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Sorted By Test Name - Mayo Medical Laboratories

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HBVQU<br />

88634<br />

at 6 to 16 weeks following exposure to HBV. In acute infection, HBsAg usually disappears in 1 to 2<br />

months after the onset of symptoms. Persistence of HBsAg for >6 months in duration indicates<br />

development of either a chronic carrier state or chronic HBV infection. See The Laboratory Approach to<br />

the Diagnosis and Monitoring of Hepatitis B Infection in Publications. See the following in Special<br />

Instructions: -HBV Infection-Diagnostic Approach and Management Algorithm -HBV<br />

Infection-Monitoring Before and After Liver Transplantation -Viral Hepatitis Serologic Profile<br />

Useful For: Diagnosis of acute, recent, or chronic hepatitis B infection Determination of chronic<br />

hepatitis B infection status<br />

Interpretation: A reactive screen result (signal to cutoff ratio [S/CO] > or =1.00 but < or =50.0)<br />

confirmed as positive by hepatitis B surface antigen (HBsAg) confirmatory test (see Method Description)<br />

or a positive screen result (S/CO >50.0) is indicative of acute or chronic hepatitis B virus (HBV)<br />

infection, or chronic HBV carrier state. Specimens with reactive screen results but negative (ie, not<br />

confirmed) HBsAg confirmatory test results are likely to contain cross-reactive antibodies from other<br />

infectious or immunologic disorders. Repeat testing is recommended at a later date if clinically indicated.<br />

Confirmed presence of HBsAg is frequently associated with HBV replication and infectivity, especially<br />

when accompanied by presence of hepatitis Be antigen and/or detectable HBV DNA. See the following in<br />

Special Instructions: -HBV Infection-Diagnostic Approach and Management Algorithm -HBV<br />

Infection-Monitoring Before and After Liver Transplantation -Viral Hepatitis Serologic Profile<br />

Reference Values:<br />

Negative<br />

See Viral Hepatitis Serologic Profiles in Special Instructions.<br />

Clinical References: 1. Servoss JC, Friedman LS: Serologic and molecular diagnosis of hepatitis B<br />

virus. Clin Liver Dis 2004;8:267-281 2. Badur S, Akgun A: Diagnosis of hepatitis B infections and<br />

monitoring of treatment. J Clin Virol 2001;21:229-237<br />

Hepatitis B Virus (HBV) DNA Detection and Quantification by<br />

Real-Time PCR, Serum<br />

Clinical Information: Diagnosis of acute or chronic hepatitis B virus (HBV) infection is based on the<br />

presence of HBV serologic markers such as hepatitis B surface antigen (HBsAg) and hepatitis B core IgM<br />

antibody (anti-HBc IgM), or the presence of HBV DNA detected by molecular assays. Although the<br />

diagnosis of acute and chronic HBV infection is usually made by serologic methods, detection and<br />

quantification of HBV DNA in serum are useful to: -Diagnose some cases of early acute HBV infection<br />

(before the appearance of HBsAg) -Distinguish active from inactive HBV infection -Monitor a patient's<br />

response to anti-HBV therapy The presence of HBV DNA in serum is a reliable marker of active HBV<br />

replication. HBV DNA levels are detectable by 30 days following infection, generally reach a peak at the<br />

time of acute hepatitis, and gradually decrease and disappear when the infection resolves spontaneously.<br />

In cases of acute viral hepatitis with equivocal HBsAg test results, testing for HBV DNA in serum may be<br />

a useful adjunct in the diagnosis of acute HBV infection, since HBV DNA can be detected approximately<br />

21 days before HBsAg typically appears in the serum. Patients with chronic HBV infection fail to clear<br />

the virus and remain HBsAg-positive. Such cases may be further classified as chronic active (replicative)<br />

HBV (high HBV levels, hepatitis Be antigen [HBeAg]-positive) or chronic inactive (nonreplicative) HBV<br />

(low or undetectable HBV DNA levels, HBeAg-negative). HBV DNA levels in serum are useful in<br />

determining the status of chronic HBV infection, by differentiating between active and inactive disease<br />

states. Patients with chronic active HBV are at greater risk for more serious liver disease and are more<br />

infectious than patients with inactive HBV infection. Reactivation of inactive chronic HBV infection<br />

(HBeAg-negative state) may occur with or without reappearance of HBeAg in serum. In patients with<br />

HBeAg-negative disease, detection of HBV DNA is the only reliable marker of active HBV replication.<br />

The therapeutic goal of anti-HBV therapy in patients who are HBeAg-positive is to achieve long-term<br />

suppression of viral replication with undetectable HBV DNA, HBe seroconversion and loss of HBeAg.<br />

The therapeutic goal in patients with HBeAg-negative disease is typically long-term viral suppression.<br />

The emergence of drug-resistant HBV strains (in response to treatment with nucleos(t)ide analogs, eg,<br />

lamivudine, adefovir, entecavir, tenofovir), is characterized by either the reappearance of HBV DNA in<br />

Current as of January 4, 2013 7:15 pm CST 800-533-1710 or 507-266-5700 or <strong>Mayo</strong><strong>Medical</strong><strong>Laboratories</strong>.com Page 893

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