Clinical characteristics of anti-glutamic acid decarboxylase antibody-positive fulminant type 1 diabetes.

This research aimed to examine the relationship between anti-glutamic acid decarboxylase antibody (GADA) titers and clinical parameters at onset and to clarify the association between clinical severity and GADA titers in GADA-positive fulminant type 1 diabetes. This cross-sectional observational study included 20 cases with GADA-positive fulminant type 1 diabetes (4 cases from our hospital and 16 from cases reported in the literature). The association between GADA titers and clinical parameters [age, sex, body weight, body mass index, period from appearance of any prodromal symptoms to diagnosis, period from development of hyperglycemic symptoms to diagnosis, GADA titer, HbA1c level, blood pH and HCO level, serum levels of ketone bodies and pancreatic exocrine enzymes] were analyzed. Spearman's rank correlation coefficient (r) was used for the correlation analysis. The results showed that there was a significant inverse correlation between GADA titers and the "period from appearance of any prodromal symptoms to diagnosis" (r = -0.559, p < 0.05). Moreover, GADA titers were inversely correlated with blood pH and HCO level (r = -0.576, p < 0.05, r = -0.578, p < 0.05, respectively), and positively correlated with serum levels of total ketone bodies, acetoacetate, and 3-hydroxybutyrate (r = 0.661, p < 0.05; r = 0.700, p < 0.05; and r = 0.782, p < 0.01, respectively). These findings suggest that higher GADA titers may be linked to more severe clinical severity of GADA-positive fulminant type 1 diabetes at onset. This association may be attributed to possible pre-existence of autoimmunity-related β-cell damage before the onset of fulminant type 1 diabetes.