2025 American Academy of Neurology Abstract Website

Objective:

To understand the incidence of infections in patients with Multiple Sclerosis (MS), with focus on those undergoing treatment with disease-modifying therapies (DMTs) and compare these infection rates with untreated individuals.

Background:

Transformative advancements in MS treatment have led many US clinicians to shift their approach and initiate treatment early in the disease course. However, a significant barrier to start DMTs is patients' hesitance due to concerns about the increased risk of infections that these therapies entail.

Design/Methods:

Single center, retrospective analysis of 351 medical records from patients diagnosed with MS, both treated with DMTs and untreated, during 2022-2023.

Results:

Infection rates were 16% higher in untreated patients (48%) compared to those receiving DMTs (32%). Urinary tract infections (UTIs) were the most common infection in both groups (38% in treated group vs 32% in untreated), followed by upper respiratory tract infections (URIs), which occurred more frequently in untreated patients (14% vs 20%). Conversely, the incidence of COVID-19 was slightly higher in patients on DMTs (10% vs 9%), potentially due to reduced immunity in patients on anti-CD20 treatments. Patient on ofatumumab had an increased rate on of UTIs 75% and URIs 25% compared to patients on ocrelizumab UTIs 26% and URIs 15%, Notably, the majority of patients on cladribine did not have report any infections.

Conclusions:

Our study revealed higher infection rates among untreated MS patients compared to those receiving DMTs. This finding suggests that DMTs may play a role in reducing cumulative infection risk in MS patients by decreasing the accumulation of neurological disability and consequently reducing the susceptibility for infections. However, further investigation is necessary to understand the mechanisms underlying this association and to ensure optimal treatment approaches for managing MS while minimizing infection risk.