Islet antigen specific IL-10+ immune responses but not CD4+CD25+FoxP3+ cells at diagnosis predict glycemic control in type 1 diabetes

The immune phenotype of the partial remission phase or “honeymoon phase” of type 1 diabetes is not well defined. We compared flow cytometry and cytokine production by ELISPOT assays in children with newly diagnosed type 1 diabetes and children in the partial remission phase of type 1 diabetes. Newly diagnosed children had higher levels of FoxP3 expression in CD4 CD25 double positive cells (56.1% +/− 24.9 vs. 24.9% +/− 24.6 p = 0.03) and higher mean numbers of IL-10 producing cells (7.3 cells/2 × 105 cells +/− 6.6 vs. 0.86 cells/2 × 105 +/− 0.36 p = 0.0043) compared to partial remission patients. Higher FoxP3 expression at diagnosis predicted worse future glycemic control while higher mean numbers of IL-10 cells were associated with better future glucose control. These data provide an immune phenotype of the honeymoon phase and suggest that analyzing IL-10 and FoxP3 at diagnosis may identify patients that will experience better glucose control.