ABIM Tx Hepatology key terms

The US deceased-donor liver allocation score adopted in 2023 that adds serum sodium, albumin, and a sex-based adjustment to the original MELD, improving prediction of three-month waitlist mortality, particularly for women.

Additional allocation priority granted to candidates whose death risk is underestimated by laboratory MELD, such as those with hepatocellular carcinoma, portopulmonary hypertension, or recurrent cholangitis; qualifying criteria and waiting periods are set by national policy.

Selection rule for transplantation in hepatocellular carcinoma limiting tumor burden to a single lesion up to 5 cm, or up to three lesions each 3 cm or smaller, without vascular invasion or extrahepatic spread; predicts low recurrence and benchmarks other criteria.

Deliberate locoregional therapy of hepatocellular carcinoma that exceeds accepted size or number limits, aiming to shrink tumor burden until criteria are met so the patient can qualify for exception points and transplant with durable outcomes.

A syndrome in patients with cirrhosis marked by acute decompensation plus organ failures, driven by systemic inflammation and infection, carrying high short-term mortality; transplant selection depends on the number of organ failures, reversibility, and center experience.

Pulmonary arterial hypertension occurring with portal hypertension, defined at right heart catheterization by mean pulmonary artery pressure above 20 mmHg with elevated pulmonary vascular resistance and normal wedge pressure; severe uncontrolled cases contraindicate transplantation unless vasodilator therapy achieves control.

Loss of physiologic reserve and skeletal muscle mass common in advanced liver disease, measured by grip strength, chair-stand testing, or cross-sectional muscle area, and independently associated with waitlist mortality, prolonged hospitalization, and poorer post-transplant survival.

Combined transplantation for candidates with liver failure plus significant irreversible kidney disease; US eligibility is governed by policy based on dialysis duration, measured or estimated glomerular filtration rate, and chronic kidney disease stage.

A liver recovered after circulatory death, exposing it to additional warm ischemia; such grafts carry higher rates of ischemic cholangiopathy and early graft dysfunction, so donor selection and perfusion strategies are used to limit risk.

Large fat droplets that displace the hepatocyte nucleus to the cell periphery; moderate to severe donor steatosis increases the risk of primary nonfunction and early graft dysfunction and often prompts graft discard or altered recipient selection.

Ex vivo preservation in which a liver is perfused at body temperature with an oxygenated blood-based solution, supporting metabolism, permitting viability testing, and potentially allowing use of grafts otherwise judged marginal or unsuitable.

A postoperative syndrome in the first week defined by one or more of peak aminotransferase levels above 2000 U/L, INR of at least 1.6, or bilirubin of at least 10 mg/dL on day 7, identifying grafts at higher risk of loss.

Complete or near-complete failure of a newly implanted liver to function, with worsening coagulopathy, acidosis, markedly elevated transaminases, and absent bile production, usually within days; it is an emergency requiring urgent retransplantation.

Abrupt hemodynamic collapse immediately after portal reperfusion, with hypotension, bradycardia, hyperkalemia, and reduced cardiac output; risk rises with steatotic grafts and prolonged cold ischemia and is managed with vasopressors, calcium, and fluid.

Implantation technique that preserves the native inferior vena cava by sewing the donor cava to it side-to-side or as a cuff, avoiding complete caval clamping and venovenous bypass, but risking outflow obstruction if the anastomosis is too tight.

A calcineurin inhibitor that blocks T-cell activation by inhibiting calcineurin and interleukin-2 production; it anchors most maintenance regimens and requires level monitoring because of nephrotoxicity, neurotoxicity, and post-transplant diabetes.

An antimetabolite that inhibits inosine monophosphate dehydrogenase and thereby lymphocyte proliferation; used to spare steroids or reduce calcineurin inhibitor exposure, with gastrointestinal intolerance, marrow suppression, and teratogenicity as key adverse effects.

Sirolimus and everolimus block the mammalian target of rapamycin and interrupt interleukin-2-driven T-cell proliferation; helpful when calcineurin inhibitor toxicity or renal dysfunction dominates, but they impair wound healing and raise early vascular thrombosis risk.

A chimeric monoclonal antibody against the interleukin-2 receptor alpha chain given on days 0 and 4 that blocks activated T cells; it permits delayed calcineurin inhibitor introduction in recipients with renal impairment and adds little infectious risk.

T-cell-mediated graft injury arising within weeks to months, with fever, graft tenderness, and rising cholestatic and hepatocellular enzymes; biopsy shows mixed portal inflammation, subendothelial venulitis, and bile duct inflammation, and pulsed corticosteroids are first-line treatment.

Late, largely irreversible rejection characterized by loss of small interlobular bile ducts, foam-cell arteriopathy, and centrilobular cholestasis; it responds poorly to intensified immunosuppression and frequently leads to graft failure and retransplantation.

HLA antibodies directed at donor antigens, preformed or arising after transplant, that bind graft endothelium and cause capillaritis, complement deposition, and graft dysfunction; treatment includes plasmapheresis, intravenous immunoglobulin, and B-cell-directed therapy.

A clinical state in which a recipient keeps a functioning graft without any immunosuppression, with normal histology and no evidence of rejection; it is uncommon after liver transplantation and mainly described in carefully selected patients undergoing monitored withdrawal.

A histologic score used on liver biopsy that grades three features, mixed portal inflammation, bile duct inflammation, and venular endothelial inflammation, each from 0 to 3; the total supports diagnosis and severity grading of acute cellular rejection.

A complement split product deposited on graft capillary endothelium after antibody binding; diffuse microvascular staining supports antibody-mediated rejection, though it appears in other conditions and is less sensitive in liver than in kidney allografts.

Occlusion of the graft artery, usually early after surgery, presenting with fever, sepsis, rising transaminases, and biliary necrosis; Doppler ultrasound is the initial test, and management ranges from thrombectomy and revision to retransplantation.

Narrowing at the surgical bile duct connection, often caused by local ischemia or technical factors, producing cholestasis months after transplantation; endoscopic dilation with stenting is first-line, and surgery is reserved for refractory narrowing.

Multifocal strictures and dilatations of the hilar or intrahepatic biliary tree caused by arterial or preservation injury, typical of donation after circulatory death grafts; it is difficult to treat, tends to recur, and is a common indication for retransplantation.

Symptomatic or tissue-invasive cytomegalovirus infection with fever, myelosuppression, hepatitis, colitis, or pneumonitis; prevented by prophylaxis or preemptive monitoring and treated with valganciclovir or intravenous ganciclovir while watching for resistance.

An Epstein-Barr virus-driven lymphoid proliferation ranging from polyclonal hyperplasia to aggressive lymphoma, favored by intense immunosuppression; management combines reduction of immunosuppression, rituximab, and chemotherapy when needed.

Kidney injury from tacrolimus or cyclosporine caused acutely by afferent arteriolar vasoconstriction and chronically by striped interstitial fibrosis or nodular glomerulosclerosis; it is a leading cause of late renal failure and often prompts regimen modification.

A neurotoxic complication of calcineurin inhibitors, especially with hypertension or low magnesium, causing headache, seizures, cortical visual loss, and posterior white-matter edema on imaging; it usually resolves after dose reduction or drug switch.

An aggressive form of recurrent hepatitis C with marked cholestasis, very high viral levels, and rapid periportal fibrosis that can destroy the graft within months; direct-acting antivirals have made it treatable and largely preventable.

Return of primary sclerosing cholangitis in the graft, producing non-anastomotic strictures and cholangitis typically years after transplantation; separating it from ischemic or anastomotic biliary disease requires cholangiography with correlation of clinical and histologic findings.

New hepatocellular carcinoma appearing after transplantation, usually growing from micrometastases present before surgery; risk relates to explant tumor burden, vascular invasion, and differentiation, and surveillance uses periodic imaging with tumor markers.

A plasma-cell-rich hepatitis with interface activity and autoantibodies arising in a graft transplanted for an unrelated disease; it mimics rejection and is managed with corticosteroids plus azathioprine, sometimes requiring a switch in maintenance therapy.

Donor lymphocytes engraft and attack recipient tissues, producing fever, rash, diarrhea, and pancytopenia, often with marrow failure; mortality is high and treatment involves reducing immunosuppression plus steroids and cellular therapy.

Replacement of a failing liver graft, most often for primary nonfunction, hepatic artery thrombosis, ischemic cholangiopathy, or recurrent disease; outcomes are inferior to first transplants, so timing and candidate selection are critical.