Immune function of erythrocytes in patients with chronic venous insufficiency of the lower extremities

Background The influence of inflammatory processes has been one of the hot topics in discussions of the etiology ofchronic venous insufficiency(CVI).Erythrocytes are very important in controlling inflammatory immunity and innateimmune reactions.The purpose of this study was to analyze the correlation between the development of CVI and thechange of CD35,Fy6 on erythrocytes,and interleukin-8(IL-8)levels.Methods A group of 43 patients with CVI were studied in parallel with 8 healthy individuals serving as control subjects.Control subjects were those with normal findings on lower extremity duplex examinations.We used an erythrocyte flowcytometer to examine the expression of both CD35 and Fy6 on red blood cells,and an enzyme-linked immunosorbentassay analysis method to measure plasma IL-8 levels.We also analyzed the change of IL-8 levels under the influence oferythrocytes using a modified method of the hemaimmune reaction.Results Compared with normal control subjects,CD35 expression increased significantly among patients with CVIclassified as C4 without lipodermatosclerosis,but tended to decrease and reach the lowest level among patientsclassified as C5-C6.Fy6 expression increased significantly among patients in the early stages of CVI,but tended todecrease remarkably among patients classified as C5-C6.The inflammatory response intensified at the C5-C6classification,where high levels of IL-8 coexisted with a low expression of Fy6.The increase in IL-8 in the CVI group washigher than in the control group in association with the complete blood cells,regardless of the presence of erythrocytes,when inactive tumour cells were added,whereas the level of IL-8 in the CVI group was significantly lower than in thecontrol group.Conclusions Abnormalities of erythrocyte innate immunity represents a fundamental derangement in CVI.Theseinadequate inflammatory responses may lead to local tissue and microvascular damage of the lower extremity.