OBJECTIVETo study the relationship between surface markers of CD56 and CD19 and karyotypes and prognosis in multiple myeloma.

METHODSA total of 126 cases of newly diagnosed multiple myeloma in the first hospital of Peking university from 2011 to 2015 were enrolled in this study. Cytogenetic abnormalities and immunophenotypes were detected by using fluorescence in situ hybridization and flow cytometry respectively before chemotherapy. Bone marrow smear was used for detection of abnormal plasma cell infiltration. By combining with their basic data, the relationship between immunophenotypes, cytogenetics and prognosis of MM was analyzed.

RESULTS(1) The median of myeloma cells in the 126 patients was 0.24（0.01-0.97）; the median of myeloma cells in 116 patients who have immunophenotype datas was 0.25（0.01-0.97）； the median of myeloma cells in CD19 positive patients was 0.11（0.01-0.53）; the median of myeloma cells in CD19 negative patients was 0.26（0.01-0.97）. The median of myeloma cells in CD19 positive patients was much lower than that in CD19 negative patients（P=0.036）. (2)In 116 patients detected by the immunophenotype, the myeloma cells expressed CD19,CD20,CD56 and CD117. Compared with CD56 negative patients(45/116,38.79%),CD56 positive patients(71/116,61.21%) had a clearly favorable disease outcome（OS was 53.0 month vs 31.0 month,P=0.016; PFS was 37.5 months vs 18.4 months, P=0.036）. (3)CD19 positive patients was 16.38%（19/116）,CD19 negative patients was 83.62%（97/116）； CD19 positive MM and CD19 negative MM had no difference in OS and PFS. (4)CD117 positive rate in CD19 positive patients was 42.11%(8/19), the CD117 positive rate in CD19 negative patients was 18.57%(18/97), the CD19 expression positively correlated with CD117 expression. (5)FISH detection was done for 67 newly diagnosed MM patients, 8 patients showed normal karyotypes(11.94%), 59 patients had abnormal karyotypes(88.06%). The most common abnormal karyotypes were IgH rearragement which occurred in 47 patients(70.15%). Other abnormal karyotypes included 1q21+, del(13q14),del(13q14.3),del(17p13) . These abnormal karyotypes occurred in 37 patients（55.22%）,31 patients（46.27%）,33 patients（49.25%） and 13 patients（19.40%） respectively. In comparison with CD19 negative MM patients, the incidence rate of 1q21+ and del(13q14.3) was significantly lower in CD19 positive patients(1q21+:33.33% vs 61.54%,P=0.016; del(13q14.3): 33.33% vs 53.85%,P=0.043）.

CONCLUSIONThe prognosis of CD56 positive MM patients is better than that of CD56 negative MM patients, CD19 negative MM has more abnormal karyotypes and bone marrow infiltration,but they have no statistical prognostic differences.