DEHYDROEPIANDROSTERONE TREATMENT IS NOT BENEFICIAL TO THE IMMUNE-RESPONSE TO INFLUENZA IN ELDERLY SUBJECTS

Background. Dehydroepiandrosterone (DHEA) is a native steroid with an immunomodulating activity that was suggested to counter-regulate some phenomena of immunosenescence. Recently, it was shown to reverse the a ge-associated decline of immune response against influenza vaccine in aged mice. The present study was designed to evaluate the effect of DH EA on the immunization of elderly volunteers against influenza. Method s. Seventy-one elderly volunteers age 61-89 yr were enrolled in a pros pective randomized, double-blind study to receive either DHEA (50 mg q d p.o. for four consecutive days starting two days before immunization ) or placebo. Antibody response to the vaccine was measured before and 28 days after vaccination. Results. DHEA treatment significantly incr eased serum DHEA sulfate (DHEA-S). No enhancement in established immun ity was observed. A significant decrease in attainment of protective a ntibody titer (1:40 or higher) against the A/Texas strain in subjects with nonprotective baseline antibody titer was recorded following DHEA treatment compared with placebo (52% vs. 84%, P < 0.05). Baseline DHE A-S serum levels were inversely related to attainment of immunization in DHEA-treated subjects. Influenza-like morbidity during the winter w as low in the study group with no difference between the DHEA and plac ebo groups. Conclusions. Although highly effective in aged rodents, a short course of DHEA treatment did not improve the age-related decline d response to immunization against influenza in human subjects. Higher baseline DHEA-S levels are not predictive of better immunization agai nst influenza in the elderly.