Do I need to obtain hepatitis B and hepatitis C screening before starting Olumiant (baricitinib)?

Yes, hepatitis B and C screening is required before starting Olumiant (baricitinib).

You must obtain hepatitis B virus (HBV) testing for HBsAg, anti-HBc, and anti-HBs, as well as hepatitis C virus (HCV) antibody testing before initiating Olumiant. 1, 2

Required Hepatitis B Screening Tests

The following three tests are mandatory for all patients:

• HBsAg (Hepatitis B surface antigen)
• Anti-HBc (Hepatitis B core antibody - total)
• Anti-HBs (Hepatitis B surface antibody)

1, 3

Required Hepatitis C Screening

• Anti-HCV antibody testing is required
• If anti-HCV is positive, obtain HCV RNA to confirm active infection 4

What to Do Based on Results

If HBsAg-Positive (Chronic HBV Infection):

Ideally avoid JAK inhibitors if possible. If Olumiant is necessary, you must:

• Consult with a hepatologist before starting therapy
• Initiate antiviral prophylaxis (entecavir, tenofovir, or tenofovir alafenamide) before starting Olumiant
• Continue antiviral therapy throughout treatment and for at least 12 months after stopping Olumiant
• Monitor HBV DNA and ALT every 6 months during therapy 1, 2

If HBsAg-Negative but Anti-HBc-Positive (Past HBV Exposure):

• Obtain baseline HBV DNA to rule out occult infection
• If HBV DNA is positive, manage as chronic HBV (see above)
• If HBV DNA is negative, patient can start Olumiant but requires monitoring:
  • Check HBsAg and HBV DNA every 3 months during treatment
  • If either becomes positive during monitoring, stop Olumiant temporarily and refer to hepatology for antiviral therapy 1

If HCV Antibody-Positive:

• Obtain HCV RNA to confirm active infection
• If HCV RNA is detectable, refer to hepatology for treatment with direct-acting antivirals before starting Olumiant 3

Why This Matters

The FDA label for Olumiant explicitly warns about viral reactivation, including hepatitis B reactivation 2. JAK inhibitors carry similar HBV reactivation risk as TNF inhibitors, and reactivation can lead to severe hepatitis, liver failure, and death 1, 5. The 2021 and 2024 consensus statements on JAK inhibitor use are unequivocal that hepatitis screening is mandatory before initiation 1, 3.

Common Pitfall to Avoid

Do not rely on HBsAg testing alone. Studies show that screening with only HBsAg misses patients with past HBV exposure (anti-HBc-positive) who remain at risk for reactivation during immunosuppression 1. The complete three-test panel (HBsAg, anti-HBc, anti-HBs) is required to properly risk-stratify patients 5, 3.

Do not delay starting Olumiant while awaiting hepatology consultation if screening is negative, but do not start if HBsAg-positive until antiviral prophylaxis is established 1.