The prognostic significance of bone marrow histological evaluation in patients with multiple myeloma

Introduction: Recently, there has been enormous progress in the diagnosis and treatment of multiple myeloma (MM). Despite the importance of flow cytometry and cytogenetic, biomarkers are being sought to assess prognosis and response to treatment. The aim of this study was to determine the significance of histological evaluation and immunohistochemical markers in MM patients. Material and methods: A retrospective analysis was performed in 90 bone marrow (BM) biopsies collected during the diagnosis period and related to the recognized prognostic factors and response to treatment. The standardized staining methods and monoclonal antibodies were used to detect cluster of differentiation antigens — CD138, CD56, CD20, CD117, cyclin D1, p53, kappa and lambda light chains. Results: During the follow-up period of 49.6 (2–119.7) months in patients with increased levels of β2-microglobulin, higher International Prognostic Classification stage, with resistance to induction and higher relapse rate after first-line, a clonal lambda plasmocytes infiltration was observed. It also affected the response to induction with immunomodulatory drugs (IMiDs), but not bortezomib. The lowest response rate to IMiDs was noted in patients with CD117-lambda+ and CD56-lambda+ plasma cells. Clonal lambda hyperplasia connected with reduction in overall survival [hazard ratio (HR) 2.4; 95% confidence interval (CI): 0.96–5.92; p =0.047) and progression-free survival (PFS) (HR 4,32, 95% CI: 1.9–9.5; p =0.0002). The presence of plasmocytes with phenotype CD117-lambda+ (HR 3.37; 95% CI: 1.57–7.24; p =0.002) and CD56-lambda+ (HR 3,44; 95% CI: 1,63–7,27; p =0.001) contributed to PFS shortening. Conclusions: In conclusions, BM biopsy with immunohistochemistry allow the identification of poorly prognostic patients with MM