concanavalin-a and Hyperparathyroidism

The possibility of a link between parathyroid hyperfunction and cellular immune functions was studied in primary hyperparathyroid (1 degree HP) patients. The effect of cimetidine on lymphocyte functions in 1 degree HP patients and control subjects was also investigated. Histamine-induced suppressor activity of lymphocytes from 1 degree HP patients was significantly greater than that of controls. Cimetidine addition to both normal and 1 degree HP lymphocyte cultures abolished histamine-induced suppression. In vivo administration of cimetidine, while ineffective towards normal lymphocytes, depressed phytohemagglutinin stimulation of 1 degree HP lymphocytes, indicating possible immunological damage caused by this drug, which is frequently used in the treatment of patients with 1 degree HP.

Topics: Cimetidine; Concanavalin A; Histamine; Humans; Hyperparathyroidism; Immunity, Cellular; In Vitro Techniques; Lymphocyte Activation; Phytohemagglutinins; T-Lymphocytes, Regulatory

Altered immunological reactivity in primary hyperparathyroidism is suggested by the strong association between this disorder and malignancy. The present study was carried out to determine whether altered lymphocyte proliferation in response to common mitogens (PHA, Con-A, PWM) exists in primary hyperparathyroidism, and, if so, whether the abnormality resides in the lymphocytes or in humoral factors present in the plasma of patients with hyperparathyroidism. Ficoll-Hypaque purified lymphocytes from 6 patients with primary hyperparathyroidism and 4 normal volunteers were stimulated with PHA, Con-A and PWM in the presence of plasma from patients with primary hyperparathyroidism and normal AB+ plasma. The incorporation of [3H]thymidine in unstimulated (control) and stimulated cultures was determined. The results demonstrate that lymphocyte proliferation was significantly higher when both patients' and normal lymphocytes were stimulated with mitogens in the presence of patients' plasma. These findings suggest that plasma from patients with primary hyperparathyroidism contains a potentiator of lymphocyte mitogenesis, or, alternatively lacks an inhibitor of lymphocyte activation that is present in normal plasma.

Topics: Adult; Aged; B-Lymphocytes; Concanavalin A; Female; Humans; Hyperparathyroidism; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Lymphocyte Activation; Male; Middle Aged; Phytohemagglutinins; Pokeweed Mitogens; T-Lymphocytes