Suppressor alveolar macrophages in experimentally induced uremia.

The effect of uremic alveolar macrophages (AM phi) on the response of control nonadherent (NA) spleen cells to mitogens was examined. Alveolar macrophages purified from experimentally induced uremic rats were found to be significantly more suppressive than alveolar macrophages purified from control rats. When studying the characteristics of uremic AM phi, it was found that neither indomethacin nor anti-Ia antibody reverses their suppressive activity. In addition, uremic AM phi are shown to suppress via a suppressor factor released to the supernatant over an 18-hr incubation. The enhanced suppressive activity of uremic AM phi may have relevance to the severely suppressed cell-mediated immunity, the increased rate of infections, and the common presence of uremic pneumonitis in humans with chronic renal failure.