SUPPRESSION OF CELL-MEDIATED-IMMUNITY IN HYPOTHYROIDISM

A 71-year-old man had severe hypothyroidism, chronic autoimmune thyroi ditis, and bacteremia due to Edwardsiella tarda. Review of the literat ure identified the hypothesis that E tarda infections may occur more f requently in immunocompromised patients. Previous animal studies have shown decreases in lymphocyte function during hypothyroidism, with ret urn of normal lymphocyte function during euthyroid states. Therefore, lymphocyte transformation studies were obtained, demonstrating severe decreases in our patient's lymphocyte function. Except for chronic aut oimmune thyroiditis, other immune system abnormalities were excluded. Serial lymphocyte transformation studies showed gradual improvement in lymphocyte function during gradual return to euthyroid state. Possibl e pathophysiologic mechanisms for these findings will be reviewed.