C4d是补体经典途径激活以后补体C4的降解产物 ,能与内皮细胞共价结合。当肾移植患者发生含有体液性成分的排异时 ,由于免疫因素的参与 ,常伴有补体经典途径激活 ,管周毛细血管C4d的沉积。从而C4d可作为在移植肾排异时存在体液性成分的重要诊断标准。本文综述了C4d的检测方法 ,及在预测其排异预后和指导治疗方面的应用价值。 C4d is a degradation product of complement C4 after the activation of the complement classical pathway and can be covalently bound to endothelial cells. When renal transplant patients with rejection of humoral components, due to the involvement of immune factors, often accompanied by the activation of the complement of the classical pathway, the deposition of the perivascular capillaries C4d. Thus C4d can be used as an important diagnostic criteria for the presence of humoral components in rejection of renal allografts. This article reviews the detection of C4d, and its value in predicting the prognosis of rejection and guiding treatment.