Determination of antipituitary antibody in patients with endocrine disorders by enzyme-linked immunosorbent assay and Western blot analysis.

The identification of pituitary antigens recognized by human antipituitary antibodies (APAs) is important in evaluating the pathophysiology of multiendocrine disorders linked to autoimmune factors. However, there is no convenient method for the quantitative analysis of circulating APAs. This study reports the development of an enzyme-linked immunosorbent assay (ELISA) for the detection of APAs. APAs were measured by ELISA and confirmed by Western blot analysis in sera from patients with endocrine disorders. APAs were detected frequently in patients with autoimmune thyroiditis, insulin-dependent diabetes mellitus (IDDM), or pituitary dwarfism. Circulating APAs were detected in 18% of patients with autoimmune thyroiditis. Confirmation by Western blot revealed positivity for APAs in the serum of 36% of patients with Hashimoto disease and in 29% of patients with Graves disease. Notably, 39% of patients with IDDM were also positive for APAs by ELISA. The identification of APAs by ELISA may be useful in evaluating autoimmune mechanisms involved in patients with multiendocrine disorders.