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Background: Hemodialysis (HD) patients are at increased risk for COVID-19 infection, hospitalization, and mortality. Early COVID-19 diagnosis is thus critical to mitigate SARS-CoV-2 spread and improving patients' health outcomes. Generally, nasopharyngeal (NP) specimens are considered the most sensitive biological samples to diagnose SARS-CoV-2 infections. However, NP swabbing is considered uncomfortable by most patients, and it requires health professionals, thus impacting its cost-effectiveness. In a previous proof-of-principle study, we demonstrated that face masks worn by in-center HD patients can harbor SARS-CoV-2. In this Kidney-X funded study, we determined efficiency of face mask testing by comparing results to saliva specimen collected from same individuals. Method(s): Disposable 3-layer masks were provided to each subject at the time of entering the dialysis center. Masks were collected 4 hours after worn. Saliva was collected using Salivette kit at the time of mask collection. RT-PCR based testing were performed using Thermo Fisher COVID-19 Combo Kit (A47814). Result(s): We collected 179 pairs of saliva/masks, 114 from 42 dialysis staff and patients without recent COVID-19 infection (control group), and 65 from 30 HD patients with COVID-19, diagnosed by NP RT-PCR (COVID-19 group). Patients provided 1 to 7 sample pairs on average 11+/-8 days (0 to 36) after COVID-19 diagnosis. Thirty-one of the 65 sample pairs were SARS-CoV-2 positive either in the saliva or the mask samples (26 positive saliva;20 positive masks). Saliva and mask testing sensitivities were 84% and 65% with a mean cycle threshold (CT) of 31.8 and 32.2, respectively. Fifteen pairs tested positive for both worn masks and saliva. Mask and saliva CT values did not differ significantly. Of note, in 5 sample pairs saliva tested negative while masks tested positive. In the control group, all 114 saliva samples tested negative;one mask tested weakly positive, resulting in saliva and mask testing specificities of 100% and 99%, respectively. S gene dropout was observed in all positive samples, indicating Omicron BA.1 infection. Conclusion(s): While the sensitivity of mask testing is less compared to saliva testing, its operational ease, lack of patient discomfort, seamless repeatability, and lower costs make it a viable option for SARS-CoV-2 screening.
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Background: Hemodialysis (HD) patients are vulnerable to COVID-19. Early detection of COVID-19 in dialysis clinics informs isolation and infection control policies. Saliva testing is an alternative to nasopharyngeal swab to detect SARS-CoV-2. The understanding of viral shedding in HD patients is limited. We explore viral shedding duration in HD patients and determine its correlation with immunosuppression. Method(s): Eligible patients diagnosed with COVID-19, confirmed by nasal swab RTPCR within 2 weeks of COVID-19 diagnosis, were recruited. They were given Salivette Saliva Collection kits and instructed to chew a cotton swab for 60 seconds. Result(s): 30 COVID-19 positive patients participated (Table 1). Each patient provided up to 7 saliva samples. 65 samples were collected for an average of 11+/-8 days (range 0-36) after diagnosis. 26 samples showed at least one COVID-19 target gene (N, ORF1ab) with cycle threshold <38 cycles. 12 patients had at least 1 positive sample, and 23 patients had at least 1 negative sample. Of the 23 patients who had at least one negative sample, median days to first negative sample is 9 days (range 0-36). For the 7 patients who only had positive samples, median days to last positive sample is 9 days (range 0-36). There is no observed difference between vaccinated (n=24) and vaccinated patients (n=6). 6 out of 30 patients took immunosuppressants such as Tacrolimus, Hydroxychloroquine, and Mycophenolate sodium. Median days to turn negative (or use last positive date if negative results never achieved) was 15 days for immunocompromised group and 8 days for nonimmunocompromised group (Fig.1) Conclusion(s): Immunocompromised HD patients shed COVID-19 virus for a significantly longer period. While our study did not explore the shedding of viable SARS-CoV-2, a longer isolation should be considered in immunosuppressed HD patients. Studies on shedding of viable SARS-CoV-2 are warranted in immunocompromised HD patients to inform policies regarding isolation and contact tracing protocols, and vaccination strategies.
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Background: Hemodialysis (HD) patients are less likely to mount a response to the COVID-19 vaccination (CoVac). Poor sleep is associated with blunted vaccination response in the general population. We aim to explore the association between CoVac and sleep quality (SQ) in HD patients. Method(s): Patients from 3 HD clinics were enrolled if they were >=18 years and able to give written consent. Patients were administered the Insomnia Severity Index (ISI) and the Pittsburg Sleep Quality Index (PSQI). Blood specimen were collected after the primary series of COVID-19 vaccination. SARS-CoV-2 neutralization antibodies (nAB) were assayed using the GenScript SARS-CoV-2 Surrogate Virus Neutralization Test Kit (Cat#L00847-A). nAB titers are presented as Unit/ml on a natural log scale. PSQI scores of >5 were categorized as poor SQ and <=5 as good SQ. ISI scores were grouped as no clinically significant insomnia (NI;score 0-7), subthreshold insomnia (SI;score 8-14), and clinical insomnia (CI;score 14-28). T-test and ANOVA analysis were performed on PSQI and ISI scores, respectively, to determine the statistical association between SQ and nAB levels Results: 58 patients were included (60+/-9 years old, HD vintage 4.7+/-4.5 years, 62% male, 66% Black, 21% Hispanic). In the PSQI, 72% (n=42) had poor SQ. In the ISI, 52% = NI, 31% = SI, and 17% CI. Box plots of nAB levels with median and IQR are shown in Fig. 1. There is no association between SQ and nAB levels. Conclusion(s): There is no association between SQ and CoVac response. Given the immune dysfunction in this population, any modifying effect SQ has on CoVac, as observed in the general population, is unlikely. Other methods of improving CoVac response in this vulnerable population should be explored. (Figure Presented).
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Background: Data on the persistence of COVID-19 antibodies against SARSCoV-2 in maintenance hemodialysis (MHD) patients from the U.S. is still scarce and an association with race and ethnicity is unknown. We explore antibody dynamics in MHD patients from three U.S. states with a diverse racial and ethnic background. Methods: We obtained consent from MHD patients with COVID-19, confirmed by RT-PCR, from 12 clinics. Phase 1 antibody testing was done between June and August 2020. Re-testing was done 6-8 months later. Antibodies were tested with an emergency use authorized assay (Diazyme DZ-LITE SARS-CoV-2 IgG CLIA kit). Linear mixedeffects models were employed to estimate the IgG half-life in patients with repeated IgG measurements. Patients were stratified by sex, race, ethnicity, obesity, and medians of age, dialysis vintage and body mass index. Results: 104 patients (age 63.8±13 years, 67 (64.4%) males;48 (46.2%) Africa-American, and 34 (32.7%) Hispanics) were studied. IgG was obtained 82 days (range 13 to 151) and 253 days (range 170 to 309) post-COVID-19. At initial testing, 101 (97.1%) patients were positive for IgG. 89 of them were available for repeated testing, where 74 (83.1%) showed persistent IgG. The luminescence signal was declined by 35.5 AU/ mL (95% CI 28.7 to 42.4) from 47.8 ± 44.9 to 12.3 ± 21.1 AU/mL (P<0.0001;paired t-test;Figure.1). The estimated half-life of IgG was 62.8 days (95% CI 56.8 to 68.8). We observed no significant differences in the stratified analysis (Table 1;all p > 0.05). Conclusions: The half-life of IgG against SARS-CoV-2 was approximately 63 days, corroborating reports from both the general and other MHD populations. Importantly, we found no association between IgG half-life, race and ethnicity.
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BACKGROUND AND AIMS: Dialysis patients are at higher risk for severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection. Longevity of antibody response to SARS-CoV-2 infection remains unclear. It is reported that maintenance hemodialysis (MHD) patients can mount an antibody response that is similar in intensity and timing to the non-dialysis population. We aim to investigate the prevalence and persistence of antibodies in hemodialysis patients. METHOD: We measured IgG and IgM antibodies in MHD patients as part of a quality improvement project. Four New York City dialysis clinics participated in this study. Strict policy of RT-PCR testing was implemented in clinics for patients with signs and symptoms of Coronavirus Disease 2019 (COVID-19). Initial antibody testing was done on June 10 and July 13, 2020 (phase 1) and retesting was done for previously positive patients between December 9 and 17, 2020 (phase 2). Upon obtaining verbal consent, 3.5 ml of pre-dialysis blood samples were taken via vascular access. SARS-CoV-2 antibodies were determined using the emergency use authorized Diazyme DZ-Lite SARS-CoV-2 IgM / IgG CLIA assays with 100% sensitivity and 98% specificity. Detection of formed immune-complexes is achieved with N-(4-amino-butyl)-N-ethylisoluminol;the luminescence signal is reported as units per ml (AU/ml), values ≥ 1.00 AU/ml are considered as 'reactive' and < 1.00 AU/ml as 'non-reactive.' RESULTS: A total of 429 MHD patients were studied in phase 1. Antibodies were present in 130 (30.3%) and only 55 patients with Covid-19 diagnosis confirmed by RTPCR test were reactive for IgG antibodies. The time to antibody testing was 73 days (median 77;range 30-111) days. In the phase 2 antibody testing, IgG antibodies were only detected in 47 patients (85.5%) 242 days (median 245, range 204 to 268) after clinical diagnosis of Covid-19. Between the two phases of antibody testing, the luminescence signal declined by 40.9 AU/mL (95% confidence interval 31.5 to 50.3) from 54.1±45.3 to 13.2±20.9 AU/mL (P<0.0001 by paired t-test;Figure 1). In univariate logistic regression, a higher number of days between clinical diagnosis of COVID-19 and the second antibody measurement was associated with a lower seropositivity rate (odds ratio 0.929, 95% confidence interval 0.864 to 0.998, P=0.044). Antibody persistence was not associated with age, gender, race, and ethnicity. CONCLUSION: We observed that about 6 out of 7 MHD patients maintain SARSCoV-2 antibodies over 6-9 months but there is a significant decline of IgG level. The time between clinical diagnosis and IgG testing was associated with IgG decline. Follow up study to understand antibody dynamics in MHD population is a crucial step once vaccines become available.
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Background: On March 20, 2020, to stop the spread of the COVID-19, the New York State Governor issued a strict stay at home order for all tasks that were deemed as “nonessential” starting March 22 at 8PM. We would like to determine what change, if any, in physical activity levels (PAL) took place because of the lockdown order in HD patients. Methods: HD patients were enrolled from 4 clinics in New York City starting in May 2018 and followed for a period of up to 1 year. Patients ≥18 years, on HD ≥3 months, able to walk, and owning a smartphone were enrolled. PAL was defined by steps taken per day measured by with a wrist-based monitoring device (Fitbit Charge 2). Patients still in the study as of March 22, 2020 were included in the study cohort. Average steps per day was calculated for Jan 1-Feb 13, 2020 and the five weeks prior to and after the lockdown went into place. A linear mixed-effect model was used to estimate the average steps per day and 95% confidence intervals. Socioeconomic parameters such as age, race, employment status, and education level were taken at the beginning of the study. Results: 42 patients were included in this analysis. At enrollment patients were 55±11 years old with a dialysis vintage of 4.5±4.4 years, and a BMI of 28.9±8.6 kg/ m2. 33% lived alone, 48% were single, 50% unemployed, 69% were African American, and 50% had an education level of some college or higher. Results on average steps per day are presented in Figure 1. Steps per day decreased significantly after the lockdown order with the most significant drop when the COVID-19 pandemic was declared a national emergency Conclusions: There was a decrease in PAL due to the mandated lockdown. As sedentary behavior is a risk factor for negative outcomes in the HD population, we must implement interventions to promote PAL, such as intradialytic exercise. (Figure Presented).