Racial and Neighborhood-Level Disparities in COVID-19 Incidence among Patients on Hemodialysis in New York City.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has disproportionately affected socially disadvantaged populations. Whether disparities in COVID-19 incidence related to race/ethnicity and socioeconomic factors exist in the hemodialysis population is unknown. METHODS: Our study involved patients receiving in-center hemodialysis in New York City. We used a validated index of neighborhood social vulnerability, the Social Vulnerability Index (SVI), which comprises 15 census tract-level indicators organized into four themes: socioeconomic status, household composition and disability, minority status and language, and housing type and transportation. We examined the association of race/ethnicity and the SVI with symptomatic COVID-19 between March 1, 2020 and August 3, 2020. COVID-19 cases were ascertained using PCR testing. We performed multivariable logistic regression to adjust for demographics, individual-level social factors, dialysis-related medical history, and dialysis facility factors. RESULTS: Of the 1378 patients on hemodialysis in the study, 247 (17.9%) developed symptomatic COVID-19. In adjusted analyses, non-Hispanic Black and Hispanic patients had significantly increased odds of COVID-19 compared with non-Hispanic White patients. Census tract-level overall SVI, modeled continuously or in quintiles, was not associated with COVID-19 in unadjusted or adjusted analyses. Among non-Hispanic White patients, the socioeconomic status SVI theme, the minority status and language SVI theme, and housing crowding were significantly associated with COVID-19 in unadjusted analyses. CONCLUSIONS: Among patients on hemodialysis in New York City, there were substantial racial/ethnic disparities in COVID-19 incidence not explained by neighborhood-level social vulnerability. Neighborhood-level socioeconomic status, minority status and language, and housing crowding were positively associated with acquiring COVID-19 among non-Hispanic Whites. Our findings suggest that socially vulnerable patients on dialysis face disparate COVID-19-related exposures, requiring targeted risk-mitigation strategies.

Conflict Nephrology: War and Natural Disasters.

Access to care for patients with ESKD is frequently disrupted after natural disasters, public health crises, and human conflict. Emergency preparation can mitigate the risk of harm and improve outcomes. Before Hurricane Katrina in 2005, the United States was unprepared to assist patients facing disaster. We evaluate responses to Hurricane Katrina which caused unprecedented damage to health and property in the Gulf Coast. As a result of the multitude of identified problems with the national, local, and kidney-specific responses to Katrina, new systems were created that mitigated loss after Hurricane Sandy in 2012. The improved disaster response system was no match for the coronavirus disease 2019 pandemic; real-time changes worsened the effect on highly vulnerable populations, including patients with ESKD. Similarly, preparation can only mitigate the difficulties faced by patients with ESKD living in a war zone. Government agencies need to provide tools and dialysis centers need to educate patients. Beginning with steps implemented in the aftermath of Hurricane Katrina and augmented after Hurricane Sandy, every patient with ESKD and those who care for them must begin emergency preparations before the need arises. Recognizing that it is not possible to prepare for every possible emergency, our health care systems must be ready to adapt to our ever-changing world. After reviewing the responses to previous events, we suggest steps that should be considered to improve preparations for our uncertain future.

A Distinct Nasal Microbiota Signature in Peritoneal Dialysis Patients.

Rationale & Objective: The nasal passages harbor both commensal and pathogenic bacteria. In this study, we sought to characterize the anterior nasal microbiota in PD patients using 16S rRNA gene sequencing. Study Design: Cross-sectional. Setting & Participants: We recruited 32 PD patients, 37 kidney transplant (KTx) recipients, 22 living donor/healthy control (HC) participants and collected anterior nasal swabs at a single point in time. Predictors: We performed 16S rRNA gene sequencing of the V4-V5 hypervariable region to determine the nasal microbiota. Outcomes: Nasal microbiota profiles were determined at the genus level as well as the amplicon sequencing variant level. Analytical Approach: We compared nasal abundance of common genera among the 3 groups using Wilcoxon rank sum testing with Benjamini-Hochberg adjustment. DESeq2 was also utilized to compare the groups at the ASV levels. Results: In the entire cohort, the most abundant genera in the nasal microbiota included: Staphylococcus, Corynebacterium, Streptococcus , and Anaerococcus . Correlational analyses revealed a significant inverse relationship between the nasal abundance of Staphylococcus and that of Corynebacterium . PD patients have a higher nasal abundance of Streptococcus than KTx recipients and HC participants. PD patients have a more diverse representation of Staphylococcus and Streptococcus than KTx recipients and HC participants. PD patients who concurrently have or who developed future Staphylococcus peritonitis had a numerically higher nasal abundance of Staphylococcus than PD patients who did not develop Staphylococcus peritonitis. Limitations: 16S RNA gene sequencing provides taxonomic information to the genus level. Conclusions: We find a distinct nasal microbiota signature in PD patients compared to KTx recipients and HC participants. Given the potential relationship between the nasal pathogenic bacteria and infectious complications, further studies are needed to define the nasal microbiota associated with these infectious complications and to conduct studies on the manipulation of the nasal microbiota to prevent such complications.

Changes in Bone Quality after Treatment with Etelcalcetide.

INTRODUCTION: Secondary hyperparathyroidism is associated with osteoporosis and fractures. Etelcalcetide is an intravenous calcimimetic for the control of hyperparathyroidism in patients on hemodialysis. Effects of etelcalcetide on the skeleton are unknown. METHODS: In a single-arm, open-label, 36-week prospective trial, we hypothesized that etelcalcetide improves bone quality and strength without damaging bone-tissue quality. Participants were 18 years or older, on hemodialysis ≥1 year, without calcimimetic exposure within 12 weeks of enrollment. We measured pretreatment and post-treatment areal bone mineral density by dual-energy X-ray absorptiometry, central skeleton trabecular microarchitecture by trabecular bone score, and peripheral skeleton volumetric bone density, geometry, microarchitecture, and estimated strength by high-resolution peripheral quantitative computed tomography. Bone-tissue quality was assessed using quadruple-label bone biopsy in a subset of patients. Paired t tests were used in our analysis. RESULTS: Twenty-two participants were enrolled; 13 completed follow-up (mean±SD age 51±14 years, 53% male, and 15% White). Five underwent bone biopsy (mean±SD age 52±16 years and 80% female). Over 36 weeks, parathyroid hormone levels declined 67%±9% ( P < 0.001); areal bone mineral density at the spine, femoral neck, and total hip increased 3%±1%, 7%±2%, and 3%±1%, respectively ( P < 0.05); spine trabecular bone score increased 10%±2% ( P < 0.001); and radius stiffness and failure load trended to a 7%±4% ( P = 0.05) and 6%±4% increase ( P = 0.06), respectively. Bone biopsy demonstrated a decreased bone formation rate (mean difference -25±4 µ m 3 / µ m 2 per year; P < 0.01). CONCLUSIONS: Treatment with etelcalcetide for 36 weeks was associated with improvements in central skeleton areal bone mineral density and trabecular quality and lowered bone turnover without affecting bone material properties. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: The Effect of Etelcalcetide on CKD-MBD (Parsabiv-MBD), NCT03960437.

Peritoneal Effluent Cell-Free DNA Sequencing in Peritoneal Dialysis Patients With and Without Peritonitis.

RATIONALE & OBJECTIVE: Conventional culture can be insensitive for the detection of rare infections and for the detection of common infections in the setting of recent antibiotic usage. Patients receiving peritoneal dialysis (PD) with suspected peritonitis have a significant proportion of negative conventional cultures. This study examines the utility of metagenomic sequencing of peritoneal effluent cell-free DNA (cfDNA) for evaluating the peritoneal effluent in PD patients with and without peritonitis. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: We prospectively characterized cfDNA in 68 peritoneal effluent samples obtained from 33 patients receiving PD at a single center from September 2016 to July 2018. OUTCOMES: Peritoneal effluent, microbial, and human cfDNA characteristics were evaluated in culture-confirmed peritonitis and culture-negative peritonitis. ANALYTICAL APPROACH: Descriptive statistics were analyzed and microbial cfDNA was detected in culture-confirmed peritonitis and culture-negative peritonitis. RESULTS: Metagenomic sequencing of cfDNA was able to detect and identify bacterial, viral, and eukaryotic pathogens in the peritoneal effluent from PD patients with culture-confirmed peritonitis, as well as patients with recent antibiotic usage and in cases of culture-negative peritonitis. LIMITATIONS: Parallel cultures were not obtained in all the peritoneal effluent specimens. CONCLUSIONS: Metagenomic cfDNA sequencing of the peritoneal effluent can identify pathogens in PD patients with peritonitis, including culture-negative peritonitis.

Renal Considerations in COVID-19: Biology, Pathology, and Pathophysiology.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged into a worldwide pandemic of epic proportion. Beyond pulmonary involvement in coronavirus disease 2019 (COVID-19), a significant subset of patients experiences acute kidney injury. Patients who die from severe disease most notably show diffuse acute tubular injury on postmortem examination with a possible contribution of focal macro- and microvascular thrombi. Renal biopsies in patients with proteinuria and hematuria have demonstrated a glomerular dominant pattern of injury, most notably a collapsing glomerulopathy reminiscent of findings seen in human immunodeficiency virus (HIV) in individuals with apolipoprotein L-1 (APOL1) risk allele variants. Although various mechanisms have been proposed for the pathogenesis of acute kidney injury in SARS-CoV-2 infection, direct renal cell infection has not been definitively demonstrated and our understanding of the spectrum of renal involvement remains incomplete. Herein we discuss the biology, pathology, and pathogenesis of SARS-CoV-2 infection and associated renal involvement. We discuss the molecular biology, risk factors, and pathophysiology of renal injury associated with SARS-CoV-2 infection. We highlight the characteristics of specific renal pathologies based on native kidney biopsy and autopsy. Additionally, a brief discussion on ancillary studies and challenges in the diagnosis of SARS-CoV-2 is presented.

Optimizing Kidney Replacement Therapy During the COVID-19 Pandemic Across a Complex Healthcare System.

The unprecedented surge of nephrology inpatients needing kidney replacement therapy placed hospital systems under extreme stress during the COVID-19 pandemic. In this article, we describe the formation of a cross campus "New-York Presbyterian COVID-19 Kidney Replacement Therapy Task Force" with intercampus physician, nursing, and supply chain representation. We describe several strategies including the development of novel dashboards to track supply/demand of resources, urgent start peritoneal dialysis, in-house preparation of kidney replacement fluid, the use of unconventional personnel resources to ensure the safe and continued provision of kidney replacement therapy in the face of the unanticipated surge. These approaches facilitated equitable sharing of resources across a complex healthcare-system and allowed for the rapid implementation of standardized protocols at each hospital.

Removal of gadolinium by dialysis: review of different strategies and techniques.

Nephrogenic systemic fibrosis (NSF) has been related to the administration of gadolinium-based contrast agents for magnetic resonance imaging studies in patients with kidney disease. After reviewing the pathophysiology of NSF, we discuss the possible factors contributing to the toxicity of gadolinium in susceptible patients, including the excessive amounts of intravenous iron and erythropoietin as well as the inflammatory states commonly seen in patients treated with hemodialysis. Since free gadolinium is the most accepted risk factor for NSF, we provide some suggestions to improve clearance of both free and chelated gadolinium using different dialysis strategies and techniques. J. Magn. Reson. Imaging 2009;30:1347-1349. (c) 2009 Wiley-Liss, Inc.

Incidence of nephrogenic systemic fibrosis at two large medical centers.

PURPOSE: To determine the incidence and associated risk factors of nephrogenic systemic fibrosis (NSF) in patients who undergo gadolinium-based contrast agent (GBCA)-enhanced magnetic resonance (MR) imaging. MATERIALS AND METHODS: Institutional review board approval was obtained for retrospective review of the medical records from two hospitals to identify all cases of biopsy-confirmed NSF and all patients administered a GBCA from January 1, 1997, to June 30, 2007. Informed patient consent was not required. The incidence of NSF was calculated for patients who received a standard dose of GBCA, patients who received a high dose, and subgroups of patients with renal impairment. RESULTS: Fifteen patients developed NSF after gadolinium-enhanced MR imaging. All of them had an estimated glomerular filtration rate (eGFR) lower than 30 mL/min, and 11 had acute renal failure or acute deterioration of chronic renal failure. The incidence of NSF after gadolinium-enhanced MR imaging without screening for renal function was zero of 74,124 patients with the standard dose of GBCA and 15 (0.17%) of 8997 patients with the high dose (P < .001). The NSF incidence associated with a high dose of GBCA increased to 0.4% in patients in a chronic hemodialysis program and to 8.8% in those who had an eGFR lower than 15 mL/min but were not undergoing hemodialysis (P < .001). The NSF incidence in the patients with acute renal failure who received a high dose when their creatinine level was increasing was 19% (11 of 58 patients) when hemodialysis was delayed for longer than 2 days. More patients with NSF had proinflammatory events, and compared with patients without NSF, these patients had lower pH, younger age, lower eGFR, elevated serum phosphorus levels, and a longer delay between GBCA injection and hemodialysis. CONCLUSION: For patients with an eGFR lower than 15 mL/min, hemodialysis helped to prevent NSF. For patients with an eGFR lower than 30 mL/min who received a high dose of GBCA, acute renal failure, delayed hemodialysis after contrast agent injection, proinflammatory events, and hyperphosphatemia were associated with increased risk of NSF.

Retropharyngeal phlegmon in a hemodialysis patient with Staphylococcus aureus bacteremia.

Staphylococcus aureus bacteremia is a frequent occurrence in patients with indwelling catheters. Endocarditis, osteomyelitis, and septic arthritis are common metastatic complications. A hemodialysis patient developed fever, headache, neck pain, sore throat, and dysphagia in the setting of S. aureus bacteremia. Contrast computed tomography scan of the neck revealed a retropharyngeal phlegmon. Recurrent bacteremia led to the identification of the access graft as the infectious source. We present this case to increase awareness among emergency physicians that retropharyngeal infection by S. aureus can arise by hematogenous spread and should be considered in the differential diagnosis of a bacteremic patient with sore throat or neck pain.

A protocol for a pilot randomized controlled trial to assess the feasibility and effect of a cognitive behavioral intervention on quality of life for patients on hemodialysis.

INTRODUCTION: Poor health-related quality of life (HrQOL) is highly prevalent in patients on hemodialysis (HD), and is associated with increased hospitalizations and mortality. Cognitive behavioral (CB) techniques have improved HrQOL in HD patients but have not been routinely translated into clinical practice. The investigators present the rationale, study design and protocol of a randomized controlled trial to pilot the feasibility and effect of a translatable, behavioral-education intervention using CB techniques to improve poor HrQOL and self-management in hemodialysis patients. METHODS: Forty-eight HD patients will be randomly assigned to either the study intervention which includes 8-12 behavioral-education sessions with incorporated CB techniques delivered over 12 weeks or a control group of dialysis education without incorporated CB techniques. Subjects will be followed for 16 weeks and the primary outcome, change in kidney disease quality of life (KDQOL)-36 scores, will be measured at 0, 8, and 16 weeks. The study will have 85% power to detect an 8-point change in KDQOL-36 scores. At the end of the study, qualitative data will be gathered through end-of-study focus groups, and semi-structured interviews. These data will be used to refine the intervention and help translate it into clinical practice. DISCUSSION: There is promising evidence in support of CB-based interventions to improve HrQOL for patients on HD. Despite this, these interventions have not been routinely incorporated into clinical practice. The proposed intervention has the potential to improve both HrQOL and self-management, while also being easily translatable to other HD units.