Cytokine profiles during clinical high-flux dialysis : no evidence for cytokine generation by circulating monocytes (original) (raw)
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Kidney International, 1996
Effects of ultrapure and non-sterile dialysate on the inflammatory response during in vitro hemodialysis. Several studies support the hypothesis that bacterial contamination of the dialysate stimulates the inflammatory response to hemodialysis (HD) and increases the long-term morbidity of HD patients; this phenomenon could also be modulated by the nature of the HD membrane. Therefore, this study was designed to compare the effects of non-sterile (NSBD, mean endotoxin content SEM 97 22 EU/ml) and ultrapure bicarbonate dialysate (UPBD, sterile and pyrogenfree, obtained by ultrafiltration through polyamide) on several aspects of the inflammatory reaction during in Vitro HD. The HD sessions (7 in each experimental group) were performed using miniaturized new cuprophane (CU) and polyacrylonitrile (PAN) hollow fiber dialyzers, and closed dialysate and blood circuits (the latter filled with heparinized blood from healthy donors). Plasma C3aDesarg levels were significantly increased after 15 minutes (ti) and increased further after three hours (t2) of CU HD, while during PAN dialysis they decreased from tO to ti and t2; however, no difference appeared between experiments with NSBD and UPBD. Granulocyte (PMN) and monocyte (MNC) expression of LFA-i, Mac-i, and CD45 at the start (tO), ti and t2 was quantitated by flow cytometry analysis, after staining of the cells with specific fluorescinated monoclonal antibodies. In contrast with published data of in vivo HD, LFA-i was overexpressed at ti and peaked at t2, which suggests that the leukocytes expressing more LFA-1 leave the systemic circulation during in vivo HD. During CU HD, Mac-I and CD45 on PMN and MNC were significantly increased at tI, and still more at t2. During PAN HD, Mac-i and CD45 remained unchanged at ti, but increased significantly at t2 on PMN as on MNC. Again, no significant difference was found between NSBD and UPBD in LFA-I, Mac-i and CD45 expression on PMN and MNC, during both CU and PAN HD. After three hours of dialysis, plasma levels of TNF-a, but not of IL-6, were significantly increased with CU and PAN. Again, no difference appeared when NSBD and UPBD were compared. Moreover, the lack of influence of bacterial contamination of the dialysate on TNF-a production was confirmed when MNC were cultured up to 24 hours after the end of the HD session. We conclude that complement activation products, either in plasma (CU) or those adsorbed on the HD membrane (CU and PAN) play the major role in the overexpression of 132-integrins and CD45 by PMN and MNC during HD. Also, bacterial products (at the levels that can be found in clinical conditions) do not influence either /32-integrin overexpression or TNF-a production induced by the dialysis membrane.
Filtration of Dialysate Using An On-Line Dialysate Filter
The International Journal of Artificial Organs, 1991
Increased concerns about pyrogenic contamination of dialysate have led to the development of an on-line dialysate filtration system. Bacteriological testing of the system was performed (n=6) by introducing bicarbonate concentrate contaminated with E. coli 026:B 6 (3x109 cfu/ml) into a dialysis machine equipped with a two-stage polysulfone filtration system. The bacterial concentration of the dialysate entering the filtration system was maintained above 106 cfu/ml and endotoxin levels ranged from 30-300 ng/ml during the 3-hour test period. Bacterial and endotoxin levels on the input side of the first-stage filter reached minimum concentrations of 5.4x109 cfu/ml and 30,000 ng/ml respectively. All output samples of filtered dialysate showed no bacterial growth and endotoxin levels were below the sensitivity (0.003 ng/ml) of the LAL assay. A dialysis machine (QD = 500), equipped with a single stage filtration system, was used for 18 months of clinical testing. In order to evaluate the s...
Cytokine profiles during clinical high-flux dialysis
Journal of the American Society of Nephrology, 1997
Secretion of cytokines by monocytes has been implicated in the pathogenesis of dialysis-related morbidity. Cytokine generation is presumed to take place in two steps: induction of mRNA transcription for cytokines by C5a and direct membrane contact, followed by lipopolysaccharide (LPS)-induced translation of mRNA (priming/second signal theory, Kidney Int 37: 85-93, 1990). However, the in vitro conditions on which this theory was based differed markedly from clinical dialysis. To test this postulate for routine hemodialysis, 13 patients were studied cross-over with high-flux cuprammonium (CU), cellulose triacetate (CTA), and polysulfon dialyzers, using standard bicarbonate dialysate, as well as CTA with filtered dialysate (fCTA). Besides leukocytes, C3a, C5a, and limulus amebocyte lysate reactivity, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-6, IL-1RA, soluble TNF receptors, and IL-1 beta mRNA were assessed. Only during dialysis with CU did C5a increase significant...
Lipopolysaccharide Concentrations During Superflux Dialysis Using Unfiltered Bicarbonate Dialysate
ASAIO Journal, 2002
In the present report, the design of a new dialysate delivery system to produce low to moderately contaminated dialysate is described. In addition, the first data on bacterial counts and lipopolysaccharide (LPS) concentrations in both the dialysate and the blood during hemodialysis (HD) with superflux dialyzers are presented. In this prospective study, 37 patients were randomized into two consecutive periods of 12 weeks to HD with a high flux polysulfon (PS), a superflux PS, a superflux cellulosic tri-acetate (CTA) or a superflux CTA dialyzer with filtered dialysate (CTA f), resulting in 74 periods in which measurements were obtained. Filtered dialysate showed significantly lower bacterial counts, if compared with nonfiltered dialysate (p < 0.001). As for LPS, marked differences were not observed between filtered and nonfiltered dialysate, whereas mean plasma LPS concentrations were below the value of the dialysate at all time points (p < 0.001). Plasma LPS concentrations decreased significantly during HD with all four modalities (F 60: t 0 0.032 ؎ 0.005, t 180 0.026 ؎ 0.009 endotoxin units (EU)/ml, p ؍ 0.001; F 500S, t 0 0.031 ؎ 0.004, t 180 0.027 ؎ 0.005 EU/ml, p ؍ 0.001; Tricea 150G: t 0 0.032 ؎ 0.004, t 180 0.025 ؎ 0.005 EU/ml, p < 0.001; and Tricea 150G f : t 0 0.034 ؎ 0.007, t 180 0.025 ؎ 0.006 EU/ml, p < 0.001). During HD with highly permeable dialyzers and moderately contaminated dialysate, plasma LPS concentrations decreased significantly, irrespective of the material used (PS or CTA), the flux characteristics of the devices (high flux or superflux), or the presence of a bacterial filter.
Comparison of techniques for culture of dialysis water and fluid
Introduction Microbiological culture of dialysis water and fluid is a routine safety measure. In the United States (U.S.), laboratories perform these cultures on trypticase soy agar at 35–378C for 48 h (TSA-48h), not on the tryptone glucose extract agar or Reasoner's 2A agar at 17–238C for 7 days (TGEA-7d and R2A-7d, respectively) recommended by international standards. We compared culture methods to identify samples exceeding the accepted action level of 50 CFU/mL. Methods Dialysis water and fluid samples collected from 41 U.S. dialysis programs between 2011 and 2014 were cultured at two U.S. laboratories. Each sample was cultured using (1) either TGEA-7d or R2A-7d and (2) TSA-48h. We compared proportions exceeding the action level by different methods and test characteristics of TSA-48h to those of TGEA-7d and R2A-7d. Findings The proportion of water samples yielding colony counts 50 CFU/mL by TGEA-7d was significantly different from the proportion by TSA-48h (P 5 0.001; difference in proportion 4.3% [95%CI 1.3–7.3%]). The proportions of dialysis fluid samples 50 CFU/mL by TGEA-7d and TSA-48h were not significantly different; there were no significant differences for comparisons of R2A-7d to TSA-48h. Discussion In dialysis fluid, TSA-48h was comparable to TGEA-7d and R2A-7d in identifying samples as having bacterial counts 50 CFU/mL. In dialysis water, TSA-48h was comparable to R2A-7d in identifying samples 50 CFU/mL, but TGEA-7d did yield significantly more results above 50 CFU/mL. Nonetheless, the negative predictive value of a TSA-48h result of <50 CFU/mL in dialysis water exceeded 95%.
Journal of the American Society of Nephrology, 1992
High-efficiency (HE) and high-flux (HF) hemodialysis are becoming increasingly popular methods for treating patients with chronic renal failure because they reduce the time required for dialysis treatment. HF and HE dialyzers require bicarbonate dialysate, often prepared from concentrates that can support bacterial growth with endotoxin production. There is a concern that endotoxins or bacteria may cross or interact at the membranes of these dialyzers, triggering the release of endogenous pyrogens (cytokines) by peripheral blood mononuclear cells to cause pyrogenic reactions (PR). To determine the incidence of PR and to examine the association between PR and levels of bacteria and endotoxin in dialysate, a cohort of patients receiving conventional, HE, or HF hemodialysis with bicarbonate dialysate and reprocessed dialyzers at three dialysis centers during a 12-month period was studied prospectively. All dialyzers underwent a test of membrane integrity before use. A total of 19 PR we...
Long Term Analysis Changes of 35 Biochemical and Biolelecrical Parameters in a Dialytic Population
ASAIO Journal, 2001
H3GlY6, Canada administration of genetically engineered cells can lower urea, uric acid, and creatinine in uremic rats. The present study is to see whether this can lower K+, P, el-, and P in uremic rats. B) Methods used: Genetically engineered E. coli DH5 cells are encapsulated in artificial cells. The efficacy for the removal of electrolytes was analyzed in-vitro in batch bioreactors and in-vivo in daily oral administration to partially nephrectomized male Wistar rats. C) Results summary: In-vitro: Significant lowering of plasma K' , P, Na' , and CI-occurs in in-vitro experiments in batch bioreactors. In-vivo experiments in uremic rats show that oral administration also resulted in lowering of plasma electrolytes levels. For example, plasma K+ decreases from 5.66 +I. 15 (mmol/L) to 4.23 0.90 (mmol/L), plasma P from 2.44 2 0.56 (mmol/L) to 1.54 5 0.59 (mmoVL), plasmaNa+ 1462 6.30 (mmol/L) to 13 1.20+ 8.60 (mmol/L), plasma Cf from 206.00 5 49.70 (mmol/L) to 101.00 5 15.00 (mmol/L), and alkaline phosphatase from 212.33 5 63.21 (dl) to 87.66 24.54 (dl). On discontinuation of the therapy, electrolyte levels increased again. Ref.: www.artcell.mcgill.ca A) Purpose of study: We have shown earlier that oral Mean Arterial Blood Pressures during Extended Daily Dialysis (EDD) vs. Intermittent Hemodialysis in Intensive Care Unit (ICU) Patients.
Nephrology Dialysis Transplantation, 2008
Background. Biological purity of dialysis water is considered as one of the primary conditions to deliver optimal haemodialysis. Methods. The present study explores the added value of a novel cytokine (IL-1ß) induction assay, using a monocytic THP-1 cell line, compared to the classical detection methods for microbial dialysis fluid contaminants. Results. In contrast to the Limulus Amebocyte Lysate (LAL)-test, which only detects intact lipopolysaccharide (LPS), the THP-1 assay was also sensitive to peptidoglycan, short bacterial DNA fragments and LPS fragments <5 kD. The purity of 269 dialysis fluid samples was tested by the THP-1 assay and compared to the LAL-test. Two hundred and sixty samples complied with the definition of 'pure' dialysis fluid as laid down in the European Pharmacopeia (European Best Practice Guidelines for Hemodialysis. Section IV. Dialysis fluid purity. Nephrol Dial Transplant 2002; 17: 45-62) but 27 of these so-called pure dialysates (10.3%) provoked a pro-inflammatory response in the THP-1 assay. Furthermore, among the 230 samples that complied the definition of an ultrapure dialysis fluid, 21 samples (9.1%) were pro-inflammatory. These data illustrate that this novel bio-assay detects microbiological entities with an inflammatory potential that cannot be found by the classical LAL screening method. Conclusions. Adding this novel THP-1 assay to the classical methods will be helpful in the prevention of biofilm formation in the delivery system and should have relevance by more accurate detection of dialysate contamination, hence decreasing micro-inflammation in the haemodialysis patient.
Bacteria- and Endotoxin-Free Dialysis Fluid for Use in Chronic Hemodialysis
Artificial Organs, 1994
As the quality of water in the dialysis fluid varies considerably, dialysis fluid is contaminated with a high percentage of bacteria and endotoxins. The bacterial populations contained in the dialysis fluid are as heterogeneous as the chemical structure of the endotoxins that result. The latter can pass through the dialysis membrane whereby high-flux membranes permit a larger number of retransportable molecules than low-flux membranes. A central aim toward a future, safe dialysis process should, therefore, be the production of a dialysate that is free of bacteria and endotoxins. As we were able to demonstrate