The Prognostic Value of Late Kidney Transplant Rejection Pathology Characteristics

Abstract

Renal allograft rejection, represented by the wide spectrum of lesions with different pathogenesis, pathology patterns, clinical course and prognosis, still remains the most often cause of late graft dysfunction. Moreover, a combination of several factors, either of which may impact the post-transplant course, generally take place. We aimed to analyze the incidence of late renal allograft rejection variants, and to determine clinical factors and pathology features, influencing prognosis in the specific types of late renal allograft rejection.The data obtained from 361 patients with acute (n=227) or chronic (n=134) late allograft rejection (mean time after kidney transplantation 48.8 ± 46.1 months) were analyzed retrospectively. C4d expression was found in 34% cases of acute rejection and in 58% cases of chronic rejection (64% in chronic transplant glomerulopathy and 52% in transplant vasculopathy). 5-year graft survival comprised 48% and 24% for acute and chronic transplant rejection respectively (Р<0.01). Combination of acute cell-mediated rejection with chronic transplant rejection did not influence significantly the prognosis for the latter. Diffuse C4d expression on peritubular capillaries turned to be an independent prognostic factor regardless the pathology variant of renal allograft rejection. In contrast, focal C4d expression had no impact on the prognosis, which did not differ significantly from C4d-negative type. On the other hand, in acute rejection prognosis for C4d-positive forms was worse compared to C4d-negative (55% vs 25%; P <0.01), while in chronic rejection there was no difference between C4d-positive and C4d-negative forms (26% vs 24%; P=NS). In multivariate Cox-model analysis, the following factors appeared to influence the prognosis: presence of chronic transplant glomerulopathy, features of vasculitis, severity of tubulitis, presence of thrombotic micrioangiopathy and prominence of interstitial fibrosis.