Further studies on the immunosuppressive effects of indomethacin.

Oral administration of indomethacin inhibited immune response to sheep red blood cells in mice as assessed by direct plaque-forming cells. Serum titers, subsequent to immunization with Pseudomonas aeruginosa lipopolysaccharide, were also diminished in the indomethacin-treated mice. These effects were independent of both the antigen used as well as the magnitude of the primary immune response obtained. Prostaglandins are suggested to play a positive role in in vivo B cell proliferation and function.