Effect of chronic ingestion of a prostaglandin E analogue on immunologic function in healthy elderly subjects

The immunologic effects of an oral prostaglandin E₁ (PGE₁) analogue were tested in 25 individuals over age 65, compared to 25 individuals given placebo. Elderly subjects were chosen because previous in vitro studies had found an increased sensitivity to PGE of lymphocytes in older subjects. After 2 weeks of ingestion of PGE analogue or placebo, there was a small but statistically significant decrease in IgM-rheumatoid factor in the PGE analogue group compared to control and a significant decrease in the in vitro sensitivity of lymphocytes from the PGE analogue group to inhibition by PGE. There were no differences in total lymphocyte count, T cell or T cell subset count, delayed hypersensitivity skin test reactivity, serum immunoglobulins, or response to mitogens between the two groups. Administration of an oral PGE analogue to normal elderly individuals is not associated with any detrimental effects on immunologic function after 2 weeks.