Cytokine plasma levels and lymphocyte subsets in patients with newly diagnosed insulin-dependent (type 1) diabetes mellitus before and following initial insulin treatment.

Changes in the plasma concentrations of interleukin-1 beta (IL-1 beta), tumour necrosis factor alpha (TNF alpha), interleukin 2 (IL-2), and lymphocyte subsets were investigated in 19 persons with newly diagnosed (type 1) insulin-dependent diabetes mellitus (IDDM) from admission to hospital prior to insulin treatment and following 1 week and 1 month of treatment. Furthermore, the cytokines were measured 16-28 months after the presentation of IDDM. The mean TNF alpha values were all within the normal range, but demonstrated a slight increase in all the samples taken (Friedman 0.06). The mean plasma IL-1 beta value was initially at the upper normal limit, but gradually increased significantly from admission to hospital to 1 week, 1 month, and 16-28 months afterwards (Friedman 0.031). No IL-2 activity was detectable in the majority of the samples. No significant changes in total leukocyte and lymphocyte counts were found. The lymphocyte subsets (CD5+, CD8+, CD4+, CD16+, CD20+, HLA-DR+) did not show any significant changes from admission to after the start of insulin treatment. It is concluded that the gradual increase in IL-1 beta and TNF alpha plasma levels may reflect an ongoing autoimmune inflammatory reaction at the onset of IDDM.