Abstract: OBJECTIVE: To determine immunophenotype characteristics of plasma cells in bone marrow of multiple myeloma (MM) patients and to correlate with clinical prognosis. METHODS: Bone marrow smears and sections were stained with Wright Giemsa and HE,respectively,and their morphological and pathological characteristics were analyzed. In addition,bone marrow or peripheral blood samples were collected for flow cytometry immunophenotyping and related laboratory tests. RESULTS: There was a significantly increased number of bone marrow plasma cells in MM patients and marked morphological abnormality. Their distributions included plug solid type in 16 cases (45.71%),nodular type in 14 cases (40.00%) and interstitial type in 5 cases (14.29%). Proportion of increased serum LDH,β2-MG,Cr and BUN in MM patients was 80%,85.71%,62.86% and 60%,respectively. There was positive expression of CD38 and CD138 in the plasma cells. The absence of expression of Igκor Igλ chain was monoclonal hyperplasia. The positive rates of CD56,CD200,CD117 and CD28 were 65.71%,94.29%,60% and 54.29%,respectively,and those of CD20,CD81,CD33,CD27 and CD13 were 37.14%,42.86%,28.57%,57.14% and 34.29%,respectively,as opposed to 22.86% and 31.42% in CD19 and CD45,respectively. The expressions of CD27 and CD28 were closely related to prognosis of MM patients,and the 5-year overall survival rate was lower in patients with the loss of CD27 expression in plasma cells and the positive expression of CD28 (P < 0.05). CONCLUSION: Abnormal immunophenotype was observed in plasma cells from bone marrow of MM patients,and expressions of CD27 and CD28 were significantly correlated with disease progression and prognosis. Therefore,immunophenotype detection can be of great significance in clinical diagnosis and treatment monitoring of MM patients.

Key words: multiple myeloma, immunophenotype, CD27, CD28, prognosis