Histologic Findings Predictive of a Diagnosis of De novo Autoimmune Hepatitis After Liver Transplantation in Adults

Background. Autoimmune hepatitis (AIH) after liver transplantation has been defined histologically as a "hepatitic" pattern of injury, characterized by lymphoplasmacytic inflammation with necroinflammatory activity (NIA), comparable with findings seen in native livers. This definition, however, is difficult to apply in practice because specific histologic criteria are not clearly delineated. This study aimed to determine which histologic features correlated best with clinical and serologic features of dAIH. Methods. Index liver biopsies from patients with autoimmune-like hepatitis transplanted for non-AIH in two centers (n=35 and 20) were reviewed. Histologic features were correlated with the clinical diagnosis of AIH based on a retrospective review of clinical and serologic data, including therapeutic response. Results. A clinical diagnosis of AIH was retrospectively assigned to 24 of 35 (68%) and 18 of 20 (90%) patients, respectively (P=0.10). In multivariate analysis, centrilobular NIA and centrilobular plasma cell (PC) ratio of 30% to 50% were independently discriminating for a clinical diagnosis of AIH (P=0.04 and 0.05, respectively). The best level of predictability (99.6%) was mathematically achieved when severe centrilobular NIA and centrilobular PC ratio of 30% to 50% were both present. Conclusion. A histologic pattern of centrilobular injury including increased NIA and increased PC infiltration correlates with measurements of autoimmunity in liver recipients. It could be used to segregate cases for further study and introduced into the AIH scoring systems when applied in the context of liver transplantation.