Patients treated for multiple sclerosis with immunomodulatory therapies — especially alemtuzumab — may develop thyroid eye disease (TED) years later, and it's going largely undetected. A new case series found TED emerged a median of 38.5 months after treatment, often progressing to severe disease. Experts now recommend at least 3–5 years of thyroid and ocular monitoring after immune reconstitution therapy.
A new retrospective case series is shining a light on an underrecognized complication of multiple sclerosis (MS) treatment: thyroid eye disease (TED) that develops years after immunomodulatory therapy. The study, presented at ENDO 2026, tracked six MS patients at Imperial College Healthcare NHS Trust in London who developed TED following treatment — four with alemtuzumab, one with natalizumab, and one with interferon-based therapy. Crucially, none had a prior history of Graves disease or TED before treatment.
The findings are a wake-up call for long-term monitoring. All six patients were ultimately diagnosed with Graves disease at the time of TED presentation, and disease severity escalated to severe in four of them — with three requiring surgical interventions including orbital decompression and strabismus surgery.
By the Numbers:
Why it matters: TED following immune reconstitution therapy is a delayed, potentially severe complication that clinicians may not be watching for. Experts are calling for routine thyroid and ocular surveillance for at least 3–5 years post-treatment, along with early multidisciplinary referral to improve patient outcomes.
