Approach Considerations
Please note that the guidelines for the current diagnostic workup and management of hepatitis B virus (HBV) infection continue to evolve. Clinicians are advised to refer frequently to the most recent recommendations of the American Association for the Study of Liver Diseases (AASLD).
Laboratory evaluation of hepatitis B disease generally consists of liver enzyme tests, including levels of alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transpeptidase (GGT), as well as liver function tests (LFTs) that include total and direct serum bilirubin, albumin, and the measurement of the international normalized ratio (INR). [41] Hematologic and coagulation studies also include a platelet count and a complete blood count (CBC). Ammonia levels may be obtained, but the results often create diagnostic confusion in clinicians. [42]
Serologic tests for hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) immunoglobulin M (IgM) are required for the diagnosis of acute hepatitis B virus (HBV). [1, 43, 44] HBsAg is positive in both acute and chronic HBV infection; however, the presence of IgM anti-HBc is diagnostic of acute or recently acquired infection. [43] Antibody to HBsAg (anti-HBs) is produced after a resolved infection and is the only HBV antibody marker present after vaccination. The presence of HBsAg and total anti-HBc, with a negative test for IgM anti-HBc, indicates chronic HBV infection; the absence of IgM anti-HBc or the persistence of HBsAg for 6 months indicates chronic HBV infection. The presence of anti-HBc alone might indicate acute, resolved, or chronic infection or a false-positive result. [43]
To evaluate the patient’s level of infectivity, quantification of hepatitis (HBV) DNA is essential, and the presence of hepatitis B e antigen (HBeAg) should be determined. Indeed, the best indication of active viral replication is the presence of HBV DNA in the serum. Hybridization or more sensitive polymerase chain reaction (PCR) assay techniques are used to detect the viral genome in the serum, as well as specific genotypes, mutants resistant to oral nucleoside and nucleotide analogues, and core and precore mutations.
A positive result suggests not only the likelihood of active hepatitis but also that the disease is much more infectious, as the virus is actively replicating. [44]
HBV DNA testing is also recommended when occult HBV is suspected (positive anti-HBc and negative antibody to HBsAg [anti-HBs] and HBsAg) or in cases in which all of the serologic tests are negative. [45]
American Association for the Study of Liver Diseases (AASLD) recommendations
The 2015 AASLD recommendations for the initial evaluation of HBsAg-positive patients is summarized below. [41]
All patients
History and physical examination: Thoroughly evaluate for the following:
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Alcohol, metabolic, and other risk factors for HBV infection
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Patient's HBV vaccination status
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Family history of HBV infection and hepatocellular carcinoma
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The presence of symptoms/signs of cirrhosis
Routine laboratory studies
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CBC, platelet count; INR
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Levels of AST, ALT, total bilirubin, ALP, and albumin
Serologic/virologic studies
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Hepatitis B e antigen (HBeAg)/anti-HBe
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HBV DNA level
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Anti-hepatitis A virus (anti-HAV) (to determine need for vaccination)
Imaging/staging studies
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Abdominal ultrasonography
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Vibration-controlled transient elastography (eg, FibroScan) or a serum fibrosis marker panel (APRI [AST-to-platelet ratio index], FIB-4 [platelet count, ALT, AST, age], or FibroTest [gamma-2 macroglobulin, gamma-2 globulin, gamma globulin, apolipoprotein A1, gamma-GGT, total bilirubin])
Select patients
Routine laboratory studies: In the setting of elevated liver function test results, obtain tests to exclude other causes of chronic liver disease. Obtain levels of alpha-fetoprotein (AFP) and GGT.
Serologic/virologic studies
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HBV genotyping
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Tests for coinfection with hepatitis C virus (HCV), hepatitis D (delta) virus (HDV), and/or human immunodeficiency virus (HIV) in at-risk individuals aged 13-64 years who have not undergone one-time screening
Screening
HBV
In June 2020, the US Preventive Services Task Force (USPSTF), which had recommended against screening asymptomatic persons for HBV infection prior ro 2014, recommended the screening of asymptomatic, nonpregnant adolescents and adults at high risk for HBV infection, including the following [46, 47, 48, 49, 50] :
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Those born in countries and regions where prevalence of HBV infection is at least 2%
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Individuals born in the United States who were not vaccinated as infants and whose parents were born in regions with a high prevalence of HBV infection, such as sub-Saharan Africa and southeast and central Asia
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HIV-positive individuals
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Injection drug users
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Men who have sex with men
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Household contacts of individuals with HBV infection
Testing should be performed with a HBsAg test followed by a licensed, neutralizing confirmatory test for initially reactive screening results. [47, 48, 49, 50]
The United States currently screens foreign-born residents for HBV infection if their country of origin has an HBV prevalence of 2% or greater. According to a model developed by Eckman et al, although this threshold for screening is cost-effective, a broader screening program with a threshold of 1.3% or even 0.3% country-of-origin prevalence would be cost-effective as well, suggesting a reconsideration of the current policy. [51]
The following screening recommendations are from the 2018 AASLD guidance update [52] :
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Perform screening with both hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti-HBs).
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Individuals who should undergo screening include all those born in countries that have an HBsAg seroprevalence of 2% or greater, US-born persons in areas with high HBV endemicity (≥8%), pregnant women, those who require immunosuppression, and specific at-risk populations.
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Vaccinate screened individuals who are negative for anti-HBs.
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Although routine screening is not recommended for antibody to hepatitis B core antigen (anti-HBc) to assess for previous exposure, it is a valuable test in HIV patients; those about to receive hepatitis C or anticancer and other immunosuppressive treatment or renal dialysis; and in donated blood (or, organs, if feasible).
HCV
As previously mentioned, the prevalence of hepatocellular carcinoma (HCC) among patients with HBV and HCV coinfection is higher than in those with a single infection.
The Centers for Disease Control and Prevention (CDC) guidelines recommend universal HCV screening for all patients aged 18 years and older and all pregnant women during each pregnancy, except in populations where the HCV prevalence is less than 0.1%. [53]
Additionally, it is recommended that the following populations be screening for HCV:
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Patients with HIV
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History of intravenous drug use
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Current or previous hemodialysis
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Persistently elevated alanine transminase (ALT) levels,
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Patients who received clotting factor concentrates prior to 1987
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Patients who received blood products prior to July 1992
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Transplant patients who received an organ prior to July 1992
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Patients who received blood from a donor later determined to be positive for HCV
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Occupational exposure of through needle stick or other sharp object injury
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Children born to HCV positive mothers
Diagnostic Tests
Laboratory studies will be discussed according to the stage of the disease.
Acute hepatitis B disease
High levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), within a range of 1000-2000 IU/mL, is the hallmark of this stage of HBV disease, although values 100 times above the upper limit of normal (ULN) can be also be identified. Higher values are found in patients with icteric hepatitis. ALT levels are usually higher than AST levels.
Gamma-glutamyl transpeptidase (GGT) and alkaline phosphatase (ALP) levels may be elevated, but they are usually not more than 3 times the ULN.
Albumin levels can be slightly low, and serum iron levels may be elevated as an acute phase reactant. In the preicteric period (ie, before the appearance of jaundice), leukopenia (ie, granulocytopenia) and lymphocytosis are the most common hematologic abnormalities and are accompanied by an increase in the erythrocyte sedimentation rate (ESR).
Anemia due to a shortened red blood cell survival period is an infrequent finding, although hemolysis may be noted. Thrombocytopenia is a rare finding. Patients with severe hepatitis experience a prolongation of the international normalized ratio (INR).
Several viral markers can be identified in the serum and the liver. Hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) (marker of infectivity) are the first markers that can be identified in the serum in acute disease. Hepatitis B core antibody (anti-HBc) immunoglobulin M (IgM) follows.
For patients who recover, seroconversion to hepatitis B surface antibody (anti-HBs) and hepatitis B e antibody (anti-HBe) is observed. The anti-HBc is of the IgG class. Patients with persistent HBsAg lasting more than 6 months are considered to have chronic hepatitis.
Inactive hepatitis B disease
The term “healthy carriers” is no longer used due to the fact that a person who is positive for HBsAg has a high risk of cirrhosis and hepatocellular carcinoma (HCC) and, therefore, cannot be defined as healthy. Such individuals have normal AST and ALT levels, with markers of infectivity, such as HBeAg, being negative and HBV DNA going undetected or being detected at very low levels (usually below 2,000 IU/ml). HBsAg, anti-HBc of IgG type, and anti-HBe are present in the serum. A minimum follow-up of these patients for 1 year with laboratory evaluation every 3 to 4 months is recommended.
Chronic active hepatitis B disease
Chronic active HBV disease is categorized into HBeAg-positive and HBeAg-negative disease.
Subtype “wild type” or HBeAg-positive disease
Patients have mild to moderate elevation of the aminotransferases (≤5 times the ULN). The ALT levels are usually higher than the AST levels. Extremely high levels of ALT can be observed during exacerbation or reactivation of the disease, and they can be accompanied by impaired synthetic function of the liver (ie, decreased albumin levels, increased bilirubin levels, and prolonged prothrombin time [PT]).
HBV DNA levels are high during this phase. HBsAg and anti-HBc of IgG or IgM type (in case of reactivation) are identified in the serum.
If the AST levels are higher than the ALT levels, the diagnosis of cirrhosis must be considered. Hyperglobulinemia is another finding, predominantly with an elevation of the IgG globulins. Tissue-nonspecific antibodies, such as anti–smooth muscle antibodies (ASMAs) (20-25%) or antinuclear antibodies (ANAs) (10-20%), can be identified. Tissue-specific antibodies, such as antibodies against the thyroid gland (10-20%), can also be found. Mildly elevated levels of rheumatoid factor (RF) are usually present, indicating the presence of cryoglobulins on further assessment.
Subtype chronic HBV HBeAg-negative disease
Note that although the HBeAg result is negative in this stage, HBeAg negativity can be associated with greater HBV DNA replication and more rapid disease progression in patients who carry mutations in either the precore or the basic core promoter region of the HBV genome. [45]
Cirrhosis
In the early stages of cirrhosis, findings of chronic viral hepatitis can be found. Later, as the disease progresses, low albumin levels, hyperbilirubinemia, prolonged PT, low platelet and white blood cell counts, and AST levels higher than ALT levels can be identified. Alkaline phosphatase (ALP) and GGT levels can be slightly elevated.
Radiologic Studies
Findings on imaging studies are briefly reviewed according to the disease stage.
Acute and chronic hepatitis B disease
Performing abdominal ultrasonography, computed tomography (CT) scanning, or magnetic resonance imaging (MRI) in patients with hepatitis B is important to help exclude biliary obstruction (see the following images). Nonspecific findings include increased echogenicity of the liver parenchyma.
Hepatitis B. Radiologic studies may be useful in all stages of hepatitis B infection. Ultrasonography, computed tomography (CT) scanning, or magnetic resonance imaging (MRI) may exclude biliary obstruction in acute infection. In chronic disease, ultrasonograms may show nonspecific increased echogenicity of the liver parenchyma. In patients with long-standing disease, CT imaging may be used to detect cirrhosis or hepatocellular carcinoma (as shown).
Hepatitis B. Long-standing cirrhosis leads to progressive replacement of liver parenchyma with fibrotic tissue. Over time, the liver contracts and develops a lobulated contour. These changes are readily apparent on cross-sectional imaging. This contrast-enhanced computed tomography (CT) scan demonstrates extensive cirrhosis, as well as malignant hepatocellular lesions (arrow).
Cirrhosis
Imaging findings in cirrhosis include coarse echogenicity of the liver, with a nodular appearance, and findings compatible with portal hypertension (eg, varices, splenomegaly, ascites, pleural effusion [ie, hepatic hydrothorax]).
Neoplastic lesions can also be detected but may be very difficult to evaluate because they can be mistaken for regenerating nodules. In such cases, highly sophisticated techniques, such as MRI with superparamagnetic iron oxide (ferumoxides), should be considered. Ferumoxides (negative contrast material) are phagocytosed by the reticuloendothelial cells of the normal liver, producing predominant T2 imaging on MRI. Therefore, a marked decrease in the signal in the normal liver parenchyma occurs, effectively permitting the identification of tumors.
In a trial that compared ultrasonographic surveillance at 3- or 6-month intervals to detect hepatocellular carcinoma (HCC) in 1278 patients with cirrhosis due to hepatitis B virus (12.5%), hepatitis C virus (44.1%), or alcohol (39.2%), investigators reported that ultrasonographic surveillance at 3-month intervals detected more small focal lesions (≤10 mm) than at 6-month intervals; however, the shorter interval did not improve detection of small HCC. [54]
On December 17, 2014, the FDA gave marketing approval for the Hepatiq radiologic image processing system. [55, 56] The software application uses quantitative analysis of nuclear medicine liver-spleen images to determine the severity of the liver disease and to predict the clinical outcomes. [56] The developer notes that Hepatiq "automates the Quantitative Liver Spleen Scan (QLSS) that has been proven to be an accurate predictor of clinical outcomes in the recently concluded HALT-C [H epatitis C A ntiviral L ong-term T reatment against C irrhosis] trial." [56] The HALT-C trial was a multicenter, randomized controlled study that evaluated whether long-term interferon would suppress HCV, prevent progression to cirrhosis, prevent liver cancer, and reduce the need for liver transplantation. [57]
Finally, liver stiffness can be measured via shear wave, transient, or magnetic resonance elastography. These modalities involve the measurement of tissue response to a mechanical stimulus. The emergence of these techniques has provided a noninvasive alternative to liver biopsy for fibrosis assessment. [58]
Liver Biopsy and Histologic Features
Liver biopsy, percutaneous or laparoscopic, is the standard means of assessing the severity of disease in patients with features of chronic active liver disease (ie, abnormal aminotransferase levels and detectable levels of hepatitis B virus [HBV] DNA).
Although liver biopsy is not indicated for patients with acute hepatitis B disease, the findings in the acute phase are predominantly lobular, with degenerative and regenerative hepatocellular changes, as well as accompanying inflammation. Necrosis may be predominantly centrilobular.
Acute vs chronic histologic findings
Acute hepatitis B
The hallmark of acute hepatitis B is liver cell death. Scattered within the lobule are small, individual clusters of dying hepatocytes in apoptosis. (When the nucleus is extruded, it is an eosinophilic, or Councilman, body). Many of the surviving hepatocytes show hydropic swelling known as ballooning degeneration. Lymphocytes diffusely infiltrate the lobule, with macrophages and neutrophils seen occasionally.
Chronic hepatitis B
The hallmark of chronic hepatitis B infection is lymphoid inflammation, mostly involving the portal tracts. However, occasional Councilman bodies are seen in the lobule. Hepatocytes that are distended with viral particles may acquire an unusual “ground-glass” appearance on the hematoxylin and eosin (H&E) stain (see the following image). Ground-glass cells are seen in approximately 50-75% of livers affected by chronic HBV infection, and they stain positive for hepatitis surface B antigen (HBsAg). Immunohistochemical staining of the specimen can help to identify the presence of HBsAg or hepatitis B core antigen (HBcAg) (ie, chronic infection).
Hepatitis B. Under higher-power magnification, ground-glass cells may be visible in chronic hepatitis B virus (HBV) infection. Ground-glass cells are present in 50% to 75% of livers with chronic HBV infection. Immunohistochemical staining is positive for hepatitis B surface antigen (HBsAg.)
As the severity of the histologic changes advances, interface hepatitis (piecemeal necrosis) appears, with erosion of the limiting plate by chronic inflammation from the portal side of the lobule. Over time, this ongoing type of inflammation may lead to increasing degrees of fibrosis that spreads out from that portal tract to connect with other nearby portal tracts (bridging fibrosis). When the fibrosis advances further in severity, regenerating nodules of hepatocytes appear; this constitutes cirrhosis (see the image below).
Hepatitis B. Liver biopsy with hematoxylin stain showing stage 4 fibrosis (ie, cirrhosis) in a patient with hepatitis B.
Staging
Liver damage is graded according to the inflammatory component and is described as follows:
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Grade 0 – Portal inflammation only, no activity
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Grade 1 – Minimal portal inflammation and patchy lymphocytic necrosis, with minimal lobular inflammation and spotty necrosis
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Grade 2 – Mild portal inflammation and lymphocytic necrosis involving some or all portal tracts, with mild hepatocellular damage
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Grade 3 – Moderate portal inflammation and lymphocytic necrosis involving all portal tracts, with noticeable lobular inflammation and hepatocellular change
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Grade 4 – Severe portal inflammation and severe lymphocytic bridging necrosis, with severe lobular inflammation and prominent, diffuse hepatocellular damage
Liver damage staging (ie, fibrosis) is described as follows:
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Stage 0 – No fibrosis
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Stage 1 – Portal fibrosis
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Stage 2 – Periportal fibrosis
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Stage 3 – Septal, bridging fibrosis
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Stage 4 – Cirrhosis
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Hepatitis B. Under higher-power magnification, ground-glass cells may be visible in chronic hepatitis B virus (HBV) infection. Ground-glass cells are present in 50% to 75% of livers with chronic HBV infection. Immunohistochemical staining is positive for hepatitis B surface antigen (HBsAg.)
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Hepatitis B. Liver biopsy with hematoxylin stain showing stage 4 fibrosis (ie, cirrhosis) in a patient with hepatitis B.
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Hepatitis B. Hepatitis B virus (HBV) is a hepadnavirus, highly resistant to extremes of temperature and humidity, that invades the hepatocytes. The viral genome is a partially double-stranded, circular DNA linked to a DNA polymerase that is surrounded by an icosahedral nucleocapsid and then by a lipid envelope. Embedded within these layers are numerous antigens that are important in disease identification and progression. Within the nucleocapsid are the hepatitis B core antigen (HBcAg) and precore hepatitis B e antigen (HBeAg), and on the envelope is the hepatitis B surface antigen (HBsAg). Transmission electron micrograph (TEM) from Graham Colm and Wikipedia, licensed under the Creative Commons Attribution 3.0 Unported license.
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Hepatitis B. Serologic course of hepatitis B virus (HBV) infection. The flat bars show the duration of seropositivity in self-limited acute HBV infection. The pointed bars show that HBV DNA and e antigen (HBeAg) can become undetectable during chronic infection. Only immunoglobulin G (IgG) antibodies to the HBV core antigen (anti-HBc) are predictably detectable after resolution of acute hepatitis or during chronic infection. Antibody to hepatitis B surface antigen (anti-HBs) is generally detectable after resolution of acute HBV infection but may disappear with time. It is only rarely found in patients with chronic infection and does not indicate that immunologic recovery will occur or that the patient has a better prognosis. ALT = alanine transaminase. (Adapted from Liaw YF, Chu CM. Hepatitis B virus infection. Lancet. 2009;373(9663):582-92.)
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Hepatitis B. Radiologic studies may be useful in all stages of hepatitis B infection. Ultrasonography, computed tomography (CT) scanning, or magnetic resonance imaging (MRI) may exclude biliary obstruction in acute infection. In chronic disease, ultrasonograms may show nonspecific increased echogenicity of the liver parenchyma. In patients with long-standing disease, CT imaging may be used to detect cirrhosis or hepatocellular carcinoma (as shown).
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Hepatitis B. Long-standing cirrhosis leads to progressive replacement of liver parenchyma with fibrotic tissue. Over time, the liver contracts and develops a lobulated contour. These changes are readily apparent on cross-sectional imaging. This contrast-enhanced computed tomography (CT) scan demonstrates extensive cirrhosis, as well as malignant hepatocellular lesions (arrow).
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Hepatitis B. Liver biopsy with hematoxylin stain showing stage 4 fibrosis (ie, cirrhosis) in a patient with hepatitis B.
