Therapy directed at chronic HCV infection should be considered once the patient has ceased all immunosuppressive drugs and has no evidence of active GVHD. Among 6225 consecutive HCT recipients, 1.4% had AST > 1500 U/L; the most common causes were hypoxic hepatitis related to SOS, respiratory

failure, and shock syndromes.23 In SOS, AST increases occurred 2-6 weeks after the onset of liver injury; peak AST was 2252 U/L and the case fatality rate was 76%. In patients with shock Smoothened inhibitor or prolonged hypoxemia, peak serum AST was 3545 U/L within days, and the case fatality rate was 88%.23 Elevations of serum ALT (∼100-300 U/L) are common during the onset of hepatic GVHD during a time when GVHD prophylaxis is being given. In the absence of prophylaxis or after donor lymphocyte infusion, serum

ALT may rise rapidly, followed by jaundice, a result of an acute lobular hepatitis and damage to small bile ducts.37 Although drug-liver injury is the probable cause of AST/ALT elevation in many cases, attribution to a single find more drug is mostly guesswork because every patient receives multiple drugs. Isolated AST/ALT elevation has been reported after cyclophosphamide infusions, liposomal amphotericin, trimethoprim-sulfamethoxazole, itraconazole, voriconazole and imatinib.12, 23 Biliary sludge (composed of calcium bilirubinate and crystals of calcineurin inhibitors) may cause transient epigastric pain, nausea, and abnormal serum liver enzymes. Biliary sludge may also cause acute “acalculous” cholecystitis, acute pancreatitis, and bacterial cholangitis. The gallbladder may also become

infected by cytomegalovirus and fungi. Biliary obstruction caused by stones or sludge is rare. Therapeutic endoscopic retrograde cholangiopancreatography is needed only in patients with clinical evidence of cholangitis or radiologic evidence of persistent biliary obstruction.41 EBV-lymphoproliferative disease is now an infrequent complication because of EBV-DNA surveillance and pre-emptive treatment with rituximab. Presenting signs are sweats, generalized malaise, enlarged tonsils, and cervical lymphadenopathy, with liver infiltration by transformed immunoblasts (Fig. 3F) occurring in over 50%, manifest by abnormal serum alkaline phosphatase and massive hepatosplenomegaly. A lethal but LY294002 rare syndrome of hyperammonemia and coma has been described after high dose chemotherapy, including conditioning therapy for HCT.42 Patients present with progressive lethargy, confusion, weakness, incoordination, vomiting, hyperventilation with respiratory alkalosis, and plasma ammonia over 200 μmol/L. The pathogenesis of idiopathic hyperammonemia likely involves the unmasking of a latent genetic disorder similar to ornithine transcarbamylase deficiency. Fully-referenced discussions of this topic can be found in two recent textbooks.