Hemodialysis Population Research Articles

Therapeutic Efficacy of Erythropoietin Alpha and Erythropoietin Beta in Anemia of Chronic Kidney Disease.

To compare the effectiveness of erythropoietin alpha and erythropoietin beta in anemia management in the hemodialysis population. Quasi-experimental study. Department of Nephrology, The Kidney Center Postgraduate Training Institute (TKC-PGTI), Karachi, from December 2019 to July 2020. All participants were initially started on erythropoietin alpha and then converted to erythropoietin beta after three months. The effectiveness of the erythropoietin alpha and erythropoietin beta was calculated on the basis of net change of mean hemoglobin and mean hematocrit level in the last four weeks on either erythropoietin therapy. A total of 80 patients completed the study, in which 47 (58.8%) were males while 33 (41.3%) were females. The mean age was 59.7 ± 14.7 years. The net mean hemoglobin change during last 04 weeks was ̶ 0.19 ± 1.2 and ̶ 0.03 ± 1.0 for erythropoietin alpha and erythropoietin erythropoietin beta, respectively (p = 0.41). The net mean hematocrit change during the last four weeks was ̶ 0.45 ± 3.9 and ̶ 0.49 ± 3.7 for erythropoietin alpha and erythropoietin beta, respectively (p = 0.95). The mean weekly erythropoietin dosage per Kg body weight during the last four weeks was 177.6 ± 130.4 IU/Kg/week for erythropoietin alpha and 121.3 ± 69.6 IU/Kg/week for erythropoietin beta (p = <0.001). Erythropoietin alpha and erythropoietin beta have similar therapeutic efficacy in anemia management in chronic kidney disease patients. Reduced dosage of erythropoietin beta achieves and maintains the target hemoglobin level. Key Words: Efficacy, Erythropoietin, Anemia, Chronic kidney disease.

Diabetes increases the risk of bone fractures in patients on kidney replacement therapy: A Danish national cohort study.

Patients treated with dialysis or living with a kidney transplant (kidney replacement therapy, KRT) have an increased risk of bone fracture. Patients with diabetes also have an increased risk of fracture. The aim of this study was to investigate whether the presence of diabetes in patients on KRT aggravates the risk of fracture. Nationwide Danish registries were used in this retrospective cohort study. All prevalent adult patients on hemodialysis (HD) or peritoneal dialysis (PD) on 1st of January 2000 and all incident patients starting KRT (HD, PD, kidney transplanted (KTX)) until 31st of December 2011 were included in the KRT group. Adult persons not on KRT and without diabetes on 1st of January 2000 were used as a reference group. Patients were separated in groups with and without (+/-) diabetes. They were followed until first fracture, emigration, death, or end-of-study on 31st of December 2016. A total of 4,074,085 not on KRT +/- diabetes and 9053 patients on KRT +/- diabetes were included. Comparing the different groups with diabetes to the corresponding group without diabetes, the unadjusted HR (95% CI) for any first fracture were 1.2 (1.0-1.3) in the HD population, 1.4 (1.1-1.7) in the PD population, and 1.7 (1.4-2.2) in the KTX population. Further adjustments for age, sex, prior fractures, comorbidity and medication did not change these results significantly. Diabetes increases the risk of fracture in patients on KRT.

Weekly pattern of dialysis unit blood pressure is a promising marker for prognosis evaluation in hemodialysis population.

Dialysis unit blood pressure (BP) pattern showed superiority in prognostic evaluation and interdialytic BP burden assessment. However previous studies mainly focused on the recurrent BP pattern within a session (intradialytic BP change or intradialytic BP slope), the clinical value of the weekly pattern of dialysis unit BP is unknown. We performed a prospective cohort study in adult end stage renal disease (ESRD) patients on thrice weekly hemodialysis (HD). The slope and the change of the postdialysis systolic BP (SBP) in the course of a week (post-SBP slope and post-SBP change) were used to characterize the weekly pattern of dialysis unit BP. Outcomes included all-cause mortality, cardiovascular mortality, and first cardiovascular event. We also measured the home BP in our cohort. One hundred and twenty-nine subjects were followed over a median of 31 months. Higher post-SBP slope (≥0.185) was independently associated with increased risk of all-cause mortality, cardiovascular mortality, and first cardiovascular event. Results were similar for increased post-SBP change. HD patients with a higher post-SBP slope or an increased post-SBP change also had significant increased interdialytic BP burden measured by home SBP on both dialysis days and non-dialysis days. Post-SBP slope and post-SBP change might be promising dialysis unit BP markers for prognostic evaluation and interdialytic BP burden assessment.

Prevalence of SARS-CoV-2 antibodies in hemodialysis patients in Senegal: a multicenter cross-sectional study

BackgroundHemodialysis patients are among high-risk groups for COVID-19. Africa is the continent with the lowest number of cases in the general population but we have little information about the disease burden in dialysis patients.ObjectivesThis study aimed to describe the seroprevalence of SARS-CoV-2 antibodies in the hemodialysis population of Senegal.Patients and methodsWe conducted a multicenter cross-sectional survey, between June and September 2020 involving 10 public dialysis units randomly selected in eight regions of Senegal. After seeking their consent, we included 303 patients aged ≥ 18 years and hemodialysis for ≥ 3 months. Clinical symptoms and biological parameters were collected from medical records. Patients’ blood samples were tested with Abbott SARS-CoV-2 Ig G assay using an Architect system. Statistical tests were performed with STATA 12.0.ResultsSeroprevalence of SARS-CoV-2 antibodies was 21.1% (95% CI = 16.7–26.1%). We noticed a wide variability in SARS-CoV-2 seroprevalence between regions ranging from 5.6 to 51.7%. Among the 38 patients who underwent nasal swab testing, only six had a PCR-confirmed infection and all of them did seroconvert. Suggestive clinical symptoms were reported by 28.1% of seropositive patients and the majority of them presented asymptomatic disease. After multivariate analysis, a previous contact with a confirmed case and living in a high population density region were associated with the presence of SARS-CoV-2 antibodies.ConclusionThis study presents to our knowledge the first seroprevalence data in African hemodialysis patients. Compared to data from other continents, we found a higher proportion of patients with SARS-CoV-2 antibodies but a lower lethality rate.

Chronic Pain Assessment in Moroccan Hemodialysis Population

Introduction: This study aims to assess the prevalence, as well as the impact of chronic pain on the daily life of hemodialysis patients and to determine the associated socio-demographic, clinical-biological, and psychological factors. Methods: This study was a cross-sectional study that included 441 hemodialysis patients. The characteristics of the chronic pain were collected by the Brief Pain Inventory questionnaire and by the visual analog scale. The anxious and depressed mood was assessed by the Hospital Anxiety and Depression Scale, factors associated with chronic pain were determined through univariate and multivariate analysis. Results: the prevalence of chronic pain was 72.8%. It was severe in 40.8% of cases and it completely interfered with general activity in 72.9% of cases. The most frequently reported pain site was: lowers extremities (39.9%). Thus, 59.9% of patients reported using analgesics, with a frequent intake in 74.3% of cases. Anxiety and depression were found respectively in 68% and 66% of cases. The chronic pain was significantly associated with depression (p<0.001), anxiety (p<0.001), living conditions (p<0.001), level of studies (p<0.001), and marital status (p=0.020). Conclusion: A multidisciplinary approach is recommended for the management of chronic pain, involves Nurses, physiotherapists, psychologists, health educators and family.

Prognosis and Long-Term Overall Survival in Hypertensive Patients Undergoing Chronic Hemodialysis: A Multicenter Parametric Mixture Split-Population Analysis.

Hemodialysis (HD) patients face long-term complications which require ongoing dialysis and follow-up. The management of hypertension among HD populations has often been neglected. This study aimed at identifying the determinants of death in hypertensive HD (HTN-HD) patients. In a multicenter retrospective cohort study (conducted from 2005 to 2018 in thirty-four HD centers affiliated with Shiraz University of Medical Sciences), the data of 725 HTN-HD patients who had at least 3 months of regular dialysis and follow-up were analyzed. Accelerated failure time mixture split-population (AFTMSP) regression was utilized to identify the factors with significant effects on long- and short-term overall survival (OS) separately. Among the different AFTMSP models, the extended generalized gamma (EGG) model outperformed the others. Sex (male: event time ratio [ETR]=1.30), initial vascular access type (arteriovenous fistula: ETR=1.50), and the type of membrane flux used for HD (high-flux: ETR=1.27) had important impacts on short-term OS. Moreover, age (OR=1.06), dialysis adequacy (Kt/ Vurea≤1.2: OR=2.30), initial vascular access type (central venous catheter: OR=2.08), serum sodium (OR=0.90) concentration, and potassium (OR=0.66) concentration had significant effects on long-term OS. The split-population analyses were able to demonstrate that the predictors of long-term OS were different from those of short-term OS. Although the superiority of the parametric EGG model was proved in this study, further research with different databases is suggested. Moreover, these findings can be considered by health policy decision-makers to create a new guideline to enhance the long-term OS of HTN-HD patients.

Skeletal Muscle Phenotype in Patients Undergoing Long-Term Hemodialysis Awaiting Kidney Transplantation.

Age and comorbidity-related sarcopenia represent a main cause of muscle dysfunction in patients on long-term hemodialysis. However, recent findings suggest muscle abnormalities that are not associated with sarcopenia. The aim of this study was to isolate functional and cellular muscle abnormalities independently of other major confounding factors, including malnutrition, age, comorbidity, or sedentary lifestyle, which are common in patients on maintenance hemodialysis. To overcome these confounding factors, alterations in skeletal muscle were analyzed in highly selected patients on long-term hemodialysis undergoing kidney transplantation. In total, 22 patients on long-term hemodialysis scheduled for kidney transplantation with few comorbidities, but with a long-term uremic milieu exposure, and 22 age, sex, and physical activity level frequency-matched control participants were recruited. We compared biochemical, functional, and molecular characteristics of the skeletal muscle using maximal voluntary force and endurance of the quadriceps, 6-minute walking test, and muscle biopsy of vastus lateralis. For statistical analysis, mean comparison and multiple regression tests were used. In patients on long-term hemodialysis, muscle endurance was lower, whereas maximal voluntary force was not significantly different. We observed a transition from type I (oxidative) to type II (glycolytic) muscle fibers, and an alteration of mitochondrial structure (swelling) without changes in DNA content, genome replication (peroxisome proliferator activator receptor γ coactivator-1α and mitochondrial transcription factor A), regulation of fusion (mitofusin and optic atrophy 1), or fission (dynamin-related protein 1). Notably, there were autophagosome structures containing glycogen along with mitochondrial debris, with a higher expression of light chain 3 (LC3) protein, indicating phagophore formation. This was associated with a greater conversion of LC3-I to LC3-II and the expression of Gabaralp1 and Bnip3l genes involved in mitophagy. In this highly selected long-term hemodialysis population, a low oxidative phenotype could be defined by a poor endurance, a fiber-type switch, and an alteration of mitochondria structure, without evidence of sarcopenia. This phenotype could be related to uremia through the activation of autophagy/mitophagy. NCT02794142 and NCT02040363.

COVID-19 Vaccination Imperatives in People on Maintenance Dialysis: An International Perspective.

COVID-19 Vaccination Imperatives in People on Maintenance Dialysis: An International Perspective.

Smoking and risk of fractures requiring hospitalization in haemodialysis patients: a nationwide cohort study in Japan.

Smoking is a well-established lifestyle risk factor for fractures in the general population, but evidence specific to haemodialysis populations is lacking. This nationwide cohort study used data from the Japanese Society for Dialysis Therapy Renal Data Registry to examine the association between smoking status and fractures. A total of 154 077 patients (64.2% men; mean age 68 years) aged≥20 years undergoing maintenance haemodialysis thrice weekly at the end of 2016 were followed for 1 year. Among these, 19 004 (12.3%) patients were current smokers. Standardized incidence rate ratios of hospitalization due to any fracture were calculated and analysed by multivariable logistic regression analysis, controlling for potential confounders. Propensity score (PS) matching and subgroup analyses were also performed as sensitivity analyses. During the 1-year follow-up period, 3337 fractures requiring hospitalization (1201 hip, 479 vertebral and 1657 other fractures) occurred in 3291 patients. The age- and sex-standardized incidence ratio for current smokers was 1.24 (95% confidence interval 1.12-1.39) relative to non-smokers. Standardized incidence ratios were similar after stratification by age group and sex. Multivariable logistic regression analysis revealed a 1.25-fold higher risk of any fracture requiring hospitalization (95% confidence interval 1.10-1.42) in current smokers relative to non-smokers in a fully adjusted model. PS matching showed similar results (odds ratio 1.25; 95% confidence interval 1.05-1.48). Subgroup analyses for baseline covariates revealed no significant interactions. Smoking is a significant risk factor for any fracture requiring hospitalization in haemodialysis patients.

Time-dependent evolution of IgG antibody levels after first and second dose of mRNA-based SARS-CoV-2 vaccination in haemodialysis patients: a multicentre study.

BackgroundVaccination programs are essential for the containment of the COVID-19 pandemic, which has affected hemodialysis populations especially hard. Early reports suggest a reduced immunologic response to SARS-Cov-2 vaccines in dialysis patients, in spite of a high degree of seroconversion. We aimed to identify risk factors for a reduced efficacy of an mRNA vaccine in a cohort of hemodialysis patients.MethodIn a multicenter study, including 294 Portuguese hemodialysis patients who had received 2 doses of BNT162b2 with a three week interval, IgG-class antibodies against the SARS-CoV-2 spike protein were determined 3 weeks after the first dose (M1) and 6 weeks after the second dose (M2). The threshold for seroconversion was 10UR/mL. Demographic and clinical data was retrieved from a quality registry. Adverse events were registered using a questionnaire.ResultsAt M2, seroconversion was 93.1% with a median antibody level of 197.5U/mL (1.2–3237.0) and a median increase of 180.0U/mL (-82.9–2244.6) from M1. Age (beta -8.9; 95%CI: -12.88 to -4.91; P < 0.0001), ferritin > 600ng/mL (beta 183.93; 95%CI: 74.75 to 293.10; P = 0.001) and physical activity (beta 265.79; 95%CI: 30.7 to 500.88; P = 0.03) were independent predictors of SARS-Cov-2 antibody levels after two vaccine doses. Plasma albumin > 3.5g/dL independently predicted the increase of antibody levels between both doses (OR 14.72; 95%CI: 1.38 to 157.45; P = 0.03). Only mild adverse reactions were observed in 10.9% of patients.ConclusionsThe SARS-Cov-2 vaccine BNT162b2 is safe and effective in hemodialysis patients. Besides age, iron status and nutrition are possible modifiable modulators of the immunologic response to SARS-Cov-2 mRNA vaccines. This data suggests the need for an early identification of populations at higher risk for diminished antibody production and the potential advantage of the implementation of oriented strategies to maximize the immune response to vaccination in these patients.

Hemodialysis vascular access in children – A retrospective study in a pediatric dialysis unit

Objective: Permanent access in the form of a fistula is the preferred form of vascular access for most pediatric patients on maintenance hemodialysis (HD) therapy; however, the technical aspects of the procedure that are unique to the pediatric population, the expectation of a short waiting time for kidney transplantation and the need to cannulate every other day (with the pain and fear associated with it) limit its use. Our objective was to analyze the long-term outcomes of pediatric arteriovenous fistulas in our institution. Methods: A retrospective review was performed of all arteriovenous fistula (AVF) created in a HD population aged 0 to 18 years at a single institution from 2007 to 2019. Data abstracted included age, weight, etiology of renal failure, time on dialysis, central venous catheter history and transplantation history. Data were analyzed to determine the primary and secondary patency. Results: During the study period, 19 AVFs were performed in 16 patients, of whom 9 patients (56.3%) were male. Mean patient age was 12.3 years (range 5-17 years), and mean weight was 38.3kg (range 12-83kg). At the time of AVF creation, 9 patients were on dialysis and 7 patients had a central venous catheter (CVC), with a median length of CVC dependence of 10 months. Procedures performed included 4 radiocephalic fistulas, 11 brachiocephalic fistulas and 4 brachiobasilic. Five accesses failed to mature (26.3%). Mean follow-up was 6 years. The 2-year primary and secondary patency rates were 92.3% and 100%, respectively. The 4-year primary and secondary patency rates were 76.9% and 100%, respectively. No thrombosis was documented during follow-up. During the postoperative period, 10 patients (62.5%) received a kidney transplant, in a mean time of 23 months. Conclusions: AVFs demonstrate excellent long-term patency in pediatric HD patients. No significant complications were reported and no thrombosis occurred.

Impact of the vascular access on morbidity and mortality in chronic hemodialysis patients

Abstract Background Patients with endstage renal disease (ESRD) have high rates of mortality and morbidity. Adequate dialysis is essential to maintain a high quality of life and survival in these patients. Vascular access is also known as a ‘lifeline’ for patients receiving hemodialysis (HD). Complications associated with vascular access result in frequent hospitalizations and often require intervention. These complications have significant impacts on the morbidity and mortality of dialysis patients, while also leading to high medical costs. As a result, having a wellfunctioning point of vascular access is very important. We aimed to study the prevelance of different types of vascular access and practice patterns at Ain Shams university hospitals and to study the impact of vascular access related problems on morbidity and mortality. Patients and Methods This study is a prospective cohort study conducted in Ain shams university hospitals dialysis units in which all adults with end-stage kidney disease (ESRD) from the three units were included in the study. All patients were assessed as regard basic demographics, patient characteristics and vascular access characteristics. At the start of the study and then after one year data about vascular access related mortality and morbidity were collected. Statistical data analysis was done using SPSS (statistical package for the social sciences, version 2019, SPSS, Inc, Chicago, III, USA) Results In our HD population where the majority of catheters were temporary nontunneled catheters, dialysis catheter use was associated with higher mortality and increased hospitalization rates compared with AV access. These results emphasize the urgent need to minimize the use of dialysis catheters. Conclusion Using dialysis catheter carries a higher risk for life threatening complications compared to AV access.

Mortality in an Emergency-Only Hemodialysis Population from COVID-19 in a Large Safety Net

Mortality in an Emergency-Only Hemodialysis Population from COVID-19 in a Large Safety Net

Fatigue Prevalence and Associations with Non-Diuretic Anti-Hypertensive Medications in the Maintenance Hemodialysis Population

Fatigue Prevalence and Associations with Non-Diuretic Anti-Hypertensive Medications in the Maintenance Hemodialysis Population

End of life care preference among hemodialysis population: Revisit Q methodology

ObjectiveEnd-of-life care is often overlooked in the dialysis unit despite high mortality rates. This study aimed to understand the diverse subjectivity of opinions on end-of-life care preferences, feelings, needs, value and goals in life among a haemodialysis population. MethodsThe Q methodology was used where 37 opinion statements were ranked in order of importance in a unimodal shaped grid. Results were explored using the Centroids factor extraction and Varimax rotation. ResultsFour-three persons living with haemodialysis, mean age± SD= 56.58 ± 10.22 years, participated in the study. Five-factors were identified: living in the present, family preference, self preservation, power vs. control and autonomy in decision making, loaded by eleven, four, four, three and three participants with 16 individuals not loading significantly and two were confounded. Preferences for remaining positive in the face of illness through a healthy lifestyle and preserving relationships and autonomy were demonstrated. ConclusionsEnd-of-life discussions are potentially inhibited by preferences to live for the present which should be explored in future studies. Practice implicationStatement sets may be used to help facilitate end-of-life discussions through identification of opinion groups. Establishing preferences may guide identification of those willing to initiate discussions.

The Accuracy of Hemoglobin A1c and Fructosamine Evaluated by Long-Term Continuous Glucose Monitoring in Patients with Type 2 Diabetes Undergoing Hemodialysis

Introduction: The accuracy of hemoglobin A1c (HbA1c) as a glycemic marker in patients with type 2 diabetes (T2D) receiving hemodialysis (HD) remains unknown. To assess accuracy, we compared HbA1c and fructosamine levels with interstitial glucose measured by continuous glucose monitoring (CGM) in patients with T2D receiving HD. Methods: Thirty patients in the HD group and 36 patients in the control group (T2D and an estimated glomerular filtration rate >60 mL/min/1.73 m²) completed the study period of 17 weeks. CGM (Ipro2^®, Medtronic) was performed 5 times for periods of up to 7 days (with 4-week intervals) during a 16-week period. HbA1c (mmol/mol), the estimated mean plasma glucose from HbA1c (eMPGA1c [mmol/L]) and fructosamine (μmol/L) was measured at week 17 and compared with mean sensor glucose levels from CGM. Findings: In the HD group, mean sensor glucose was 1.4 mmol/L (95% confidence interval [CI]: 1.0–1.8) higher than the eMPGA1c, whereas the difference for controls was 0.1 mmol/L (95% CI: −0.1–[0.4]; p < 0.001). Adjusted for mean sensor glucose, HbA1c was lower in the HD group (−7.3 mmol/mol, 95% CI: −10.0–[−4.7]) than in the control group (p < 0.001), with no difference detected for fructosamine (p = 0.64). Discussion: HbA1c evaluated by CGM underestimates plasma glucose levels in patients receiving HD. The underestimation represents a clinical challenge in optimizing glycemic control in the HD population. Fructosamine is unaffected by the factors affecting HbA1c and appears to be more accurate for glycemic monitoring. CGM or fructosamine could thus complement HbA1c in obtaining more accurate glycemic control in this patient group.

Vancomycin pharmacokinetics in patients treated with intermittent haemodialysis based on therapeutic drug monitoring

Vancomycin is frequently used in haemodialysis (HD) patients but generally accepted target serum ranges and dosing strategy are still lacking in this group. Based on retrospective analysis of data from 118 HD patients treated with vancomycin the interdialytic elimination constant (Ke), apparent volume of distribution (Vd) and dialysis efficacy were calculated. The influence of possible clinical variables on the pharmacokinetic parameters of vancomycin have been tested. The median of Ke in interdialytic periods, corresponding half-life and Vd were 0.0073 h−1, 95.0 h and 0.87 L/kg, respectively. We found significant positive correlation between time in dialysis program and Ke. The Vd correlated best with lean body mass (LBM). For high- and low flux membrane HD of 4 hours duration the decline in vancomycin levels was 20.88% and 12.86%, respectively. Based on these data loading dose for vancomycin in HD patient should be calculated as 24.483 × LBM (kg) + 455 mg. The utility of this equation for entire HD population should be also verified prospectively.

Stable incidence and survival of arteriovenous fistulas over 39 years: A long-term national cohort study.

The age and number of comorbidities in the hemodialysis population has increased over time. This may influence the construction and survival of the arteriovenous fistula (AVF). The present study explored the incidence and survival of AVFs over a period of 39 years. A retrospective cohort study was conducted based on Danish registries. Incident hemodialysis patients between 1977 and 2015 were included. The incidence of AVF and factors associated with the construction of an AVF were described. Risk factors for AVF survival and repair were explored by Kaplan Meier and Cox proportional hazard analysis. The total number of arteriovenous accesses (AVF and arteriovenous grafts) were 10,187 and there were 4201 central venous catheters (CVC). No significant difference in the proportion of AVFs during the 39 years was seen. Age and renal diagnosis did not influence the proportion of AVFs. Patients with CVCs were found to have a significantly higher prevalence of comorbidities (p < 0.01). AVF survival remained stable during the 39 years. The first constructed AVF had the best survival, 35% still functioning after 15 years. Factors such as brachiocephalic AVF, female sex, and diabetic nephropathy increased the risk of AVF failure (Odds Ratio (OR): 2.46, 95% Confidence Interval (CI) (2.29-2.65), 1.17 (1.10-1.25), and 1.21 (1.12-1.3)), respectively. Despite an older dialysis population, the proportion and survival of the AVF in the Danish dialysis population has not changed, probably because of increased awareness of AVF as the first choice of vascular access and improved surveillance, surgery, and repair.

Use of Sertraline in Hemodialysis Patients.

Depression and anxiety are the most common psychiatric disorders in end-stage renal disease (ESRD) patients treated with hemodialysis (HD) and may correlate with lower quality of life and increased mortality. Depression treatment in HD patients is still a challenge both for nephrologists and psychiatrists. The possible treatment of depressive disorders can be pharmacological and non-pharmacological. In our article, we focus on the use of sertraline, the medication which seems to be relatively safe and efficient in the abovementioned population, taking under consideration several limitations regarding the use of other selective serotonin reuptake inhibitors (SSRIs). In our paper, we discuss different aspects of sertraline use, taking into consideration possible benefits and side effects of drug administration like impact on QTc (corrected QT interval) prolongation, intradialytic hypotension (IDH), chronic kidney disease-associated pruritus (CKD-aP), bleeding, sexual functions, inflammation, or fracture risk. Before administering the medication, one should consider benefits and possible side effects, which are particularly significant in the treatment of ESRD patients; this could help to optimize clinical outcomes. Sertraline seems to be safe in the HD population when provided in proper doses. However, we still need more studies in this field since the ones performed so far were usually based on small samples and lacked placebo control.

Evaluation of the SARS-CoV-2 Antibody Response to the BNT162b2 Vaccine in Patients Undergoing Hemodialysis

Patients undergoing hemodialysis have a high mortality rate associated with COVID-19, and this patient population often has a poor response to vaccinations. Randomized clinical trials for COVID-19 vaccines included few patients with kidney disease; therefore, vaccine immunogenicity is uncertain in this population. To evaluate the SARS-CoV-2 antibody response in patients undergoing chronic hemodialysis following 1 vs 2 doses of BNT162b2 COVID-19 vaccination compared with health care workers serving as controls and convalescent serum. A prospective, single-center cohort study was conducted between February 2 and April 17, 2021, in Toronto, Ontario, Canada. Participants included 142 patients receiving in-center hemodialysis and 35 health care worker controls. BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine. SARS-CoV-2 IgG antibodies to the spike protein (anti-spike), receptor binding domain (anti-RBD), and nucleocapsid protein (anti-NP). Among the 142 participants undergoing maintenance hemodialysis, 94 (66%) were men; median age was 72 (interquartile range, 62-79) years. SARS-CoV-2 IgG antibodies were measured in 66 patients receiving 1 vaccine dose following a public health policy change, 76 patients receiving 2 vaccine doses, and 35 health care workers receiving 2 vaccine doses. Detectable anti-NP suggestive of natural SARS-CoV-2 infection was detected in 15 of 142 (11%) patients at baseline, and only 3 patients had prior COVID-19 confirmed by reverse transcriptase polymerase chain reaction testing. Two additional patients contracted COVID-19 after receiving 2 doses of vaccine. In 66 patients receiving a single BNT162b2 dose, seroconversion occurred in 53 (80%) for anti-spike and 36 (55%) for anti-RBD by 28 days postdose, but a robust response, defined by reaching the median levels of antibodies in convalescent serum from COVID-19 survivors, was noted in only 15 patients (23%) for anti-spike and 4 (6%) for anti-RBD in convalescent serum from COVID-19 survivors. In patients receiving 2 doses of BNT162b2 vaccine, seroconversion occurred in 69 of 72 (96%) for anti-spike and 63 of 72 (88%) for anti-RBD by 2 weeks following the second dose and median convalescent serum levels were reached in 52 of 72 patients (72%) for anti-spike and 43 of 72 (60%) for anti-RBD. In contrast, all 35 health care workers exceeded the median level of anti-spike and anti-RBD found in convalescent serum 2 to 4 weeks after the second dose. This study suggests poor immunogenicity 28 days following a single dose of BNT162b2 vaccine in the hemodialysis population, supporting adherence to recommended vaccination schedules and avoiding delay of the second dose in these at-risk individuals.