Cytokine gene expression in peripheral blood mononuclear cells during graft-versus-host disease after allogeneic bone marrow transplantation

Summary. Cytokine gene expression in peripheral blood mononuclear cells during the development of graft-versus-host disease (GVHD) in patients who underwent allogeneic bone marrow transplantation (allo BMT) was analysed using a semiquantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The expression of interleukin (IL)-lβ, IL-6, and tumour necrosis factor (TNF)-α mRNA was increased during the development of GVHD and the degree of this increment depended on the severity of the disease. IL-2 expression was not detected at all and interferon-γ expression was not much changed during GVHD. In patients with hepatic veno-occlusive disease (VOD), another transplantation-related complication, the expression of IL-1β and TNF-a mRNA was increased but IL-6 mRNA expression showed little increase. These findings suggest that IL-lβ, IL-6 and TNF-α produced by peripheral blood mononuclear cells play an important role in the development of GVHD. Furthermore, liver dysfunction due to GVHD or VOD may be distinguishable by this type of cytokine analysis. Analysis of cytokine mRNA expression in peripheral blood mononuclear cells after allogeneic bone marrow transplantation may provide important information concerning the immune response and the cytokine network system in marrow transplant patients.