Intragraft platelet-derived growth factor-α and transforming growth factor-β1 during the development of accelerated graft vascular disease after clinical heart transplantation

This study was to determine whether the growth factors platelet-derived growth factor-alpha (PDGF-alpha) and transforming growth factor-beta1 (TGF-beta1) contribute to the development of graft vascular disease (GVD) after clinical heart transplantation. We analysed intragraft PDGF-alpha and TGF-beta1 messenger RNA (mRNA) expression levels by competitive template reverse transcriptase polymerase chain reaction (RT-PCR). Endomyocardial biopsies (EMB) were obtained at 1 and 9 months post-transplant from cardiac allograft recipients with (n = 11) and without (n = 11) angiographic evidence of GVD at 1 year. In 1-month EMB, comparable TGF-beta1 mRNA levels were found in patients with and without GVD at 1 year (p = 0.84, Mann-Whitney U-test). In contrast, in 9-month EMB during the development of GVD, intragraft mRNA levels of both PDGF-alpha (p = 0.08) and TGF-beta1 (p = 0.03) were higher in patients with GVD after the first year compared to patients without GVD. These results suggest that intragraft PDGF-alpha and TGF-beta1 play a role in the pathogenesis of accelerated GVD after clinical heart transplantation.