Hyperthyroidism associated with autoimmune hemolytic anemia and periodic paralysis: a report of a case in which antihyperthyroid therapy alone was effective against hemolysis.

We describe a case of a 29-year-old man with hyperthyroidism associated with autoimmune hemolytic anemia and periodic paralysis. Euthyroidism, which was achieved by propylthiouracil, brought inhibition of hemolysis and amelioration of anemia in spite of continuously positive direct and indirect Coombs' tests. Neither adrenocortical steroid nor blood transfusion was administered. Since indirect monospecific Coombs' test was negative against anti-human complements serum, the membrane of red blood cells may be less fragile. This is one reason why hemolysis was inhibited by anti-hyperthyroid therapy only. This may indicate that the hyperdynamic circulatory state secondary to hyperthyroidism plays an important role in the destruction of red blood cells which were coated by anti-red blood cell antibody.