Lymphocyte cyclic AMP levels in primary hypogammaglobulinaemia: lack of correlation with response to phytohaemagglutinin.

Normal levels of lymphocyte cyclic AMP were found in fourteen of fifteen patients with primary hypogammaglobulinaemia. One patient with adult-onset hypogammaglobulinaemia had low cyclic AMP levels with a very poor rise after prostaglandin E1 stimulation. Five of the patients had severely depressed thymidine uptake by their phytohaemagglutinin-stimulated lymphocytes but there was no significant difference between their lymphocyte cyclic AMP levels and those of patients with normal lymphocyte responses. Removal of monocytes from concanavalin A-stimulated lymphocyte cultures from three of these patients did not affect the severe depression of leucine uptake. These findings indicate that the depression of lymphocyte response to mitogens seen in some patients with late-onset primary hypogammaglobulinaemia is not due to raised levels of lymphocyte cyclic AMP; and not usually due to prostaglandins released by monocytes in the cultures.