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The pituitary-specific transcriptional factor-1 (PIT-1, also known as POU1F1), is an essential factor for multiple hormone-secreting cell types. A genetic defect in the PIT-1 gene results in congenital growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone (TSH) deficiency. Here, we investigated 3 cases of adult-onset combined GH, PRL, and TSH deficiencies and found that the endocrinological phenotype in each was linked to autoimmunity directed against the PIT-1 protein. We detected anti-PIT-1 antibody along with various autoantibodies in the patients' sera. An ELISA-based screening revealed that this antibody was highly specific to the disease and absent in control subjects. Immunohistochemical analysis revealed that PIT-1-, GH-, PRL-, and TSH-positive cells were absent in the pituitary of patient 2, who also had a range of autoimmune endocrinopathies. These clinical manifestations were compatible with the definition of autoimmune polyendocrine syndrome (APS). However, the main manifestations of APS-I--hypoparathyroidism and Candida infection--were not observed and the pituitary abnormalities were obviously different from the hypophysitis associated with APS. These data suggest that these patients define a unique 'anti-PIT-1 antibody syndrome,' related to APS., Introduction The pituitary-specific transcriptional factor-1 (PIT-1, also known as POU1F1), plays a pivotal role in regulating the expressions of growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone β (TSHβ). PIT-1 [...]

Genetically abnormal growth hormone may be responsible for extremely short stature. Researchers found a mutation in the growth hormone gene of a small boy. At just under 5 years old, the boy had the bone age of a two-year-old and measured 81.7 cm, a height much below the average. Bioactivity of the boy's growth hormone was lower than normal, compared to his sisters and parents. Insensitivity to growth hormone was ruled out after a good response and a better growth rate following intensive treatment with growth hormones. The defective growth hormone failed to stimulate tyrosine phosphorylation and inhibited wild-type growth hormone activity despite a high concentration of the latter. The father of the boy had the same genetic abnormality but a height close to normal.