Lactate dehydrogenase (LDH)-linked immunoglobulin in a patient with Graves' disease treated with methimazole

A 26-year-old woman who received methimazole treatment for Graves' disease is discussed. Two months following treatment, her serum GOT level rose to 45 K.U, her GPT to 60 K.U, and her lactate dehydrogenase (LDH) to 645 W.U; a hepatic disorder was then suspected. Later, the serum GOT and GPT concentrations decreased to a normal range, but her serum LDH continued to maintain a high level. An LDH isoenzyme analysis showed an abnormally broad LDH. The IgG that was linked to the LDH is suspected to have been the result of her underlying autoimmunity, the methimazole treatment, and the development of her hepatic disorder. Thus, this IgG was thought to be the autoantibody to LDH.