk) with different prognosis and therapy. Alterations currently included in risk scores are: ploidy index, IGH gene rearrangements, TP53 inactivation, and chromosome 1 abnormalities (1p deletion and/or 1q gain). The standard method for detection of CA in MM, both upon initial diagnostic assessment and at subsequent evaluations, is fluorescence in situ hybridization (FISH) performed on samples with high purity of plasma cells (PC). Purified PC can be obtained by different methods, multiparameter flow cytometry (MFC) or cell sorting proving the highest efficiency. The present study describes the results obtained by evaluating the presence of CA in a real-life cohort of patients with MM and comparing two different groups: S group, in which FISH was performed on a population of purified plasma cells, and NS group, in which the technique was performed on the entire sample. The results are comparable to those published in other series and prove that the use of sorting prior to FISH studies significantly enhances the sensitivity of detecting CA in patients with MM, and enables accurate staging, optimizing therapeutic strategies and improving survival.