MS – DMF Lymphopenia — SCE Neurology MCQ

Instant feedback + full explanation. One question, done properly.

ModerateMultiple Sclerosis & CNS InflammationMS – DMF LymphopeniaSCE Neurology

A 40-year-old man with RRMS on dimethyl fumarate has lymphocytes below 0.5 × 10⁹/L for 6 months. He is asymptomatic. What action is required?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — Discontinue dimethyl fumarate

The SmPC states that if lymphocytes remain below 0.5 × 10⁹/L for more than 6 months, dimethyl fumarate should be discontinued due to PML and infection risk. A: Continuing with persistent severe lymphopenia is unsafe. C: Dose reduction is not recommended. D: Prophylaxis alone does not mitigate PML risk. E: The decision is correct but must account for washout.

Reference: Dimethyl Fumarate SmPC; NICE TA320 (2014)