Adjunctive rapamycin and CsA treatment inhibits monocyte/macrophage associated cytokines/chemokines in sensitized cardiac graft recipients

Background. Although treatment of LEW rats with Rapamycin (RPM) prolongs the survival of LBNF1 cardiac allografts to ca. 50 days, it fails to prevent late activation of macrophage/monocyte-associated chemokines. Methods. A 7-day course with RPM or CsA was introduced at 1-week posttransplant in RPM-pretreated hosts. At day 35, intragraft mRNA expression of IL-2, IFN-γ TGF-β, IL-12 (p40), MCP-1, and RANTES was evaluated. Results. RPM as a sequential treatment markedly inhibited mRNA levels coding for IL-2/IFN-γ, and MCP-1. However, RPM monotherapy failed to prevent the expression of IL-12 (p40) and RANTES. Adjunctive treatment with CsA markedly depressed IL-12 (p40) and RANTES, and to a lesser extent MCP-1 mRNA, as compared with RPM-treated groups. Significant increase of TGF-β mRNA expression was revealed after sequential RPM and adjunctive CsA treatment. Conclusions. A combination of RPM and CsA is more effective in restraining mRNA expression than RPM alone; however, either therapy is associated with TGF-βhyperexpression.