What laboratory tests are recommended for a patient with a positive hepatitis B diagnosis?

Laboratory Testing for Hepatitis B Positive Patients

All patients with confirmed hepatitis B infection require a comprehensive initial laboratory evaluation including HBeAg/anti-HBe, quantitative HBV DNA, complete liver panel (ALT, AST, bilirubin, albumin, prothrombin time), complete blood count, creatinine, and screening for hepatitis A immunity, hepatitis C, hepatitis D (if HBsAg positive), and HIV. 1, 2, 3

Initial Serologic Completion

If only HBsAg is known to be positive, complete the hepatitis B serologic panel immediately:

• Anti-HBs (hepatitis B surface antibody) - to confirm active infection pattern 2, 3
• Anti-HBc total (hepatitis B core antibody) - to distinguish infection patterns 2, 3
• IgM anti-HBc - if acute infection is suspected, this differentiates acute from chronic infection 2, 3

Viral Replication and Disease Phase Assessment

HBeAg and anti-HBe status must be determined to identify the disease phase, with HBeAg-positive indicating high viral replication and anti-HBe-positive suggesting lower replication 1, 2, 3

Quantitative HBV DNA (viral load) is essential for treatment decisions:

• Levels ≥20,000 IU/mL in HBeAg-positive patients indicate active disease requiring treatment consideration 1, 2, 3
• Levels ≥2,000 IU/mL in HBeAg-negative patients indicate active disease requiring treatment consideration 1, 2, 3

Liver Function and Synthetic Capacity

Complete liver panel including:

• ALT and AST - to assess hepatic inflammation and determine treatment candidacy; patients with ALT >2× upper limit of normal with elevated HBV DNA should be considered for treatment 1, 4
• Bilirubin, albumin, and prothrombin time - to assess liver synthetic function and identify decompensated disease 1, 4

Complete blood count - to establish baseline and assess for cytopenias suggesting cirrhosis 1, 3

Creatinine - mandatory baseline before antiviral therapy, particularly if tenofovir or adefovir are being considered due to nephrotoxicity risk 1

Mandatory Coinfection Screening

HIV antibody/antigen testing is required for all hepatitis B positive patients, as coinfection accelerates liver disease progression and fundamentally alters treatment approach 2

Anti-HCV antibody must be checked, as hepatitis C coinfection significantly worsens prognosis 2

Anti-HDV (hepatitis delta virus) antibody is required when HBsAg is positive, as HDV only infects in the presence of HBV and dramatically worsens outcomes 2

Hepatitis A immunity assessment (anti-HAV total or IgG) - all patients without immunity should receive 2 doses of hepatitis A vaccine 6-18 months apart 1

Hepatocellular Carcinoma Surveillance

Baseline abdominal ultrasound to assess for cirrhosis and exclude focal liver lesions 1, 4

Alpha-fetoprotein (AFP) - establish baseline for ongoing HCC surveillance 1, 2

High-risk patients (Asian men >40 years, Asian women >50 years, patients with cirrhosis, family history of HCC, Africans >20 years, any patient >40 years with persistent ALT elevation or HBV DNA >2,000 IU/mL) require ultrasound every 6-12 months with AFP 1

Ongoing Monitoring Schedule

For patients NOT on treatment:

• HBeAg-positive patients with normal ALT: Check ALT every 3-6 months; when ALT becomes elevated, add HBV DNA testing; check HBeAg status every 6-12 months 1, 2
• HBeAg-negative patients with normal ALT and HBV DNA <2,000 IU/mL: Check ALT every 3 months during the first year to confirm inactive carrier state, then every 6-12 months; add HBV DNA testing if ALT rises 1

For patients ON antiviral treatment:

• Monitor ALT, HBV DNA, and HBeAg/anti-HBe (if initially HBeAg-positive) every 12-24 weeks during treatment 1
• Renal function monitoring is critical for patients on tenofovir or adefovir, particularly those at risk of impaired renal function 1

Special Populations

Patients anticipating immunosuppressive or cancer therapy require hepatology referral even if HBsAg-negative but anti-HBc-positive, as occult HBV can reactivate; HBV DNA testing is necessary even with negative HBsAg 1, 2

Pregnant women with hepatitis B require additional monitoring and consideration for antiviral prophylaxis in the third trimester if HBV DNA is elevated 1

Common Pitfalls to Avoid

Do not rely on ALT alone to assess disease activity - patients can have significant liver disease with normal ALT, particularly in the immune-tolerant phase 1

Do not skip HBV DNA quantification - this is the most critical test for treatment decisions and cannot be inferred from HBeAg status alone 1, 2

Do not forget hepatitis D screening in HBsAg-positive patients - this coinfection is easily missed and dramatically changes prognosis 2

Do not delay HCC surveillance in high-risk patients - hepatocellular carcinoma can develop even without cirrhosis in chronic hepatitis B 1