CD200 is an independent prognostic factor in multiple myeloma

Background CD200 is a membrane glycoprotein belonging to the immunoglobulin superfamily and seems to play an immunosuppressive and protumor role. However, the diagnostic and prognostic role of its expression in multiple myeloma is not fully examined. Aim of work The aim of this study was to detect the expression of CD200 in patients with plasma cell myeloma (PCM) and correlate its expression with other known clinical and laboratory prognostic factors. Patients and methods A total of 68 PCM patients were enrolled and divided into 50 newly diagnosed and 18 treated patients with residual disease. Flow cytometry was applied on bone marrow samples from all patients to detect CD200 expression using monoclonal anti-CD200. Results Our results showed CD200-positive expression in 76.5% of the studied PCM patients. A significant relation was found between CD200 expression and many prognostic factors such as advanced age, lytic bone lesions, advanced clinical staging, hematopoietic dysfunction, low level of residual polyclonal γ-globulins, and elevated serum creatinine. Moreover, CD200 expression was strongly related to factors associated with tumor burden and activity, such as low serum albumin, high lactate dehydrogenase, high β2 microglobulin level, and elevated bone marrow plasma cell count. Follow-up of patients revealed a significantly shorter event-free survival of CD200-positive patients. Receiver operating characteristic curve showed that 78% is the best prognostic cutoff for CD200 expression, with 92% specificity and 66.7% sensitivity. Conclusion CD200 is an independent prognostic factor that should be measured to determine PCM patients who are at risk of developing residual disease after standard treatment and thus must be subjected to intensified chemotherapy regimens from the start.