Antipituitary antibodies as pathogenetic factors in patients with pituitary disorders

Our previous reports showed detection of antipituitary antibodies (APA) by immunoblot analysis and enzyme linked immunosorbent assay (ELISA) by using rat pituitary tissue as antigen in patients with certain endocrine disorders. In the present report, we evaluated APA by using our immunoblot and ELISA technique in 76 patients with various pituitary disorders. The prevalence of a 22 kDa band of APA detected by immunoblot was found to be significantly higher (P<0.01) in patients with pituitary disorders (20 of 76, 26%) than in the controls (3 of 209, 1%). APA levels detected by ELISA were significantly higher in patients with GH deficiency, isolated ACTH deficiency, acromegaly, and idiopathic panhypopituitarism compared with control (mean +/- SD; 2.40+/-2.66, 2.36+/-1.87, 2.09+/-1.87, 3.10+/-1.96 versus 1.42+/-0.64 (C.I.) P<0.05, respectively). APA levels detected by ELISA in 7 patients with GH deficiency showed a statistically significant decrease (p<0.05) after administration of GH replacement therapy. APA detection by immunoblot is useful in examining as pathogenesis, while ELISA may be useful as an objective index of pathological state in patients with autoimmune-related pituitary disorders.