Peter Danielsson

Inflammatory markers and IL-6 polymorphism in peripheral arterial disease with and without diabetes mellitus.

Peripheral arterial disease (PAD) is a manifestation of systemic atherosclerosis, recognized as an inflammatory disease of the vessel wall, probably accelerated by diabetes mellitus (DM). Elevated interleukin (IL)-6 levels have been associated with increased cardiovascular morbidity and a common polymorphism has been identified in the promoter region of the IL-6 gene. The aim of this prospective study was to investigate inflammatory mediators in PAD patients (±DM) and to investigate a possible relationship to the IL-6 gene polymorphism. Five groups of patients (DM, intermittent claudication ±DM, critical limb ischemia (CLI) ±DM) and a control group of 20 individuals each were included. Hemoglobin, high sensitive C-reactive protein (hsCRP), creatinine, blood lipids, white blood cells (WBC); CD11b/CD18; vascular cell adhesion molecule (sVCAM-1), intercellular adhesion molecule (sICAM-1), sE-selectin, sP-selectin; IL-6, IL-8, tumour necrosis factor (TNF)α, sTNFα-R1 and sTNFα-R2 were analysed. The IL-6 gene polymorphism was determined in all groups and also compared with 200 healthy controls from a larger study of blood donors. In a multiple regression analysis, adjusted for gender, smoking and age, the effect of CLI was significantly (p < 0.05) associated with elevated levels of the WBC count, hsCRP, proinflammatory cytokines (IL-6, TNFα-R1-2) and endothelial (sICAM, sVCAM) and WBC (CD11b gran) markers. The effect of less advanced PAD (intermittent claudication) was related to an increased concentration of sVCAM-1 and the number of monocytes and granulocytes. DM or leg ulcers were not significantly related to any of the markers. No significant difference in frequency of the various IL-6 genotypes was found between the groups or when compared with the group of 200 blood donors (p > 0.3). Activation of cytokines, endothelial cells and WBC was related to the Fontaine stage of PAD but not to the presence of DM or ulcers. No association was found between the polymorphism in the IL-6 promoter region and PAD.

Flavonoid treatment in patients with healed venous ulcer: flow cytometry analysis suggests increased CD11b expression on neutrophil granulocytes in the circulation

The objective was to determine the activation of white blood cells (WBCs) and endothelial cells in patients with healed venous ulcer and the influence of the standing position and of treatment with flavonoids. Ten patients with a healed venous ulcer were treated with flavonoid substance (90% diosmin), 1000 mg three times daily for 30 days. Blood samples were taken from arm and dorsal foot veins before and after standing for 30 minutes. Blood sampling was performed before treatment, after three days, one month and three months. The activation of WBCs was determined by measuring adhesion molecule CD11b and CD18 expression on the surface of granulocytes and monocytes. In addition, interleukin 6 (IL-6), IL-8, soluble E-selectin (sE-selectin), sL-selectin and sICAM-1 levels in serum were quantified. The results showed that standing did not influence any of the measured parameters significantly. Expression of CD11b adhesion molecules on granulocytes was significantly up-regulated (p = 0.044) after treatment with flavonoids for one month, but this increase was not significant (p = 0.056) two months after the treatment period compared with the baseline level. The expression of CD18 remained unchanged. Baseline expression of CD11b or CD18 on monocytes did not change significantly during the study period. Neither was any significant change observed in the levels of IL-6, IL- 8 or the soluble adhesion molecules. It was concluded that flavonoid treatment for 30 days increased the expression of CD11b adhesion molecules on circulating granulocytes. No general effect on the inflammatory process could be observed as assessed by levels of cytokines and soluble adhesion molecules. Possible explanations for these findings could be that a decreased number of primed granulocytes leave the circulation due to a changed WBC/endothelial cell interaction or that flavonoids have a direct effect on granulocytes. Further studies are needed to clarify the mode of action of flavonoids in chronic venous disease.