Autoimmunity to insulin in a child with hypoglycemia.

Plasma insulin antibodies were present in a 5-year-old boy who had been suffering from frequent hypoglycemic episodes during a year without exogenous insulin administration. The antibodies were of low titre one month after the last hypoglycemic episode, although a possible previous higher titre could have been responsible for the child's symptoms. After 17 months, during which the child remained asymptomatic, insulin antibodies could not be detected in his plasma. This is a new case of insulin autoimmunity associated with hypoglycemia.