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Lamivudine Resistance — SCE Infectious Diseases MCQ

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ModerateHepatitisLamivudine ResistanceSCE Infectious Diseases

A 45-year-old man with known chronic hepatitis B develops flare of hepatitis (ALT 1,200 U/L) while on immunosuppressive therapy for a kidney transplant. His HBV DNA rises from undetectable to 5 × 10⁷ IU/mL. He had been on Lamivudine prophylaxis. Resistance testing shows rtM204V mutation. What is the cause of this flare?

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Correct answer: B — Lamivudine resistance (rtM204V) has developed

Lamivudine has a very low genetic barrier to resistance — rtM204V/I mutations develop in up to 70% of patients by year 5 of monotherapy. This is the key reason Lamivudine is no longer recommended as first-line for chronic HBV by NICE or EASL. Management: immediately switch to Tenofovir (DF or AF) which has no cross-resistance with Lamivudine. Entecavir dose should be increased to 1 mg daily if used in Lamivudine-resistant patients (cross-resistance exists at standard 0.5 mg dose). HBV DNA and LFTs should be monitored closely for flare resolution.

Reference: https://www.nice.org.uk/guidance/conditions-and-diseases/infections