Predicting autoimmunity in patients treated with alemtuzumab

The use of alemtuzumab in highly active MS has been limited by adverse events (AEs) in the form of secondary autoimmune disorders, especially involving the thyroid gland. A low percentage of blood circulating CD19+ B cells –cut-off value 7.6%– before starting alemtuzumab treatment may predict a lower risk of autoimmune AEs [1].

A multicentre, prospective, longitudinal study evaluated whether patients’ blood lymphocyte profile before the initiation of alemtuzumab treatment may help predict the development of later autoimmunity. The Spanish study included 54 relapsing-remitting MS (RRMS) patients (34 female), with a median age of 35 years and a median follow-up of 2.8 years. Of these, 14 patients (25.9%) experienced autoimmune AEs, in all cases dysthyroidism. No immune thrombocytopenia or nephropathies were observed.

There were no significant differences in clinical and demographic baseline characteristics (e.g. EDSS) in patients who developed autoimmune AEs versus those who did not. Patients who experienced autoimmune AEs before treatment onset did have a higher percentage of baseline blood CD19+ B cells (P=0.001), with a higher relative percentage of naïve B cells and plasmablasts. In total cell numbers, only plasmablast levels remained significant (P=0.02). Previous treatments did not significantly influence the percentage of B lymphocytes. There was a lower risk of autoimmune AEs after alemtuzumab treatment among patients with <7.6% of blood CD19+ B cells (OR 14.67; 95% CI 3.4-54.5; P<0.0001).

1. Walo Delgado P, et al. Predictive biomarkers of the development of autoimmunity in patients treated with alemtuzumab. MSVirtual 2020, Abstract PS09.03.

 



Posted on 25 November, 2020