Expression of CD40 ligand, interferon-gamma and Fas ligand genes in endomyocardial biopsies of human cardiac allografts: correlation with acute rejection

The purpose of the present study was to investigate the expression Key word s (mRNA) of CD40 ligand (CD40L), interferon-gamma (IFN-gamma) and Fas ligan d (FasL) genes in human cardiac allografts in relation to the Cardiac a occ urrence of acute cardiac allograft rejection as well as its possible value in predicting acute rejection. The mRNA levels were determined by a semiqua ntitative reverse transcriptase-polymerase chain reaction method in 39 samp les of endomyocardial biopsies obtained from 10 adult cardiac transplant re cipients within the first six months after transplantation. Biopsies with o ngoing acute rejection showed signifi cantly higher CD40L, IFN-gamma and Fa st mRNA expression than biopsies without rejection. The median values of mR NA expression in biopsies with and without rejection were 0.116 and zero fo r CD40L (P <0.003), 0.080 and zero for IFN-gamma (P <0.0009), and 0.156 and zero for Fast (P <0.002), respectively. In addition, the levels of IFN-gam ma mRNA were significantly increased 7 to 15 days before the appearance of histological evidence of rejection (median of 0.086 in prerejection biopsie s), i.e., they presented a predictive value. This study provides further ev idence of heightened expression of immune activation genes during rejection and shows that some of these markers may present predictive value for the occurrence of acute rejection.