A case of pegylated interferon alpha-related diabetic ketoacidosis: can this complication be avoided?

We report the case of a 42-year-old woman with chronic hepatitis C (genotype 1), who in June 2004 started therapy with pegylated interferon alpha (PEG-IFNalpha) plus ribavirin. Two months later, she discontinued treatment because of polydipsia, polyuria and vomiting leading to a marked dehydration. Biochemical data showed type 1 diabetes mellitus with ketoacidosis, and insulin therapy was started. The patient, who before starting PEG-IFN alpha plus ribavirin therapy tested negative for glutamic acid decarboxylase antibodies (GADAb) and islet cell (ICAb) antibodies, became strongly positive for both autoimmune markers. This case confirms that patients with chronic hepatitis C who do not have baseline markers of pancreatic autoimmunity may develop severe ketoacidosis during treatment with PEG-IFNalpha, as well as with standard IFNalpha. In order to avoid this complication, as no guidelines are available and the pancreatic autoimmunity markers are not routinely analysed, we suggest frequent monitoring (e.g., every one to two weeks) of glycaemic values: e.g., every one to two weeks during the first 3 months (when this complication occurs most frequently) and monthly thereafter so as to identify diabetes at an early stage and before the onset of the appearance of severe ketoacidosis, which is life-threatening.