Tumefactive MS lesions under fingolimod: a case report and literature review.

Abstract

To report about a possible association between fingolimod treatment and tumefactive demyelinating lesions (TDL) as seen in a patient developing repeated TDL on continued fingolimod therapy. We performed serial clinical and radiologic assessments and immunophenotyping of blood and CSF immune cells. We also present a literature review about recent similar cases. Clinical course and radiologic findings were consistent with diagnosis of TDL. Immune cell phenotyping showed pronounced shifts in the immune cell composition related to fingolimod treatment. In addition, we observed a subset of highly differentiated effector cells (CD45R0negCCR7neg) within the CD8+ T-cell population, which was about 2-fold enriched in the CSF compared to the peripheral blood. Our observations add further evidence for the development of atypical demyelinating lesions in some patients receiving fingolimod. These might be related to a treatment-associated shift in the immunopathology of specifically susceptible individuals.