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.

Outcomes of PD for AKI treatment during COVID-19 in New York City: A multicenter study.

BACKGROUND: The high incidence of acute kidney injury (AKI) requiring dialysis associated with COVID-19 led to the use of peritoneal dialysis (PD) for the treatment of AKI. This study aims to compare in-hospital all-cause mortality and kidney recovery between patients with AKI who received acute PD versus extracorporeal dialysis (intermittent haemodialysis and continuous kidney replacement therapy). METHODS: In a retrospective observational study of 259 patients with AKI requiring dialysis during the COVID-19 surge during Spring 2020 in New York City, we compared 30-day all-cause mortality and kidney recovery between 93 patients who received acute PD at any time point and 166 patients who only received extracorporeal dialysis. Kaplan-Meier curves, log-rank test and Cox regression were used to compare survival and logistic regression was used to compare kidney recovery. RESULTS: The mean age was 61 ± 11 years; 31% were women; 96% had confirmed COVID-19 with median follow-up of 21 days. After adjusting for demographics, comorbidities, oxygenation and laboratory values prior to starting dialysis, the use of PD was associated with a lower mortality rate compared to extracorporeal dialysis with a hazard ratio of 0.48 (95% confidence interval: 0.27-0.82, p = 0.008). At discharge or on day 30 of hospitalisation, there was no association between dialysis modality and kidney recovery (p = 0.48). CONCLUSIONS: The use of PD for the treatment of AKI was not associated with worse clinical outcomes when compared to extracorporeal dialysis during the height of the COVID-19 pandemic in New York City. Given the inherent selection biases and residual confounding in our observational study, research with a larger cohort of patients in a more controlled setting is needed to confirm our findings.

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.

Worldwide Early Impact of COVID-19 on Dialysis Patients and Staff and Lessons Learned: A DOPPS Roundtable Discussion.

As the worst global pandemic of the past century, coronavirus disease 2019 (COVID-19) has had a disproportionate effect on maintenance dialysis patients and their health care providers. At a virtual roundtable on June 12, 2020, Dialysis Outcomes and Practice Patterns Study (DOPPS) investigators from 15 countries in Asia, Europe, and the Americas described and compared the effects of COVID-19 on dialysis care, with recent updates added. Most striking is the huge difference in risk to dialysis patients and staff across the world. Per-population cases and deaths among dialysis patients vary more than 100-fold across participating countries, mirroring burden in the general population. International data indicate that the case-fatality ratio remains at 10% to 30% among dialysis patients, confirming the gravity of infection, and that cases are much more common among in-center than home dialysis patients. This latter finding merits urgent study because in-center patients often have greater community exposure, and in-center transmission may be uncommon under optimal protocols. Greater telemedicine use is a welcome change here to stay, and our community needs to improve emergency planning and protect dialysis staff from the next pandemic. Finally, the pandemic's challenges have prompted widespread partnering and innovation in kidney care and research that must be sustained after this global health crisis.

Use of peritoneal dialysis for acute kidney injury during the COVID-19 pandemic in New York City: a multicenter observational study.

To demonstrate feasibility of acute peritoneal dialysis (PD) for acute kidney injury during the coronavirus disease 2019 (COVID-19) pandemic, we performed a multicenter, retrospective, observational study of 94 patients who received acute PD in New York City in the spring of 2020. Patient comorbidities, severity of disease, laboratory values, kidney replacement therapy, and patient outcomes were recorded. The mean age was 61 ± 11 years; 34% were women; 94% had confirmed COVID-19; 32% required mechanical ventilation on admission. Compared to the levels prior to initiation of kidney replacement therapy, the mean serum potassium level decreased from 5.1 ± 0.9 to 4.5 ± 0.7 mEq/L on PD day 3 and 4.2 ± 0.6 mEq/L on day 7 (P < 0.001 for both); mean serum bicarbonate increased from 20 ± 4 to 21 ± 4 mEq/L on PD day 3 (P = 0.002) and 24 ± 4 mEq/L on day 7 (P < 0.001). After a median follow-up of 30 days, 46% of patients died and 22% had renal recovery. Male sex and mechanical ventilation on admission were significant predictors of mortality. The rapid implementation of an acute PD program was feasible despite resource constraints and can be lifesaving during crises such as the COVID-19 pandemic.

Telehealth for Home Dialysis in COVID-19 and Beyond: A Perspective From the American Society of Nephrology COVID-19 Home Dialysis Subcommittee.

The coronavirus disease 2019 (COVID-19) pandemic, technological advancements, regulatory waivers, and user acceptance have converged to boost telehealth activities. Due to the state of emergency, regulatory waivers in the United States have made it possible for providers to deliver and bill for services across state lines for new and established patients through Health Insurance Portability and Accountability Act (HIPAA)- and non-HIPAA-compliant platforms with home as the originating site and without geographic restrictions. Platforms have been developed or purchased to perform videoconferencing, and interdisciplinary dialysis teams have adapted to perform virtual visits. Telehealth experiences and challenges encountered by dialysis providers, clinicians, nurses, and patients have exposed health care disparities in areas such as access to care, bandwidth connectivity, availability of devices to perform telehealth, and socioeconomic and language barriers. Future directions in telehealth use, quality measures, and research in telehealth use need to be explored. Telehealth during the public health emergency has changed the practice of health care, with the post-COVID-19 world unlikely to resemble the prior era. The future impact of telehealth in patient care in the United States remains to be seen, especially in the context of the Advancing American Kidney Health Initiative.

Safety and Efficacy of Bedside Peritoneal Dialysis Catheter Placement in the COVID-19 Era: Initial Experience at a New York City Hospital.

INTRODUCTION: Acute kidney injury (AKI) requiring renal replacement therapy (RRT) is common in critically ill patients with COVID-19. Unparalleled numbers of patients with AKI and shortage of dialysis machines and operative resources prompted consideration of expanded use of urgent-start peritoneal dialysis (PD) and evaluation of the safety and efficacy of bedside surgical placement of PD catheters. STUDY DESIGN: Bedside, open PD catheter insertions were performed in early April 2020, at a large academic center in New York City. Patients with SARS-CoV-2 infection and AKI and ambulatory patients with chronic kidney disease and impending need for RRT were included. Detailed surgical technique is described. RESULTS: Fourteen catheters were placed at the bedside over 2 weeks, 11 in critically ill COVID-19 patients and three in ambulatory patients. Mean patient age was 61.9 years (43-83), and mean body mass index was 27.1 (20-37.6); four patients had prior abdominal surgery. All catheters were placed successfully without routine radiographic studies or intraoperative complications. One patient (7%) experienced primary nonfunction of the catheter requiring HD. One patient had limited intraperitoneal bleeding while anticoagulated, which was managed by mechanical compression of the abdominal wall and temporarily holding anticoagulation. All other catheters had an adequate function at 3-18 days of follow-up. CONCLUSIONS: Bedside placement of PD catheters is safe and effective in ICU and outpatient clinic settings. Our surgical protocols allowed for optimization of critical hospital resources, minimization of hazardous exposure to healthcare providers and a broader application of urgent-start PD in selected patients. Long-term follow-up is warranted.

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.