CD138/Syndecan-1在多發性骨髓瘤免疫表型中的意義

To establish the method of immunophenotyping testing for patients with multiple myeloma (MM), to analyze the characteristics of antigen expression on myeloma cells, and to purify primary myeloma cells, CD45/side scatter (SSC) gating tri-color immunofluorescence (IF) flow cytometry (FCM) was used to test immunophenotype of 18 patients with MM, 20 patients with acute leukemia (AL) and 7 normal controls. Purified primary myeloma cells were obtained by means of anti-CD138 monoclonal antibody and immunomagnetic microbeads. The results showed that myeloma cells displayed a CD45 negative/low positive expression, and SSC was located between nucleated red blood cells and neutrophils. Both CD138 and CD38 were positive while most antigens of T cell, B cell and myeloid cell were negative. Positive rate of CD56 was 83.3% and HLA-DR was 44.4% positive. Compared with MM patients, CD138 was negative and CD38 was 100% positive in AL patients. CD56 was 25% positive. In normal controls, neither CD138 nor CD56 was positive. The positive rate of primary myeloma cells after purification was 73%-95% with a mean of 86%. It is concluded that CD45/SSC gating procedure is a stable and reliable method to detect immunophenotype of MM. CD138 is a correspondingly special antigen for myeloma cells. Highly enriched primary myeloma cells can be obtained by anti-CD138 antibody and immunomagnetic microbeads.