Fig. 4.

Changes in anti-GAD antibody titer in a patient with FT1D [26]. A 48‐year‐old man was admitted to our hospital with complaints of fever, abdominal discomfort, thirst, polyuria, and weight loss over the preceding 10 days. Based upon the presence of diabetic ketoacidosis, relatively low HbA1c level (7.3%) at the onset, absence of islet-associated autoantibodies including anti-GAD antibody, and extremely low level of serum and urinary C‐peptide levels, he was diagnosed as FT1D. Seroconversion of anti-GAD antibody was observed 1 year after the onset of the disease. Anti-GAD antibody, anti-glutamic acid decarboxylase antibody; FT1D, fulminant type 1 diabetes