Abstract:

Objective To evaluate the utility of CD229 as a new flow cytometry（FCM） plasma cell gating marker in immunophenotyping. Methods The expression of CD229 was determined in 150 patients（110 cases of plasma cell diseases and 40 cases of non-blood diseases）,which was compared with CD138 and CD38 expressions on plasma cell and other hematopoietic cells（lymphocyte,granulocyte and monocyte）. The plasma cell percentages obtained by different gating strategies were compared. Results The mean fluorescence intensities（MFI） of CD229,CD138 and CD38 were 25.54（10.01-68.34）,30.59（4.77-88.94） and 67.04（18.57-98.26）,respectively,and the coefficients of variation（CV） were 69.2%（30.9%-110.4%）,96.5%（38.4%-221.0%） and 42.8%（31.5%-110.2%）. The MFI of CD229 on plasma cell was stronger than those on other hematopoietic cells（P<0.05）. Pearson correlation analysis showed that plasma cell percentages using CD229+CD38+CD45 and CD229+CD45 revealed positive correlation with a reference gating strategy using CD38+CD45+CD138 recommended by European Myeloma Network（EMN）（r=0.98 and 0.94,P<0.05）. The MFI of CD229 between abnormal plasma cell and normal plasma cell had statistical significance（P<0.05）. Conclusions CD229 is a reliable plasma cell gating marker. It can make up for the deficiency of the combination of CD38 and CD138 and also can be used to judge the characteristic of plasma cells.

Key words: CD229, Immunophenotyping, Plasma cell disease