Phenotypic and functional abnormalities of T lymphocytes in pathological hyperprolactinemia.

The phenotype and function of T cells circulating in patients with pathological hyperprolactinemia were analyzed and compared to those in sex- and age-matched control subjects. Two-color immunofluorescence study revealed an increased number of CD4+ TQ1+ cells and the presence of phenotypically immature CD1+ T cells, also exhibiting transferrin surface receptor, in peripheral blood of the hyperprolactinemic patients. After chronic treatment with the dopamine agonist bromocriptine, T-cell abnormalities disappeared. In addition, some untreated patients showed enhanced T-cell suppressor activity in an in vitro pokeweed mitogen-driven B-cell transformation assay. These immunological findings confirm a link between neuroendocrine and immune systems in humans.