🧠 TLDR Primary Care #021 | Test your Knowledge (#021)

In This Issue:

📈 Hepatitis serology interpretation

✅ Review signs and symptoms of hepatitis

💉 Hepatitis B vaccine recommendations

🧵 And more!

🧠 Test your Knowledge: What does this lab mean?

Keep sharpening your clinical skills

A 55-year-old female presents to your clinic with results from work-related blood tests. She is concerned because one of her hepatitis tests was positive. See below for her lab results.

Anti-HAV IgM Negative

HBsAg Negative

Anti-HBc Negative

Anti-HBs Positive

Anti-HCV Negative

The best explanation for this patient’s lab results is:

[A] Immune to hepatitis C due to previous vaccination

[B] Immune to hepatitis C due to previous infection

[C] Immune to hepatitis B due to previous infection

[D] Immune to hepatitis B due to previous vaccination

Scroll down to find the answer at the end! 👇

Need to refresh your memory before answering this question? Head over to Pathway to review the latest guidelines on hepatitis C virus infection and hepatitis B virus infection, as well as related landmark trials. 

Case Conclusion

Keep sharpening your clinical skills

Answer - D. Immune to Hepatitis B due to previous vaccination

Explanation - This patient has an isolated positive hepatitis B surface antibody. This means that she has immunity to hepatitis B as a result of prior vaccination, and does not need repeat hepatitis B vaccination. Importantly, her hepatitis B surface antigen, the marker of active infection, was negative as well. The hepatitis C antibody is used to screen patients for infection, but can not determine active infection or immunity.

What if our patient had been positive for hepatitis B core antibody (cAb)? 

• This would indicate immunity from hepatitis B due to previous infection, not from vaccination. 

When should you screen for hepatitis B or C?

• Screen for hepatitis B virus (HBV) infection in patients with HIV infection (A) and other people at high risk of infection (B), such as:
  • Persons born in countries with > 2% HBV prevalence
  • Patients with hepatitis C infection
  • Injection drug users
  • Incarcerated people
  • Patients with elevated ALT levels (> 19 IU/L in females and > 30 IU/L in males)
  • Patients with ESRD 
  • Pregnant patients
  • Men who have sex with men
• Obtain one-time, routine opt-out hepatitis C virus (HCV) testing in all persons > 18 years of age. (B)
• Obtain annual HCV testing in all injection drug users, patients with HIV and having sex with men, and men having sex with men taking PrEP. (B)

Acute hepatitis B infection varies in presentation, but generally has a prodromal period of a few days to 2 weeks. It can result in acute liver failure, but more commonly leads to mild symptoms of jaundice, nausea, anorexia, and right upper quadrant pain. Most patients (> 95%) with acute HBV infection recover spontaneously and will not progress to chronic HBV infection. 

See below for a comprehensive review of hepatitis B serology interpretation.

Instagram Link

🗞 Key Guideline Recommendations on Hepatitis B vaccination:

• Administer the first dose of hepatitis B vaccine in all infants as soon as possible after birth, preferably within 24 hours, followed by 2-3 doses to complete the series. (E)
• Administer vaccination against hepatitis A and hepatitis B in all susceptible patients with HCV infection. (B)
• Offer vaccination against HBV in all adults with the following risk factors:

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- The Pathway Team

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