INCREASED CD5-LYMPHOCYTES AT THE ONSET OF TYPE-1 DIABETES IN CHILDREN(CD19+ B)

The aim of this study was to determine whether the proportion of circu lating B cells expressing the differentiative antigen CD5 was increase d in children affected by type 1 diabetes, and whether the number of t hese cells was correlated with the presence of anti-islet cell autoant ibodies. Sixteen children affected by insulin-dependent diabetes melli tus (type 1) were investigated for the presence of B lymphocytes beari ng the CD5 surface molecule, T-cell-specific activation markers, organ - and nonorgan-specific autoantibodies. The number of CD5+CD19+ cells was higher in type 1 children with a very recent onset of the disease, as compared with patients on insulin therapy for more than 30 days an d controls (P < 0.05). No correlation was found between the number of CD5+CD19+ cells and the presence of either organ- or nonorgan-specific autoantibodies. Our re suits indicate that CD5+CD19+ cells are involv ed in the pathogenesis of type 1 diabetes in children. A potential imm unoregulatory role of this B cell population is discussed.