Investigations
1st investigations to order
liver function tests
Test
Order in all patients as part of the initial evaluation.
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.
Biochemical response to treatment has been defined as normalisation of ALT based on usual values. However, the upper limits of normal for ALT for healthy people are lower than levels based on the general population, including for people with subclinical liver disease, and ALT may also fluctuate over time. At least 1 year of follow-up with levels at 3-month intervals is needed to determine biochemical responses following therapy.[38]
Result
elevated aminotransferases (ALT/AST), alkaline phosphatase, and bilirubin; low albumin
FBC
Test
Order in all patients as part of the initial evaluation.
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.
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.
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
Test
Order in all patients as part of the initial evaluation.
A positive hepatitis B surface antigen (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 hepatitis B virus (HBV) infection, HBsAg usually becomes undetectable after 4-6 months of infection. Persistence of HBsAg for >6 months implies chronic HBV infection.[70]
Result
positive
serum antibody to hepatitis B surface antigen
Test
Order in all patients as part of the initial evaluation.
Appears several weeks after hepatitis B surface antigen has disappeared, and in most patients provides life-long immunity, suggestive of resolved infection. It is also detectable in those immunised with hepatitis B vaccine.
Result
positive
serum antibody to hepatitis B core antigen
Test
Order both IgM and IgG antibody to hepatitis B core antigen (anti-HBc) in all patients as part of the initial evaluation.
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, detection of IgM anti-HBc may be the only way to make the diagnosis of acute hepatitis B virus (HBV) infection. Some patients with chronic HBV 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.[47]
IgM and IgG anti-HBc antibodies are detectable in virtually all patients who have been exposed to HBV (acute or chronic HBV 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 who are co-infected with HIV or hepatitis C. This is the best single test for screening household contacts of HBV-infected individuals to determine need for vaccination.[91]
Result
positive
serum hepatitis B e antigen
Test
Order in all patients as part of the initial evaluation.
This is a soluble viral protein found in serum in the early part of acute hepatitis B virus (HBV) infection, and it usually disappears at or soon after the peak in serum alanine aminotransferase (ALT) levels. Its presence ≥3 months after onset of illness indicates a high likelihood of development of chronic HBV infection.
Hepatitis B e antigen (HBeAg) found in the serum of hepatitis B surface antigen carriers indicates greater infectivity, with a high level of viral replication. The vast majority of patients with HBeAg-positive chronic HBV 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 is usually associated with reduction in HBV DNA (≥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.
HBeAg status should be periodically checked in HBeAg-positive patients during therapy for chronic HBV infection, particularly if levels of HBV DNA are undetectable in the serum, to monitor seroconversion.[2]
Result
positive
serum antibody to hepatitis B e antigen
Test
Order in all patients as part of the initial evaluation.
Seroconversion from hepatitis B e antigen (HBeAg)-positive to antibody to hepatitis B e antigen (anti-HBe)-positive is a useful indicator of clearance of virus, suggestive of treatment-related clearance of HBV. 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) or development of an asymptomatic chronic carrier state.
Seroconversion can be a temporary phenomenon and should be analysed in association with the serum hepatitis B virus DNA level.
Result
positive
serum HBV DNA
Test
Order in all patients as part of the initial evaluation.
Hepatitis B virus (HBV) DNA levels are generally measured by polymerase chain reaction (PCR) amplification assay. Newer PCR technology has allowed for improved sensitivity.
HBV DNA level is commonly used to assess viral load and candidacy for antiviral therapy and to monitor response to therapy.[38][64][71]
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.[64][Evidence C]
Reflex HBV DNA testing (i.e., testing triggered automatically among all people who have a positive initial HBsAg screening test) may be used, where available.[64]
Result
undetectable or elevated
Investigations to consider
abdominal ultrasound
Test
Order in all patients to evaluate the liver for fibrosis, cirrhosis and portal hypertension, and hepatocellular carcinoma (HCC).
The sensitivity of ultrasound for HCC detection is 60% and specificity is 97%.[92]
Result
poorly defined margins and coarse, irregular internal echoes
liver biopsy
Test
May be required in some patients with chronic infection to grade and stage liver disease before initiating therapy, and to rule out other causes of liver disease. It is also useful for guiding ongoing surveillance and assisting with management decisions.
US guidelines recommend biopsy in patients with persistent borderline normal or slightly elevated alanine transaminase levels, particularly in patients aged >40 years who have been infected from a young age.[2] European guidelines recommend a liver biopsy when biochemical and HBV markers reveal inconclusive results.[38] In general, liver biopsy is indicated if it is likely to influence subsequent treatment decisions.
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.[77]
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
transient elastography
Test
Non-invasive alternative to evaluate liver biopsy. Evaluates liver injury by measuring liver stiffness on ultrasound.[2][38] May be the preferred noninvasive test in settings where it is available and cost is not an issue.[64]
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).[64]
In Europe, transient elastography is popular in identifying cirrhosis. However, its use has been limited by false positive results secondary to marked liver inflammation, as well as the lack of uniform standard to calculate liver stiffness.[38][84][86][87]
Magnetic resonance elastography has been shown to be more accurate than Fibroscan® in diagnosing liver fibrosis in patients with chronic hepatitis B virus infection.[88]
Result
increased liver stiffness
serum liver fibrosis biomarkers
aspartate aminotransferase-to-platelet ratio index (APRI)
alpha-fetoprotein
Test
Used for screening of hepatocellular carcinoma (HCC) in conjunction with ultrasound every 6 months in patients with cirrhosis, or in adults at high risk for HCC (e.g., Asian or black men >40 years of age, Asian women aged >50 years, patients with a first-degree family member with a history of HCC).[2]
Alpha-fetoprotein (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%.[93] AFP level >400 nanograms/mL has a 95% specificity for HCC.[94]
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 where this is thought to be likely, based on history, physical examination, and laboratory investigations, including elevated alpha-fetoprotein.
Result
typical hypervascular pattern (CT); high-intensity pattern on T2-weighted images, and a low-intensity pattern on T1-weighted images (MRI)
testing for hepatitis D coinfection
Test
Serological testing for anti-hepatitis D virus (anti-HDV) antibodies may be performed in all patients who are HBsAg positive. In settings where universal testing is not available, anti-HDV testing should be prioritised in the following: people born in HDV-endemic regions; people with advanced liver disease, those receiving HBV antiviral therapy, and those with features that suggest HDV infection (e.g., low HBV DNA level with high ALT levels); and people considered to have an increased risk of HDV infection. If the patient is anti-HDV positive, HDV RNA testing is recommended.[64]
Reflex testing (i.e., testing triggered automatically among all people who have a positive initial HBsAg screening test) may be used, where available.[64]
Result
variable
testing for other co-infections
Test
Check the patient’s HIV and hepatitis C status as this affects management options. Testing for tuberculosis may be recommended as co-infection can occur. Patients on anti-tuberculosis multi-drug regimens are at increased risk of drug-induced liver injury, particularly those with underlying liver disease.[75][76]
Result
variable
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
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 HBV infection. However, it may be useful for selecting patients to be treated with peginterferon alfa.[2][38]
Result
positive for specific genotype (A to J)
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