Omicron variant neutralizing antibodies following BNT162b2 BA.4/5 versus mRNA-1273 BA.1 bivalent vaccination in patients with end-stage kidney disease.

Neutralization of Omicron subvariants by different bivalent vaccines has not been well evaluated. This study characterizes neutralization against Omicron subvariants in 98 individuals on dialysis or with a kidney transplant receiving the BNT162b2 (BA.4/BA.5) or mRNA-1273 (BA.1) bivalent COVID-19 vaccine. Neutralization against Omicron BA.1, BA.5, BQ.1.1, and XBB.1.5 increased by 8-fold one month following bivalent vaccination. In comparison to wild-type (D614G), neutralizing antibodies against Omicron-specific variants were 7.3-fold lower against BA.1, 8.3-fold lower against BA.5, 45.8-fold lower against BQ.1.1, and 48.2-fold lower against XBB.1.5. Viral neutralization was not significantly different by bivalent vaccine type for wild-type (D614G) (P = 0.48), BA.1 (P = 0.21), BA.5 (P = 0.07), BQ.1.1 (P = 0.10), nor XBB.1.5 (P = 0.10). Hybrid immunity conferred higher neutralizing antibodies against all Omicron subvariants. This study provides evidence that BNT162b2 (BA.4/BA.5) and mRNA-1273 (BA.1) induce similar neutralization against Omicron subvariants, even when antigenically divergent from the circulating variant.

Determining the Longitudinal Serologic Response to COVID-19 Vaccination in the Chronic Kidney Disease Population: A Clinical Research Protocol.

Background: People living with chronic kidney disease (CKD) have been disproportionately affected by the coronavirus disease 2019 (COVID-19) pandemic, including higher rates of infection, hospitalization, and death. Data on responsiveness to COVID-19 vaccination strategies and immunogenicity are limited, yet required to inform vaccination strategies in this at-risk population. Objective: The objective of this study is to characterize the longitudinal serologic response to COVID-19 vaccination. Design: This is a prospective observational cohort study. Setting: Participating outpatient kidney programs within Ontario and British Columbia. Patients: Up to 2500 participants with CKD G3b-5D receiving COVID-19 vaccination, including participants receiving dialysis and kidney transplant recipients (CKD G1T-5T). Measurements: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies (anti-spike, anti-receptor binding domain, anti-nucleocapsid) will be detected by ELISA (enzyme-linked immunosorbent assay) from serum or dried blood spot testing. In a subset of participants, neutralizing antibodies against novel variants of concern will be evaluated. Peripheral blood mononuclear cells will be collected for exploratory immune profiling of SARS-CoV-2 specific cellular immunity. Methods: Participants will be recruited prior to or following any COVID-19 vaccine dose and have blood sampled for serological testing at multiple timepoints: 1, 3, 6, 9, and 12 months post vaccination. When possible, samples will be collected prior to a dose or booster. Participants will remain in the study for at least 1 year following their last COVID-19 vaccine dose. Strengths and limitations: The adaptive design of this study allows for planned modification based on emerging evidence or rapid changes in public health policy surrounding vaccination. Limitations include incomplete earlier timepoints for blood collection due to rapid vaccination of the population. Conclusions: This large multicenter serologic study of participants living with kidney disease will generate data on the kinetics of SARS-CoV-2 immune response to vaccination across the spectrum of CKD, providing insights into the amplitude and duration of immunity conferred by COVID-19 vaccination and allowing for characterization of factors associated with immune response. The results of this study may be used to inform immunization guidelines and public health recommendations for the 4 million Canadians living with CKD.

Contexte: Les personnes atteintes d'insuffisance rénale chronique (IRC) ont été touchées de façon disproportionnée par la pandémie de COVID-19 ayant notamment présenté des taux plus élevés d'infection, d'hospitalisation et de décès. Les données sur la réactivité aux stratégies de vaccination de la COVID-19 et à l'immunogénicité sont limitées, mais elles sont nécessaires pour développer des stratégies de vaccination dans cette population à risque. Objectif: Caractériser la réponse sérologique longitudinale à la vaccination contre la COVID-19. Conception: Étude de cohorte observationnelle prospective. Cadre: Les programmes ambulatoires de santé rénale participants en Ontario et en Colombie-Britannique. Sujets: Jusqu'à 2 500 personnes atteintes d'IRC G3B-5D recevant un vaccin contre la COVID-19, y compris des patients suivant des traitements de dialyse et des receveurs d'une greffe rénale (IRC G1T-5T). Mesures: Les anticorps IgG anti-SARS-CoV-2 (anti-spike, anti-domaine de liaison au récepteur, anti-nucléocapside) seront détectés par ELISA à partir du sérum ou de taches de sang séché. Un sous-groupe de sujets participera également à l'évaluation d'anticorps neutralisants dirigés contre les nouveaux variants préoccupants. Des cellules mononuclées de sang périphérique seront prélevées pour établir un profil immunitaire exploratoire de l'immunité cellulaire spécifique au SARS-CoV-2. Méthodologie: Les sujets seront recrutés avant ou après toute dose du vaccin contre la COVID-19 et se soumettront à des prélèvements sanguins pour les tests sérologiques à 1, 3, 6, 9 et 12 mois post-vaccination. Lorsque possible, des échantillons seront prélevés avant l'administration d'une dose ou d'un rappel. Les sujets demeureront dans l'étude pendant au moins un an après leur dernière dose de vaccin contre la COVID-19. Points forts et limites: La conception adaptative de l'étude permet d'apporter des modifications planifiées fondées sur de nouvelles données ou des changements rapides dans les politiques de santé publique entourant la vaccination. Les résultats sont limités par l'absence de certains prélèvements sanguins antérieurs (point temporels) en raison de la vaccination rapide de la population. Conclusion: Cette vaste étude sérologique multicentrique menée auprès de personnes atteintes de néphropathie fournira des données sur la cinétique de la réponse immunitaire à la vaccination contre le SARS-CoV-2 dans l'ensemble du spectre de l'IRC. Elle fournira des informations sur l'amplitude et la durée de l'immunité conférée par la vaccination contre la COVID-19 et permettra de caractériser les facteurs associés à la réponse immunitaire. Ces résultats serviront à orienter les recommandations de santé publique et les lignes directrices en matière d'immunisation pour les quatre millions de Canadiens et Canadiennes qui vivent avec l'IRC.

Albuminuria post-liver transplant is a predictor of kidney disease progression and mortality.

BACKGROUND: Albuminuria is a marker of chronic kidney disease (CKD) associated with an increased risk of end-stage kidney disease (ESKD) and mortality in the general population, but it is uncertain whether the same association exists in liver transplant (LT) recipients. This study examined the association between albuminuria and kidney failure and mortality in LT recipients.METHODS: Retrospective cohort study of 294 adults who received a LT between January 1, 1989, and December 31, 2011, in British Columbia, Canada. Cox multivariable regression was used to determine the association between ACR and a primary combined outcome of mortality, doubling of serum creatinine, or ESKD; and a secondary outcome of a decrease in estimated glomerular filtration rate (eGFR) ≥30%. RESULTS: At baseline, mean eGFR was 67 (SD 20.9) mL/min/1.73 m2, and 10% had severe albuminuria (ACR >30 mg/mmol). The primary outcome occurred in 20.4% (60) of patients and was associated with ACR >30 mg/mmol (HR 2.77, 95% CI 1.28-6.04; P = 0.01). A decline in eGFR ≥30% occurred in 21.8% (64) of patients, and was associated with ACR >30 mg/mmol (HR 4.77, 95% CI 2.31-9.86; P < 0.0001). CONCLUSIONS: Severe albuminuria (ACR >30 mg/mmol) was associated with an increased risk of loss of kidney function and mortality after LT. Prospective studies are needed to determine if specific interventions directed at reducing albuminuria can improve long-term outcomes in LT recipients.

The use of nurse-administered vascular access audit in home hemodialysis patients: A quality initiative.

INTRODUCTION: Vascular access complications are associated with increased morbidity and mortality in home hemodialysis (HHD). Nurse-administered vascular access checklist is a feasible quality improvement strategy aimed to lower HHD access errors. METHODS: We conducted a prospective quality improvement initiative for consecutive HHD patients between April 2013 and December 2016 at the Toronto General Hospital. Vascular access audits were administered every 6 months during clinic visits and during retraining sessions after an infection. We aimed to (1) determine whether prospective serial administration of vascular audit will decrease in the number of errors performed by the patient and (2) to determine whether there is an association between the number of errors and vascular access related infection. FINDINGS: A total of 370 audits were performed on 122 patients with a mean HHD vintage of 6.7 (0.8-19.5) years. The mean number of errors per patient decreased from 1.24 ± 1.75 (baseline) to 0.33 ± 0.49 (last follow-up), P < 0.001. Among patients who had serial vascular access audits performed, there was a significant decrease in median number of errors (baseline median 1, [0-2] end of study median 0, [0-1] P = 0.01). Patients performing buttonhole cannulation made most proportion of errors as compared to CVC, 54% vs. 40% (P = 0.01) respectively; and as compared to rope ladder cannulation 54% vs. 37% (P = 0.008). We were unable to demonstrate an association between the change in patient reported errors and vascular access related infection. DISCUSSION: Vascular access audit is a feasible quality initiative, which leads to a decrease in the number of patient reported errors in vascular access. The longitudinal clinical sequelae of this strategy warrants further examination.

Klebsiella pneumoniae Renal Abscess and Peritonitis in a Peritoneal Dialysis Patient: A Novel Route of Infection.

We present a peritoneal dialysis (PD) patient who had a renal biopsy performed during an episode of urosepsis and subsequently presented with a renal abscess at the biopsy site along with concurrent peritonitis. Microbiology from the PD effluent and from the renal abscess were both positive for Klebsiella pneumoniae We propose that the PD peritonitis was the result of seeding of the peritoneal cavity with bacteria from the renal abscess. Successful treatment was achieved through drainage of the abscess and intraperitoneal antibiotics.

Case of Mycobacterium mucogenicum in a home hemodialysis patient.

We present a case of a patient on home hemodialysis who developed Mycobacterium mucogenicum bacteremia. While infections with this particular organism are rare, disseminated infections have been reported and have been associated with significant morbidity and mortality. Diagnosis required appropriate cultures, understanding of natural habitat of organism and complete environmental analysis including blood, dialysis sample port, reverse osmosis and incoming water supply cultures. The patient was treated successfully with systemic antibiotics, removal of central venous catheter, patient education and complete exchange of the hemodialysis circuit.

Antibiotic Prophylaxis in Peritoneal Dialysis Patients.

Peritonitis is an important cause of morbidity, mortality, and technique failure in patients on peritoneal dialysis (PD). The most effective approach to peritonitis is prevention, which includes careful patient training and follow-up. Although peritonitis as a result of contiguous spread of bacteria or fungi during invasive procedures, or as a result of seeding of the peritoneum during bacteremia, is uncommon, the likelihood of such spread is often predictable, and the risk can be mitigated with antibiotic prophylaxis. Here, we describe the rationale for, and approach to, antibiotic prophylaxis in PD patients for the prevention of infective episodes.