ABIM Tx Hepatology flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

MELD 3.0 components

MELD 3.0 uses bilirubin, INR, creatinine, serum sodium, albumin, and sex to rank candidates for liver transplant. Scores range from 6 to 40 and replaced MELD-Na in 2023.

Milan criteria for HCC

Listing criteria for hepatocellular carcinoma: one nodule 5 cm or less, or up to three nodules each 3 cm or less, without vascular invasion or extrahepatic spread. It predicts roughly 70% five-year survival after transplant.

Absolute contraindications to transplant

Transplant is contraindicated by active extrahepatic malignancy, uncontrolled sepsis, active substance use without an agreed abstinence interval, severe irreversible cardiopulmonary disease, and inability to adhere to lifelong immunosuppression and follow-up.

Hepatopulmonary syndrome MELD exception

Hepatopulmonary syndrome qualifies for standardized MELD exception points once the diagnosis is confirmed by contrast echocardiography, an elevated alveolar-arterial oxygen gradient, and hypoxemia with arterial partial pressure of oxygen below 60 mm Hg on room air.

Acuity circles allocation

The acuity circles system distributes livers to candidates in expanding radii from the donor hospital, beginning at 250 nautical miles and then 500 miles before broader and national sharing, replacing the prior donation service area framework.

Portopulmonary hypertension thresholds

Portopulmonary hypertension contraindicates transplant when mean pulmonary artery pressure exceeds 35 mm Hg with pulmonary vascular resistance above 240 dynes per second per cm⁵, unless vasodilator therapy lowers resistance into a transplantable range.

Postreperfusion syndrome

Postreperfusion syndrome is a mean arterial pressure decline of more than 30%, or a pressure below 60 mm Hg, lasting at least one minute within five minutes of graft reperfusion, driven by potassium, acidosis, and vasoactive mediators.

Piggyback caval implantation

Piggyback implantation preserves the recipient inferior vena cava by anastomosing the donor caval cuff to a side-clamped recipient cava, avoiding complete caval cross-clamping and improving hemodynamic stability during the reperfusion phase.

Early allograft dysfunction criteria

Olthoff criteria define early allograft dysfunction by any of: peak AST or ALT above 2,000 IU/L within seven days, INR of 1.6 or greater on day seven, or bilirubin of 10 mg/dL or greater on day seven.

Primary nonfunction

Primary nonfunction presents with rapidly rising transaminases above several thousand, INR above 2.5, worsening lactic acidosis, hemodynamic instability, and absent bile output in the first days after transplant. Urgent retransplantation is the only definitive treatment.

Tacrolimus mechanism of action

Tacrolimus binds FK506-binding protein 12, inhibiting calcineurin and blocking nuclear factor of activated T cell signaling, which reduces interleukin-2 transcription and downstream T cell activation and proliferation.

Mycophenolate mofetil

Mycophenolate mofetil inhibits inosine monophosphate dehydrogenase, depleting guanosine nucleotides in lymphocytes. Typical dosing is 1 to 2 grams daily, with leukopenia, anemia, diarrhea, and teratogenicity as important adverse effects.

mTOR inhibitor risks

Sirolimus and everolimus inhibit mammalian target of rapamycin and block interleukin-2 driven T cell proliferation. They are generally avoided in the first month because of hepatic artery thrombosis, wound dehiscence, hyperlipidemia, and proteinuria.

Acute cellular rejection histology

The Banff triad of acute cellular rejection comprises mixed portal inflammation rich in eosinophils, bile duct epithelial injury, and subendothelial inflammation of portal vein branches. Severity is graded by the rejection activity index.

Chronic rejection features

Chronic rejection shows vanishing bile duct syndrome with ductopenia involving fewer than half of portal tracts, foam cell arteriopathy, and centrilobular cholestasis. It is usually irreversible and is an indication for retransplantation.

Antibody-mediated rejection

Antibody-mediated rejection is suggested by circulating donor-specific antibodies, microvascular C4d deposition, and capillary margination of neutrophils. Treatment includes plasmapheresis, intravenous immunoglobulin, and rituximab combined with intensified immunosuppression.

Hepatic artery thrombosis

Hepatic artery thrombosis affects 3% to 5% of adult grafts and presents with fever, transaminitis, and bile leak. It causes ischemic cholangiopathy and graft failure, requiring urgent revascularization or retransplantation.

Anastomotic biliary stricture

Anastomotic strictures are the most common biliary complication after liver transplant, usually appearing within the first year. They are managed endoscopically with dilation and stenting, reserving surgical revision for refractory cases.

CMV prophylaxis

Cytomegalovirus prophylaxis with valganciclovir for three to six months is standard for high-risk seronegative recipients of seropositive donor organs, who otherwise face the greatest risk of primary infection and invasive disease.

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome results from calcineurin inhibitor toxicity and presents with seizures, headache, visual disturbance, and posterior white matter edema on imaging. Treatment is dose reduction or drug substitution.

Post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder is usually Epstein-Barr virus driven, often presents as a nodal or extranodal mass, and is first managed by reducing immunosuppression, followed by rituximab and chemotherapy for nonresponders.

HBV recurrence prophylaxis

Hepatitis B recurrence after transplant is prevented with hepatitis B immunoglobulin plus a potent nucleos(t)ide such as entecavir or tenofovir, reducing recurrence to under 10% and substantially improving graft and patient survival.

Recurrent PSC

Recurrent primary sclerosing cholangitis after transplant is diagnosed by nonanastomotic strictures on cholangiography with compatible histology. It occurs in roughly 20% to 30% by ten years and can progress to graft failure.

Fibrosing cholestatic hepatitis

Fibrosing cholestatic hepatitis is a severe recurrent viral pattern with cholestasis, ductular proliferation, periportal fibrosis, and minimal inflammation, typically in heavily immunosuppressed patients with high viral replication. It can rapidly progress to graft failure.

Alcohol relapse after transplant

Return to harmful alcohol use after transplant for alcohol-associated liver disease occurs in roughly 10% to 20% of recipients and is associated with accelerated graft injury and reduced long-term survival.

Banff rejection activity index

The Banff rejection activity index sums mixed portal inflammation, bile duct inflammation, and subendothelial venulitis, each scored zero to three, plus an edema score in some versions, giving a total that grades rejection severity.

Macrovesicular steatosis

Moderate to severe macrovesicular steatosis, generally affecting more than 30% of hepatocytes, increases the risk of primary nonfunction and early graft dysfunction, and steatosis above 60% generally contraindicates donation.

Ischemic cholangiopathy

Ischemic cholangiopathy produces nonanastomotic biliary strictures with biliary epithelial necrosis and patchy fibrosis, typically from hepatic artery thrombosis or prolonged cold ischemia, and rarely responds to endoscopic therapy alone.

C4d immunostaining

C4d immunostaining along graft capillaries supports a diagnosis of antibody-mediated rejection and is interpreted alongside circulating donor-specific antibodies and neutrophil capillary margination, though no single finding is diagnostic on its own.

Long-term causes of death

Death with a functioning graft dominates late graft loss, with cardiovascular disease, de novo malignancy, infection, and renal failure being the leading causes of mortality beyond the first postoperative year.

Graft survival figures

Contemporary adult liver transplantation yields roughly 90% one-year and 75% five-year patient survival, with one-year graft survival near 85% to 88% and an overall graft half-life approaching 12 to 15 years.

Nonadherence to immunosuppression

Nonadherence to immunosuppression is a leading preventable cause of late acute rejection, graft loss, and death, with the highest risk during adolescence and after transition from pediatric to adult care.