Abstract: Objective To investigate the pathological and immunological changes of renal grafts in recipients experiencing graft
rejection. Methods The clinicopathologic data of 56 renal needle biopsy samples obtained from renal transplant recipients
were analyzed retrospectively. The specimens were classified histopathologically according to the Banff 2009 classification
system and analyzed by immunohistochemical labeling and immunofluorescence. Results In the 56 recipients, 1 (1.79%)
experienced hyperacute rejection, 8 (14.29%) had suspected acute rejection, 12 (21.43%) developed acute T-cell rejection, 6
(10.71%) had acute antibody-mediated rejection, 2 (3.57%) had acute T-cell rejection with acute antibody-mediated rejection, 12
(21.43%) had chronic active T cell-mediated rejection, 2 (3.57%) had chronic active antibody-mediated rejection, 2 (3.57%) had
chronic active T cell-mediated rejection with antibody-mediated rejection, 8 (14.29%) had non-specific interstitial fibrosis and
tubular atrophy, and 3 (5.36%) had normal graft function. The expression levels of immune markers CD3, CD4, CD8, CD20,
GrB and perforin differed with the types of T cell-mediated graft rejection, and the positivity and expression levels of these
markers tended to increased with the severity of graft rejection. The expression of C4d was positive in all cases with
antibody-mediated graft rejection. Conclusion The pathological characteristics of the renal biopsy specimens and expression
levels of the immune markers allow timely and accurate evaluation of graft rejection type to provide a reliable pathological
and etiological basis for clinical treatment and prognostic assessment.