Lecanemab treatment improves B cell subpopulation immune homeostasis in patients with Alzheimer's disease

Lecanemab, the first disease-modifying therapy for Alzheimer's disease (AD), mitigates pathology primarily by clearing amyloid plaques, but its impact on peripheral immunity remains unclear.

To assess Lecanemab's immunological effects, we performed antibody array analysis of serum and single-cell RNA sequencing of peripheral blood mononuclear cells collected from healthy controls and patients with AD at baseline, 3, and 6 months post-treatment.

Lecanemab restored multiple serum chemokines to healthy levels in patients with AD. Compared to controls, baseline samples from patients with AD showed altered frequencies and functions of naïve and unswitched memory (UswM) B cells. Lecanemab treatment corrected the abnormal naïve and UswM B cell proportions and rebuilt their functional homeostasis by alleviating chronic inflammation and reversing the dysregulation of key pathways including immune response, NF-κB, RAGE, and cell adhesion.

These findings uncover a novel peripheral immunomodulatory mechanism of Lecanemab, offering new insights into AD therapeutics.