Effect of vitamin E modified cellulose membrane on human lymphocyte, monocyte, and granulocyte CD11b/CD18 adhesion molecule expression during hemodialysis

Polystyrene surface coated with vitamin E modulates human granulocyte adhesion and MMP-9 release

Vitamin E (Vit.E, alpha-tocopherol) is a natural biological antioxidant and antinflammatory agent, which protects cells from the effects of free radicals and inhibits inflammation. For such properties Vit.E has been used to improve the biocompatibility of materials such as cellulose membrane for hemodialysis. In this study granulocytes adhesion and activation have been studied after contact with normal cell culture grade polystyrene (PS) and Vit.E-coated polystyrene (Vit.E 0.1 and 0.3% (v/v)) using optical microscopy, flow cytometry and substrate zymography. Vit.E increased the number of adherent granulocytes both at 0.1% (11470 +/- 1064 cells/cm(2), P < 0.01) and 0.3% ( 13706 +/-818) cells/cm(2), P < 0.001) concentration compared to normal PS (5529+/-692 cells/cm(2)). The morphology of granulocytes adherent to Vit.E-PS appeared lightly altered and no differences have been observed in their respiratory burst compared to control granulocyte, while matrix metalloproteinase 9 or gelatinase B (MMP-9) release and activation were increased compared to the normal PS samples. Our data indicate that Vit.E-coated surface induced an increase in granulocytes adhesion and MMP-9 release in the absence of the typical oxidative stress, hallmark of granulocytes activation. A possible explanation of the phenomenon is that Vit.E modifies the surface protein adsorption thus increasing cell adhesion and in turn MMP-9 releasing.

Antioxidant therapy in uremia: evidence-based medicine?

Because of correlations between cardiovascular disease, inflammation, and renal failure, many investigators are pursuing nontraditional risk factors and therapies in order to reduce cardiovascular morbidity and mortality in the end-stage renal disease (ESRD) population. Despite the disappointing lack of clinical effects with antioxidative therapies seen in large studies of the general population, some studies suggest a diminished cardiovascular risk in individuals with renal failure. This expanding new line of evidence is promising as a method to help alleviate the more than 20-fold increase in risk of cardiovascular events in the ESRD population. Most of the current available studies have evaluated laboratory or physiologic endpoints, such as endothelial function and measures of oxidative burden, and have evaluated relatively small numbers of patients. However, it is currently premature to initiate widespread clinical therapy with antioxidants. Further investigation in this area should be supported to see if reported benefits can be duplicated in more widespread study populations, and to more accurately define the most appropriate choice of therapy, mode of therapy, and dose.