Biologic Safety — SCE Dermatology MCQ

Correct answer: A — Monitor clinically — drug-induced autoantibody formation is common with anti-TNF therapy and does not require treatment cessation in the absence of clinical lupus

Explanation lettering: D = shown as A · E = shown as D · A = shown as E

D is correct because monitoring clinically is appropriate: drug-induced autoantibody formation, particularly ANA and anti-dsDNA, is well recognised with anti-TNF agents such as infliximab and does not by itself indicate drug-induced lupus. Up to 50 percent of patients on long-term infliximab develop a positive ANA and a smaller proportion develop anti-dsDNA, yet clinically significant drug-induced lupus-like syndrome is rare, affecting well under 1 percent. The key discriminator in this stem is the absence of any lupus symptoms (no rash, arthralgia, serositis or fever), meaning there is no clinical syndrome to treat, only a laboratory finding. Current UK biologic safety guidance supports continuing effective anti-TNF therapy with clinical surveillance in this scenario, reserving cessation for patients who develop actual lupus-like features. Why the other options are wrong: A. Stop Infliximab immediately: Stopping a drug that is controlling severe psoriasis based on an asymptomatic serological finding is unjustified; withdrawal is only indicated if clinical drug-induced lupus develops. B. Ignore the results completely: Ignoring the results means missing the opportunity to monitor for future development of clinical lupus-like features, which requires ongoing clinical vigilance even though no action is needed now. C. Start Hydroxychloroquine prophylactically: There is no evidence base for prophylactic antimalarial treatment to prevent progression from asymptomatic autoantibodies to clinical lupus, and it exposes the patient to unnecessary drug risk (including retinopathy monitoring burden) with no established benefit. E. Switch to Secukinumab immediately: Switching biologic class is not warranted for an asymptomatic serological abnormality alone; this would abandon an effective, well-tolerated treatment without clinical justification and risks losing disease control. Key point: In the absence of clinical features of lupus, a positive ANA and anti-dsDNA during anti-TNF therapy warrants clinical monitoring, not drug cessation, switching, or empirical antimalarial treatment.

Reference: electronic Medicines Compendium (emc), Remicade (infliximab) Summary of Product Characteristics, Section 4.8 Undesirable Effects (autoimmunity, lupus-like syndrome), www.medicines.org.uk/emc/product/1067/smpc