66-P

Abstract

Aim The initial ischemia/reperfusion injury (IRI) may have impact on the recipient immune response after transplantation. Allograft inflammatory factor-1 (AIF-1), an evolutionary conserved structural protein has been implicated in the regulation of inflammation, associated with rejection. AIF-1 is either passively released from injured tissue cells during procurement, or actively secreted by allograft infiltrating cells contributing to allograft rejection. We investigated the impact of ischemia/reperfusion in association with the presence of AIF-1, IL-18, TLR-2 and TLR-4, markers with the goal to demonstrate the presence of these markers in donor tissue during IRI, and in peripheral blood and biopsy specimen with allograft rejection. Methods Tissue from donor atrium was subjected to IRI using 1X PBS for 90 minutes. Tissue array was prepared for immunohistochemistry (IHC) stains. Recipients peripheral blood mononuclear cells (MNCs) and endomyocardial specimens were tested by RT-PCR and IHC stains for identification of AIF-1, TLR2, -4, and IL-18 markers. Results Only AIF-1 and IL-18 specific immunoreactivity were detected in cardiomyocytes and interstitial tissues after IRI. The TLR-2 immunoreactivity was strongly detected in infiltrating MNCs and CMCs in grade 3A rejection. IL-18 immunoreactivity was strongly detected in grade 3A rejection. In peripheral blood MNCs, AIF-1 expression was 4.2-fold-increased in the group with 3A rejection as compared with grade 1A or 0. The mRNA expression levels were varied significantly for TLR-2 in MNCs with different ISHLT grades (grades 3A ® 1A rejection: mean ± SEM both peripheral blood and local tissue was 64.0 ± 3.8; vs. 38.4 ± 3.5, p Conclusions AIF-1 and IL-18 are initial inflammatory markers associated with IRI present in the donor. The expression profile of the recipient AIF-1, TLR-2 and IL-18 were correlated with biopsy-proven allograft rejection, suggesting a potential for diagnostic biomarkers for early detection of allograft rejection.