Classic Type 1 Diabetes Mellitus and Fulminant Type 1 Diabetes Mellitus: Similarity and Discrepancy of Immunological Characteristics and Cytokine Profile.

We aimed to explore the immunological characteristics and cytokine profile of the initial stage of type 1 diabetes. In total, 123 age- and sex-matched subjects with newly diagnosed classic type 1 diabetes mellitus (T1ADM), fulminant type 1 diabetes mellitus (FT1DM), and normal glucose tolerance (NGT) were enrolled. Serum cytokine levels were measured using Milliplex MAP multifactor detection. There was a significant increase in the levels of transforming growth factor β (TGFβ1) and TGFβ2 and decrease in programmed death-1 (PD-1), PD ligand 1 (PD-L1), pro-inflammatory cytokines, and anti-inflammatory cytokines in type 1 diabetes patients compared with the NGT subjects (all P < 0.05). There was no significant difference in C-reactive protein (CRP) and blood routine indicators between the two groups. Type 1 diabetes was further divided into T1ADM and FT1DM subgroups. FT1DM patients had much higher CRP levels than T1ADM patients (4.90 [0.95-26.05] mg/L vs 0.39 [0.20-0.74] mg/L, P < 0.01). Blood routine results showed that the number of leukocytes was significantly increased in FT1DM compared with that in T1ADM (9.2 [5.1-18.8] × 109 cells/L vs 5.4 [4.5-6.7] × 109 cells/L, P < 0.01). In FT1DM patients, neutrophil% was increased, and lymphocyte% was declined significantly, compared with that in T1ADM patients (neutrophil%: 80.2 [59.2-85.2]% vs 59.5 [54.8-64.0]%; lymphocyte%: 18.3 [10.1-32.3]% vs 32.6 [26.8-35.9]%; both P < 0.01). However, there was no difference between FT1DM and T1ADM in cytokine profile except for the decrease in CTLA-4 in T1ADM (P < 0.05). Compared with T1ADM, CRP and leukocytes' levels were increased significantly in FT1DM, with an increase in neutrophil% and decline in lymphocyte%, suggesting that FT1DM may have more abrupt onset and occur as a more serious subtype of type 1 diabetes mellitus.