Dynamic thyroid dysfunction postalemtuzumab therapy in multiple sclerosis: A case of autoimmune switch and pregnancy challenges

ABSTRACT Autoimmune thyroid disease (AITD) following alemtuzumab therapy is a well-documented phenomenon, though the switch from Hashimoto’s thyroiditis to hyperthyroidism remains a rare occurrence. Hyperthyroidism during pregnancy presents unique clinical challenges due to its potential impact on both maternal and fetal health. Here, we present a case of a young female with relapsing-remitting multiple sclerosis (RRMS) who developed autoimmune thyroid dysfunction postalemtuzumab therapy, with a dynamic thyroid course and associated challenges during pregnancy. A 26-year-old female with RRMS, treated with alemtuzumab, developed autoimmune thyroid dysfunction. Initially presenting with thyroiditis and subsequent hypothyroidism, she later transitioned to hyperthyroidism. The patient experienced weight loss, tremors, and tachycardia and was managed with propranolol. During pregnancy, her hyperthyroidism posed additional risks, requiring close monitoring to balance maternal and fetal health. Postpartum, her condition evolved into overt Graves’ disease, necessitating antithyroid therapy. Alemtuzumab-induced thyroid dysfunction exhibits a dynamic and unpredictable course, emphasizing the need for regular thyroid function monitoring. The autoimmune switch phenomenon, though uncommon, necessitates heightened clinical vigilance. Hyperthyroidism during pregnancy is associated with significant maternal and fetal complications, including preterm labor and fetal growth restriction, warranting individualized management strategies. Postpartum considerations include breastfeeding safety with antithyroid drugs and the need for long-term surveillance due to the fluctuating nature of autoimmune thyroid disorders. This case underscores the complexity of autoimmune thyroid dysfunction postalemtuzumab therapy, particularly during pregnancy. Periodic thyroid assessment is crucial in patients receiving immune-modulating treatments. A personalized approach to management, considering pregnancy and postpartum changes, is essential to optimize patient outcomes.