Current Evidence Cardiac Transplantation Acute cellular rejection (T cell mediated) most commonly occurs in the first months after heart transplant Twenty to forty percent of heart transplant recipients experience at least one episode of acute cellular rejection in the first postoperative year Acute antibody-mediated rejection is less common than cellular rejection, and occurs in about 10% of patients in conjunction with hemodynamic instability Most patients are asymptomatic during the early phases of rejection Surveillance, with serial echocardiography or right heart cardiac catheterization and endomyocardial biopsy, is required to identify early rejection and initiate treatment Clinical evidence of rejection signals a more advanced process, and may be identified by tachycardia and S3 gallop on examination Contributory symptoms may include malaise, pallor, fatigue, anorexia, nausea, or respiratory complaints More advanced rejections may be evidenced by hemodynamic instability, and on examination, hepatomegaly, pulmonary congestion, and JVD Liver Transplantation Acute cellular rejection occurs in up to two-thirds of patients following liver transplantation and is suspected when there is an increase in liver enzymes including bilirubin, GGT, and transaminases Rejection should also be suspected if immunosuppression levels are low Acute rejection is primarily diagnosed histologically because elevated LFTs can also be seen in other settings such as infection The histologic triad of bile duct injury, endothelialitis, and lymphocytic