Application Value Of CD229 And USP2a In Plasma Cell Diseases

Objectives CD138,CD38 and CD45 expression are popularly used in flow-cytometric to gate the plasma cell(PC).The disadvantage of CD138 is variable expression and loss during storage and processing.Introduction of anti-CD38 and anti-CD138 monoclonal-antibody immunotherapy has limited the use of these markers during the detection.So,we require additional and reliable PC gating markers.CD229 has been tested as an qualified PC gating marker.We evaluated the utility of CD229 as a new PC gating and analyzing marker in immunophenotyping.In this study,ubiquitin specific protease(USP)was found to be highly expressed in myeloma cell lines.We investigated the expression of USP2 a in plasma cells and explored whether USP2 a and CD229 can be used as important targets for the diagnosis and treatment of plasma cell diseases.Methods We studied the expression of CD229 in 150 bone marrow(BM)samples(110plasma-cell disorders and 40 controls)and multiple myeloma stem cells and compared with CD138 and CD38 expression.Immunohistochemistry was used to reveal the expression of USP2 a in 30 cases of bone marrow(20 cases of plasma cell disease and 10 cases of control group).Finally,the proliferation and apoptosis of the cells before and after the knockout were analyzed by knockout of USP2 a expression in MM cell lines.Results Expression of CD229 was consistently stronger on PC than other hematopoietic-cells (p<0.05).PC-percentages using CD229 in combination with CD38 or CD138 and CD45 revealed high correlation with a reference gating-strategy using CD138,CD38 and CD45(r=0.98)and gating-strategy using CD229 and CD45 without CD38 or CD138(r=0.94).In contrast,The expression of CD138 showed obvious variability(CV-MFI,96.5)and loss from PC(39% of samples).MMSC expressed CD229.Immunohistochemical results showed that USP2 a was significantly expressed in MM samples,but not in other control samples.Inhibition of USP2 a significantly reduced proliferation of MM cell lines and induced apoptosis.Conclusion CD229 is a reliable and substitutable new PC gating marker.CD229 can be one of the immunophenotypes of MMSC.The expression of USP2 a in myeloma patients and cell lines is closely related to proliferation and apoptosis of myeloma cells.