Diagnosis: Acute Hepatitis B with Resolved Hepatitis C
This patient has acute hepatitis B infection (indicated by HBsAg-positive and Anti-HBc IgM-positive) with a history of resolved hepatitis C infection (Anti-HCV-positive but HCV RNA-negative), presenting with abdominal pain that requires hospital admission for monitoring and evaluation of acute liver injury. 1, 2
Hepatitis B Interpretation
The presence of both HBsAg and Anti-HBc IgM is diagnostic of acute hepatitis B infection, distinguishing this from chronic HBV infection where Anti-HBc IgM is typically absent or present at low levels 3, 2
Anti-HBc IgM remains positive for at least 2 months during acute HBV infection and persists until HBsAg clearance, making it the definitive marker for acute versus chronic infection 4
High ratio unit (RU) values for Anti-HBc IgM (typically >5) at disease onset confirm acute infection rather than chronic carriage, where RU values range only 2.5-5.5 4
Hepatitis C Interpretation
A patient who is Anti-HCV-positive but HCV RNA-negative does not have active HCV infection and represents resolved infection 1
According to CDC guidelines, persons with positive Anti-HCV but negative HCV RNA should be informed they do not have HCV infection and do not need follow-up HCV testing 1
Among anti-HCV-positive persons who acquired infection as adults, 15-25% spontaneously resolve their infection, which explains this serologic pattern 1
Clinical Significance of Abdominal Pain
Hospital admission is warranted for patients presenting with abdominal pain and suspected acute viral hepatitis to monitor for severe liver injury and perform serial liver function tests 5
The combination of abdominal pain with acute hepatitis B requires evaluation of AST/ALT levels, as significantly elevated transaminases (particularly AST:ALT ratio abnormalities) indicate potential severe liver injury requiring close monitoring 5
Serial liver function tests including AST, ALT, alkaline phosphatase, bilirubin, albumin, and prothrombin time should be performed to track disease progression 1, 5
Initial Evaluation Required
Complete blood count, comprehensive metabolic panel including liver enzymes (AST/ALT, alkaline phosphatase, bilirubin, albumin), and coagulation studies (prothrombin time/INR) are essential 1, 6
HBeAg/anti-HBe testing and quantitative HBV DNA should be obtained to assess viral replication and infectivity 1
Testing for other coinfections should be performed: anti-HDV (hepatitis D) given the acute HBV infection, and anti-HIV given the risk profile 1
Hepatitis A serology (anti-HAV IgG) should be checked, as coinfection with HAV in HBV carriers increases mortality risk 5.6- to 29-fold 1
Management Plan
Immediate Actions
Admit to hospital for monitoring of liver function, clinical status, and potential complications of acute hepatitis 5
Obtain baseline imaging (right upper quadrant ultrasound) to assess liver parenchyma and exclude biliary obstruction as cause of abdominal pain 6
Assess for signs of acute liver failure: encephalopathy, coagulopathy (INR >1.5), and hyperbilirubinemia 1
Monitoring Strategy
Serial liver function tests every 24-48 hours initially to monitor for worsening liver injury or development of acute liver failure 5
Daily clinical assessment for development of hepatic encephalopathy, ascites, or other complications 1
Monitor for progression to chronic infection: most adults (>95%) with acute HBV will clear the infection spontaneously, but 5% develop chronic infection 1
Supportive Care
Abstinence from alcohol is mandatory during acute hepatitis B 1
Avoid hepatotoxic medications including acetaminophen, herbal supplements, and unnecessary over-the-counter medications 1
Ensure adequate hydration and nutritional support, particularly if nausea/vomiting is present 6
Antiviral Therapy Considerations
Antiviral therapy is generally NOT indicated for uncomplicated acute hepatitis B in immunocompetent adults, as spontaneous clearance occurs in >95% of cases 1
Consider antiviral therapy (entecavir or tenofovir) only if: severe acute hepatitis with coagulopathy (INR >1.5), protracted course (>4 weeks with persistent symptoms), or signs of acute liver failure 1
If antiviral therapy is initiated, use entecavir (0.5mg daily) or tenofovir disoproxil fumarate (300mg daily) or tenofovir alafenamide (25mg daily) 1
Follow-Up Testing Schedule
Repeat HBsAg, anti-HBs, and liver function tests at 1,3, and 6 months post-diagnosis to document clearance of infection 1
If HBsAg persists beyond 6 months, the patient has developed chronic hepatitis B and requires long-term management 1
HBV DNA should be checked at 6 months if HBsAg remains positive to assess for chronic infection 1
Vaccination and Prevention
Hepatitis A vaccination is recommended once acute hepatitis resolves, given the significantly increased mortality risk with HAV/HBV coinfection 1
Counsel on prevention of transmission: avoid sharing personal items (razors, toothbrushes), use barrier protection during sexual activity, and inform household/sexual contacts who should be tested and vaccinated if susceptible 1
Household and sexual contacts should receive HBV vaccination series if they are HBsAg-negative and anti-HBs-negative 1
Common Pitfalls to Avoid
Do not assume chronic HBV infection without checking Anti-HBc IgM, as this is the critical distinguishing marker between acute and chronic infection 2, 4
Do not treat the positive Anti-HCV as active infection when HCV RNA is negative - this represents resolved infection and requires no HCV-specific therapy 1
Do not initiate antiviral therapy reflexively for acute HBV - reserve for severe cases or those with signs of liver failure, as most cases resolve spontaneously 1
Do not discharge without establishing close outpatient follow-up, as progression to fulminant hepatic failure, though rare, can occur within days 5
Avoid checking Anti-HBc IgM in known chronic HBV carriers for diagnosis of acute exacerbation, as low-level positivity (RU 2.5-5.5) can persist in chronic carriers and does not indicate acute infection 4