A young woman with metabolic acidosis and recently discovered IDDM without ketonuria. A rare autoimmune (?) combination of hypothyroidism, diabetes mellitus and distal renal tubular acidosis

A case of a 29-year-old woman with a multiple autoimmune disorder is reported. She had a history of hypothyroidism since the age of 18. She was admitted to hospital due to hyperglycaemia. At admission she had hyperglycaemia, metabolic acidosis, but no urinary ketone bodies. Further laboratory studies revealed that the acidosis was due to distal renal tubular acidosis rather than diabetic ketoacidosis (although the patient had type 1 diabetes mellitus). Blood tests revealed antibodies to glutamic acid decarboxylase (GAD-65; associated with type 1 diabetes mellitus), thyroid and adrenal tissue, and gastric parietal cells. The patient had not developed pernicious anaemia or Addison's disease. The multiple positive antibody titres in this patient indicate that the diabetes, hypothyroidism and distal renal tubular acidosis are part of an autoimmune syndrome.