Interleukin-1 is a critical effector molecule during cytokine dysregulation in graft versus host disease to minor histocompatibility antigens.

Cytokines are believed to cause a number of inflammatory diseases. We have investigated the role of 3 inflammatory cytokines, IL-1, IL-2, and TNFα, during graft-versus-host disease (GVHD), a paradigm disease of cytokine dysregulation in vivo. Measuring cytokine mRNA transcripts with a quantitative polymerase chain reaction technique, we demonstrate that IL-1 transcript levels are increased several hundred-fold in GVHD target organs, whereas TNFα transcripts increase only 4-to 6-fold. Kinetic studies during the first month after transplant unexpectedly show that GVHD never induces IL-2 transcripts in the skin and only induces IL-2 transcripts in the spleen during the first week, whereas levels of IL-1 transcripts continue to increase through-out the entire 4 weeks