Differences in mRNA-1273 (Moderna) and BNT162b2 (Pfizer-BioNTech) SARS-CoV-2 vaccine immunogenicity among patients undergoing dialysis.

BACKGROUND: Differences in immunogenicity between mRNA SARS-CoV-2 vaccines have not been well characterized in patients undergoing dialysis. We compared the serologic response in patients undergoing maintenance hemodialysis after vaccination against SARS-CoV-2 with BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna). METHODS: We conducted a prospective observational cohort study at 2 academic centres in Toronto, Canada, from Feb. 2, 2021, to July 20, 2021, which included 129 and 95 patients who received the BNT162b2 and mRNA-1273 SARS-CoV-2 vaccines, respectively. We measured SARS-CoV-2 immunoglobulin G antibodies to the spike protein (anti-spike), receptor binding domain (anti-RBD) and nucleocapsid protein (anti-NP) at 6-7 and 12 weeks after the second dose of vaccine and compared those levels with the median convalescent serum antibody levels from 211 controls who were previously infected with SARS-CoV-2. RESULTS: At 6-7 weeks after 2-dose vaccination, we found that 51 of 70 patients (73%) who received BNT162b2 and 83 of 87 (95%) who received mRNA-1273 attained convalescent levels of anti-spike antibody (p < 0.001). In those who received BNT162b2, 35 of 70 (50%) reached the convalescent level for anti-RBD compared with 69 of 87 (79%) who received mRNA-1273 (p < 0.001). At 12 weeks after the second dose, anti-spike and anti-RBD levels were significantly lower in patients who received BNT162b2 than in those who received mRNA-1273. For anti-spike, 70 of 122 patients (57.4%) who received BNT162b2 maintained the convalescent level versus 68 of 71 (96%) of those who received mRNA-1273 (p < 0.001). For anti-RBD, 47 of 122 patients (38.5%) who received BNT162b2 maintained the anti-RBD convalescent level versus 45 of 71 (63%) of those who received mRNA-1273 (p = 0.002). INTERPRETATION: In patients undergoing hemodialysis, mRNA-1273 elicited a stronger humoral response than BNT162b2. Given the rapid decline in immunogenicity at 12 weeks in patients who received BNT162b2, a third dose is recommended in patients undergoing dialysis as a primary series, similar to recommendations for other vulnerable populations.

Anxiety and psychosocial impact during coronavirus disease 2019 in home dialysis patients.

The severe acute respiratory syndrome coronavirus (SARS-Cov-2) resulting in the coronavirus disease 2019 (COVID-19) is documented to have a negative psychosocial impact on patients. Home dialysis patients may be at risk of additional isolating factors affecting their mental health. The aim of this study is to describe levels of anxiety and quality of life during the COVID-19 pandemic among home dialysis patients. This is a single-centre survey of home dialysis patients in Toronto, Ontario. Surveys were sent to 98 home haemodialysis and 43 peritoneal dialysis patients. Validated instruments (Haemodialysis and Peritoneal Dialysis Treatment Satisfaction Questionnaire, Generalized Anxiety Disorder 7 Item [GAD7] Scale, Patient Health Questionnaire [PHQ-9], Illness Intrusiveness Ratings Scale, Family APGAR Questionnaire and The Self Perceived Burden Scale) assessing well-being were used. Forty of the 141 patients surveyed, participated in September 2020. The mean age was 53.1 ± 12.1 years, with 60% male, and 85% home haemodialysis, 80% of patients rated their satisfaction with dialysis at 8/10 or greater, 82% of respondents reported either "not at all" or "for several days" indicating frequency of anxiety and depressive symptoms, 79% said their illness minimally or moderately impacted their life, 76% of respondents were almost always satisfied with interactions with family members, 91% were never or sometimes worried about caregiver burden. Among our respondents, there was no indication of a negative psychosocial impact from the pandemic, despite the increased social isolation. Our data further supports the use of home dialysis as the optimal form of dialysis.

The need for outpatient back-up for home hemodialysis patients: Implications for resource utilization.

INTRODUCTION: The provision of sufficient support contributes to home hemodialysis (HHD) technique survival. The need for back-up treatment in incident and prevalent patients on HHD has not been well described previously, and is important from both technique survival and resource allocation. We aimed to quantify the amount of back-up treatment given to patients in our HHD unit, and hypothesized that the provision of back-up HD facilitated technique survival. METHODS: This was a retrospective, single-center cohort study quantifying the provision of back-up HD between January and December 2018. Electronic and paper medical records were accessed for data collection. FINDINGS: One hundred and nineteen patients dialyzed independently at home during the study period (96 patient years of HHD). Seventy-eight (66%) patients required a total of 292 back-up HD sessions in the HHD unit, representing an average of three back-up HD runs per patient year of HHD. Fifty-three percent of back-up HD runs were required for vascular access related issues. The most common clinical issue requiring assessment and back-up HD was extracellular fluid volume management. An equal proportion (95%) of those that utilized back-up HD and those that did not utilize back-up HD maintained a positive disposition (transplant or ongoing HHD) in relation to technique survival in the short term. CONCLUSIONS: From a resource viewpoint, this program of approximately 100 HHD patients required the availability of one to two staffed HD stations each weekday for back-up HD. The provision of back-up HD was not a harbinger of HHD discontinuation.

Are adverse events in newly trained home dialysis patients related to learning styles? A single-centre retrospective study from Toronto, Canada.

OBJECTIVES: Home haemodialysis (HD) and peritoneal dialysis (PD) have seen growth in utilisation around the globe over the last few years. However, home dialysis, with its attendant technical complexity and risk of adverse events continues to pose challenges for wider adoption. We examined whether differences in patients' learning styles are associated with differing risk of adverse events in both home HD and PD patients. DESIGN: Retrospective cohort study. SETTING: Tertiary care hospital in Toronto, Ontario, Canada. PARTICIPANTS: One hundred and eighteen prevalent adult (≥18 years) home dialysis patients (40 PD and 78 home HD) were enrolled. Patients on home dialysis for less than 6 months or receiving home nursing assistance for dialysis were excluded from the study. INTERVENTIONS: Enrolled patients completed (VARK) Visual, Aural, Reading-writing and Kinesthetic questionnaires to determine learning styles. PRIMARY AND SECONDARY OUTCOME MEASURES: Home HD and PD adverse events were identified within 6 months of completing home dialysis training. Event rates were then stratified and compared according to learning styles. RESULTS: Thirty patients had a total of 53 adverse events. We used logistic regression analysis to determine unadjusted and adjusted ORs for a single adverse event. Non-visual learners were 4.35 times more likely to have an adverse event (p=0.001). After adjusting for age, gender, dialysis modality, training duration, dialysis vintage, prior renal replacement therapy, visual impairment, education and literacy, an adverse event was still four times more likely among non-visual learners compared to visual learners (p=0.008). A subgroup analysis of home HD patients showed adverse events were more likely among non-visual learners (OR 11.1; p=0.003), whereas PD patients showed a trend for more adverse events in non-visual learners (OR: 1.60; p=0.694). CONCLUSIONS: Different learning styles in home dialysis patients exist. Visual learning styles are associated with fewer adverse events in home dialysis patients within the first 6 months of completing training. Individualisation of home dialysis training by learning style is warranted.

A prototype line clamp for venous access bleeding in hemodialysis: A prospective cohort study.

INTRODUCTION: Venous needle dislodgement (or venous port disconnection) during hemodialysis (HD) may lead to catastrophic blood loss, particularly during unsupervised home HD. A prototype venous line clamp was developed for use in conjunction with the Redsense blood loss sensor. We hypothesize that this prototype device will provide additional safety to dialysis without excessive burden. METHODS: This was a single-center, prospective cohort study. Participants kept a log of bleeding, troubleshooting and clamp deployment events, and completed questionnaires before device first use and after device final use. The primary outcome was appropriate device function, evaluated by review of bleeding and clamp deployment events. The secondary outcomes were patient/nursing staff expectations and experience of the device. FINDINGS: Fourteen patients used the device during a combined total of 214 HD treatments. Five participants (36%) had experienced a bleeding or disconnection event prior to study recruitment. All vascular access types were represented. The device was tested during incenter HD (n = 7 patients) and home HD (n = 7 patients). There were eight clamp deployment events, three of which were in the setting of minor bleeding at the venous access site. No other bleeding events were reported. The main troubleshooting issues were related to cumbersome device connections. Participants perceived additional safety with the device (median score 4.25 out of 5; range 1-5). However, the amount of additional work created was variable, and large in some cases (median score 2 out of 5; range 0-4.5). There was no association between HD vintage and device burden (P = 0.55). DISCUSSION: This "proof of concept" study confirmed that a clamp on the venous line, operating in conjunction with a venous access blood detector, is feasible regardless of HD location or vascular access type. The device improved patient safety perception during HD but was burdensome. Design modifications could improve future device iterations.

Quotidian nocturnal hemodialysis improves cytokine profile and enhances erythropoietin responsiveness.

Inflammation is implicated in the pathogenesis of erythropoietin (EPO) resistance in patients with end-stage renal disease. Interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha are suggested to suppress erythropoiesis in uremia. Insulin like growth factor (IGF)-1 has been proposed to stimulate erythropoiesis. Nocturnal hemodialysis (NHD) has been demonstrated to improve anemia management with enhanced EPO responsiveness without altering survival of red blood cells. We tested the hypothesis that augmentation of uremia clearance by NHD results in a reduction of proinflammatory cytokine levels, thereby enhancing EPO responsiveness. Using a cross-sectional study design, 14 prevalent patients on NHD and 14 patients on conventional hemodialysis (CHD) matched for age and comorbidities and controlled for hemoglobin concentrations and iron status were studied. Outcome variables included EPO requirement and plasma levels of EPO, parathyroid hormone, C reactive protein, IL-6, TNF-alpha, and IGF-1. The primary outcome was to determine the between group differences in (1) cytokine profile and (2) EPO requirement. The secondary outcome was to examine the potential correlation between cytokine levels and EPO requirement. There were no significant differences in patient characteristics, comorbidities, hemoglobin, iron indices, and parathyroid hormone levels between the two cohorts. EPO requirement was significantly lower in the NHD cohort [90.5 +/- 22.1 U/kg/ week (NHD) vs. 167.2 +/- 25.4 U/kg/week (CHD), p = 0.04]. Plasma IL-6 levels were lower in the NHD cohort [3.9 +/- 0.7 pg/ml (NHD) vs. 6.5 +/- 0.8 pg/ml (CHD), p = 0.04]. C reactive protein tended to decrease [4.59 +/- 1.34 (NHD) vs. 8.43 +/- 1.83 mg/L (CHD), p = 0.14]. TNF-alpha, and IGF-1 levels did not differ between the two groups. Direct associations were found between EPO requirement and C reactive protein levels (R = 0.62, p = 0.001), and IL-6 levels (R = 0.57, p = 0.002). Augmentation of uremic clearance by NHD improves EPO responsiveness in end-stage renal disease. A possible mechanism for this improvement is through better control of inflammation, as manifested by lowering of plasma IL-6 levels. Further studies are required to clarify the mechanisms by which NHD decreases inflammation.