Investigations
1st investigations to order
liver function tests
Test
Order in all patients as part of the initial evaluation.[2][29]
Aminotransferases (alanine aminotransferase [ALT]/aspartate aminotransferase [AST]), alkaline phosphatase, or bilirubin levels may be elevated due to chronic hepatitis B virus (HBV) infection and/or cirrhosis, including decompensated HBV-related cirrhosis. Albumin level may be low.
Result
elevated aminotransferases (ALT/AST), alkaline phosphatase, and bilirubin; low albumin
FBC
Test
Order in all patients as part of the initial evaluation.[2][29]
Patients with low mean corpuscular volume and low haemoglobin may have possible gastrointestinal bleeding from portal hypertension associated with HBV-related cirrhosis. Low platelet count is indicative of portal hypertension resulting from hepatitis B virus-related cirrhosis.
Result
microcytic anaemia and/or thrombocytopenia
urea and electrolytes
Test
Order in all patients as part of the initial evaluation.[2][29]
Patients may have hyponatraemia due to volume overload or use of diuretics in patients with hepatitis B virus-related cirrhosis with ascites. Urea can be elevated secondary to pre-renal azotaemia, acute renal insufficiency, chronic renal insufficiency, or hepatorenal syndrome in cirrhosis of the liver.
Result
hyponatraemia; high urea
coagulation profile
Test
Order in all patients as part of the initial evaluation.[2][29]
Helpful in determining the synthetic functional capacity of the liver. An elevated prothrombin time (PT) and INR indicates that the patient might have synthetic dysfunction due to cirrhosis of the liver, or liver failure related to hepatitis B virus infection.
Result
normal or elevated
serum hepatitis B surface antigen (HBsAg)
Test
Order in all patients with symptoms or those who are at increased risk for exposure to hepatitis B virus (HBV) as part of the initial evaluation.[2][29][83] Included in the triple panel test.[83]
A positive HBsAg result establishes the diagnosis and indicates active infection. HBsAg will be detected an average of 4 weeks (range 1-9 weeks) after exposure to the virus. In self-limiting acute infection, HBsAg usually becomes undetectable after 4-6 months of infection. Persistence of HBsAg for >6 months indicates chronic infection.[82] While qualitative HBsAg may be used for initial diagnosis and screening, quantitative HBsAg is used to characterise disease phase, guide treatment, and define prognosis.[2][29][83]
HBsAg rapid diagnostic tests have excellent specificity and good sensitivity compared with laboratory immunoassays.[85]
Result
positive <6 months (acute infection); positive ≥6 months (chronic infection)
serum antibody to hepatitis B surface antigen (anti-HBs)
Test
Order in all patients with symptoms or those who are at increased risk for exposure to hepatitis B virus (HBV) as part of the initial evaluation.[2][29][83] Included in the triple panel test.[83]
Appears several weeks after hepatitis B surface antigen (HBsAg) has disappeared, and in most patients provides lifelong immunity, suggestive of resolved infection. It is also detectable in those immunised with a hepatitis B vaccine. Useful to determine immunisation status if HBsAg is negative, and to evaluate seroconversion after HBsAg loss.[2][29][83]
Result
may be positive (resolved infection or prior vaccination)
serum antibody to hepatitis B core antigen (anti-HBc)
Test
Order total anti-HBc (IgM and IgG) in all patients with symptoms or those who are at increased risk for exposure to hepatitis B virus (HBV) as part of the initial evaluation.[2][29][83] Included in the triple panel test.[83]
IgM anti-HBc appears within weeks of acute infection and remains detectable for 4-8 months. During the window period (several weeks to months) after the disappearance of hepatitis B surface antigen (HBsAg) and before appearance of antibody to hepatitis B surface antigen (anti-HBs), detection of IgM anti-HBc may be the only way to make the diagnosis of acute infection. Some patients with chronic infection or some inactive HBV carriers become positive for IgM antibody during acute flares or acute reactivation, making positive IgM anti-HBc not an absolutely reliable marker for acute infection.[60]
IgM and IgG anti-HBc antibodies are detectable in virtually all patients who have been exposed to HBV (acute or chronic infection). It does not provide protective immunity. It may be positive in the following settings: 1) acute infection: during the window period (mostly IgM anti-HBc); and 2) chronic infection (IgG anti-HBc), when HBsAg has decreased to undetectable levels. It is common in areas with high prevalence of HBV infection and in those patients with HIV or hepatitis C co-infection. This is the best single test for screening household contacts of HBV-infected individuals to determine need for vaccination.[95]
Result
positive
serum hepatitis B e antigen (HBeAg)
Test
Order in all patients with symptoms or those who are at increased risk for exposure to hepatitis B virus (HBV) as part of the initial evaluation.[2][29]
Soluble viral protein found in serum in the early part of acute infection, but usually disappears at or soon after the peak in serum alanine aminotransferase (ALT) level. Persistence ≥3 months after onset of illness indicates a high likelihood of chronic infection.[2][29]
HBeAg found in the serum of hepatitis B surface antigen (HBsAg) carriers indicates greater infectivity, with a high level of viral replication. The vast majority of patients with HBeAg-positive chronic infection have active liver disease; exceptions include children and young adults with perinatally acquired infection, with normal ALT. The spontaneous seroconversion from HBeAg-positive to HBeAg-negative with positive antibody to hepatitis B surface antigen (anti-HBs) is usually associated with reduction in HBV DNA level (≥3 log). Some patients (mostly older individuals) may have active liver disease with high or detectable HBV DNA without the presence of HBeAg in serum, resulting in HBeAg-negative chronic HBV infection.
Useful for classifying the phase of chronic infection. May also be recommended to establish the indication for treatment in resource-limited areas where HBV DNA is not available.[2][29]
Result
may be positive
serum antibody to hepatitis B e antigen (anti-HBe)
Test
Order in all patients with symptoms or those who are at increased risk for exposure to hepatitis B virus (HBV) as part of the initial evaluation.[2][29]
Seroconversion from hepatitis B e antigen (HBeAg)-positive to anti-HBe-positive is a useful indicator of clearance of virus, suggestive of treatment success.[2][29] Patients with sustained seroconversion typically have improvement of liver histology. However, some patients will become anti-HBe-positive spontaneously without complete clearance of virus, due to pre-core or core-promoter mutations (HBeAg-negative chronic HBV infection) or development of an asymptomatic chronic carrier state. Seroconversion can be a temporary phenomenon and should be analysed in association with the serum HBV DNA level.
Useful for classifying the phase of infection (especially if HBeAg is negative). Also used to assess disease progression and the patient’s response to therapy.[2][29]
Result
may be positive
serum quantitative hepatitis B virus (HBV) DNA
Test
Order in all patients with symptoms or those who are at increased risk for exposure to hepatitis B virus (HBV) as part of the initial evaluation.[2][29]
A key marker for HBV viraemia. A number of commercial tests are available, most commonly real-time polymerase chain reaction (PCR). Required for establishing the indication for antiviral therapy and treatment monitoring.[2][29]
Point-of-care HBV DNA assays may be used as an alternative to laboratory-based testing to assess the patient for treatment eligibility and to monitor treatment response.[75][Evidence C]
Reflex HBV DNA testing (i.e., testing triggered automatically among all people who have a positive initial hepatitis B surface antigen [HBsAg] screening test) may be used, where available.[75]
Result
undetectable or elevated
testing for co-infections
Test
Order in all patients as part of the initial evaluation.[2][29]
Check the patient’s HIV and hepatitis C and D status as this affects management options. Testing for hepatitis E and tuberculosis may be recommended, if indicated, as co-infection can occur. Hepatitis A virus immunity status should be checked to determine the need for hepatitis A vaccination.[2][29]
Patients on antituberculosis multidrug regimens are at increased risk of drug-induced liver injury, particularly those with underlying liver disease.[96][97]
Result
variable
Investigations to consider
abdominal ultrasound
Test
Order a baseline ultrasound in all patients who are hepatitis B surface antigen (HBsAg)-positive to evaluate the liver for coexisting conditions (e.g., hepatic steatosis), fibrosis, cirrhosis, portal hypertension, and liver tumours.[2][29]
The sensitivity of ultrasound for hepatocellular (HCC) detection is 60% and specificity is 97%.[98]
Result
poorly defined margins and coarse, irregular internal echoes
vibration-controlled transient elastography (VCTE)
Test
Staging of liver disease severity and fibrosis assessment is recommended in all patients who are hepatitis B surface antigen (HBsAg)-positive to guide surveillance and assist with treatment decisions.[2][29]
Non-invasive methods, such as VCTE, are preferred over liver biopsy. VCTE is preferred over other imaging-based tests, where available.[29][75][86] VCTE evaluates liver injury by measuring liver stiffness on ultrasound.
The World Health Organization (WHO) recommends a cut-off value of >7.0 kPa for significant fibrosis and >12.5 kPa for cirrhosis (cut-offs apply to Fibroscan® - other elastography techniques may have different cut-off values).[75]
Sensitivity and specificity were 75.1% and 79.3%, respectively, for the diagnosis of significant fibrosis (>6.0 to 8.0 kPa). Sensitivity and specificity were 82.6% and 89%, respectively, for the diagnosis of cirrhosis (>11.0 to 14.0 kPa).[99]
Result
>7.0 kPa indicates significant fibrosis; >12.5 kPa indicates cirrhosis (cut-off values vary)
serum liver fibrosis biomarkers
Test
Staging of liver disease severity and fibrosis assessment is recommended in all patients who are hepatitis B surface antigen (HBsAg)-positive to guide surveillance and assist with treatment decisions.[2][29]
Non-invasive methods, such as serum liver fibrosis markers, are preferred over liver biopsy. However, serum-based tests are less preferred to imaging-based tests.[29] Serum-based tests are more widely available, but have limited accuracy.[87][88] Liver fibrosis markers (e.g., FIB-4®, FibroTest®) take factors such as patient age, liver enzyme counts, and platelet count into consideration. These tests require specialised laboratory facilities.
Result
score indicates risk for fibrosis (cut-off values vary)
aspartate aminotransferase-to-platelet ratio index (APRI)
Test
Staging of liver disease severity and fibrosis assessment is recommended in all patients who are hepatitis B surface antigen (HBsAg)-positive to guide surveillance and assist with treatment decisions.[2][29]
Non-invasive methods, such as APRI, are preferred over liver biopsy. However, serum-based tests are less preferred to imaging-based tests.[29] Serum-based tests are more widely available, but have limited accuracy.[87][88] These tests require specialised laboratory facilities.
In resource-limited settings, APRI is recommended as the preferred non-invasive test to assess for significant fibrosis or cirrhosis.[75][89]
The World Health Organization (WHO) recommends a cut-off value of >0.5 for significant fibrosis and >1.0 for cirrhosis.[75]
Sensitivity and specificity were 72.9% and 64.7%, respectively, for the low cut-off (>0.3 to 0.7), and 30.5% and 92.3%, respectively, for the high cut-off (>1.3 to 1.7) for the diagnosis of significant fibrosis. Sensitivity and specificity were 59.4% and 73.9%, respectively, for the low cut-off (>0.8 to 1.2), and 30.2% and 88.2%, respectively, for the high cut-off (>1.8 to 2.2) for the diagnosis of cirrhosis.[99]
Result
score >0.5 indicates significant fibrosis; score >1.0 indicates cirrhosis (cut-off values vary)
liver biopsy
Test
Staging of liver disease severity and fibrosis assessment is recommended in all patients who are hepatitis B surface antigen (HBsAg)-positive to guide surveillance and assist with treatment decisions.[2][29]
Liver biopsy may be required in select patients to assess fibrosis and inflammatory activity, determine the aetiology in cases with unclear or negative serological results, or when alternative or additional aetiologies of liver disease are suspected.[2][29] However, non-invasive methods are preferred over liver biopsy.[29]
Liver biopsy is only recommended when there is diagnostic uncertainty, discordant non-invasive test results, or the presence of liver-related comorbidities. The decision to perform a biopsy is based on whether the results will directly influence treatment decisions.[29] However, it may also be considered in patients with persistent borderline normal, or slightly elevated, ALT level, particularly in patients >40 years of age who have been infected from a young age.[2]
The size of the liver biopsy is of paramount importance, since small-size biopsies may not be adequate to evaluate the stage of fibrosis and liver disease.
Although there are risks with a percutaneous liver biopsy, the reported risk of complications is low, with one complication in every 4000-10,000 procedures.[91] The procedure carries an increased risk of bleeding in patients with advanced cirrhosis.[29]
Result
normal without necro-inflammation and/or fibrosis; mild-to-moderate necro-inflammation with/without fibrosis; moderate-to-severe necro-inflammation with advanced fibrosis or cirrhosis
alpha-fetoprotein (AFP)
Test
Used for screening of hepatocellular carcinoma (HCC) in conjunction with ultrasound.[2]
AFP level is elevated in 75% of patients with HCC, but can also be normal. The sensitivity ranges from 41% to 65% and specificity ranges from 80% to 94%.[100] AFP level >400 nanograms/mL has a 95% specificity for HCC.[101]
Result
normal or elevated
CT/MRI abdomen
Test
Either a triphasic contrast CT scan or contrast MRI of the abdomen can be used to diagnose hepatocellular carcinoma (HCC) where this is thought to be likely, based on history, physical examination, and laboratory investigations.
Result
typical hypervascular pattern (CT); high-intensity pattern on T2-weighted images, and a low-intensity pattern on T1-weighted images (MRI)
drug resistance testing
Test
Hepatitis B antiviral drug resistance testing is not recommended in treatment-naive patients, but can be useful in patients who are treatment experienced, those with persistent viraemia despite antiviral therapy, or those who experience virological breakthrough during treatment.[2]
Result
variable
hepatitis B virus (HBV) genotype
Test
Genotyping is not necessary in the initial evaluation, and it is not currently recommended for routine testing, or for follow-up of patients with chronic infection. However, it may be useful for selecting patients to be treated with peginterferon alfa and estimate the risk for hepatocellular carcinoma (HCC).[2][29]
Result
positive for specific genotype (A to J)
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