Benign hereditary leukopenia-neutropenia does not result from lack of low grade inflammation. A new look in the era of microinflammation

The purpose of this study was to determine whether benign hereditary leukopenia-neutropenia in Yemenites may be reflective of an absent or a lesser degree of chronic low grade inflammation that has been documented to exist in most apparently healthy subjects. The white blood cell count (WBCC), fibrinogen as well as high sensitivity C-reactive protein (hs-CRP) concentrations were determined in a group of apparently healthy individuals during their routine health screening program. These inflammatory biomarkers in a group of 82 Yemenite Jews were compared to those measured in a group of 1817 individuals whose parents immigrated to Israel from Central and East Europe, from countries surrounding the Mediterranean Sea as well as the Middle East. The two study groups were matched for possible confounding factors that may have an influence on the intensity of the microinflammatory response including age, gender, body mass index, components of the metabolic syndrome and the Ten Year Calculated Coronary Heart Disease Framingham Risk Score. The expected reduced WBCC was noted in the group of Yemenite Jews (6.99 ± 1.64 versus 5.88 ± 2.06 × 10³/μL cells, P = 0.001). However, they had significantly enhanced concentrations of hs-CRP, the respective values being 2.1 ± 2 versus 1.4 ± 2.4 mg/L in men (P = 0.002) and 2.5 ± 2.2 versus 1.4 ± 2.9 in women (P < 0.0005). An increased concentration of fibrinogen was found in the Yemenite Jews, although the difference was not statistically significant in men. Thus, the leukopenia-neutropenia in Yemenite Jews is probably not an expression of an absent or lesser degree of chronic low grade inflammation. These findings shed more light on the potential mechanisms that are responsible for the low WBCC in this particular ethnic group.