HNF1B-related diabetes triggered by renal transplantation

Background. A 37-year-old man developed cholestasis-associated pruritus followed by overt hyperglycemia (blood glucose level 23 mmol/l), necessitating insulin treatment, within weeks of undergoing renal transplantation. He had a history of gout, but his fasting blood glucose and glycated hemoglobin concentrations had been normal before transplantation. Investigations. Physical examination; laboratory tests, including assessment of glycated hemoglobin, anti-glutamic-acid-decarboxylase and anti-islet-antigen-2 antibodies, liver enzymes, renal function, tacrolimus blood trough level, exocrine (fecal elastase) and endocrine (c-peptide) pancreatic function; abdominal CT scan; liver biopsy; and screening of the hepatocyte nuclear factor 1 homeobox B (transcription factor 2) gene, HNF1B. Diagnosis. New-onset diabetes after transplantation associated with a newly described deletion in HNF1B. Management. Minimization of tacrolimus exposure and withdrawal of steroids considerably reduced the patient's insulin requirement, and cholestasis-related pruritus was dramatically improved by administration of ursodeoxycholic acid. Renal ultrasonography and screening for the HNF1B molecular abnormality were offered to the patient's relatives.