Hepatology & Infectious Diseases & Family Medicine
HBV-DNA (Hepatitis B viral load)
HBV-DNA refers to the quantitative measurement of hepatitis B virus (HBV) viral DNA circulating in blood, expressed in international units per milliliter (IU/mL) or copies/mL (1 IU/mL ≈ 5.3 copies/mL depending on the kit). It is the direct marker of active HBV viral replication and one of the most important parameters for guiding therapeutic decisions in chronic hepatitis B. HBV is a partially double-stranded DNA virus belonging to the Hepadnaviridae family - its genome persists in hepatocytes in the form of covalently closed circular DNA (cccDNA), a veritable intrahepatocyte viral reservoir, responsible for the persistence of infection and the difficulty of eradicating it. Chronic HBV infection affects some 260 million people worldwide (WHO 2023), and remains the leading cause of cirrhosis and hepatocellular carcinoma (HCC) in highly endemic countries (Southeast Asia, sub-Saharan Africa). In Canada, the prevalence of chronic hepatitis B is estimated at 0.7 % of the population, or around 250,000 people - with a significant over-representation among immigrants from highly endemic areas. HBV-DNA, interpreted in parallel with HBsAg (surface antigen), HBeAg and anti-HBe, transaminases (ALAT/ASAT) and liver fibrosis markers, is used to determine the phase of infection, identify patients requiring antiviral treatment and monitor therapeutic response.
Virology, serological markers, and phases of chronic hepatitis B
- Structure of HBV, replication and cccDNA: HBV genome: 3.2 kb circular partially double-stranded DNA → 4 overlapping open reading frames (ORFs): ORF S (PreS1 + PreS2 + S genes → envelope proteins: large AgHBs + medium AgHBs + small AgHBs) + ORF C (genes PreC + C → precore → secreted AgHBe + core → nucleocapsid AgHBc) + ORF P (DNA polymerase - reverse transcriptase - therapeutic target of nucleos[t]idic analogues) + ORF X (protein X - transactivator - role in hepatic oncogenesis + in cccDNA transcription) → HBV genotypes: 9 major genotypes (A to I) + one genotype J → genotype A: North America + Northern Europe → best response to pegylated interferon → genotype B + C: Asia → C associated with higher HCC risk → genotype D : Mediterranean basin + Eastern Europe; cccDNA (Covalently Closed Circular DNA): episomal nuclear form of the HBV genome in the nucleus of infected hepatocytes → transcriptional matrix of all viral mRNAs (including pregenomic RNA - pgRNA - precursor of viral DNA) → not eliminable by current nucleos(t)idic analogues → responsible for viral persistence even after suppression of HBV-DNA → responsible for viral reactivation after treatment discontinuation or during immunosuppression → intrahepatic cccDNA cannot be measured in clinical practice (liver biopsy required) → indirect serum markers of cccDNA : HBsAg (indirect reflection) + serum HBV RNA (encapsidated pgRNA - emerging marker - assayed as part of research); serological markers of hepatitis B - interpretation: HBsAg (surface antigen): marker of active infection → positive: ongoing infection (acute or chronic) → persistence >6 months = chronic infection → HBsAg quantification (IU/mL): correlates indirectly with intrahepatic cccDNA pool → used to monitor response to pegylated interferon + anti-HBs: protective antibodies → positive after natural cure or vaccination → protective rate: ≥10 IU/L → anti-HBs isolated positive = effective vaccination + HBeAg: marker of active replication and infectivity → its presence generally indicates a high viral load + immune tolerance (phase 1) or chronic hepatitis HBeAg+ (phase 2) → its disappearance (HBe seroconversion) and the appearance of anti-HBe → transition to a lower replication phase (phase 3) or to hepatitis B HBeAg- (phase 4) + anti-HBe : marker of HBe seroconversion → may be associated with active HBeAg- hepatitis (precore + core promoter variants) + anti-HBc IgM: marker of recent acute hepatitis or intense reactivation + anti-HBc IgG (or total): marker of old infection (past or chronic) → positive for life after any HBV infection
- Phases of Chronic HBV Infection — EASL 2017 Revised Classification: the current classification (EASL Clinical Practice Guidelines 2017 - European Association for the Study of the Liver) distinguishes 5 phases - NB: the term «healthy carrier» is abandoned as potentially misleading; phase 1 - HBeAg positive chronic infection (formerly «immune tolerance»): HBsAg+ + HBeAg+ + anti-HBe- + HBV-.very high DNA (>10⁷ IU/mL often) + normal or slightly elevated ALT + absent or minimal liver fibrosis → intense viral replication but weak immune response against HBV → frequent in people infected at birth (vertical transmission - Asia ++) → variable duration (decades) → no indication for antiviral treatment in the majority of cases according to current guidelines (poor response to treatment) → regular monitoring of ALT + HBV-DNA + phase 2 - HBeAg-positive chronic hepatitis : HBsAg+ + HBeAg+ + elevated HBV-DNA (variable - 10⁴ to 10⁷ IU/mL) + elevated ALT (significant liver activity) + progressing fibrosis → immune system attempts to control infection → active liver necroinflammation → risk of progression to cirrhosis if untreated → indication for treatment if elevated ALT + HBV-DNA >20,000 IU/mL + biopsy or non-invasive: significant fibrosis (≥F2) → phase 3 - HBeAg-negative chronic infection (formerly «inactive carrier»): HBsAg+ + HBeAg+ + anti-HBe+ + low HBV-DNA (2,000 IU/mL - often fluctuating) + elevated ALT (often fluctuating) + progressive fibrosis → HBeAg- variant known as «pre-core mutant» or «core promoter» → viral variant escapes HBeAg expression → active replication despite HBeAg- → insidious form as less easily detected → high risk of cirrhosis and HCC → indication for antiviral treatment + phase 5 - occult infection / HBsAg negative : HBsAg + anti-HBc+ (with or without anti-HBs) + HBV-DNA undetectable or very low in serum (but cccDNA persisting in hepatocytes) → resolution of apparent infection → risk of reactivation during profound immunosuppression (chemotherapy + rituximab + corticosteroids) → anti-HBc screening before any immunosuppressive treatment
- HBV-DNA Measurement Techniques and Threshold Interpretation: HBV-DNA quantification techniques: quantitative real-time PCR (qPCR): reference method → sensitivity: lower limit of detection 10-20 IU/mL depending on platforms (Roche COBAS AmpliPrep/TaqMan + Abbott RealTime HBV + Hologic Panther Aptima) → WHOMIMOSA standardization: values expressed in IU/mL since 2010 (WHO international standard) → conversion: 1 IU/mL ≈ 5.3 copies/mL (variable depending on kits - use IU/mL exclusively to avoid confusion) → important clinical thresholds (EASL 2017 + AASLD 2018 guidelines): HBV-DNA undetectable (<10-20 IU/mL depending on kit): complete viral suppression on treatment → therapeutic goal + HBV-DNA 20,000 IU/mL (HBeAg+) or >2,000 IU/mL (HBeAg-): treatment indication thresholds according to EASL/AASLD if elevated ALT + significant fibrosis + HBV-DNA >10⁶-10⁷ IU/mL: intense replication - phase 1 or phase 2 or untreated → sexual and parenteral transmission more likely; analytical and pre-analytical variability: HBV-DNA can fluctuate spontaneously even without treatment → an isolated value is not sufficient → serial measurements (every 3-6 months) required to assess trend + pre-analytical conditions: serum or EDTA plasma - store at -20°C if >24h delay + interference: hemolysis + lipemia → false results → repeat on a quality sample + result rendered in logarithm (log₁₀ IU/mL) in clinic: 10⁴ IU/mL = 4 log₁₀ = 10,000 IU/mL → significant variation = ≥1 log₁₀ (factor 10) between two measurements
Treatment indications, antivirals, and monitoring
| Clinical situation | Therapeutic evaluation and decision | Treatment and monitoring |
|---|---|---|
| Initial assessment of chronic hepatitis B Serologies — HBV-DNA — fibrosis — genotype |
The initial work-up for newly diagnosed chronic hepatitis B is structured and aims to determine the phase of infection, the state of the liver and the indication for treatment; full serological work-up: Quantitative HBsAg (IU/mL) + HBeAg + anti-HBe + anti-HBc IgG + anti-HBs (if negative → confirms chronic active infection) + quantitative HBV-DNA (PCR - expressed in IU/mL and log₁₀) + co-infections to be systematically excluded: anti-HCV Ac + HCV RNA (if Ac+) + anti-HDV Ac (delta virus - aggravating co-infection → if anti-HDV Ac+ → HDV RNA) + HIV serology (AgP24 + anti-HIV Ac) → HBV-HIV co-infection modifies choice of antiviral treatment (need to treat both simultaneously) + HBV-HDV co-infection: accelerated cirrhosis + HCC risk × 3 vs HBV alone → indication for quasi-systematic treatment + liver biology workup: ALAT + ASAT + GGT + alkaline phosphatases + total bilirubin + albumin + TP/INR + CBC (thrombocytopenia if cirrhosis) + creatinine + phospho-calcium workup (if tenofovir considered - renal and bone monitoring); non-invasive assessment of liver fibrosis (recommended before any therapeutic decision): hepatic elastometry (FibroScan - measurement of hepatic elasticity in kPa): non-invasive reference method → thresholds for HBV (different from HCV): F0-F1 (absent or minimal fibrosis): 12 kPa → reduced reliability if ALAT very high (inflammation → false high elasticity) → repeat at distance from flare-up + non-invasive biochemical scores: FIB-4 (Age × ASAT) / (platelets × √ALAT) → FIB-4 3.25: probable advanced fibrosis + APRI (AST-to-Platelet Ratio Index): less effective than FIB-4 + ELF test (Enhanced Liver Fibrosis - TIMP-1 + PIIINP + hyaluronic acid) → more expensive → reserved for indeterminate cases + liver biopsy: gold standard (METAVIR score F0-F4 + A0-A3) → current indications reduced (FibroScan + non-invasive serum markers now preferred) → useful if: discordant results + suspicion of associated pathology (steatosis + NAFLD + hemochromatosis) + evaluation before time-limited treatment (interferon) | HBV genotyping and resistance: viral genotyping (Sanger sequencing or NGS): useful if pegylated interferon treatment envisaged (genotype A + B → better response) + in case of antiviral resistance + genotypes B and C: Asia → C associated higher HCC risk + genotype D: Mediterranean + Eastern Europe; search for nucleos(t)idic analog resistance mutations: not necessary in 1st line (tenofovir + entecavir: high genetic barrier → extremely rare resistances) → useful if: history of lamivudine or adefovir treatment (lamivudine resistance rate: 80 % at 5 years) + documented virological failure (HBV-DNA >2,000 IU/mL under well-conducted treatment at 48 weeks); phase 1 monitoring (chronic HBeAg+ infection - old immune tolerance) without treatment: ALT + HBV-DNA + HBeAg every 3-6 months → switch to phase 2 (hepatitis) = elevated ALT + fibrosis → treatment decision → FibroScan every 12-24 months + HCC screening: important even in phase 1 in high-risk patients (Asian man >40 years + African man at any age + Asian woman >50 years + family history of HCC + cirrhosis) → liver ultrasound + AFP every 6 months → don't wait for symptoms; phase 3 workup (chronic HBeAg- infection - inactive former carrier): ALT + HBV-DNA every 3-6 months for 12 months → if stable and low → annual monitoring → if fluctuating ALT or HBV-DNA >2,000 IU/mL → progression to phase 4 possible → FibroScan + assessment of indication for treatment |
| Antiviral treatment indications and agent selection EASL 2017 — AASLD 2018 — tenofovir — entecavir — pegylated interferon |
Indications for treatment of chronic hepatitis B are based on the combination of HBV-DNA + ALT + liver fibrosis - the EASL 2017 and AASLD 2018 guidelines agree on the major principles; formal criteria for antiviral treatment (EASL 2017): any patient with compensated or decompensated cirrhosis + detectable HBV-DNA → immediate treatment regardless of ALT + HBeAg+ chronic hepatitis (phase 2): ALT >2× LSN + HBV-DNA >20,000 IU/mL + fibrosis ≥F2 (FibroScan or biopsy) → treatment recommended → if ALT elevated but HBV-DNA <20,000 IU/mL: look for other cause of hepatitis + if fibrosis LSN + HBV-DNA >2,000 IU/mL + ± fibrosis → treatment recommended → lower threshold because risk of silent evolution + phase 1 (old immune tolerance): very high HBV-DNA + normal ALAT + F0-F1 fibrosis → treatment not routinely recommended according to EASL 2017 → BUT: treatment conceivable in >30s if HBV-DNA >10⁷ IU/mL + individual discussion + NB: AASLD 2018 has slightly different but converging criteria → treat if: ALT >2× LSN + HBV-DNA >2,000 IU/mL (HBeAg-) or >20,000 IU/mL (HBeAg+) + or any cirrhosis + or HCC; two classes of treatment available: nucleos(t)idic analogues (NTAs): lifelong oral treatment (in most cases) + inhibit viral DNA polymerase (reverse transcriptase) → reduce viral replication → suppression of HBV-DNA below detection threshold in 48-96 weeks in >90 % of patients → do not eliminate cccDNA → virological rebound on discontinuation → treatment generally lifelong + pegylated interferon alpha-2a (PEG-IFN): time-limited treatment (48 weeks) + objective: lasting immune response → HBs seroconversion possible (5-10 % long-term) → advantage: limited duration + disadvantages: weekly subcutaneous injections + significant side effects (flu-like syndrome + cytopenias + psychiatric disorders + dysthyroidism) + numerous contraindications → selection of essential candidates | Choice of first-line antiviral (preferred NTAs) - EASL 2017 + AASLD 2018: tenofovir disoproxil fumarate (TDF - Viread): 300 mg/d PO → high genetic barrier → quasi-inexistent resistance (<0.01 % at 8 years) → viral suppression at 48 weeks: 76 % (HBeAg+) + 93 % (HBeAg-) (Heathcote 2011 - NEJM) → adverse effects: proximal tubular renal toxicity (Fanconi syndrome - rare) + loss of bone mineral density (BMD) → creatinine + phosphatemia + BMD monitoring (DEXA if prolonged use) → IC if GFR 60 years + on nephrotoxic agents + entecavir (ETV - Baraclude): 0.5 mg/d (1 mg/d if lamivudine history) PO → very high genetic barrier → resistance rare unless prior lamivudine resistance → viral suppression at 48 weeks: 67 % (HBeAg+) + 90 % (HBeAg-) (Chang 2006 - NEJM) → adverse effects: well tolerated + very rare cases of lactic acidosis in immunocompromised → CI if <16 years + severe renal failure (adjust dose) → RAMQ reimbursement: TDF + ETV + TAF: listed on the RAMQ Drug List → check current listing criteria + lamivudine (3TC) and adefovir: discontinued in 1st line (high resistance) → may be encountered in previously treated patients → switch to TDF or ETV if resistance documented |
| Monitoring during antiviral treatment and therapeutic goals Viral suppression — HBe seroconversion — HBs seroconversion — HCC |
Monitoring under antiviral treatment is standardized - it aims to confirm viral suppression, detect adverse effects, and identify rare cases of virological failure; hierarchical therapeutic objectives (EASL 2017): ideal objective (functional cure): HBs seroconversion (disappearance of HBsAg + appearance of anti-HBs) → functional elimination of the virus + maximum reduction in the risk of HCC → rate with NTAs: <1-3 % at 10 years → rare but possible + intermediate goal: HBe seroconversion (HBeAg + anti-HBe+) in HBeAg+ patients: reduced viral load + reduced liver activity → allows an attempt to stop treatment in some cases after consolidation 12 months of seroconversion + basic goal (recommended for all): suppression of HBV-DNA below detection threshold (<10-20 IU/mL) → normalization of ALT → prevention of fibrosis progression + possible regression of fibrosis (even partial) → reduction of HCC risk (but not to zero - especially if pre-existing cirrhosis) → monitoring schedule under ANT: HBV-DNA + ALT + HBeAg + anti-HBe every 3 months for 12 months → then every 6 months if HBV-DNA undetectable + quantitative HBsAg: annually (look for decline towards HBs seroconversion) + CBC + creatinine + liver workup + phosphatemia every 6 months + DEXA (bone densitometry) at baseline then every 2-3 years if long-term TDF + HCC screening: liver ultrasound + AFP every 6 months (even under antiviral treatment - especially if cirrhosis) - antiviral treatment reduces the risk of HCC but does not cancel it out (residual risk especially if cirrhosis) | Definitions of virological response and failure: complete virological response: HBV-DNA 90 % of patients on TDF or ETV → if not achieved at 96 weeks: check adherence + genotyping + search for resistance + primary virological failure: HBV-DNA does not decrease by 1 log₁₀ after 12 weeks of correct treatment → rare with TDF or ETV → consider pre-existing resistance or poor adherence + virological relapse (virologic breakthrough): HBV-DNA rebound ≥1 log₁₀ above treatment nadir → first cause: poor adherence (question without judgment) → genotypic resistance: rare with TDF/ETV → genotyping + lamivudine resistance (M204V/I) + L180M sequences: if lam resistance → switch to TDF or ETV (1 mg) → do not add a 2nd ANT from the same family (risk of cross-resistance); stop treatment - when is this possible? hepatitis B HBeAg+ : discontinuation possible after: confirmed HBe seroconversion (anti-HBe+ stable) + HBV-DNA undetectable + ALAT normal + 12 months of consolidation after seroconversion → risk of relapse: 30-50 % → monthly post-discontinuation monitoring × 3 months + quarterly × 12 months + hepatitis B HBeAg- (phase 4): cessation very difficult → relapse almost constant → treatment generally for life except HBs seroconversion + cirrhosis: treatment for life without discussion + general rule: never stop treatment without hepatological advice → risk of severe hepatic flare-up with decompensation |
| Reactivation of HBV under immunosuppression Rituximab - chemotherapy - biotherapy - prophylaxis |
HBV reactivation is a serious and potentially fatal complication when using immunosuppressive therapies - it can occur in HBsAg+ patients but also in phase 5 (anti-HBc+ HBsAg-) patients; definition of HBV reactivation: increase in HBV-DNA ≥2 log₁₀ (×100) from baseline + or HBV-DNA ≥3 log₁₀ if basal value undetectable + or reappearance of HBsAg in an anti-HBc+ HBsAg patient → clinically: severe acute hepatitis → fulminant liver failure → mortality 5-40 % if untreated (Chen 2012 - Gastroenterology); drugs at high risk of reactivation (AASLD 2018 risk score): very high risk (>10 %): rituximab + obinutuzumab + ofatumumab (anti-CD20) + combination chemotherapy (especially anthracyclines) + high-dose corticoids + ibrutinib + midostaurin → antiviral prophylaxis mandatory BEFORE initiation of immunosuppressive therapy + high risk (1-10 %): corticosteroids ≥10 mg/d × >4 weeks + TNF inhibitors (adalimumab + infliximab + etanercept) + JAK inhibitors (tofacitinib + baricitinib) + methotrexate + azathioprine + immune checkpoint inhibitors (pembrolizumab + nivolumab) → prophylaxis recommended if HBsAg+ or anti-HBc+; screening mandatory BEFORE any immunosuppressive treatment: HBsAg + total anti-HBc + anti-HBs → if HBsAg+ or anti-HBc+ → quantitative HBV-DNA + assessment of infection phase + hepatology consultation before initiation of immunosuppressive therapy | Antiviral prophylaxis of HBV reactivation: HBsAg+ patient with undetectable HBV-DNA: prophylaxis with tenofovir (TDF 300 mg/d or TAF 25 mg/d) or entecavir 0.5 mg/d → start ≥7 days BEFORE immunosuppressive treatment → continue throughout treatment + 12 months after completion if rituximab (18-24 months according to some centers) + 6 months if other immunosuppressants → do not discontinue prematurely → risk of post-stop rebound + anti-HBc+ / AgHBs- patient (phase 5 - occult infection): risk of reactivation varies according to immunosuppressive treatment → if rituximab or intensive chemotherapy: prophylaxis recommended (TDF or ETV) → if moderate immunosuppression (MTX + anti-TNF): enhanced HBV-DNA monitoring every 1-3 months acceptable as an alternative according to some guidelines + post-prophylaxis follow-up: HBV-DNA + HBsAg + ALT every 1-3 months during prophylaxis + after discontinuation: monthly monitoring × 3 months then quarterly × 12 months → if reactivation despite prophylaxis (rare): intensify treatment + urgent hepatology opinion; HBV and pregnancy: mother-to-child vertical transmission: major risk (90 % if mother HBeAg+ + HBV-DNA elevated without prevention) → standard prevention in Canada: vaccination + anti-HBs immunoglobulins (HBIg 200 IU IM) to newborn within 12h of life → efficacy: 85-95 % + if mother with HBV-DNA >200,000 IU/mL in 3rd trimester → maternal antiviral treatment with TDF from 28-32 SA → further reduces transmission (Han 2011 trial - Hepatology) → TDF: category B (reassuring data in pregnant women) → entecavir not recommended in pregnancy (limited data + animal teratogen) → breastfeeding: TDF compatible with breastfeeding according to most guidelines (EASL 2017) but individualized decision |
| VHB and co-infections — VHD, HIV, alcohol, and fatty liver Co-infection HDV—HBV-HIV—HCV—new treatments |
Management of hepatitis B is modified by the presence of hepatic co-infections and comorbidities; HBV-HDV co-infection (delta virus): HDV is a satellite virus of HBV - can only replicate in the presence of HBVsAg → simultaneous HBV-HDV co-infection: severe acute hepatitis → more frequent spontaneous recovery + superinfection (chronic HBV patient superinfected by VHD) → chronic hepatitis D → cirrhosis × 3 times faster + risk of HCC × 2 + risk of fulminant hepatitis + screening: anti-HDV Ac in any HBsAg+ → if positive → quantitative HDV RNA + treatment: pegylated interferon alpha: only approved treatment with proven efficacy on HDV → 48-72 weeks → virological response (HDV RNA undetectable) on cessation of treatment: 25-40 % + bulevirtide (Hepcludex): VHD entry inhibitor (blocks NTCP → sodium-taurocholate cotransporting polypeptide receptor) → approved in Europe (EMA 2020) + not yet available in Canada (under evaluation by Health Canada) → efficacy: suppression of VHD RNA + normalization of ALT in 45 % at 24 weeks (D-LIVR trial 2023 - NEJM); HBV-HIV co-infection: prevalence: 5-10 % of people living with HIV in Canada → HIV accelerates progression of hepatitis B to cirrhosis × 4-6 + treatment: antiretroviral treatment (ART) must mandatorily include two agents active against both viruses: tenofovir (TDF or TAF) + emtricitabine (FTC) or lamivudine (3TC) → never lamivudine alone for HBV in an HIV+ patient (rapid selection of HBV M204V resistances) → in practice: Descovy (TAF/FTC) or Truvada (TDF/FTC) as ART backbone → active against HIV and HBV simultaneously → monitor HBV-DNA + ALAT separately + HCC screening: every 6 months in co-infected patients (very high risk) | HCC screening and monitoring in chronic hepatitis B: HBV is a direct oncogenic virus (protein X → activation of oncogenic pathways + integration of the viral genome into the hepatocyte genome → genomic instability) → can induce HCC even in the absence of cirrhosis (unlike HCV) → high-risk HCC populations to be monitored by ultrasound + AFP every 6 months: Asian male HBsAg+ >40 years + Asian female HBsAg+ >50 years + African male HBsAg+ at any age + any HBsAg+ patient with family history of HCC + any patient with HBV cirrhosis (compensated or decompensated) → antiviral treatment reduces the risk of HCC by 50-80 % but does not eliminate it (especially if pre-existing cirrhosis) → monitor even under treatment + advanced stage (HCC discovered): Barcelona Clinic Liver Cancer (BCLC) criteria for therapeutic decision: stage 0-A: resection + radiofrequency ablation + liver transplantation → stage B: chemoembolization (TACE) → stage C: sorafenib + atezolizumab + bevacizumab → stage D: comfort care; new treatments in development (pipeline 2024-2026): cccDNA silencers (interfering RNAs - JNJ-3989 + AB-729): degrade viral mRNA → reduce HBsAg → phase 2-3 trials underway + viral entry inhibitors (bulevirtide - already approved for VHD in Europe) + capsid assembly modulators (CAMs - NVR 3-778): disrupt viral capsid assembly → unencapsidated pregenomic RNA → reduce replication → hope for a finished therapy («functional cure») within 5-10 years |
ℹ️
An undetectable HBV DNA does not mean a cure. The viral cccDNA persists indefinitely in hepatocyte nuclei, even when plasma HBV-DNA is undetectable under antiviral treatment. This is why stopping nucleos(t)ide analogs leads to viral relapse in almost all HBeAg-negative patients with chronic hepatitis B, and in 30–50 % of HBeAg-positive patients who have seroconverted. Current antiviral treatment is suppressive, not eradicative—the goal of «functional cure» (disappearance of HBsAg) remains the horizon for new therapies in development.
Situations requiring urgent medical assessment
Jaundice + ascites + encephalopathy + collapsed PT (<50 %) + positive HBsAg → Fulminant hepatitis on HBV or decompensation of HBV cirrhosis → Emergency hospitalization → Immediate antiviral treatment (tenofovir or entecavir) → Urgent liver transplant evaluation → Level 3 hepatology consultation.
Brutal increase in HBV DNA (>2 log₁₀ compared to nadir) + ALT >3-fold in a patient on immunosuppressive therapy → reactivation of HBV → urgent antiviral treatment (tenofovir or entecavir) even if already under prophylaxis → intensification + urgent hepatology consultation → hospitalization if signs of severe hepatitis.
Liver nodule found on surveillance ultrasound + rising AFP in an HBsAg-positive patient or a patient with HBV cirrhosis → Suspicion of hepatocellular carcinoma → Triphasic CT scan or hepatic MRI with gadoxetate on an urgent basis (LI-RADS protocol) → Multidisciplinary team meeting in hepatic oncology within 2 weeks.
Fever + jaundice + worsening liver tests in an anti-HBc+ patient who received rituximab or chemotherapy without antiviral prophylaxis → HBV reactivation without prophylaxis → hepatological emergency → immediate tenofovir + hospitalization + suspend immunosuppressant if possible.
Consult at Clinique Omicron
Clinique Omicron physicians provide screening for hepatitis B (HBsAg, anti-HBc, anti-HBs), initiate the initial workup for newly diagnosed chronic hepatitis B—including HBV-DNA, complete serologies, FibroScan prescription, and co-infection screening—and coordinate referrals to hepatology or infectious diseases based on the stage and severity. Longitudinal follow-up of patients in stage 3 (chronic HBeAg− infection, formerly inactive carriers) and hepatocellular carcinoma (HCC) surveillance via semi-annual liver ultrasounds can be integrated into routine medical follow-up at several service points in Quebec. To book an appointment, visit cliniqueomicron.ca.
The content of this page is provided for informational purposes only and does not replace medical advice from a physician or hepatologist. Interpretation of HBV-DNA and treatment decisions in chronic hepatitis B should be made by an experienced healthcare professional, taking into account all clinical, biological, and histological parameters.
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