Latent TB Screening — IGRA and Tuberculin Skin Testing
All patients are screened for latent TB before biologic therapy begins.
- ~90%: IGRA sensitivity (placeholder figure)
- ≥5mm: TST cutoff (placeholder figure)
- Pre-therapy: Screening timing (placeholder figure)
- Annual: Repeat testing (placeholder figure)
Why screening precedes biologic initiation
Placeholder: latent TB must be identified before immune suppression begins.
Hepatitis B and C Serology Panel
HBsAg, anti-HBc, and HCV antibody testing detect chronic or resolved infection.
- Active: HBsAg marker (placeholder figure)
- Past exposure: Anti-HBc marker (placeholder figure)
- Screening: HCV antibody (placeholder figure)
- ~296M: Global HBV carriers (placeholder figure)
Serology markers and chronic carrier detection
Placeholder: serology distinguishes active, resolved, and occult hepatitis infection.
How Biologics Suppress Granuloma and Viral Control
TNF-α blockade destabilizes the granuloma wall containing dormant bacteria.
- Granuloma upkeep: TNF-α role (placeholder figure)
- HBV flare: B-cell depletion risk (placeholder figure)
- Elevated: JAK inhibitor risk (placeholder figure)
- Weeks-months: Onset of risk (placeholder figure)
Mechanism of immune suppression on latent reservoirs
Placeholder: cytokine blockade weakens containment of dormant pathogens.
Reactivation Risk of Latent TB and Hepatitis B
Untreated latent infection can reactivate rapidly once therapy begins.
- ~10-15%/yr: TB reactivation (placeholder figure)
- 10-40%: HBV reactivation (placeholder figure)
- Weeks: Time to flare (placeholder figure)
- Elevated: Mortality if missed (placeholder figure)
Clinical consequences of missed reactivation
Placeholder: reactivation can be severe and sometimes fatal if unscreened.
Prophylaxis Before Starting Biologic Therapy
Isoniazid or antiviral prophylaxis is started before or with biologic therapy.
- 9 months: INH course (placeholder figure)
- Entecavir/TDF: Antiviral choice (placeholder figure)
- ~4 weeks: Delay to biologic (placeholder figure)
- Ongoing: Monitoring (placeholder figure)
Preemptive therapy protocol
Placeholder: prophylaxis clears infection risk before immune suppression starts.
Placeholder: screening and prophylaxis together prevent most reactivation events.