2024 American Academy of Neurology Abstract Website

Objective:

To compare IgG and IgM levels in MS patients on B-cell depleting therapies

Background:

There is a lack of direct comparison of Immunoglobulin G and M (IgG/IgM) profiles across different B-cell depleting therapies (BCDTs) in MS patients, representing a knowledge gap of associated infection risks. We compared IgG and IgM levels between MS patients on Ocrevus, Kesimpta, and Rituximab and its derivatives.

Design/Methods:

Data was retrospectively collected from the time of patient enrolment until April 1,2023. The number of years between the start of BCDT and the date of the first recorded abnormal IgG and IgM levels among different BCDTs and MS types was measured using Chi-squared tests

Results:

140 (64%) were female, 18 (8.2%; average time of treatment 1.4 years) were on Kesimpta, 78 (35.8%;3.9 years) on Ocrevus and 122 (55.9%;1.1 years) on Rituximab. 21 (9.6%) had primary progressive MS (PPMS, average time on BCDTs 3.8 years), 185 (85%) had relapsing remitting MS (RRMS;1.5 years) and 12 (5.5%) had secondary progressive MS (SPMS; 1.6 years). More Ocrevus patients (IgG:17%, IgM:28%) had abnormal IgM and IgG levels (IgG:p=0.07,IgM:p=0.04). More SPMS patients (IgG:42%, IgM:58%) had abnormal IgG and IgM (IgG:p=0.03,IgM:p=0.01). It took longer to observe abnormal levels of IgG/M in patients on Ocrevus (IgG:1.4,IgM:1.5) and longer time periods to observe abnormal levels of IgG/M in PPMS patients (IgG:1.8,IgM:1.0).

Conclusions:

Findings reveal immunological differences between patients on different BCDTs, and the impact of treatment duration on IgG and IgM levels. Longitudinal monitoring of IgG and IgM may be a valuable tool to assess the safety of BCDTs.