High levels of (un)switched memory B cells are associated with better outcome in patients with advanced atherosclerotic disease

Background--atherosclerosis is an inflammatory lipid disorder and the main underlying pathology of acute ischemic events. despite a vast amount of data from murine atherosclerosis models,evidence of b-cell involvement in human atherosclerotic disease is limited. we therefore investigated the association of circulating b-cell subtypes with the occurrence of secondary cardiovascular events in advanced atherosclerotic disease. methods and results--this cohort study consists of 168 patients who were included in the athero-express biobank between 2009 and 2011. before surgery,peripheral blood mononuclear cells were isolated and stored in liquid nitrogen. after gentle thawing of the peripheral blood mononuclear cells,different b-cell subtypes including naïve,(un)switched memory,and cd27+cd43+ b1-like b cells,were analyzed by flow cytometry. univariable and multivariable cox proportional hazard models were used to analyze associations between b-cell subtypes,circulating antibodies and secondary cardiovascular manifestations during the 3-year follow-up period. mean age was 70.1±9.6 years,males represented 62.8% of the population,and 54 patients had secondary manifestations during follow-up. high numbers of unswitched memory cells were protective against secondary outcome (hazard ratio,0.30 [95% ci,0.13-0.69]; p < 0.01). similar results were obtained for the switched memory cells that also showed to be protective against secondary outcome (hazard ratio,0.33 [95% ci,0.14-0.77]; p = 0.01). conclusions--a high number of (un)switched memory b cells is associated with better outcome following carotid artery endarterectomy. these findings suggest a potential role for b-cell subsets in prediction and prevention of secondary cardiovascular events in patients with atherosclerosis. © 2017 the authors.