CD5-CELLS AT THE ONSET OF TYPE-1 DIABETES AND IN THE PREDIABETIC PERIOD( B)

OBJECTIVE - B-cells expressing CD5 are associated with the production of autoantibodies and are present at increased levels in several autom immune diseases. The aim of this study was to investigate the relation ship of these cells to the development of type I diabetes and the pres ence of organ and non-organ-specific autoantibodies. RESEARCH DESIGN A ND METHODS - We measured percentage levels of CD5(+) B-cells in patien ts with recent-onset (n = 34) and long-standing (n = 21) type I diabet es and in a cohort of 18 identical twins of patients with type I diabe tes studied prospectively, 8 of whom became diabetic (prediabetic twin s) during the study; the rest remained nondiabetic after at least 7 ye ars and are now unlikely to develop the disease. Forty-seven healthy i ndividuals were studied as control subjects. RESULTS - Percentage leve ls of total B-cells (CD20(+)) and the proportion expressing CD5 were i ncreased in patients with recent-onset (P < 0.001 for both) but not lo ng-standing type I diabetes compared with control subjects. Percentage levels of CD20(+) B-cells were increased in prediabetic twins through out the prediabetic period (P < 0.05), and there was an increased prop ortion of CD5-expressing B-cells that failed to reach statistical sign ificance (P = 0.08). Percentage levels of CD20(+) B-cells and the prop ortion expressing CD5 were normal throughout the study in twins remain ing nondiabetic. No relationship between percentage levels of CD5+ B-c ells and islet cell antibody, thyroid autoantibodies, or non-organ-spe cific autoantibodies was found. CONCLUSIONS - These results show an in crease in B-cell percentage levels at the diagnosis of type I diabetes , which is because of an expansion of the CD5(+) subset. These changes are also evident in twins throughout the prediabetic period, which su ggests that they are related to the processes that lead to diabetes.