Cryptococcus neoformans var grubii meningoencephalitis in a patient on fingolimod for relapsing-remitting multiple sclerosis: Case report and review of published cases.

INTRODUCTION: Fingolimod, a sphingosine-1-phosphate modulator used in the treatment of relapsing-remitting multiple sclerosis, has been associated with several cases of cryptococcosis. CASE REPORT: We present a case of Cryptococcal meningoencephalitis attributable to Cryptococcus neoformans var. grubii, in a 58-year-old bird-keeper from Australia, after 7 years of fingolimod therapy. We discuss this in the context of previously reported cases, our understanding of fingolimod immune modulation, and known Cryptococcus pathobiology. CONCLUSION: We suggest consideration of harm minimisation behaviours in patients requiring fingolimod, particularly in those with profound CD4 lymphopenia. Furthermore, we echo the call for improved post-marketing surveillance systems to determine the epidemiology of atypical infections with novel immunomodulatory treatments.