Immunocytes of composite tissue allografts express elevated levels of TGF beta mRNA and protein during chronic rejection.

CHRONIC REJECfION after transplantation, including experimental composite tissue grafts, is a major cause of late allograft dysfunction. Recently, we have shown that chronic rejection of rat hind limb transplants results in significant structural and immunological changes. 1 A cytokine which is known to exert a variety of immunoregulatory effects is transforming growth factor beta (TGFf3). This pleiotrophic factor has been shown to be expressed in normal skin.2 Most of its effects result in immunosuppression, but mitogenic effects are also described. Additionally, it has been implicated in causing hypertrophy of cardiac muscle as well as being involved in the onset of fibrosis.3 The aim of this study was to investigate whether the expression of TGFf3 by infiltrating immunocytes is effected during chronic rejection after composite tissue transplantation and where TGFf3 mRNA expressing cells and the TGFf3 protein are localized.