CD33+ HLA-DR– Myeloid-Derived Suppressor Cells Are Increased in Frequency in the Peripheral Blood of Type1 Diabetes Patients with Predominance of CD14+ Subset

INTRODUCTION Type 1 Diabetes Mellitus (T1D) is an autoimmune disease that results from the destruction of insulin-producing beta cells of the pancreas by autoreactive T cells. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells that can potently suppress T cell responses. AIM To detect the presence of MDSCs in T1D and compare their percentage in T1D versus healthy individuals. METHOD Thirty T1D patients were included in the study. Diabetic patients with nephropathy (n = 18) and diabetic patients without nephropathy (n = 12). A control group of healthy individuals (n = 30) were also included. CD33+ and HLA-DR- markers were used to identify MDSCs by flow cytometry. CD14 positive and negative MDSCs subsets were also identified. RESULTS MDSCs was significantly increased in T1D than the control group and diabetic patient with nephropathy compared to diabetic patients without nephropathy. M-MDSCs (CD14+ CD33+ HLA-DR-) were the most abundant MDSCs subpopulation in all groups, however their percentage decrease in T1D than the control group. CONCLUSION MDSCs are increased in the peripheral blood of T1D with a predominance of the CD14+ MDSCs subset. Future studies are needed to test the immune suppression function of MDSCs in T1D.