摘要Background Acute rejection is one of the most important factors for prognosis following liver transplantation. With the use of potent immunosuppressants, acute rejection does not always present typical manifestations. Moreover, other complications often occur concomitantly after liver transplantation, which makes early diagnosis of acute rejection more difficult. Acute rejection is best diagnosed by liver biopsy. Differentiation of clinical manifestations and pathological features plays an important role in achieving individualized immunosuppressive treatment and prolonging long term survival of patients given orthotopic liver transplants.Methods From January 2004 to December 2006, 516 orthotopic liver transplantations were performed at the First Affiliated Hospital, Sun Yat-sen University. For patients who suffered acute rejection, clinical manifestations, histopathological features, diagnosis and anti-rejection treatment were summarized and analyzed. Results In 86 cases (16.7%), of the 516 recipients, 106 episodes of acute rejection occurred, which included 9 with histopathological borderline changes, 36 Banff Ⅰ rejections, 48 Banff Ⅱ and 13 Banff Ⅲ. Among these, 36 were cured by adjusting the dose of immunosuppressant and 65 were reversed by methylprednisolone pulse treatment. Five were methylprednisolone resistant, 3 of whom were given OKT3 treatment and 2 underwent liver retransplantation. Conclusions Due to potent immunosuppressive agents, acute rejection following an orthotopic liver transplantation lacks typical clinical manifestations and pathological features. Acute rejection is best diagnosed by liver biopsy. Designing rational individualized immunosuppressive regimen based on clinical and pathological features of acute rejection plays an important role in prolonging long term survival of patients.