Cytokine Inducing Substances(CIS): Effect of Backfiltration on Inflammatory Indices in Hemodialysis

Abstract

Hemodialysis using high flux membranes is well accepted around the world. The rationale is that it offers enhanced clearance of various uremic toxins by combining diffusion with some degree of convective transport within the dialyzer (Blankestijn et al., 2010). The benefits of high flux with regard to clearance of middle molecules and a survival benefit in high risk hemodialysis patients is clear. A number of bacterial products such as lipopolysaccharides (LPS), exotoxins, and peptidoglycans share the ability to induce cytokines and are known activators of immune functions. In many studies, the biologic test of cytokine induction in peripheral blood mononuclear cells has been used to detect these substances. However, the exact chemical natures of bacterial CIS as well as the interactions between different types of CIS are not completely understood, and most likely CIS consist of a mixture of bacterial products. LPS is not the only and maybe not the most important product in dialysate that induces cytokines (Schindler et al., 2004). The majority of endotoxins found in dialysis fluid and water for dialysis fluid come from Pseudomonas contamination. Such bacteria are commonly found in most water supplies even after standardwater treatment. However, clinical water systems may also be found to harbor bacterial biofilms due to improper design or neglect in microbiological monitoring, which are difficult to detect and remove (Marion-Ferry et al., 2005). In our study the aim was to investigate the permeability of low flux and high flux membranes to cytokine inducing substances by backfiltration. We used IL-1B as a marker of the transmembrane passage of endotoxins we also measured and compared the CRP with low and high flux dialysis. This study was conducted on a 100 patients with ESRD on regular hemodialysis 53% were males and 47% were females from September 2014 to 2015. The mean age of the patients was 54 years +/- 11 as summarized in table1. Half the population had diabetes, 63% were hypertensive, 39% were HCV and had chronic liver disease, chronic glomerulonephritis accounted for 23% followed by systemic lupus erythematosus at 7%. The LAL test was used to detect the amount of endotoxin in the water treatment and the level was 0.23 EU/ml. The median dialysis fluid endotoxin concentration was 0.5 EU/ml.