Background: More research is going on markers for MM to improve treatment. Cell of origin (COO), stage and National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) are frequently used for risk evaluation and treatment tailoring in patients with MM. Relatively, few studies assess role of BCMA in MM.

Aim: The aim of the study was to assess BCMA expression in MM patients and evaluate its prognostic significance. Methods: This study was conducted on 36 newly diagnosed MM patients. BCMA was analyzed by MFC using BD FACSCanto II flow cytometer equipped with Diva software. Three months following chemotherapy, patients' bone marrow (BM) was examined for evaluation of their remission status. Results: BCMA (CD269) was expressed on malignant plasma cells of all MM cases of the studied group. There was a statistically significant difference in CD269 expression among MM groups according to International staging system, being highest in stage ІІ, also there was a significant difference in the expression of CD269 among MM patients by serum immunofixation being higher in the G type than A type. A highly statistically significant lower expression for CD269 was observed in MM patients who achieved remission. Additionally, a significant positive correlation between CD269 Mean Fluorescence Intensity (MFI), and serum LDH, and highly significant positive correlations between CD269 MFI , serum β2- macroglobulin and CD56 MFI were observed.

Conclusion: High BCMA expression was associated with low remission rate, also it was associated with high CD56 MFI, serum LDH and serum β2- microglobulin.