Effects of Fingolimod on Lymphocyte Levels in Human MS Patients

In a study of 143 adults with MS on fingolimod, 86.7% experienced lymphopenia at 6 months, including 10.5% with severe Grade 4 lymphopenia. Significant decreases in leukocyte, neutrophil, and lymphocyte counts were observed, along with increases in liver enzyme levels. Notably, no significant infection risk was linked to Grade 3-4 lymphopenia, and lower baseline lymphocyte counts correlated with severe lymphopenia.

Tags: #Fingolimod #Lymphopenia #InfectionRisk #HematologicalMonitoring
Most relevant to: Neurologist, Immunologist
Source: Read original source (PMID 42796323)

This plain-English summary was written by AI from a published abstract and may contain errors. It is not medical advice. Read the original study and talk to your MS team before making decisions about treatment.

Why it matters

These findings highlight the high incidence of lymphopenia among MS patients undergoing fingolimod treatment and raise concerns about the need to monitor lymphocyte levels and potential infection risks during treatment.

What this does not prove

The lack of a significant correlation between lymphopenia severity and infection risk limits the reliability of these findings. Additionally, the small number of Grade 4 cases restricts the ability to draw broad conclusions.

Next milestone

No next milestone was established from the available source.

Study facts

Study design: Observational
Participants / samples: 143 · study cohort
Randomised: Not reported
Controlled: Not reported
Primary endpoint met: No
Relevant MS type: Not reported
Publication date: 2026-09-07
Evidence reviewed: Abstract only
Regulatory approval: Not reported
Research areas: Not classified

Original sources

Primary evidenceImpact of Fingolimod on Lymphopenia in MS Patients ↗

Supporting passages (8)

study designThis study evaluated the frequency and severity of fingolimod-associated lymphopenia, longitudinal hematological changes and their relationship with clinical outcomes in a real-world MS cohort.

subjectsMaterials and Methods: This retrospective observational study included 143 adults with MS who initiated fingolimod treatment between May 2019 and October 2020.

sample sizeMaterials and Methods: This retrospective observational study included 143 adults with MS who initiated fingolimod treatment between May 2019 and October 2020.

sample size basisMaterials and Methods: This retrospective observational study included 143 adults with MS who initiated fingolimod treatment between May 2019 and October 2020.

primary endpoint metNo statistically significant association was detected between Grade 3-4 lymphopenia and infection risk (OR, 1.41; 95% CI, 0.42-4.71; p = 0.545).

findingsAt 6 months, lymphopenia was present in 124 patients (86.7%), including Grade 4 lymphopenia in 15 (10.5%).

limitationsNo statistically significant association between lymphopenia severity and infection was detected; however, the small number of Grade 4 cases, low event rate and wide confidence interval limited the statistical power to exclude clinically meaningful differences.

publication datePublication date: 2026-09-07

AI assessment, not yet reviewed by a person · version 1 · Community votes are separate from evidence review.