A pilot study showing associations between frequency of CD4+ memory cell subsets at diagnosis and duration of partial remission in type 1 diabetes

•Frequency of CD45RO+ memory cell subsets correlates with length of partial remission in T1D.•CD25+ CD127hi frequency is a strong predictor of remission length when used as a covariate with baseline HbA1c.•CD25+ CD127hi frequency is a strong predictor of remission length when used as a covariate with baseline C-peptide.•CD25+ CD127hi cells are neither Foxp3+ Treg nor Tr1 cells.•Frequency of CD25+ CD127hi cells correlates with the frequency of activated Treg.

In some patients with type 1 diabetes the dose of insulin required to achieve euglycemia is substantially reduced soon after diagnosis. This partial remission is associated with β-cell function and good glucose control. The purpose of this study was to assess whether frequencies of CD4+ T cell subsets in children newly diagnosed with type 1 diabetes are associated with length of partial remission. We found that the frequency of CD4+ memory cells, activated Treg cells and CD25+ cells that express a high density of the IL-7 receptor, CD127 (CD127hi) are strongly associated with length of partial remission. Prediction of length of remission via Cox regression is significantly enhanced when CD25+ CD127hi cell frequency is combined with either Insulin Dependent Adjusted A1c (IDAA1c), or glycosylated hemoglobin (HbA1c), or C-peptide levels at diagnosis. CD25+ CD127hi cells do not express Foxp3, LAG-3 and CD49b, indicating that they are neither Treg nor Tr1 cells.