A 58-year-old man with follicular lymphoma is about to start rituximab. Before the first dose, which screening test is mandatory because of a well-described risk of fatal reactivation during and after therapy?

• A Serum free light chains
• B Baseline echocardiography
• C Quantiferon TB testing
• D Serology for hepatitis B (HBsAg and anti-HBc) ✓

Explanation

Rituximab depletes CD20-positive B cells, including the B cells that control latent hepatitis B, causing reactivation that can present as fulminant hepatic failure even years after the last dose. Guidelines require HBsAg and anti-HBc testing before starting, with antiviral prophylaxis (entecavir or tenofovir) if positive. The best distractor is TB screening: it is advised before anti-TNF agents, not routinely before anti-CD20 therapy.

Reference: Katzung Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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