Cladribine tablets are approved for relapsing multiple sclerosis, mediating their clinical effect by moderately depleting lymphocytes. In a prospective, monocentric study including 22 patients completing 2 annual cycles of cladribine, B‐ and T‐cell receptor repertoires and relapse activity were assessed at baseline and after 24 months. T‐cell clonality increased, driven by loss of low‐frequency, naive clonotypes, and re‐expansion of dominant CD8 memory clonotypes, particularly in clinically stable patients. In contrast, B‐cell receptor richness increased because of reconstruction by transitional and naive B cells with higher clonotype numbers observed in relapsing patients. Therefore, competing immune reconstitution following cladribine therapy could result in differential clinical responses. ANN NEUROL 2026
Schneider‐Hohendorf et al. (Fri,) studied this question.