Evaluation of the relationship between flow cytometry findings, clinical process and prognosis in multiple myeloma patients

Introduction and purpose : Multiple myeloma is a plasma cell malignancy characterized by anemia, bone marrow infiltration and extensive skeletal destruction. Many laboratory and radiologic methods are used in the diagnosis of this disease such as flow cytometry, which is becoming increasingly important. In previous studies, flow cytometry devices were not well standardized and lack of specific markers of plasma cells was a disadvantage for researchers. Well-calibrated flow cytometers are able to study multiple markers simultaneously. Many studies have shown that flow cytometry markers are effective on prognosis. In our study, we aimed to show the effect of flow cytometry on prognosis and to shed light on new studies on the treatment of multiple myeloma disease by using the data of patients diagnosed in the adult hematology outpatient clinic of our hospital. Material and method : A total of 87 patients newly diagnosed with multiple myeloma who were admitted to Bülent Ecevit University adult hematology outpatient clinic between January 1, 2013 and May 31, 2021 and whose flow cytometry results were available and contained in our study data were included in the study. Statistical analysis of the study was performed with IBM SPSS 21.0 statistical package program. Factors affecting the survival of patients were analyzed with survival analysis Results : Laboratory data and demographic characteristics of the patients were obtained retrospectively from their file records in the hospital system. The mean age of the 87 patients included in the study was 65.76 years (±11.00), 51.7% were male and 42.3% were female. Hemoglobin, calcium, creatinine and presence of lytic lesions in the skeletal system were investigated at the time of diagnosis according to the criteria determined by the International Myeloma Study Group. According to the beta-2 microglobulin and albumin values at the time of diagnosis, the patients were grouped according to the International Staging System. 5.7% of the patients were classified as Stage I, 66.7% as Stage II and 27.6% as Stage III. Among the flow cytometry markers, those with CD 19 levels <15 were categorized as low positive, those with levels between 15-50 as moderate positive and those with levels >50 as high positive. CD19 was negative in 16.1%, low positive in 69%, intermediate positive in 9.2% and high positive in 5.7% of the patients. Patients with CD38 and CD56 values <40 were considered as low positive, and patients with ≥40 were considered as high positive. CD38 was low positive in 36.8% and high positive in 62.1% of the patients. CD38 could not be measured in 1.1%. CD56 level was low positive in 35.6% and high positive in 64.4% of the patients. Conclusion : According to the data obtained from our study, we think that flow cytometry is important both in the diagnosis and prognosis of multiple myeloma disease. The level of markers in flow cytometry helps us to get an idea about the prognosis of the disease. In particular, we found a significant correlation between CD19 level and survival. When evaluated together with the studies in the literature, although there were discrepancies, most of our data were consistent with the literature. Considering the data of our study, we can think that it will contribute to larger-scale and multicenter studies to be conducted in the coming years. Keywords : Multiple myeloma ; Flow cytometry ; Survival ; Surface antigen