Malarial immunity in pregnant mice, in relation to total and unbound plasma corticosterone.

A pregnancy dependent loss of malarial immunity is accompanied by an (excessive) increase of total as well as free plasma corticosterone. This loss of immunity was largely prevented by adrenalectomy. Moreover, malarial immunity was more sensitive to dexamethasone immunosuppression during pregnancy. Primary infections are more virulent during pregnancy and like in recrudescent mice, cause excessive total and free plasma corticosterone levels. Corticosterone may be considered an immuno-regulatory serum factor during pregnancy, the endocrine regulation of which is disturbed in pregnant, infected mice.