Longevity of SARS-CoV-2 immune responses in hemodialysis patients and protection against reinfection

Abstract

Patients with end stage kidney disease receiving in-center hemodialysis (ICHD) have had high rates of SARS-CoV-2 infection. Following infection, patients receiving ICHD frequently develop circulating antibodies to SARS-CoV-2, even with asymptomatic infection. Here, we investigated the durability and functionality of the immune responses to SARS-CoV-2 infection in patients receiving ICHD. Three hundred and fifty-six such patients were longitudinally screened for SARS-CoV-2 antibodies and underwent routine PCR-testing for symptomatic and asymptomatic infection. Patients were regularly screened for nucleocapsid protein (anti-NP) and receptor binding domain (anti-RBD) antibodies, and those who became seronegative at six months were screened for SARS-CoV-2 specific T-cell responses. One hundred and twenty-nine (36.2%) patients had detectable antibody to anti-NP at time zero, of whom 127 also had detectable anti-RBD. Significantly, at six months, 71/111 (64.0%) and 99/116 (85.3%) remained anti-NP and anti-RBD seropositive, respectively. For patients who retained antibody, both anti-NP and anti-RBD levels were reduced significantly after six months. Eleven patients who were anti-NP seropositive at time zero, had no detectable antibody at six months; of whom eight were found to have SARS-CoV-2 antigen specific T cell responses. Independent of antibody status at six months, patients with baseline positive SARS-CoV-2 serology were significantly less likely to have PCR confirmed infection over the following six months. Thus, patients receiving ICHD mount durable immune responses six months post SARS-CoV-2 infection, with fewer than 3% of patients showing no evidence of humoral or cellular immunity. Patients with end stage kidney disease receiving in-center hemodialysis (ICHD) have had high rates of SARS-CoV-2 infection. Following infection, patients receiving ICHD frequently develop circulating antibodies to SARS-CoV-2, even with asymptomatic infection. Here, we investigated the durability and functionality of the immune responses to SARS-CoV-2 infection in patients receiving ICHD. Three hundred and fifty-six such patients were longitudinally screened for SARS-CoV-2 antibodies and underwent routine PCR-testing for symptomatic and asymptomatic infection. Patients were regularly screened for nucleocapsid protein (anti-NP) and receptor binding domain (anti-RBD) antibodies, and those who became seronegative at six months were screened for SARS-CoV-2 specific T-cell responses. One hundred and twenty-nine (36.2%) patients had detectable antibody to anti-NP at time zero, of whom 127 also had detectable anti-RBD. Significantly, at six months, 71/111 (64.0%) and 99/116 (85.3%) remained anti-NP and anti-RBD seropositive, respectively. For patients who retained antibody, both anti-NP and anti-RBD levels were reduced significantly after six months. Eleven patients who were anti-NP seropositive at time zero, had no detectable antibody at six months; of whom eight were found to have SARS-CoV-2 antigen specific T cell responses. Independent of antibody status at six months, patients with baseline positive SARS-CoV-2 serology were significantly less likely to have PCR confirmed infection over the following six months. Thus, patients receiving ICHD mount durable immune responses six months post SARS-CoV-2 infection, with fewer than 3% of patients showing no evidence of humoral or cellular immunity. The efficacy results from several severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine trials provided welcome news at the end of 2020, as the rollout of effective vaccination programs set to mark the beginning of the end of the pandemic.1Polack F.P. Thomas S.J. Kitchin N. et al.Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine.N Engl J Med. 2020; 383: 2603-2615Crossref PubMed Scopus (9742) Google Scholar, 2Folegatti P.M. Ewer K.J. Aley P.K. et al.Safety and immunogenicity of the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2: a preliminary report of a phase 1/2, single-blind, randomised controlled trial.Lancet. 2020; 396: 467-478Abstract Full Text Full Text PDF PubMed Scopus (1774) Google Scholar, 3Baden L.R. El Sahly H.M. Essink B. et al.Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine.N Engl J Med. 2021; 384: 403-416Crossref PubMed Scopus (6728) Google Scholar The Moderna (mRNA-1273), Pfizer/BioNTech (BNT162b2 mRNA), and Oxford/AstraZeneca (ChAdOx1 nCoV-19) vaccines have all been shown to induce robust humoral and cellular immune responses against the spike protein of SARS-CoV-2, which importantly protect individuals from the risk of subsequent infection.4Barrett J.R. Belij-Rammerstorfer S. Dold C. et al.Phase 1/2 trial of SARS-CoV-2 vaccine ChAdOx1 nCoV-19 with a booster dose induces multifunctional antibody responses.Nat Med. 2021; 27: 279-288Crossref PubMed Scopus (217) Google Scholar,5Walsh E.E. Frenck Jr., R.W. Falsey A.R. et al.Safety and immunogenicity of two RNA-based Covid-19 vaccine candidates.N Engl J Med. 2020; 383: 2439-2450Crossref PubMed Scopus (1770) Google Scholar However, given the logistical issues associated with supply, distribution, and administration of vaccines globally, adjunct prevention and control measures are going to need to be continued in the months to come. Patients with end-stage kidney disease (ESKD) have been identified as having a poor prognosis after SARS-CoV-2 infection.6Valeri A.M. Robbins-Juarez S.Y. Stevens J.S. et al.Presentation and outcomes of patients with ESKD and COVID-19.J Am Soc Nephrol. 2020; 31: 1409-1415Crossref PubMed Scopus (258) Google Scholar, 7Clarke C. Prendecki M. Dhutia A. et al.High prevalence of asymptomatic COVID-19 infection in hemodialysis patients detected using serologic screening.J Am Soc Nephrol. 2020; 31: 1969-1975Crossref PubMed Scopus (114) Google Scholar, 8Corbett R.W. Blakey S. Nitsch D. et al.Epidemiology of COVID-19 in an urban dialysis center.J Am Soc Nephrol. 2020; 31: 1815-1823Crossref PubMed Scopus (172) Google Scholar In addition, it is recognized that patients receiving in-center hemodialysis (ICHD) are at a higher risk of acquiring infection owing to the inability to shield effectively.8Corbett R.W. Blakey S. Nitsch D. et al.Epidemiology of COVID-19 in an urban dialysis center.J Am Soc Nephrol. 2020; 31: 1815-1823Crossref PubMed Scopus (172) Google Scholar Using serological methods, we have previously shown that patients with ESKD readily seroconvert after confirmed SAR-CoV-2 infection; we have also shown that asymptomatic seroconversion is common in the high exposure setting of ICHD units.7Clarke C. Prendecki M. Dhutia A. et al.High prevalence of asymptomatic COVID-19 infection in hemodialysis patients detected using serologic screening.J Am Soc Nephrol. 2020; 31: 1969-1975Crossref PubMed Scopus (114) Google Scholar What is not currently known in this population is the durability of detectable immune responses and whether the presence of SARS-CoV-2 antibodies protects an individual with ESKD from reinfection. In this study, we report the longitudinal serological status of a large cohort of patients receiving ICHD. The aim of our study was to compare the longevity of the antibodies to the different SARS-CoV-2 antigenic targets, namely, the nucleocapsid and receptor-binding domain of the spike protein. We investigate cellular immune responses in patients in whom antibody responses have waned, and finally we evaluate whether immune responses to SARS-CoV-2 infection protect patients receiving dialysis from subsequent reinfection. Three hundred fifty-six patients receiving ICHD within 2 units affiliated with Imperial College Renal and Transplant Centre as previously reported were included.7Clarke C. Prendecki M. Dhutia A. et al.High prevalence of asymptomatic COVID-19 infection in hemodialysis patients detected using serologic screening.J Am Soc Nephrol. 2020; 31: 1969-1975Crossref PubMed Scopus (114) Google Scholar Patients were followed up from 24 February 2020 until 1 January 2021. All patient samples (n = 356) at time 0 were tested for nucleocapsid protein (anti-NP) and RBD (anti-RBD) antibodies. At 6 months, all available samples (n = 301) were retested for anti-NP (Supplementary Figure S1). In addition, samples were tested for anti-RBD if any of the following criteria were met: patients were anti-NP+ at 6 months or patients had an equivocal anti-NP result (i.e., a cutoff index [S/C] of 0.25–1.39) or were anti-NP− (i.e., an S/C of ≤0.24) at 6 months but were either anti-NP+ and/or anti-RBD+ at baseline. Patient outcomes, including all new SARS-CoV-2 infections confirmed by viral detection, were recorded up until 1 January, which incorporate data from the second wave of infections in the United Kingdom. A diagramatic overview of the outcome of patients by serological and symptomatic status is shown in Figure 1. The study was approved by the Health Research Authority Research Ethics Committee (Reference: 20/WA/0123 - The Impact of COVID-19 on Patients with Renal disease and Immunosuppressed Patients). Baseline serum from all patients were tested for both anti-NP and anti-RBD antibodies. The presence of anti-NP was assessed using the commercially available Abbott Architect SARS-CoV-2 IgG II step chemiluminescent immunoassay according to the manufacturer’s instructions. For this study, samples were interpreted as positive or negative according to the manufacturer’s instructions with a cutoff index value of 1.4.9Public Health EnglandEvaluation of the Abbott SARS-CoV-2 IgG for the detection of anti-SARS-CoV-2 antibodies.https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/887221/PHE_Evaluation_of_Abbott_SARS_CoV_2_IgG.pdfGoogle Scholar Anti-RBD was detected using an in-house double-antigen binding enzyme-linked immunoassay (Imperial SARS-CoV-2 Hybrid DABA, Imperial College London, London, UK), which detects total RBD antibodies.10Rosadas C. Randell P. Khan M. et al.Testing for responses to the wrong SARS-CoV-2 antigen?.Lancet. 2020; 396: e23Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar The in-house assay cutoff was calculated from receiver operating characteristic curve analysis, and serum reactivity was normalized by using the signal-to-cutoff ratio. For this study, a sample was considered antibody positive if the signal-to-cutoff ratio was >1.2. An RBD assay was used in addition to an anti-NP assay, as anti-RBD has been shown to correlate with anti-neutralizing antibodies.11Premkumar L. Segovia-Chumbez B. Jadi R. et al.The receptor-binding domain of the viral spike protein is an immunodominant and highly specific target of antibodies in SARS-CoV-2 patients.Sci Immunol. 2020; 5eabc8413Crossref PubMed Scopus (0) Google Scholar T-cell responses were investigated in cases where serological evidence of infection, both anti-NP and anti-RBD, had waned at 6 months. SARS-CoV-2–specific T-cell responses were detected using T-SPOT Discovery SARS-CoV-2 (Oxford Immunotec) according to the manufacturer’s instructions. In brief, peripheral blood mononuclear cells were isolated from whole blood samples using T-Cell Select (Oxford Immunotec) where indicated. A total of 250,000 peripheral blood mononuclear cells were plated in individual wells of a T-SPOT Discovery SARS-CoV-2 plate. The assay measures immune responses to 5 different overlapping SARS-CoV-2 structural peptide pools: spike protein, nucleocapsid protein, membrane protein, and a mix of structural proteins, as well as positive and negative controls. Cells were incubated, and interferon-γ–secreting T cells were detected. The sum of T-SPOT immune responses to SARS-CoV-2 structural peptides was calculated. Counts >12 spots per 250,000 peripheral blood mononuclear cells were reported as positive.12Wyllie D, Mulchandani R, Jones HE, et al. SARS-CoV-2 responsive T cell numbers are associated with protection from COVID-19: a prospective cohort study in keyworkers [e-pub ahead of print]. medRxiv. https://doi.org/10.1101/2020.11.02.20222778. Accessed December 15, 2020.Google Scholar Infection with SARS-CoV-2 was confirmed through reverse transcriptase polymerase chain reaction (PCR) assay of nasopharyngeal swab specimens, either after routine screening or after acute presentation. Reverse transcriptase PCR was performed as per Public Health England guidelines by using certification marked assays with primers directed against multiple targets of SARS-CoV-2 genes.13Public Health England. Guidance and standard operating procedure COVID-19 virus testing in NHS laboratories. Available at: https://www.rcpath.org?uploads?assets?90111431-8aca-4614-b06633d07e2a3dd9/Guidance-and-SOP-COVID-19-Testing-NHS-Laboratories.pdf. Accessed December 15, 2020.Google Scholar Between March and June 2020, patients underwent reverse transcriptase PCR testing of nasopharyngeal swabs when they presented for dialysis with symptoms. In June, all patients in our center were screened regardless of symptoms, as part of a single surveillance exercise to ascertain prevalent infection. From the start of the second wave in November 2020, all patients receiving ICHD underwent weekly routine reverse transcriptase PCR testing of nasopharyngeal swabs. Statistical and graphical analyses were performed with MedCalc v19.2.1 (STATA Corporation). The 2-sided level of significance was set at P < 0.05. The chi-square test was used for proportional assessments. Nonparametric data were compared using the Mann-Whitney test. The Wilcoxon test was used to compare antibody levels of paired samples. Using the log-rank test, Kaplan-Meier analyses were used to estimate and compare the risk of infection (or reinfection) by serological status. We recorded any positive PCR test at after a positive serological test at time 0 to of viral detection of the D. et status and of SARS-CoV-2 infection in Engl J Med. 2021; 384: PubMed Scopus Google Scholar we were not PCR all asymptomatic cases at the time of serological we also used the PCR results screening in the was for in the of PCR and At time of patients (36.2%) had detectable anti-NP and of had detectable anti-RBD. anti-NP and anti-RBD detection was in of patients The of patients by anti-NP status has been previously and are in C. Prendecki M. Dhutia A. et al.High prevalence of asymptomatic COVID-19 infection in hemodialysis patients detected using serologic screening.J Am Soc Nephrol. 2020; 31: 1969-1975Crossref PubMed Scopus (114) Google by anti-NP antibody status at time (n = (n = of at nucleocapsid kidney end-stage kidney are as or P are shown in in a new nucleocapsid kidney end-stage kidney are as or P are shown in Three hundred patients had a sample available at 6 months after the the patients who were anti-NP− at time 6 had detectable anti-NP by of whom had disease in the In patients who were anti-NP+ at time the S/C was significantly higher in symptomatic patients than in asymptomatic with a value of and = One hundred of patients who were anti-NP+ at time 0 had a sample available at 6 months. of were found to be anti-NP− at 6 months. In patients who were anti-NP+ at both time 0 and 6 months, the S/C was significantly at 6 months than at time 0 at and < the patients who were anti-NP+ at time 127 patients were the patients who were anti-NP− at time were In anti-RBD+ the antibody index at time 0 was also significantly higher in symptomatic patients that in asymptomatic with a signal-to-cutoff ratio of and = the patients with anti-RBD at baseline with samples available for testing at 6 months, patients (85.3%) remained Anti-RBD durability was significantly than anti-NP durability = and of the patients who became remained anti-RBD+ at 6 months. to for those patients antibody, the anti-RBD index value was significantly higher at time 0 than at 6 months, with a signal-to-cutoff ratio of and < patients who were anti-NP+ at time 0 were seronegative for both anti-NP and anti-RBD at 6 months. One of patients had a in the and T-cell responses were investigated in the had positive enzyme-linked immune as shown in Three patients were found to have T-cell all were than 1 had a of but were All patients had asymptomatic infection; 2 of the had both detectable anti-NP and anti-RBD at 1 of the had anti-NP but was T-cell responses were not available in patients who were anti-NP− but anti-RBD+ at time of patients who were seronegative by anti-NP and anti-RBD antibodies at 6 of SARS-CoV-2 kidney end-stage kidney nucleocapsid polymerase chain anti-RBD, receptor-binding SARS-CoV-2, severe acute respiratory syndrome coronavirus in a new kidney end-stage kidney nucleocapsid polymerase chain anti-RBD, receptor-binding SARS-CoV-2, severe acute respiratory syndrome coronavirus the results of the of the patients who were had evidence of of either serological or cellular immune responses against SARS-CoV-2 at 6 months. we investigated the of immune responses in of the risk of a subsequent of SARS-CoV-2 infection. the of the time 0 serological test, anti-NP− and 1 anti-NP+ patients and anti-NP− and anti-NP+ patients had a positive PCR test. From after serological anti-NP+ patients were at a significantly risk of with SARS-CoV-2 compared with anti-NP− patients P = as shown in Figure The 2 patients who were anti-NP+ at baseline who on to have subsequent infection both had asymptomatic infection; of the patients had subsequent asymptomatic infection by surveillance the patient had symptomatic infection and the patients who had a positive PCR test at after the serological test, had for after PCR of whom 2 had patients were also at a risk of with SARS-CoV-2 by PCR testing compared with patients P = as shown in Figure the anti-RBD+ patients who were anti-NP− at time 2 on to have a test at the was at after the serological test, and this viral than reinfection. The second was a patient in who was at after a symptomatic infection who has a We have shown that immune responses to SARS-CoV-2 infection in patients receiving ICHD are durable for up to 6 months, even in patients who had or asymptomatic infection. we have provided data that that an immune to SARS-CoV-2 infection protection against or in patients receiving dialysis in the Using serological status to exposure in receiving ICHD patients at a higher risk of infection vaccine A large longitudinal study of has shown that the presence of or anti-NP antibodies was associated with a reduced risk of over a D. et status and of SARS-CoV-2 infection in Engl J Med. 2021; 384: PubMed Scopus Google et al. antibody positive have SARS-CoV-2 infection rates than antibody negative prospective cohort study June to November 2020 [e-pub ahead of print]. medRxiv. Accessed December 15, 2020.Google Scholar data are with the of of in the Centre for and with SARS-CoV-2: for A. What for 2021; Full Text Full Text PDF PubMed Scopus Google Scholar However, given this study who are likely to be significantly and to patients with ESKD in the of data be However, a which investigated the humoral and cellular responses in patients with SARS-CoV-2 and a of has also shown that robust immune responses for at months et to SARS-CoV-2 assessed for up to months after 2021; PubMed Scopus Google Scholar this be data for patients receiving a study from this was a in immune responses in C. et to SARS-CoV-2 in acute COVID-19 and with and disease 2020; Full Text Full Text PDF PubMed Scopus Google Scholar is of for the as patients receiving dialysis are also known to have of both the and immune responses that correlate with cell and in end-stage Nephrol. PubMed Scopus Google Scholar study, which is the to investigate longevity of SARS-CoV-2 immune responses in patients receiving is of we have shown that antibody levels over time and the of with infection D. et of antibodies in with Engl J Med. 2020; 383: PubMed Scopus Google Scholar We found that symptomatic infection is associated with higher antibody and it was to that the of S/C in patients receiving dialysis is with that in as reported in using the serological D, et al. The and of SARS-CoV-2 antibody responses in individual [e-pub ahead of print]. Accessed January Scholar with data in we have shown that an anti-RBD immune is durable than an anti-NP D, et al. The and of SARS-CoV-2 antibody responses in individual [e-pub ahead of print]. Accessed January Scholar However, we that the of to SARS-CoV-2, with data showing that robust T-cell responses be detected in patients who have had or asymptomatic even in the of A. et T cell in individuals with asymptomatic or 2020; Full Text Full Text PDF PubMed Scopus Google Scholar In our cohort of patients receiving we have shown that of patients evidence of either serological or T-cell responses at 6 months we have also shown that a detectable serological to SARS-CoV-2 infection to be against in patients receiving even at 6 months data are given the high rates of infection the of patients receiving dialysis exposure to infection In our serological the of patients with infection, which have been given we were not testing for infections in asymptomatic cases the is that of the 2 patients with serological evidence of anti-NP who had subsequent viral detection by reverse transcriptase PCR at and after the detection of patient has and the patient previously had a kidney (Supplementary S1). In addition, the patients with no serological or cellular evidence of at 6 months, all were than we have shown that patients receiving dialysis per to mount an to SARS-CoV-2, be recognized that and outcome in patients receiving which The efficacy of SARS-CoV-2 vaccines in patients with ESKD is currently not known as such patients were from the preliminary SARS-CoV-2 vaccine Patients receiving dialysis are recognized to have rates of to compared with which in part is to the of on the immune the patient with J Am Soc Nephrol. PubMed Scopus Google Scholar immune to be to responses to new antigenic which is of in the outcome to SARS-CoV-2 et to and is in patients with kidney PubMed Scopus Google Scholar from the that associated with is in patients receiving dialysis and that had significantly levels of protein antibody and antibody levels at after the BNT162b2 than patients the need for prospective data in this E.E. Frenck Jr., R.W. Falsey A.R. et al.Safety and immunogenicity of two RNA-based Covid-19 vaccine candidates.N Engl J Med. 2020; 383: 2439-2450Crossref PubMed Scopus (1770) Google R.W. et of the T cell in end-stage disease PubMed Scopus Google Scholar data are that antibodies in to SARS-CoV-2 vaccination are durable than from et of responses after SARS-CoV-2 mRNA-1273 Engl J Med. 2020; 384: PubMed Scopus Google Scholar with the data we on serological responses and protection from to those in for vaccine responses in patients with D. et status and of SARS-CoV-2 infection in Engl J Med. 2021; 384: PubMed Scopus Google et of responses after SARS-CoV-2 mRNA-1273 Engl J Med. 2020; 384: PubMed Scopus Google Scholar baseline serological status of patients from exposure be of in patients with ESKD given the high prevalence of infection in patients receiving and it be of to evaluate whether vaccine responses are less robust in L. D. et vaccination and are of immune to vaccine than and status in dialysis PubMed Scopus Google Scholar study has several in part of the of the results that have to a to sample The study have been by the addition of data on viral over have been of viral which be common in Jr., D. et SARS-CoV-2 in a dialysis Med. 2021; Full Text Full Text PDF PubMed Scopus Google et SARS-CoV-2 from an asymptomatic individual with 2020; Full Text Full Text PDF PubMed Scopus Google Scholar However, we used a cutoff for PCR as used by D. et status and of SARS-CoV-2 infection in Engl J Med. 2021; 384: PubMed Scopus Google Scholar is also to that all patients routine asymptomatic PCR after this time A is that we not have data available on viral of and it is that are to new of SARS-CoV-2, which immune responses to et al. SARS-CoV-2 and by viral [e-pub ahead of print]. medRxiv. Accessed January Scholar However, if this was the we have to of new all serological data have been by screening all patients at 6 months for RBD antibodies, which have been shown to correlate with antibody L. Segovia-Chumbez B. Jadi R. et al.The receptor-binding domain of the viral spike protein is an immunodominant and highly specific target of antibodies in SARS-CoV-2 patients.Sci Immunol. 2020; 5eabc8413Crossref PubMed Scopus (0) Google Scholar we performed T-cell assays in cases as time and testing at this However, the of our study are to our this is the report of longitudinal responses in patients receiving which in addition have been with outcome data in asymptomatic and symptomatic In we have shown that patients receiving dialysis mount durable immune responses 6 months after SARS-CoV-2 infection. than 3% of patients had no detectable serological or T-cell responses at 6 months. We have also shown that the risk of subsequent confirmed infection was significantly in patients who have had detectable antibodies. data that immune responses be against reinfection. the high prevalence of SARS-CoV-2 infection the wave in ICHD this is for the vaccination programs and have to the T-SPOT Discovery SARS-CoV-2 by All the no was by the for Health Research Research Centre at Imperial College NHS and Imperial College The to the all the patients and at Renal and dialysis and in the laboratories. The are also for the from and and and was by an was by an was by a from the with to SARS-CoV-2 infection and vaccination in patients receiving kidney this of the the immunogenicity of coronavirus disease infection and the to the COVID-19 vaccines patients on dialysis and kidney is data that is durability of immune after COVID-19 infection. immune to the dose of vaccine is less in patients than individuals in both after the second vaccine dose a of patients receiving dialysis develop robust antibody kidney a immune PDF

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