Increased Ia-Antigen-Bearing T Cells in Type I Diabetes Mellitus

To the Editor: Jackson et al., in the April 1 issue, reported an increased percentage of circulating Ia-positive T cells in patients with insulin-requiring diabetes mellitus, as compared with normal controls and with patients with adult-onset diabetes mellitus who were not using insulin.¹ They have used this finding to suggest an immunologic basis for Type I diabetes mellitus. I believe that there is a more straightforward explanation for the phenomenon noted. Ia-positive T cells will increase in the circulation dramatically after even minor immunologic perturbations. For example, Yu et al. have reported that the percentage of peripheral-blood Ia-positive T cells.