Type 1 diabetes mellitus (T1DM) is a
chronic disease characterized by the autoimmune destruction of pancreatic β-cells. This paper describes the case of a 19-year-old male patient who presented with
glutamic acid decarboxylase (GAD) antibody positive and
diabetic ketoacidosis, which mandated intensive
insulin treatment. Once the
ketoacidosis was controlled, an oral dose of 100 mg of
sitagliptin was administered once a day.
Ketoacidosis was managed by
insulin and
insulin daily requirement began to dwindle after one month, until its complete withdrawal at 8 weeks, when partial remission was reached. The patient has now remained on
sitagliptin treatment alone for a year, without requiring
insulin. The benefit observed with this medication is possibly associated with its immunological effects. Inhibition of
dipeptidyl peptidase 4 in animal models deregulates the Th1 immune response, increases secretion of Th2
cytokines, activates CD4+CD25+FoxP3+ regulatory T-cells, and prevents IL17 production.
LEARNING POINTS: The use of
insulin-dose-adjusted HbA1c constitutes the best way to define partial remission in T1DM patients.The use of
sitagliptin in T1DM patients could help to decrease daily requirement of
insulin by delaying β-cell loss and improving endogenous
insulin production.The determination of
antibodies against
insulin, islet cells, and GAD permits differentiation of T1DM patients from those with atypical or
ketosis-prone diabetes.