PITUITARY AUTOANTIBODIES IN PATIENTS WITH HYPOPITUITARISM AND THEIR RELATIVES

Autoantibodies to human pituitary cytosol proteins were determined by immunoblotting in sera from patients with hypopituitarism and their re latives. Reactivity to an M-r 49000 protein was significantly more fre quent in patients (6/21 (28%) P<0.05) as well as in relatives (10/35 ( 28%) P<0.02) compared with controls (3/44 (6.80)). Autoantibodies to t his particular protein have previously been detected in sera from 70% of patients with biopsy-proven lymphocytic hypophysitis. Unlike patien ts with biopsyproven lymphocytic hypophysitis, none of the patients in this study presented with a suspected pituitary adenoma or showed an enlarged sella turcica, Cisternal herniation was seen in 6/21 patients and this may very well represent the end stage of lymphocytic hypophy sitis. Since organ specific autoantibodies are frequent in patients wi th autoimmune endocrine disease as well as in their unaffected relativ es, autoantibodies to this M-r 49000 pituitary cytosolic protein may r epresent markers for an immunological process affecting the pituitary gland.