- The aim of this study was to analyze surface expression of neutrophil adhesion molecules in Yemenite Jews as compared to other ethnic populations in Israel. The constitutive neutrophil expression of CD11b and L-selectin (LS), as well as their expression in response to an in vitro chemoattractant and growth factor stimulation were studied by flow cytometry. Mean surface expression of CD11b molecule was statistically significantly increased among the Yemenite Jews tested compared to the non-Yemenite Jews (327.1 +/- 129.2 vs. 237.0 +/- 133.1; p = 0.002), with no significant correlation to their absolute neutrophil count. LS expression was similar in the two study groups. In vitro analysis of CD11b and LS expression induced by chemoattractant and G-CSF showed no difference between neutrophils of Yemenite versus non-Yemenite Jews. The study results suggest that in Yemenite Jews, circulating neutrophils display significantly increased expression of beta2-integrin molecules on their surface compared to non-Yemenite Jews.