USMLE Prep - Medical Reference Library

HBV Reactivation - Screening and Prophylaxis

System: Hepatology • Reviewed: Aug 31, 2025 • Step 1Step 2Step 3

Synopsis:

Screen for HBsAg and anti HBc before immunosuppression; start antiviral prophylaxis for high risk regimens such as anti CD20 therapy and continue for months after completion.

Key Points

  • Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
  • Use system-specific risk tools to guide testing and disposition.
  • Order high-yield tests first; escalate imaging when indicated.
  • Start evidence-based initial therapy and reassess frequently.

Algorithm

  1. Primary survey and vitals; IV access and monitors.
  2. Focused history/physical; identify red flags and likely etiologies.
  3. Order system-appropriate labs and imaging (see Investigations).
  4. Initiate guideline-based empiric therapy (see Pharmacology).
  5. Reassess response; arrange consultation and definitive management.

Clinical Synopsis & Reasoning

For Hbv Reactivation Immunosuppression Prophylaxis, frame the differential by acuity and pathophysiology, then align diagnostics to the leading hypotheses. Prioritize stabilization while obtaining high‑yield studies such as CBC (Baseline hematology), BMP (Electrolytes/renal). Incorporate bedside imaging and targeted labs to define severity and identify complications; synthesize results with clinical trajectory to refine the working diagnosis and disposition needs.


Treatment Strategy & Disposition

Initiate disease‑directed therapy alongside supportive care, titrating to objective response. Pharmacologic options commonly include Analgesia/Antipyretics. Use validated frameworks (e.g., Who Gets Prophylaxis) to guide escalation and site of care. Address precipitating factors, de‑escalate empiric therapies with data, and arrange follow‑up for monitoring and risk‑factor modification; admit patients with instability, high risk of deterioration, or needs for close monitoring.


Epidemiology / Risk Factors

  • Risk factors vary by condition and patient profile

Investigations

TestRole / RationaleTypical FindingsNotes
CBCBaseline hematologyAbnormal counts
BMPElectrolytes/renalDerangements

Who Gets Prophylaxis

Serology and regimenPlan
HBsAg positiveProphylaxis regardless of regimen risk
HBsAg negative, anti HBc positive with high risk regimenProphylaxis
Lower risk regimensClose monitoring or prophylaxis per policy

Pharmacology

MedicationMechanismOnsetRole in TherapyLimitations
AcetaminophenAnalgesic/antipyreticHoursSymptom control as appropriateHepatotoxicity (overdose)
Ondansetron5-HT3 antagonismMinutesAntiemesis if neededQT prolongation

Prognosis / Complications

  • Prognosis depends on severity, comorbidities, and timeliness of care

Patient Education / Counseling

  • Explain red flags and when to seek emergent care.
  • Reinforce medication adherence and follow-up plan.

Notes

Vaccinate susceptible patients when feasible. Document antiviral choice and duration in the record.


References

  1. AASLD - HBV reactivation guidance — Link
  2. ASCO - HBV screening in oncology — Link