Gastrointestinal

Chronic hepatitis B: monitoring and treatment indications

Clinical Overview and When to Suspect Chronic Hepatitis B

— HBeAg-positive chronic infection ("immune tolerant"): high HBV DNA, normal ALT, minimal inflammation

— HBeAg-positive chronic hepatitis ("immune active"): elevated ALT, high DNA, active necroinflammation

— HBeAg-negative chronic infection ("inactive carrier"): DNA <2,000 IU/mL, normal ALT, low fibrosis risk

— HBeAg-negative chronic hepatitis ("reactivation"): DNA >2,000, elevated ALT, often precore/basal core mutants

— HBsAg-negative phase ("occult/resolved"): HBsAg lost; cccDNA persists, reactivation risk with immunosuppression

— All adults ≥18 at least once with triple panel: HBsAg, anti-HBs, total anti-HBc

— Pregnancy (every pregnancy), people who inject drugs, MSM, HIV/HCV co-infection, household/sexual contacts of HBsAg+, hemodialysis, immunosuppression candidates, immigrants from endemic areas (HBsAg prevalence ≥2%)

Board pearl: Anti-HBc IgM positivity differentiates acute HBV from chronic flare; in chronic reactivation, anti-HBc is IgG with negative IgM (or low-titer IgM).

Definition: Persistence of HBsAg ≥6 months. Affects ~300 million globally, ~2 million in the US, with disproportionate prevalence in Asian, sub-Saharan African, and Pacific Islander populations.

Natural history phases (AASLD 2018 nomenclature):

When to suspect/screen (USPSTF 2020, CDC 2023 universal adult screening once):

Outcomes if untreated: 15–40% lifetime risk of cirrhosis, hepatic decompensation, or HCC. Annual HCC incidence 0.5–1% in non-cirrhotic chronic HBV, 2–8% in cirrhotic HBV.

Step 3 management: A patient with newly positive HBsAg requires the full panel within the same visit—HBeAg/anti-HBe, HBV DNA, ALT/AST, platelets, INR, albumin, HIV/HCV/HDV screening, hepatitis A immunity, and abdominal ultrasound. Don't anchor on a single HBsAg result; phase assignment requires ≥3 sets of labs over 6–12 months.

Presentation Patterns and Key History

— Hepatitis flare: RUQ discomfort, fatigue, jaundice, anorexia, low-grade fever; ALT often >5× ULN

— Decompensated cirrhosis: ascites, variceal bleeding, hepatic encephalopathy, jaundice

— HCC: weight loss, RUQ mass, worsening ascites, paraneoplastic erythrocytosis/hypoglycemia

— Extrahepatic: polyarteritis nodosa, membranous nephropathy (children > adults), serum sickness–like arthritis-dermatitis, mixed cryoglobulinemia, aplastic anemia

— Country of birth (vertical transmission risk if from endemic region—Asia, sub-Saharan Africa)

— Maternal HBV status, birth practices, childhood transfusions

— Sexual history, IVDU, tattoos, incarceration, healthcare exposures

— Household contacts with HBV

— Alcohol use (synergistic fibrosis), metabolic syndrome (MASLD overlap)

— Family history of HBV and HCC in first-degree relatives (independent HCC risk modifier)

— Prior or planned immunosuppression: chemotherapy, rituximab, anti-TNF, corticosteroids ≥20 mg prednisone ≥4 weeks, transplant

— Herbal supplements, acetaminophen use (flare confounders)

Step 3 management: A 38-year-old immigrant from Vietnam with newly found HBsAg+ needs (1) phase assessment labs, (2) US liver, (3) screening of all household members and sexual partners with the triple panel, and (4) HAV vaccination if non-immune. Counsel on transmission: blood and sexual fluids, not casual contact, breastfeeding, or sharing utensils.

Key distinction: Vertical/early childhood acquisition → 90% chronicity; adult acquisition → <5% chronicity. This drives screening priorities.

Most chronic HBV is asymptomatic—discovered on routine screening, blood donation, prenatal labs, or workup of incidentally elevated aminotransferases.

Symptomatic presentations:

Key history elements:

Vaccination history: Hepatitis A status; HBV vaccine series in seronegative household/sexual contacts.

Physical Exam Findings and Hemodynamic Assessment

— Stigmata: spider angiomas (especially upper trunk), palmar erythema, gynecomastia, testicular atrophy, Dupuytren contracture, parotid enlargement

— Caput medusae, splenomegaly, firm/nodular liver on palpation

— Asterixis, fetor hepaticus in encephalopathy

— Muscle wasting (temporal, thenar)—sarcopenia is an independent mortality predictor

— Ascites: flank dullness, shifting dullness (need ≥1500 mL), fluid wave

— Jaundice, scleral icterus (bilirubin >2.5 mg/dL)

— Lower extremity edema

— Hepatic encephalopathy: asterixis, disorientation, day-night reversal

— Resting tachycardia and low-normal BP suggest hyperdynamic circulation from splanchnic vasodilation

— SBP <90 with normal volume status in advanced cirrhosis = poor prognosis; consider hepatorenal physiology

— Avoid over-diuresis; monitor orthostatics

— Livedo reticularis, mononeuritis multiplex, hypertension → PAN

— Lower extremity edema with proteinuria → membranous nephropathy

— Palpable purpura → cryoglobulinemic vasculitis

Board pearl: A previously compensated cirrhotic HBV patient who develops new ascites, weight loss, and an arterial bruit over the liver has HCC until proven otherwise—order multiphase CT or MRI, not just AFP.

CCS pearl: On Step 3 CCS, when examining a chronic HBV patient, order "abdominal exam," "skin exam," and "neurologic exam (mental status)"—this captures decompensation features and triggers appropriate downstream orders.

Compensated chronic HBV: Exam often completely normal. Subtle findings may include mild hepatomegaly or non-tender liver edge.

Signs of advancing fibrosis/cirrhosis:

Decompensation findings:

Hemodynamic assessment in cirrhotic HBV:

Extrahepatic exam clues:

HCC red flags: Rapidly enlarging firm liver, audible hepatic bruit, sudden ascites in previously compensated patient.

Diagnostic Workup — Initial Labs, Imaging, and Biomarkers

— HBsAg+, anti-HBc+ (IgG), anti-HBs−: chronic infection

— HBsAg+, IgM anti-HBc+: acute infection or severe flare

— HBsAg−, anti-HBc+, anti-HBs+: resolved/past infection

— HBsAg−, anti-HBc+, anti-HBs−: isolated anti-HBc—occult HBV, false positive, or window period; check HBV DNA

— HBsAg−, anti-HBs+, anti-HBc−: vaccine-induced immunity

— HBeAg, anti-HBe

— HBV DNA quantitative (IU/mL)—drives phase and treatment decisions

— ALT, AST—ULN: 35 U/L men, 25 U/L women (AASLD), lower than lab reference

— CBC (platelets <150K suggests portal hypertension), PT/INR, albumin, total bilirubin, alk phos

— Creatinine, phosphorus (baseline for tenofovir)

— Co-infection screen: anti-HCV, anti-HDV (in all HBsAg+ patients per 2023 guidance—prior risk-based screening missed cases), HIV

— Hepatitis A IgG; vaccinate if non-immune

— AFP baseline

— Pregnancy test in reproductive-age women

— FIB-4 (age, AST, ALT, platelets): <1.45 excludes advanced fibrosis; >3.25 suggests advanced

— APRI: >1.5 suggests significant fibrosis

— Transient elastography (FibroScan): >7 kPa significant fibrosis, >11 kPa cirrhosis in HBV

Step 3 management: Always recheck ALT and HBV DNA on at least 2 occasions ≥3 months apart before labeling a patient "inactive carrier"—single normal values can miss fluctuating HBeAg-negative chronic hepatitis.

Serologic panel interpretation (memorize cold):

Initial workup once HBsAg confirmed positive ≥6 months:

Imaging: Abdominal ultrasound with Doppler—assess for fibrosis morphology, splenomegaly, portal vein patency, focal lesions.

Noninvasive fibrosis assessment:

HCC surveillance: Ultrasound ± AFP every 6 months in all cirrhotics, plus non-cirrhotic Asian men ≥40, Asian women ≥50, sub-Saharan Africans ≥20, family history of HCC.

Diagnostic Workup — Advanced or Confirmatory Studies

— Falsely elevated by acute hepatitis flare (ALT >5× ULN), cholestasis, congestion, recent meal

— Failure rate higher with BMI >30; use XL probe

— Repeat in 6–12 months to track progression

— Multiphase contrast CT or MRI with LI-RADS classification

— LR-5 lesion (arterial enhancement + washout + capsule, ≥10 mm) = definitive HCC, no biopsy needed

— LR-3/4 → short-interval follow-up or biopsy

— DEXA scan if planning long-term tenofovir disoproxil

— Creatinine clearance, urinalysis (proteinuria, glucosuria—Fanconi from TDF)

Key distinction: In HBV, biopsy is for borderline cases, not diagnosis. In autoimmune hepatitis or Wilson disease overlap suspicion, biopsy becomes mandatory.

Board pearl: An LR-5 lesion in a cirrhotic HBV patient is HCC—proceed to multidisciplinary tumor board and Milan criteria assessment, not biopsy.

Liver biopsy: No longer routine but consider when noninvasive tests are discordant, ALT borderline with intermediate DNA, suspected concurrent disease (MASLD, autoimmune hepatitis, alcohol), or before initiating therapy in equivocal cases. Reports use METAVIR (F0–F4) or Ishak scoring.

Transient elastography (VCTE) caveats:

MR elastography: More accurate but cost/access limited; useful in obesity.

Genotyping: Not routine in US practice; genotype C associated with later HBeAg seroconversion and higher HCC risk; can guide peg-interferon candidacy (A > D response).

Quantitative HBsAg (qHBsAg): Emerging marker; very low levels (<100 IU/mL) in HBeAg-negative inactive carriers predict spontaneous HBsAg loss; used to monitor functional cure trials.

HDV testing: Anti-HDV total in all HBsAg+; if positive, confirm with HDV RNA. HDV co-infection accelerates fibrosis 2–3×.

HCC diagnostic imaging:

Pre-treatment baseline:

Resistance testing: Reserve for treatment failure (incomplete viral suppression after 48 weeks of high-genetic-barrier NA, or virologic breakthrough >1 log rebound).

Risk Stratification and Treatment Indication Logic

— All patients with cirrhosis (compensated or decompensated) and detectable HBV DNA—treat regardless of ALT

— HBeAg-positive immune active: ALT >2× ULN (≥70 men, ≥50 women) AND HBV DNA >20,000 IU/mL

— HBeAg-negative immune active: ALT >2× ULN AND HBV DNA >2,000 IU/mL

— Pregnancy with HBV DNA >200,000 IU/mL: treat in third trimester to prevent vertical transmission

— Coinfection with HIV: treat all

— Coinfection with HCV when starting DAAs: monitor and treat to prevent HBV reactivation

— Immunosuppression prophylaxis: treat if HBsAg+ before rituximab, anti-CD20, stem cell transplant, or moderate-risk regimens

— Extrahepatic manifestations (PAN, glomerulonephritis): treat

— Family history of HCC, age >40 with persistent DNA elevation and any fibrosis: consider treatment

— HBeAg+ chronic infection ("immune tolerant"): monitor every 3–6 months; treat if ALT rises or age >40 with biopsy showing inflammation/fibrosis

— HBeAg− chronic infection ("inactive carrier"): monitor every 6–12 months

— Primary: sustained HBV DNA suppression to undetectable

— Secondary: ALT normalization, HBeAg seroconversion, histologic improvement

— Ideal/functional cure: HBsAg loss ± anti-HBs (achieved in <10% with NAs)

Step 3 management: Don't treat the "immune tolerant" young patient with normal ALT and high DNA reflexively—monitor q3–6 months. But the moment ALT rises persistently or fibrosis develops on FibroScan, transition to treatment.

Board pearl: Cirrhosis + any detectable HBV DNA = treat. Period. No ALT or DNA threshold required.

AASLD 2018 treatment indications (memorize):

Observation (no treatment) indications:

HCC risk scores: PAGE-B (platelets, age, gender) for Caucasians on therapy; REACH-B for untreated Asians; mPAGE-B incorporates albumin.

Treatment goals:

Pharmacotherapy — First-Line Regimens

— Entecavir (ETV): 0.5 mg PO daily (1 mg if lamivudine-experienced or decompensated); take on empty stomach

— Tenofovir disoproxil fumarate (TDF): 300 mg PO daily; risks—nephrotoxicity, Fanconi syndrome, ↓BMD

— Tenofovir alafenamide (TAF): 25 mg PO daily; less renal/bone toxicity; preferred if CrCl 15–60, osteoporosis, or fracture risk; safe down to CrCl 15 without dose adjustment (TDF needs renal dosing)

— TDF or TAF preferred if prior lamivudine exposure (entecavir cross-resistance)

— TAF preferred in renal dysfunction, osteoporosis, age >60, postmenopausal women

— Entecavir preferred in pregnancy avoidance is not needed and renal function normal (cheapest generic in many markets); avoid in decompensated cirrhosis at standard dose

— TDF preferred in pregnancy (most safety data, category B)

— Finite duration, no resistance, higher HBsAg loss rates (~3–7%)

— Best candidates: young, HBeAg+, genotype A, high ALT, low DNA, no cirrhosis

— Contraindications: decompensated cirrhosis, autoimmune disease, pregnancy, severe depression, cytopenias, uncontrolled cardiac disease

— HBeAg+: continue until HBeAg seroconversion + 12 months consolidation AND undetectable DNA; many continue indefinitely

— HBeAg−: indefinite for most; discontinuation only if HBsAg loss

— Cirrhosis: lifelong therapy

— HBV DNA, ALT, creatinine, phosphorus q3–6 months

— HBeAg/anti-HBe q6–12 months if initially positive

— HBsAg annually

— DEXA every 2 years on TDF; urinalysis annually

Step 3 management: Patient on TDF develops eGFR drop from 80 → 55 and hypophosphatemia—switch to TAF, recheck phosphate, urine glucose, and proteinuria.

Board pearl: Never stop NA in a cirrhotic—stopping can precipitate fatal flare.

First-line nucleos(t)ide analogues (NAs) — high genetic barrier to resistance:

Choosing between agents:

Pegylated interferon alfa-2a: 180 mcg SC weekly × 48 weeks

Treatment duration:

Monitoring on therapy:

Expanded Pharmacology — Reactivation Prophylaxis and Special Scenarios

— High risk (>10%): B-cell depleting (rituximab, ofatumumab, obinutuzumab), stem cell transplant, anthracycline-based chemo in HBsAg+ patients, high-dose corticosteroids (≥20 mg prednisone ≥4 weeks)

— Moderate risk (1–10%): TNF-α inhibitors, cytokine/integrin inhibitors, tyrosine kinase inhibitors, moderate-dose steroids

— Low risk (<1%): traditional immunosuppressants (azathioprine, MTX), intra-articular steroids, short steroid bursts

— HBsAg+ patients on high or moderate risk immunosuppression → prophylactic entecavir, TDF, or TAF starting before or with immunosuppression, continued ≥6 months after (≥12 months after rituximab)

— HBsAg−/anti-HBc+ ("resolved") on rituximab or SCT → prophylaxis OR close monitoring with HBV DNA q1–3 months and on-demand therapy

— ART must include TDF or TAF + emtricitabine or lamivudine as backbone

— Never use entecavir alone (selects HIV resistance—M184V)

— Bulevirtide (HDV entry inhibitor) — EU approved, US investigational

— Peg-interferon alfa remains the mainstay where bulevirtide unavailable

— Start entecavir or tenofovir immediately; do not wait for biopsy

— Consider transplant evaluation if MELD ≥15

— TDF + NSAIDs → nephrotoxicity risk

— Entecavir + cyclosporine/tacrolimus → monitor renal function

— TAF + rifampin/St. John's wort contraindicated (CYP3A induction)

CCS pearl: When an HBsAg+ patient is being prepared for rituximab-CHOP for DLBCL, order entecavir or TAF before chemotherapy day 1 and continue for 12 months post-rituximab. Missing this is a classic Step 3 vignette trap.

HBV reactivation in immunosuppression (AGA 2015, AASLD 2018):

Prophylactic strategy:

HBV/HIV coinfection:

HBV/HCV coinfection: Start NA before or with DAA to prevent reactivation; monitor closely.

HBV/HDV coinfection:

Acute hepatitis flare with decompensation:

Drug interactions:

Special Populations — Elderly and Renal/Hepatic Impairment

— Higher fibrosis burden, sarcopenia, polypharmacy, baseline renal/bone disease

— TAF preferred over TDF due to renal and bone safety

— Lower threshold for HCC surveillance—incidence rises with age

— Address frailty, fall risk, vaccinations (PCV20, RSV, zoster, influenza)

— TDF dose adjustment by CrCl:

— CrCl ≥50: 300 mg daily

— 30–49: 300 mg q48h

— 10–29: 300 mg q72–96h

— Hemodialysis: 300 mg weekly post-HD

— TAF: 25 mg daily down to CrCl 15; not recommended <15 unless on dialysis (limited data, increasingly used)

— Entecavir dose adjustment:

— CrCl 30–49: 0.25 mg daily

— 10–29: 0.15 mg daily

— <10/HD: 0.05 mg daily

— Monitor phosphate, urine protein/glucose, eGFR every 3–6 months on TDF

— Avoid peg-interferon—precipitates decompensation

— Avoid standard-dose entecavir; use entecavir 1 mg or preferably TDF/TAF

— Monitor for lactic acidosis with entecavir in MELD >20

— Refer for transplant evaluation when MELD ≥15 or first decompensating event

— Combination HBIG + NA initially; many centers transition to NA monotherapy long-term

— Lifelong antiviral; reactivation risk persists

Step 3 management: An 82-year-old HBsAg+ woman with eGFR 42 and osteopenia needs treatment for HBeAg− chronic hepatitis—choose TAF 25 mg daily, not TDF.

Board pearl: Entecavir in decompensated cirrhosis carries a black-box lactic acidosis warning; tenofovir formulations are safer choices.

Elderly (>65):

Renal impairment:

HBV-associated glomerulonephritis: Membranous nephropathy and MPGN; treat HBV aggressively with NA—often induces remission. Avoid prolonged steroids as monotherapy (can ↑ DNA).

Hepatic impairment / decompensated cirrhosis:

Post-liver transplant:

Special Populations — Pregnancy, Pediatrics, and Vertical Transmission

— HBV DNA >200,000 IU/mL (or HBeAg+) → start TDF 300 mg daily at 28–32 weeks, continue through delivery

— Continue TDF 0–12 weeks postpartum; monitor for ALT flare after stopping

— TDF is pregnancy category B, preferred agent; entecavir and TAF have less safety data in pregnancy

— Peg-interferon contraindicated in pregnancy

— If on TDF → continue

— If on entecavir or TAF → switch to TDF (though increasing TAF data are reassuring)

— HBIG + HBV vaccine within 12 hours of birth

— Complete 3-dose vaccine series by 6 months

— Post-vaccination serology (HBsAg and anti-HBs) at 9–12 months

— With HBIG + vaccine + maternal antiviral, transmission drops to <1%

— Most asymptomatic, immune tolerant phase

— Treat if ALT >2× ULN persistent + DNA elevated, or fibrosis

— Approved pediatric agents: entecavir (≥2 years), TDF (≥2 years), TAF (≥12 years), peg-interferon (≥3 years)

— HCC surveillance starting at adolescence in high-risk cohorts

Step 3 management: A 26-year-old G2P1 at 26 weeks with HBsAg+, HBeAg+, DNA 1.2 million IU/mL → start TDF at 28 weeks, plan HBIG + vaccine for newborn within 12 hours.

Board pearl: HBIG without vaccine fails; vaccine alone is suboptimal for high-viremia mothers. Both + maternal antiviral is the trifecta.

Universal prenatal screening: HBsAg at first prenatal visit every pregnancy (USPSTF Grade A); add anti-HBc and anti-HBs per CDC 2023 if not previously done.

Maternal treatment to prevent vertical transmission:

Already on NA at conception:

Infant prophylaxis (regardless of maternal treatment):

Breastfeeding: Safe in HBsAg+ mothers with or without NA therapy (TDF compatible); not contraindicated by cracked nipples per current guidance (use HBIG/vaccine schedule).

Pediatric HBV:

Adolescent counseling: Sexual transmission, contraception, vaccinating partners, avoiding alcohol.

Complications and Adverse Outcomes

— Variceal hemorrhage: screen with EGD at cirrhosis diagnosis; nonselective beta-blocker (carvedilol/nadolol/propranolol) or band ligation for medium/large varices

— Ascites: sodium restriction <2 g/day, spironolactone + furosemide (100:40 ratio)

— SBP: ascitic PMN ≥250—third-generation cephalosporin + albumin

— Hepatic encephalopathy: lactulose ± rifaximin

— Hepatorenal syndrome: albumin + terlipressin (US-approved) or midodrine/octreotide

— Hepatopulmonary syndrome, portopulmonary hypertension

— Annual incidence 2–8% in cirrhotic HBV

— Surveillance: US ± AFP every 6 months

— HBV is the only chronic viral hepatitis that causes HCC without cirrhosis (DNA integration, X protein oncogenesis)

— Treatment: resection, ablation, transplant (Milan: 1 lesion ≤5 cm or up to 3 ≤3 cm), TACE, systemic (atezolizumab/bevacizumab first-line for advanced)

— Defined as ≥2 log rise in DNA or seroreversion HBsAg− → HBsAg+

— Triggers: immunosuppression, chemotherapy, HIV, transplantation, DAA for HCV

— Can progress to fulminant hepatic failure

— Polyarteritis nodosa (10–50% of PAN historically HBV-related)

— Membranous nephropathy, MPGN

— Cryoglobulinemia (less than HCV)

— Aplastic anemia, Guillain-Barré (rare)

— TDF: nephrotoxicity, Fanconi (proximal tubulopathy: glycosuria, phosphaturia, proteinuria), ↓BMD

— Peg-interferon: depression, suicidality, autoimmune thyroiditis, cytopenias, retinopathy

— All NAs: rare lactic acidosis; severe ALT flare with abrupt discontinuation

Key distinction: HBV → HCC even without cirrhosis (especially in genotype C, Asian/African background). HCV → HCC essentially always requires cirrhosis.

Board pearl: PAN + HBsAg+ → treat with NA + plasmapheresis + short steroid taper; avoid prolonged immunosuppression alone.

Cirrhosis-related:

Hepatocellular carcinoma:

HBV reactivation:

Extrahepatic:

Treatment-related:

When to Escalate Care — ICU, Consult, and Inpatient Triage

— Acute hepatitis flare with INR >1.5, total bilirubin >3, encephalopathy → admit, consider transfer to liver transplant center

— Variceal bleeding: ICU with octreotide drip, ceftriaxone, urgent EGD within 12 hours

— SBP, severe HE grade 3–4, AKI suspicious for HRS

— Decompensated cirrhosis: new ascites, jaundice, HE

— HBV reactivation with ALT >5× ULN and elevated bilirubin

— Acute liver failure: encephalopathy + coagulopathy (INR ≥1.5) within 26 weeks of jaundice onset, no preexisting liver disease

— King's College Criteria for transplant in non-acetaminophen ALF: INR >6.5, OR any 3 of (age <10 or >40, etiology non-A/non-B/drug, jaundice-to-encephalopathy >7 days, INR >3.5, bilirubin >17.5)

— Hemodynamic instability from variceal bleed, septic shock from SBP

— Hepatology: all cirrhotics, treatment-naïve complex cases, transplant evaluation, suspected HCC

— Transplant surgery: MELD ≥15, ALF, HCC within Milan

— Interventional radiology: TACE, TIPS for refractory ascites/variceal bleed

— Infectious disease: HIV coinfection, complex reactivation

— Nephrology: HBV-GN, HRS

— Oncology: HCC, lymphoma requiring rituximab

— Asymptomatic, normal LFTs → outpatient workup

— Symptomatic flare with normal synthetic function → close outpatient follow-up within 1 week

— Coagulopathy or encephalopathy → admit

CCS pearl: On Step 3 CCS, an HBsAg+ patient presenting with hematemesis goes immediately to ED → ICU: orders include large-bore IV × 2, type and cross, octreotide IV bolus + drip, ceftriaxone 1 g IV (reduces mortality in cirrhotic GI bleed), PPI, NPO, urgent GI consult for EGD, transfuse to Hgb ~7. Don't over-transfuse—it worsens portal pressures.

Hospitalization indications:

ICU triggers:

Specialist consults:

Outpatient vs inpatient management of new HBsAg+:

Key Differentials — Same-Category (Viral Hepatitis)

— IgM anti-HBc strongly positive (high titer) → acute

— Low-titer IgM may appear in chronic flares; rely on history of prior HBsAg+ status

— Anti-HCV positive; confirm with HCV RNA

— Higher chronicity (~75%), less HCC without cirrhosis

— Curable with 8–12 week DAA regimens (sofosbuvir/velpatasvir, glecaprevir/pibrentasvir)

— Always screen HBsAg before DAA therapy—reactivation risk

— Requires HBV coinfection (HDV is defective)

— Coinfection (simultaneous) vs superinfection (HDV on chronic HBV—worse)

— Anti-HDV + HDV RNA confirms

— Causes most aggressive chronic viral hepatitis; rapid cirrhosis

— Treatment: peg-interferon, bulevirtide

— Acute, self-limited; fecal-oral

— IgM anti-HAV positive

— No chronicity; supportive care

— Vaccinate all chronic HBV patients

— Acute, fecal-oral; high mortality in pregnancy (genotype 1)

— Chronic in immunosuppressed (genotype 3, solid organ transplant)

— Treat chronic HEV with ribavirin

— CMV, EBV, HSV (especially HSV in pregnancy/immunocompromised → acyclovir empirically)

— VZV, parvovirus B19

Key distinction: A patient with chronic HBV who suddenly develops fulminant hepatitis—think HDV superinfection until proven otherwise. Order anti-HDV + HDV RNA.

Board pearl: Before any HCV DAA, check HBsAg AND anti-HBc. Anti-HBc+/HBsAg− patients on DAA need DNA monitoring; HBsAg+ need NA prophylaxis.

Acute HBV vs chronic HBV flare:

Hepatitis C:

Hepatitis D:

Hepatitis A:

Hepatitis E:

Other viral hepatitis:

Key Differentials — Other-Category Hepatocellular Injury

— AST:ALT >2:1, both typically <300, GGT elevated, MCV elevated

— Heavy drinking history; Maddrey discriminant function ≥32 → corticosteroids if no infection/GI bleed

— Obesity, T2DM, dyslipidemia

— ALT > AST (until cirrhosis); imaging shows steatosis

— Can coexist with HBV—biopsy helps disentangle

— Acetaminophen (centrilobular necrosis, AST/ALT often >1000), isoniazid, amoxicillin-clavulanate, methotrexate, statins (mild), herbals (kava, green tea extract, black cohosh)

— RUCAM/R-value classification: hepatocellular (R≥5), cholestatic (R≤2), mixed

— Female predominance, ANA, anti-smooth muscle, anti-LKM, elevated IgG

— Interface hepatitis on biopsy

— Treat with prednisone + azathioprine

— Caution: starting steroids in HBV without antiviral coverage → reactivation

— Age <40, neurologic/psychiatric symptoms, Kayser-Fleischer rings, low ceruloplasmin, high 24-h urine copper

— Coombs-negative hemolytic anemia with acute liver failure

— HFE C282Y homozygosity, transferrin saturation >45%, ferritin elevated

— Bronze skin, diabetes, arthropathy, cardiomyopathy

— Low A1AT level, PiZZ genotype

— COPD + liver disease

— Transient massive AST/ALT elevation post-hypotension, rapid resolution

— Context-specific

Step 3 management: When a chronic HBV patient has rising ALT despite suppressed DNA on therapy, look beyond HBV—screen for hepatitis A/D/E, drugs, alcohol, MASLD, autoimmune overlap.

Alcohol-associated hepatitis:

MASLD/MASH (metabolic dysfunction-associated):

Drug-induced liver injury (DILI):

Autoimmune hepatitis:

Wilson disease:

Hemochromatosis:

Alpha-1 antitrypsin deficiency:

Ischemic hepatitis ("shock liver"):

Budd-Chiari, congestive hepatopathy, pregnancy-related (HELLP, AFLP):

Secondary Prevention and Long-Term Plan

— Cirrhotic patients: lifelong NA therapy

— HBeAg+ noncirrhotic: continue ≥12 months after HBeAg seroconversion + undetectable DNA; many continue indefinitely

— HBeAg−: indefinite unless HBsAg loss achieved

— Hepatitis A if non-immune (2 doses, 0 and 6 months)

— Pneumococcal (PCV20 or PCV15 + PPSV23) in cirrhosis

— Annual influenza

— COVID-19 per current schedule

— Zoster (Shingrix) age ≥50

— Tdap, RSV per age guidelines

— Alcohol abstinence (any alcohol accelerates fibrosis)

— Weight management for concomitant MASLD; Mediterranean diet

— Coffee 2–3 cups daily (associated with lower fibrosis and HCC risk)

— Avoid hepatotoxic supplements (kava, comfrey, high-dose niacin, anabolic steroids)

— Acetaminophen ≤2 g/day in cirrhosis; avoid NSAIDs in cirrhosis (renal, variceal bleed risk)

— Screen all sexual partners and household contacts

— Vaccinate non-immune contacts

— Avoid sharing razors, toothbrushes, needles

— Condoms until partner immune

— US ± AFP q6 months indefinitely in cirrhotics and high-risk non-cirrhotics

— Continue surveillance even after HBsAg loss in cirrhotic patients

— DEXA q2 years; calcium 1200 mg/day, vitamin D 800–1000 IU/day

— Annual urinalysis, creatinine, phosphate; switch to TAF if dysfunction

Step 3 management: Every chronic HBV outpatient visit should reassess: DNA, ALT, renal function, vaccine status, alcohol/lifestyle, contact screening, HCC surveillance compliance. Build this into a problem-list template.

Board pearl: Coffee and statins are protective in chronic liver disease; statins are safe and cardioprotective even in compensated cirrhosis.

Antiviral continuation:

Vaccinations:

Lifestyle counseling:

Household and partner protection:

HCC surveillance:

Bone and renal health on TDF:

Pregnancy planning: Preferred agent TDF; preconception counseling.

Follow-Up, Monitoring Parameters, and Counseling

— HBeAg+ chronic infection ("immune tolerant"): ALT q3–6 months, HBV DNA q6–12 months, HBeAg q6–12 months, fibrosis assessment q1–2 years

— HBeAg− chronic infection ("inactive carrier"): ALT q6–12 months, HBV DNA q6–12 months, fibrosis q2–3 years; if ALT rises, recheck DNA promptly

— All: HCC surveillance per risk profile, annual HBsAg (looking for loss)

— Months 1–3: ALT, creatinine, phosphate (TDF), HBV DNA

— Then q3–6 months: ALT, DNA, creatinine, phosphate

— Annual: HBsAg, urinalysis, lipid profile (TAF can worsen)

— HBeAg/anti-HBe q6–12 months if HBeAg+

— FibroScan annually until stable

— Weekly CBC first month, then monthly

— TSH q3 months

— Mood/depression screening at each visit

— ALT, DNA, HBeAg q3 months during therapy; 6 and 12 months post-treatment

— Adherence to NA (skipped doses → flare and resistance)

— Transmission prevention

— Alcohol abstinence

— Pregnancy planning

— Symptom recognition: jaundice, ascites, encephalopathy, weight loss

— Vaccinations up to date

— Nutrition consultation in cirrhosis—protein 1.2–1.5 g/kg/day, late evening snack to reduce muscle catabolism

— Physical activity to combat sarcopenia

— Smoking cessation (independent HCC risk factor)

CCS pearl: On CCS cases, scheduling "return appointment in 3 months" for an HBsAg+ patient on entecavir and ordering "HBV DNA, ALT, basic metabolic panel" at that visit demonstrates the longitudinal Step 3 mindset graders reward.

Board pearl: A patient with virologic breakthrough on NA—check adherence first, then resistance testing.

Untreated patients (monitoring phase):

On NA therapy:

On peg-interferon:

Counseling at every visit:

Rehab and lifestyle:

Mental health: Depression and stigma common; screen with PHQ-9; especially with interferon.

Ethical, Legal, and Patient Safety Considerations

— HBV status is protected health information under HIPAA

— Healthcare workers with chronic HBV: per CDC/SHEA, may perform exposure-prone procedures if HBV DNA <1,000 IU/mL with expert panel oversight; institutional disclosure typically required, not mandatory disclosure to individual patients in most procedures

— Acute HBV: reportable to state/local health department in all US jurisdictions

— Chronic HBV: reportable in most states (varies); used for partner notification programs

— Perinatal HBV exposure: mandatory reporting in all states

— Strongly recommended; some jurisdictions use anonymous partner services through health departments

— Counsel patients on duty-to-warn but respect autonomy; physicians generally not obligated to directly notify partners (compare to HIV in some states)

— Pregnant patient declining TDF or HBIG/vaccine for infant: document discussion, involve ethics if refusing infant prophylaxis (child welfare concern in extreme cases)

— Adolescent with HBV: confidentiality vs parental involvement varies by state

— ADA prohibits employment discrimination based on chronic HBV

— Schools cannot exclude HBV+ children

— Immigration: HBV is not a basis for visa denial (since 2009 CDC rule change)

— Highest reactivation risk = miscommunication during oncology referrals—the discharging team must explicitly hand off HBsAg+ status and prophylaxis plan to oncology before chemotherapy

— Medication reconciliation: confirm NA refills before transitions

— When patients stop NA (e.g., loss of insurance), schedule ALT/DNA at 4, 12, 24 weeks—withdrawal flares peak 8–12 weeks post-discontinuation

Step 3 management: A patient newly diagnosed HBsAg+ refuses to inform sexual partner. Counsel risks, document, offer health department partner services, vaccinate the partner if they present—do not breach confidentiality unilaterally in HBV (unlike some HIV duty-to-warn statutes).

Confidentiality and disclosure:

Mandatory reporting:

Partner and household notification:

Informed consent edge cases:

Discrimination protections:

Transition-of-care safety:

Equity: Asian Americans and African immigrants underdiagnosed; advocate for universal adult screening per CDC 2023.

High-Yield Associations and Rapid-Fire Facts

Board pearl: A patient post-needlestick from HBsAg+ source: if vaccinated with anti-HBs ≥10, no action; if unvaccinated, HBIG 0.06 mL/kg + vaccine within 24 hours.

Vertical transmission rates without intervention: HBeAg+ mother ~90%; HBeAg− mother ~10–20%. With HBIG + vaccine + maternal antiviral: <1%.

HBV genomic structure: Partially double-stranded DNA virus, family Hepadnaviridae; reverse transcriptase in replication cycle (target of NAs).

cccDNA in hepatocyte nuclei persists despite therapy—reason cure is elusive and reactivation can occur after HBsAg loss.

HBx protein: Oncogenic; promotes HCC even without cirrhosis.

Window period: HBsAg gone, anti-HBs not yet positive, only anti-HBc IgM positive.

Isolated anti-HBc: consider occult HBV, false positive, distant resolved with waning anti-HBs, window phase. Check HBV DNA before immunosuppression.

Glomerular disease: Membranous nephropathy classically in children with HBV; MPGN more common in adults.

Polyarteritis nodosa: Necrotizing vasculitis of medium vessels; HBsAg+ in subset; renal microaneurysms on angiography.

HCC without cirrhosis: Unique to HBV among viral hepatitides; explains surveillance in non-cirrhotic Asian/African patients.

Drug names ending in "-ovir"/"-fovir": entecavir (nucleoside), tenofovir (nucleotide); resistance barriers high for both.

Lamivudine and adefovir: Old agents; low genetic barrier, high resistance—not first-line.

Peg-interferon response predictors: Genotype A > B > C > D, female, high ALT, low DNA, young age.

HBsAg loss with NA therapy: ~1% per year; higher with peg-interferon (~3–7%).

MELD-Na: Used for transplant prioritization; incorporates sodium.

HBV vaccine: Recombinant HBsAg; 3-dose (0, 1, 6 months) or 2-dose Heplisav-B (0, 1 month) in adults; check anti-HBs ≥10 mIU/mL = immune.

Healthcare worker post-exposure prophylaxis: Unvaccinated/non-responder exposed to HBsAg+ source → HBIG + start vaccine series within 24 hours.

Board Question Stem Patterns

Step 3 management: When a stem gives you cirrhosis + HBsAg+, the answer is treat now, even with normal ALT and low DNA. This is the single most missed indication.

Board pearl: Always re-screen HBV in patients presenting for any new immunosuppression—stem buries "HBsAg+ 10 years ago" in social history.

Pattern 1 — Asymptomatic screening positive: "32-year-old Vietnamese man, routine labs HBsAg+, HBeAg+, DNA 10⁸, normal ALT." → Immune tolerant; monitor q3–6 months, no treatment now. Trap: jumping to entecavir.

Pattern 2 — Treatment indication: "45-year-old with HBsAg+, HBeAg−, DNA 50,000 IU/mL, ALT 90, FibroScan 9 kPa." → Treat with entecavir, TDF, or TAF.

Pattern 3 — Cirrhotic with low DNA: "Compensated cirrhosis, HBsAg+, DNA 500 IU/mL, ALT 30." → Treat regardless of DNA or ALT—cirrhosis alone is the indication.

Pattern 4 — Pregnancy: "28 weeks, HBsAg+, HBeAg+, DNA 5 × 10⁸." → Start TDF; newborn gets HBIG + vaccine within 12 hours.

Pattern 5 — Pre-chemo/rituximab: "HBsAg+, DLBCL on R-CHOP planned." → Entecavir or TAF prophylaxis before chemo, continue ≥12 months after rituximab.

Pattern 6 — Reactivation: "On rituximab, ALT 800, HBV DNA 10⁷, previously known HBsAg+." → Hold immunosuppression if possible, start tenofovir/entecavir immediately, hospitalize if INR rising.

Pattern 7 — HCV co-infection starting DAA: "HCV genotype 1, HBsAg+." → Start NA before or with DAA to prevent flare.

Pattern 8 — HDV superinfection: "Chronic HBV, sudden ALT 1500, jaundice." → Test anti-HDV + HDV RNA.

Pattern 9 — Renal/bone toxicity on TDF: "On TDF 4 years, eGFR fell, phosphate low, glucosuria." → Switch to TAF.

Pattern 10 — HCC surveillance: "Asian man, 42, HBsAg+, non-cirrhotic." → US + AFP q6 months.

Pattern 11 — Isolated anti-HBc + planned rituximab: → Check DNA; antiviral prophylaxis or close monitoring.

Pattern 12 — Post-exposure HCW: "Unvaccinated, needlestick, source HBsAg+." → HBIG + vaccine series within 24 hours.

One-Line Recap

Chronic hepatitis B is HBsAg persistence ≥6 months for which treatment with entecavir, TDF, or TAF is indicated in all cirrhotics regardless of ALT/DNA, in HBeAg+ patients with ALT >2× ULN and DNA >20,000, in HBeAg− patients with ALT >2× ULN and DNA >2,000, in pregnancy with DNA >200,000, and as prophylaxis before moderate/high-risk immunosuppression—while every patient gets lifelong HCC surveillance with ultrasound every 6 months if cirrhotic or high-risk, household/sexual contact screening and vaccination, and counseling on alcohol abstinence and HAV vaccination.

Board pearl: Cirrhosis + detectable HBV DNA = treat for life. Stopping a nucleos(t)ide analogue in a cirrhotic can be fatal.

Treatment indications mnemonic — "CHIPP": Cirrhosis (any DNA), HBeAg-positive immune active, Immunosuppression coming, Pregnancy with high viremia, Pediatric/extrahepatic disease with fibrosis.

First-line drugs: Entecavir, TDF, or TAF — high genetic barrier; TAF for renal/bone concerns; TDF for pregnancy; never use entecavir monotherapy in HIV co-infection or decompensated cirrhosis at standard dose.

HCC surveillance: US ± AFP every 6 months in all cirrhotics and high-risk non-cirrhotics (Asian men ≥40, Asian women ≥50, sub-Saharan African ≥20, family history of HCC). HBV is unique among viral hepatitides in causing HCC without cirrhosis.

Reactivation prevention: Screen HBsAg + anti-HBc before rituximab, anti-CD20, stem cell transplant, high-dose steroids ≥4 weeks, or HCV DAA therapy—prophylactic NA mandatory for HBsAg+, and considered for anti-HBc+ on B-cell depletion or SCT, continued ≥6–12 months after immunosuppression ends.