Abstract
OBJECTIVE: We present a case of multiple tumefactive demyelinating lesions (TDLs) emerging 24 months after the second cycle of alemtuzumab treatment. METHODS: A woman with relapsing-remitting multiple sclerosis (MS) discontinued fingolimod treatment due to gestational desire, which resulted in a severe disease exacerbation. Alemtuzumab was initiated, accompanied by regular clinical, radiological, and immunological monitoring. RESULTS: She relapsed prior to the second cycle, exhibiting 12 T1Gd(+) lesions, and peripheral blood showed an increase in B-cells and a decrease in T-cells. At 24 months following the second cycle, she developed cognitive impairment and multiple T1Gd(+) lesions, including TDLs, were evident on the brain MRI. We found not only an increase in B-cells but also in Th1 central memory cells. Th1/Th17 cells increased 3 months before the detection of TDLs. CONCLUSIONS: TDLs can appear 24 months after the second cycle of alemtuzumab treatment in MS. The increase in Th1/Th17 cells could be a candidate biomarker for TDLs in alemtuzumab-treated MS patients.