Risk factors for fingolimod-induced lymphopenia in multiple sclerosis

Background Lymphopenia is a well-known adverse event of fingolimod, a disease-modifying drug for multiple sclerosis (MS). Objectives The objective of this paper is to investigate risk factors for predicting fingolimod-induced lymphopenia in MS by frequent hematological monitoring. Methods We retrospectively reviewed data of fingolimod-treated MS patients. Data assessed were sex, age, disease duration, medication history, body mass index, all attacks, Kurtzke’s Expanded Disability Status Scale score, and absolute lymphocyte count (ALC) within two days before initiating fingolimod (baseline), on the day after first administration (day 2), and at least every other month after initiating fingolimod therapy. Results Of 41 MS patients, marked lymphopenia (ALC