Immunological aberration in primary hyperparathyroidism.

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.