Objective:

Describing the occurrence of infections in patients with relapsing-remitting multiple sclerosis (RRMS) treated with fingolimod and with different degrees of lymphopenia in our unit.

Patients and Methods:

Observational, descriptive, longitudinal, and retrospective study in the Hospital Centro Médico Nacional Siglo XXI. Patients with RRMS and treatment with fingolimod were grouped based on lymphocyte count and infections. Quantitative variables were expressed as mean, standard deviation, and interquartile range; qualitative variables were expressed as frequencies and percentages.

Results:

110 patients, 76 (69.1%) female, 34 (30.9%) male, mean age 38.3 years (17-63, SD 9.85). Mean of initial expanded disability status scale 1.59 (0-5.5, SD 1.15) with a mean diagnosis time of 63.6 months (3-252, SD 50.96). Prior to starting fingolimod, 90.09% of patients had lymphocyte count >1,000. At six months of treatment, 35.64% had lymphocyte >1,000. At twelve months 32.95% had lymphocyte from 501 to 700. At 24 months, 34.21% had lymphocyte from 701 to 1,000. Of the 110 patients, 31.8% had mild infections, of which pharyngitis was reported in 10%, gastroenteritis 2.7%, urinary tract infection 10.9%, HPV infection 0.9%, SARS-CoV-2 infection 3.6%, ophthalmic herpes 0.9%, molluscum contagiosum 0.9%, oral candidiasis 0.9%. 68.18% did not present infections of any kind, no serious infections were reported even with lymphocyte levels below 200.

Conclusions:

Selective lymphopenia caused by fingolimod was not associated with infections of any kind in this population even at levels of 200-500 cells/mm3.