Immunohistochemical staining of endomyocardial biopsies was done using Leucocyle Common Antigen (LCA), Cluster of Differentiation 45RO (UHCL-1), Cluster of Differentiation 20 (CD-20) and Proliferating Cell Nuclear Antigen (PCNA) in various grades of acute heart transplant rejection. The UHCL-1 positive cells (T-lymphocytes) were present in all cases and their localization closely resembled that of LCA-positive cells. All cases with moderate acute rejection grades similarly to Quilty effect infiltrations had an admixture of B lymphocytes (CD-20-positive cells). The positive staining with PCNA was present in all cases with moderate and severe rejection, and particularly intensive staining of endothelial cells was seen in vessels with graft rejection vasculopathy. Our results suggest the usefulness of immunohistochemical techniques in diagnosing moderate acute heart graft rejection and graft rejection vasculopathy.

Keywords: Heart Transplantation, Rejection, tissue inflammation