Prevalence and genotype distribution of hepatitis C virus within hemodialysis units in Thailand: role of HCV core antigen in the assessment of viremia.

BACKGROUND: Individuals with end-stage renal disease have a higher risk of hepatitis C virus (HCV) acquisition during long-term hemodialysis (HD). Our report was designed to investigate HCV prevalence and genotype, in addition to the clinical use of HCV core antigen (HCVcAg), within multiple HD facilities in Thailand. METHODS: This cross-sectional report was investigated between January and June 2019. HCV infection was assessed by anti-HCV and confirmed active infection by measuring HCV RNA and HCVcAg. HCV genotype was determined by phylogenetic analysis using nucleotide sequences of NS5B region. RESULTS: Overall, 140 of 3,305 (4.2%) patients in 15 dialysis centers had anti-HCV positive. Among them, HCV RNA was further assessed in 93 patients and was detectable in 59 (63.4%) persons. Considering HCV viremia, HCVcAg measurement exhibited high accuracy (96.8%), sensitivity (94.9%) and specificity (100%) in comparison with HCV RNA testing. Moreover, individuals infected with HCV received a longer duration of dialysis vintage when compared to anti-HCV negative controls. The major sub-genotypes were 1a, 1b, 3a, 3b, 6f and 6n. Regarding phylogenetic analysis, there were 7 clusters of isolates with high sequence homology affecting 17 individuals, indicating possible HCV transmission within the same HD centers. CONCLUSIONS: HCV frequency and common sub-genotypes in HD centers were different from those found in the Thai general population. HCVcAg might be an alternate testing for viremia within resource-limited countries. Enhanced preventive practices, dialyzer reuse policy and better access to antiviral therapy are crucial for HCV micro-elimination within HD facilities.

Toxicological risk assessment of bisphenol a released from dialyzers under simulated-use and exaggerated extraction conditions.

Bisphenol A (BPA) belongs to a group of chemicals used in the production of polycarbonate, polysulfone, and polyethersulfone which are used, among other applications, in the manufacture of dialyzers. While exposure to BPA is widespread in the general population, dialysis patients represent a population with potentially chronic parenteral BPA exposures. To assess the potential risk of BPA exposure to dialysis patients through dialyzer use, exposure estimates were calculated based on BPA levels measured by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry following extractions from dialyzers manufactured by Fresenius Medical Care. Extraction conditions included both simulated-use leaching and exaggerated extractions to evaluate possible leachable and extractable BPA, respectively, from the devices. The mean BPA concentrations were 3.6 and 108.9 ppb from simulated-use and exaggerated extractions, respectively, from polycarbonate-containing dialyzers. No BPA was detected from polypropylene-containing dialyzers. Margins of Safety (MOS) were calculated to evaluate the level of risk to patients from estimated BPA exposure from the dialyzers, and the resulting MOS were 229 and 45 for simulated-use and exaggerated extractions, respectively. The findings suggest that there is an acceptable level of toxicological risk to dialysis patients exposed to BPA from use of the dialyzers tested in the current study.

Evaluation of the influence of the surface membrane and blood flow in medium «cut-off¼ (MCO) dialyzers. / Valoración de la influencia de la superficie de la membrana y el flujo sanguíneo en dializadores de medio cut-off.

INTRODUCTION: Recently, a new class of dialyzers, medium cut-off membranes (MCO), designed to improve the permeability, which could provide an efficacy similar to hemodiafiltration, have been incorporated into our therapeutic possibilities. To increase the knowledge about its use, the objective of the study was to evaluate the effect of the surface and blood flow (Qb) on the depurative efficacy in the MCO membranes. MATERIAL AND METHODS: We included 19 patients in the hemodialysis. Each patient received 6 sessions, in which the membrane surface was varied, from 1.7 to 2.0 m2, and/or the Qb (300, 350, 400 or 450mL/min). In each session, different solutes were determined at the beginning and end of dialysis. RESULTS: The surface change of the dialyzer did not show significant differences in the removal of small or large molecules, without changes in albumin loss. The increase in Qb was accompanied by an increase in clearance of small molecules, without showing differences in the percentage reduction of ß2-microglobulin, myoglobin, prolactin, α1-microglobulin and α1-acid glycoprotein, except for some comparison with Qb 450mL/min. There were also no differences in the loss of albumin in the dialysis fluid, less than 2.5 g in all situations. CONCLUSION: The increase of the surface area from 1.7 to 2.0 m2 in the MCO dialyzer has not meant a greater depurative effectiveness. In these dialyzers the increase of Qb does not seem to be as determinant as in hemodiafiltration except for the clearance of small molecules.

Reusing dialyzer in low income countries: A good cost saving tactic with complex ethics.

Despite almost universal practice of dialyzer reuse from the earliest days of haemodialysis, reusing dialyzer always remains a controversial issue and several ethical concerns have been raised. Some of the important are safety of reuse over single use, informed consent of the patient, conflict of interest on the part of physician or manufacturer, fiscal responsibility and environmental stewardship. Indeed, at the beginning of this century, there was a drastic shift of practice in favour of single use in developed countries due to availability of biocompatible haemodialyzers, at favourable price. Despite this mega shift, dialyzer reuse is still widely practised in low-income countries. Considering cost inflation and limited medical resources in such countries, dialyzer reuse may be justified as a cost-saving strategy for this part of world. However, it poses the same ethical questions to us which were a matter of debate for the western world in the 1980s and 1990s. This review of literature was planned to revisit and highlight these concerns.

Home hemodialysis: infrastructure, water, and machines in the home.

We describe the infrastructure that is necessary for hemodialysis in the home focusing on physical requirements, the organization of plumbing and water, and the key features that should guide the selection of machines that are suitable for home use.