Abstract
Background: Changes in the dosage of immunosuppressive drugs following organ transplantation, especially the heart, can be a potential predictor of long-term post-transplant outcomes. It may also be related to the degree of histopathological involvement of endomyocardium. Objectives: We aimed to evaluate cyclosporine and tacrolimus dose changes during post-transplantation biopsies and their association with endomyocardial biopsy grades. Methods: This retrospective study was performed on 100 cardiac transplant patients who underwent endomyocardial biopsies to assess graft stability. In the present study, the patients were divided into two groups receiving cyclosporine (13 cases) and tacrolimus (87 cases). The data was collected by reviewing the recorded files. Results: Regarding the administration of cyclosporine, at different times after biopsy, there was no significant relationship between the plasma level of the drug and the grade of biopsy. Concerning tacrolimus, there was a significant reverse association between serum concentration and biopsy grade at the first biopsy after transplantation (about one month after transplantation), although this relationship was not observed in the subsequent steps of biopsy. Also, the Quilty effect frequency was not significantly associated with biopsy grade in different biopsies for both drugs. Conclusions: There is a lack of association between endocardial biopsy grade in the heart and the serum level of cyclosporine after transplantation. However there is a significant reverse relationship between endomyocardial biopsy grade and serum Tacrolimus concentration in the first weeks after transplantation and thus monitoring serum Tacrolimus after transplantation may play an important role in predicting acute rejection.