Acute sarcoidosis in a multiple sclerosis patient after alemtuzumab treatment

Background: Understanding the long-term effect of alemtuzumab on the immune system of multiple sclerosis (MS) patients is crucial. Objective: To report a case of acute sarcoidosis (Lofgren's syndrome) in a relapsing-remitting MS patient, 1.5 years after the second course of alemtuzumab treatment. Case report: Sarcoidosis was confirmed dermatohistologically, radiologically, and serologically. Analysis of the lymphocyte subpopulations showed a persistent effect of alemtuzumab treatment (CD4/CD8 ratio increased, absolute lymphocyte count of CD19-positive cells increased while CD3/4/8-positive cells were decreased). Conclusion: Our case highlights the profound effect of alemtuzumab on the immune system and its possible risk for autoimmune complications.