PERIPHERAL-BLOOD LYMPHOCYTE SUBSETS AND SERUM IMMUNOGLOBULINS IN SHEEHANS-SYNDROME AND IN NORMAL WOMEN DURING THE MENSTRUAL-CYCLE

Objective. There has been increasing evidence on the mechanisms underl ying the interactions between the neuroendocrine and the immune system s, particularly in animal models with relatively few information in th e human. In this study, we evaluate the cellular and humoral immunity in female patients with hypopituitarism and in normal women throughout the menstrual cycle in an attempt to determine the role of pituitary and gonadal hormones on the immune system. Design. Serum immunoglobuli ns, peripheral blood lymphocyte subsets, and serum hormones were measu red in eight patients with postpartum pituitary necrosis (Sheehan's sy ndrome) and in six normal women along different phases of the menstrua l cycle, taking advantage of the lack of pituitary function and the cy clic variations in serum hormones, respectively. Results. Patients wit h Sheehan's syndrome had higher T lymphocytes (CD2), including helper (CD4) and suppressor (CD8) cell subpopulations and B lymphocytes (CD 1 9) when compared with normal menstruating women. An increase of serum IgA concentrations was also observed. Normal women showed little non-s tatistically different changes along the menstrual cycle in peripheral blood cell parameters and in serum immunoglobulin levels. Conclusions . a) Hypopituitarism in humans, in contrast with the animal model, may associate with immune up-regulation at both cellular and humoral leve ls; and b) hormonal changes along the normal menstrual cycle probably do not influence in great extent the immune system.