Diminishing Immune Responses against Variants of Concern in Dialysis Patients 4 Months after SARS-CoV-2 mRNA Vaccination.

Patients undergoing chronic hemodialysis were among the first to receive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinations because of their increased risk for severe coronavirus disease and high case-fatality rates. By using a previously reported cohort from Germany of at-risk hemodialysis patients and healthy donors, where antibody responses were examined 3 weeks after the second vaccination, we assessed systemic cellular and humoral immune responses in serum and saliva 4 months after vaccination with the Pfizer-BioNTech BNT162b2 vaccine using an interferon-γ release assay and multiplex-based IgG measurements. We further compared neutralization capacity of vaccination-induced IgG against 4 SARS-CoV-2 variants of concern (Alpha, Beta, Gamma, and Delta) by angiotensin-converting enzyme 2 receptor-binding domain competition assay. Sixteen weeks after second vaccination, compared with 3 weeks after, cellular and humoral responses against the original SARS-CoV-2 isolate and variants of concern were substantially reduced. Some dialysis patients even had no detectable B- or T-cell responses.

Chronic kidney disease progression and mortality risk profiles in Germany: results from the Chronic Kidney Disease Outcomes and Practice Patterns Study.

BACKGROUND: Chronic kidney disease (CKD) progression among German patients in a representative setting has not been described previously. The Verband Deutsche Nierenzentren and Chronic Kidney Disease Outcomes and Practice Patterns Study established a longitudinal observational cohort among German CKD patients to research variations in patient care and outcomes in real-world nephrology practices. METHODS: A cohort of CKD Stages 3 (25%) and 4 (75%) patients was established from German nephrologist-run CKD clinics in 2013-16. Linear models were used to determine the estimated glomerular filtration rate (eGFR) slope during follow-up and Cox models were used to assess outcomes of end-stage kidney disease (ESKD) and death. RESULTS: A total of 1834 patients (median age 75 years, 58% male, 42% diabetics, median baseline eGFR 25 mL/min/1.73 m2) were followed for a median of 29 months. More than 50% had slow or no decline and 17% declined ≥5 mL/min/1.73 m2/year. After 4.5 years, the incidence of ESKD was 8% and of deaths without ESKD 16% among patients with eGFR ≥30 mL/min/1.73 m2 and 37% and 19% for eGFR <30 mL/min/1.73 m2. Adjusted models showed higher risks of ESKD or death for patients with worse kidney function at baseline, male sex, diabetes and higher blood pressure; a higher risk of ESKD with higher albuminuria; and a higher risk of death with older age or cardiovascular comorbidity. CONCLUSIONS: Routine nephrology care of patients in Germany comprises mostly elderly patients, many with slow CKD progression. Identification of risk factors for CKD progression and mortality may help guide resources by closer follow-up of high-risk patients.

Results from a safety cohort of patients with renal anemia receiving the biosimilar epoetinzeta: The PASCO I study.

BACKGROUND: Epoetin-zeta (epoetin-ζ) (sold as Retacrit™/Silapo™) is a biologic product that was approved by the European Medicines Agency in 2007 after demonstrating biosimilarity to its reference product epoetin-α (Eprex™), based on a comprehensive comparability exercise including extensive biophysical characterization and three double-blind randomized controlled trials. Since 2008, epoetin-ζ has been prescribed by physicians across Europe to treat anemia of renal disease in many thousands of patients. METHODS: Provided here are results of the PASCO I study (post-authorization safety cohort observation of silapo/retacrit (epoetin-ζ) administered intravenously for the treatment of renal anemia). The primary study endpoint was the frequency of adverse events of special interest (AESI) occurring in patients receiving epoetin-ζ over a 1-year study observation period. RESULTS: The safety set included 1,634 patients who received at least 1 dose of epoetin-ζ during the study period. These patients experienced AESI at these frequencies: clotting of artificial kidney 9.8%, lack of efficacy 2.3%, cerebrovascular events (including cerebrovascular accident, cerebral infarction, cerebral hemorrhage, and transient ischemic attack) 1.8%, myocardial infarction 1.7%, acute myocardial infarction 1.2%, clinically relevant hyperkalemia 0.4%, deep vein thrombosis 0.2%, convulsion 0.2%, hypertensive encephalopathy 0.1%, and pulmonary embolism 0.1%. No patients were reported as having anaphylactoid reactions, angioedema, erythropoietinneutralizing antibodies, or pure red cell aplasia. The median weekly follow-up dose of epoetin-ζ was 158.6 IU/kg. Mean hemoglobin concentration ranged between 11.3 and 11.7 g/dL. From the safety set, 228 patients died (14.0%), while 1,135 patients (74.9%; excluding 119 with data missing) continued treatment with epoetin-ζ following the 12-month observation. CONCLUSION: The PASCO I study contributes significantly to current knowledge about the frequency of adverse events associated with the use of epoetin-ζ for the treatment of renal anemia and demonstrates a pattern of adverse events comparable with data for other existing epoetin products in Europe.

Implementation and first results of a German chronic kidney disease registry.

Advanced chronic kidney disease (CKD) is gaining increasing medical and economical importance, but little information exists about treatment variation and the impact of routine clinical treatments on survival, quality of life, and cost. We demonstrate the first results of a national electronic registry of nephrology clinic data that will serve as a resource for the prospective observation of CKD patients in Germany. A large network of German nephrologist practices is currently joining the project. Routinely obtained clinical data for non-dialysis dependent CKD patients are documented in health records electronically, and elements from these data are extracted using QuaNT (Qualitätssicherung Nephrologie und Transplantation) to create a centralized database. Here, we report cross-sectional data from 59 participating nephrology clinics and 6,187 patients with CKD Stage 3 - 5 in 2011. Mean age ± standard deviation (SD) was 72 ± 12 years. The distribution of CKD 3, 4, and 5 (non-dialysis) was 60%, 33%, and 8%, respectively. The major renal diseases were hypertension/vascular nephropathy (47%) and diabetic nephropathy (26%). Reninangiotensin-system inhibitor prescription was 78%. Vitamin D prescription was 50%, phosphate binders 6%, iron (oral or i.v.) 19%, and erythropoietin-stimulating agents 14%. This electronic registry follows clinical nephrology care and outcomes for CKD patients in Germany, and increased participation is anticipated. As a component of the initiative, variation in patient care will be studied to identify best treatment practices in analyses integrated into the international CKD Outcomes and Practice Patterns Study (CKDopps).

Reimbursement of dialysis: a comparison of seven countries.

Reimbursement for chronic dialysis consumes a substantial portion of healthcare costs for a relatively small proportion of the total population. Each country has a unique reimbursement system that attempts to control rising costs. Thus, comparing the reimbursement systems between countries might be helpful to find solutions to minimize costs to society without jeopardizing quality of treatment and outcomes. We conducted a survey of seven countries to compare crude reimbursement for various dialysis modalities and evaluated additional factors, such as inclusion of drugs or physician payments in the reimbursement package, adjustment in rates for specific patient subgroups, and pay for performance therapeutic thresholds. The comparison examines the United States, the province of Ontario in Canada, and five European countries (Belgium, France, Germany, The Netherlands, and the United Kingdom). Important differences between countries exist, resulting in as much as a 3.3-fold difference between highest and lowest reimbursement rates for chronic hemodialysis. Differences persist even when our data were adjusted for per capita gross domestic product. Reimbursement for peritoneal dialysis is lower in most countries except Germany and the United States. The United Kingdom is the only country that has implemented an incentive if patients use an arteriovenous fistula. Although home hemodialysis (prolonged or daily dialysis) allows greater flexibility and better patient outcomes, reimbursement is only incentivized in The Netherlands. Unfortunately, it is not yet clear that such differences save money or improve quality of care. Future research should focus on directly testing both outcomes.

Longitudinal cellular and humoral immune responses after triple BNT162b2 and fourth full-dose mRNA-1273 vaccination in haemodialysis patients.

Haemodialysis patients respond poorly to vaccination and continue to be at-risk for severe COVID-19. Therefore, dialysis patients were among the first for which a fourth COVID-19 vaccination was recommended. However, targeted information on how to best maintain immune protection after SARS-CoV-2 vaccinations in at-risk groups for severe COVID-19 remains limited. We provide, to the best of our knowledge, for the first time longitudinal vaccination response data in dialysis patients and controls after a triple BNT162b2 vaccination and in the latter after a subsequent fourth full-dose of mRNA-1273. We analysed systemic and mucosal humoral IgG responses against the receptor-binding domain (RBD) and ACE2-binding inhibition towards variants of concern including Omicron and Delta with multiplex-based immunoassays. In addition, we assessed Spike S1-specific T-cell responses by interferon γ release assay. After triple BNT162b2 vaccination, anti-RBD B.1 IgG and ACE2 binding inhibition reached peak levels in dialysis patients, but remained inferior compared to controls. Whilst we detected B.1-specific ACE2 binding inhibition in 84% of dialysis patients after three BNT162b2 doses, binding inhibition towards the Omicron variant was only detectable in 38% of samples and declining to 16% before the fourth vaccination. By using mRNA-1273 as fourth dose, humoral immunity against all SARS-CoV-2 variants tested was strongly augmented with 80% of dialysis patients having Omicron-specific ACE2 binding inhibition. Modest declines in T-cell responses in dialysis patients and controls after the second vaccination were restored by the third BNT162b2 dose and significantly increased by the fourth vaccination. Our data support current advice for a four-dose COVID-19 immunisation scheme for at-risk individuals such as haemodialysis patients. We conclude that administration of a fourth full-dose of mRNA-1273 as part of a mixed mRNA vaccination scheme to boost immunity and to prevent severe COVID-19 could also be beneficial in other immune impaired individuals. Additionally, strategic application of such mixed vaccine regimens may be an immediate response against SARS-CoV-2 variants with increased immune evasion potential.

Cellular and humoral immunogenicity of a SARS-CoV-2 mRNA vaccine in patients on haemodialysis.

BACKGROUND: Patients with chronic renal insufficiency on maintenance haemodialysis face an increased risk of COVID-19 induced mortality and impaired vaccine responses. To date, only a few studies have addressed SARS-CoV-2 vaccine elicited immunity in this immunocompromised population. METHODS: We assessed immunogenicity of the mRNA vaccine BNT162b2 in at-risk dialysis patients and characterised systemic cellular and humoral immune responses in serum and saliva using interferon γ release assay and multiplex-based cytokine and immunoglobulin measurements. We further compared binding capacity and neutralization efficacy of vaccination-induced immunoglobulins against emerging SARS-CoV-2 variants Alpha, Beta, Epsilon and Cluster 5 by ACE2-RBD competition assay. FINDINGS: Patients on maintenance haemodialysis exhibit detectable but variable cellular and humoral immune responses against SARS-CoV-2 and variants of concern after a two-dose regimen of BNT162b2. Although vaccination-induced immunoglobulins were detectable in saliva and plasma, both anti-SARS-CoV-2 IgG and neutralization efficacy was reduced compared to a vaccinated non-dialysed control population. Similarly, T-cell mediated interferon γ release after stimulation with SARS-CoV-2 spike peptides was significantly diminished. INTERPRETATION: Quantifiable humoral and cellular immune responses after BNT162b2 vaccination in individuals on maintenance haemodialysis are encouraging, but urge for longitudinal follow-up to assess longevity of immunity. Diminished virus neutralization and interferon γ responses in the face of emerging variants of concern may favour this at-risk population for re-vaccination using modified vaccines at the earliest opportunity. FUNDING: Initiative and Networking Fund of the Helmholtz Association of German Research Centres, EU Horizon 2020 research and innovation program, State Ministry of Baden-Württemberg for Economic Affairs, Labour and Tourism.

Timely Referral to Outpatient Nephrology Care Slows Progression and Reduces Treatment Costs of Chronic Kidney Diseases.

INTRODUCTION: We present a new approach to evaluate the importance of ambulatory nephrology care in patients with chronic kidney disease (CKD). METHODS: An anonymized health claims database of German insurance companies was searched in a retrospective analysis for patients with CKD using the codes of the International Classification of Diseases, 10th German modification. A total of 105,219 patients with CKD were identified. Patients were assigned to the group "timely referral," when nephrology care was present in the starting year 2009, or initiated during the following 3 years in CKD1-4. Using frequency matching for age and gender, 21,024 of the late referral group were matched with the equal number of patients in the timely referral group. Hospital admission rates, total treatment costs, and kidney function (change in CKD stages, start of dialysis, mortality) were documented each year during the 4-year follow-up. RESULTS: Hospital admission rates (110%-186%) and total treatment costs (119%-160%) were significantly higher (P < 0.03) in late referral compared with timely referral. In the timely referral group, significantly more patients did not change their CKD stage (65%-72.9% vs. 52%-64.6%, P < 0.05) compared with late referral. Starting in CKD3 more patients tended to start dialysis in 1 year in timely referral (1.9 ± 0.6 vs. 1.0 ± 0.4, P = 0.1). In contrast, death rates were significantly higher in the late referral group (18.8 ± 1.8% vs. 6.7 ± 0.4%, P = 0.0001). DISCUSSION: Timely referral to outpatient nephrology care is associated with slowed disease progression, less hospital admissions, reduced total treatment costs, and improved survival in patients with CKD.

When good water goes bad: how it happens, clinical consequences and possible solutions.

Dialysis fluid produced by state-of-the-art water preparation and distribution is contaminated with gram-negative bacteria and cytokine-inducing substances (CIS) derived from these microorganisms. The presence of a biofilm increases the risk of continuous contamination of dialysis fluid. Depending on the type of dialyzer membrane (cellulosic vs. synthetic) and the mode of dialysis (low flux vs. high flux with backfiltration), CIS may penetrate intact dialyzer membranes, induce cytokine production in the patient's blood and contribute to chronic inflammation associated with long-term hemodialysis therapy. Measures to improve the microbiological quality of dialysis fluid are: (1) the awareness of the problem and regular testing of dialysate samples using adequate methods; (2) disinfection of the entire water preparation and distribution system on a regular basis, replacement of biofilm-containing tubings, and (3) installation of ultrafilters in the dialysate circuit in particular when high-flux hemodialysis modalities are performed.

Beta(2)-microglobulin amyloidosis: effects of ultrapure dialysate and type of dialyzer membrane.

The available data on the pathophysiology of beta(2)-microglobulin amyloidosis (beta(2)mA) suggest that this progressive disease associated with end-stage renal failure develops in several consecutive phases. First, declining kidney function leads to retention of beta(2) microglobulin (beta(2)m) and its deposition preferentially in the synovial tissue of bigger joints such as wrists, shoulders, and hips. Second, at the site of deposition, formation of unique amyloid fibrils, whose major component is beta(2)m, takes place. Deposition and fibril formation occur in the absence of modification of beta(2)mA by advanced glycoxidation end products and also in the absence of a local inflammatory response. It is later, in the third phase, that advanced glycoxidation end product modification of beta(2)m induces a local inflammatory response by attracting macrophages chemotactically and by stimulating these cells to produce and release proinflammatory cytokines. In addition, unmodified beta(2)m itself induces inflammatory activities such as upregulation of cyclooxygenase-2 and metalloproteinase-1. The severity of the local inflammation seems to determine the degree of the destructive processes in tissue and bone accompanying beta(2)mA.

Interleukin 18 and interleukin 18 binding protein: possible role in immunosuppression of chronic renal failure.

Although interleukin (IL)-18 is a member of the IL-1 family of ligands, IL-18 appears to have unique characteristics, particularly in the regulation of the T helper type 1 (Th1) response. Th1 responses are required for tumor surveillance, killing intracellular organisms, and to provide help for antibody production. In patients with chronic renal failure, the well-known immunosuppression contributes to a failure to respond to infectious challenges and vaccinations. The most salient biological property of IL-18, linking this cytokine to the Th1 response, is its ability to induce interferon gamma (IFN-gamma). In fact, IL-18 was originally identified as an IFN-gamma-inducing factor, and IFN-gamma production is the hallmark of the Th1 response. Dysregulation of IFN-gamma production resulting from reduced activity of IL-18 would explain one of the mechanisms of immunosuppression in patients with chronic renal failure. The activity of IL-18 can be regulated by the IL-18-binding protein (IL-18BP), a glycoprotein of 40,000 daltons, which is constitutively expressed and appears to be the natural inhibitor of IL-18 activity. Unlike soluble receptors for IL-18, IL-18BP does not have a transmembrane domain; IL-18BP is a secreted protein possessing a high-affinity binding and ability to neutralize IL-18. IL-18BP was discovered in human urine and is excreted in health following glomerular filtration. With decreasing renal function, the concentrations of IL-18BP in the circulation are elevated as compared with subjects with a normal renal function, and these elevated levels may result in a decreased IL-18 activity. Because of the importance of IL-18 and IFN-gamma in the Th1 response, the biology of IL-18 and IL-18BP is reviewed here in the context of the immunosuppression of chronic renal failure.

A switch to high-flux helixone membranes reverses suppressed interferon-gamma production in patients on low-flux dialysis.

UNLABELLED: Long-term hemodialysis (HD) induces an inflammatory response and is associated with a suppressed cellular immune response manifested, in part, by impaired interferon (IFN-gamma) production. We investigated the effect of high-flux HD using the synthetic Helixone membrane and ultrafiltered dialysate on plasma levels of inflammatory mediators and on the whole blood production of IFN-gamma. METHODS: Twelve ESRD patients were dialyzed under low-flux HD (polysulfone F6) and again after 6 weeks of high-flux HD (Helixone FX100). Ultrafiltered bicarbonate dialysate without bacterial growth and no detectable endotoxin was used throughout the study. Plasma levels of urea, albumin, beta(2)-microglobulin (beta(2)-m), interleukin (IL)-6, C-reactive protein (CRP), IL-1 receptor antagonist (IL-1Ra), IL-18, and IL-18-binding protein (IL-18BP) were measured. In addition, the Staphylococcus epidermidis-induced production of IFN-gamma and IL-18 was assessed in whole blood cultures of HD patients as well as in 9 healthy subjects. RESULTS: Plasma levels of urea, albumin, IL-6, IL-1Ra and CRP were not significantly different between high-flux and low-flux HD. In contrast, beta(2)-m levels decreased significantly by 31% with high-flux Helixone (p < 0.002). Stimulated whole blood production of IFN-gamma was reduced in low-flux HD but increased to near normal levels after 6 weeks of high-flux HD. Plasma levels of free IL-18 and its specific inhibitor IL-18BP were not different between the two dialyzer membranes. CONCLUSION: Compared to low-flux polysulfone HD with ultrafiltered dialysate, high-flux HD with the synthetic Helixone membrane did not result in a significant change in plasma levels of proinflammatory (IL-6, CRP, IL-18) and anti-inflammatory (IL-1Ra, IL-18BP) cytokines. However, high-flux HD restores whole blood IFN-gamma production without significant changes in free IL-18. Therefore, the immune modulation in high-flux HD is likely due to removal of inhibitors of IFN-gamma production other than IL-18BP.

A pilot study of coupled plasma filtration with adsorption in septic shock.

OBJECTIVE: To test the hypothesis that nonselective plasma adsorption by a hydrophobic resin (coupled plasmafiltration and adsorption) could improve hemodynamics and restore leukocyte responsiveness in patients with septic shock. DESIGN: Prospective, pilot, crossover clinical trial. SETTING: General intensive care unit in a teaching hospital. SUBJECTS: Ten patients with hyperdynamic septic shock. INTERVENTIONS: Patients were randomly allocated to 10 hrs of either coupled plasma filtration adsorption plus hemodialysis (treatment A) or continuous venovenous hemodiafiltration (treatment B) in random order. We measured the change in mean arterial pressure, norepinephrine requirements, and leukocyte tumor necrosis factor-alpha (TNF-alpha) production (both spontaneous and lipopolysaccharide-stimulated) after 10 hrs of each treatment. We also tested TNF-alpha production from normal human adherent monocytes incubated with patients' plasma obtained before and after the resin, both with or without incubation with an anti-interleukin-10 monoclonal antibody. RESULTS: Mean arterial pressure increased after 10 hr by 11.8 mm Hg with treatment A and by 5.5 mm Hg with treatment B (p =.001). There was an average decrease of norepinephrine requirement of 0.08 microg/kg/min with treatment A and 0.0049 microg/kg/min with treatment B (p =.003). All patients but one survived. Spontaneous and lipopolysaccharide-induced TNF-alpha production from patients' whole blood increased over time with treatment A. This increase was more marked in blood drawn after the device (plasmafiltrate-sorbent plus hemodialyzer) (p =.009). Preresin plasma suppressed lipopolysaccharide-stimulated production of TNF-alpha by 1 x 10(6)cultured adherent monocytes from healthy donors. This suppressive effect was significantly reduced after passage of plasma through the resin (p =.019) and after incubation with anti-interleukin-10 monoclonal antibodies (p =.028). CONCLUSIONS: In patients with septic shock, coupled plasmafiltration-adsorption combined with hemodialysis was associated with improved hemodynamics compared with continuous venovenous hemodiafiltration. This result might be related to its ability to restore leukocyte responsiveness to lipopolysaccharide. These findings suggest a potential role for blood purification in the treatment of septic shock.