The ratio of circulating CD56 NK cells to follicular T helper cells as a promising predictor for disease activity of relapsing-remitting multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system primarily mediated by CD4 T helper cells. This study investigated the dynamic changes of natural killer (NK) cells and follicular T helper (Tfh) cells and their associations in relapsing-remitting MS patients. The findings revealed inverse relationships between NK cells and CD4 T cells or Tfh cells. Specifically, CD56 NK cells, not CD56 NK cells, were negatively correlated with CD4 T cells and Tfh cells. However, no significant correlations were found between NK cells and sNfL levels or EDSS scores. The ratio of CD56 NK cells to circulating Tfh (cTfh) cells demonstrated superior discriminatory ability in distinguishing relapsing MS patients from healthy controls (HCs) and remitting patients, as determined by receiver operating characteristic (ROC) analysis. Following treatment with immunosuppressants or disease-modifying therapies (DMTs), a significant increase in the CD56 NK/cTfh ratio was observed. These findings suggest that the CD56 NK/cTfh ratio holds promise as a prognostic indicator for clinical relapse and treatment response in MS.