Collagen profile in the transplanted heart

To substantiate the finding of interstitial myocardial fibrosis in the transplanted heart and to characterize the collagen profile of the transplanted heart, we studied endomyocardial biopsy specimens from 30 heart transplants and four heart-lung transplants at 1 to 82 months after transplantation. Indirect immunofluorescent techniques with affinity-purified antibodies for collagen types I, III, IV, and V were used. The degree of interstitial collagen present was scored. The amount of type I collagen was increased in transplants from distant donors (mean ischemia time, 154 minutes) compared with those from on-site donors (mean ischemic time, 59 minutes): collagen scores 1.1 and 1.7, respectively (P < .01). There was a trend toward a positive correlation, not statistically significant, between cyclosporine dose and collagen III deposition (r = .35), collagen IV (r = .38), and collagen V (r = .56). There was a negative correlation between number of rejection episodes and mean cyclosporine dose (r = -.41) and amount of collagen III (r = -.42) or collagen IV (r = -.42). No correlations were found between collagen deposition and any other variables studied. These results confirm the mixed nature of the collagen deposited and suggest that some fibrosis is related to cyclosporine administration rather than to the number of prior healed rejection episodes.