Skip to main content

Main menu

  • Home
  • Content
    • Published Ahead of Print
    • Current Issue
    • Subject Collections
    • JASN Podcasts
    • Archives
    • Saved Searches
    • ASN Meeting Abstracts
  • Authors
    • Submit a Manuscript
    • Author Resources
  • Editorial Team
  • Subscriptions
  • More
    • About JASN
    • Alerts
    • Advertising
    • Editorial Fellowship Program
    • Feedback
    • Reprints
    • Impact Factor
  • ASN Kidney News
  • Other
    • CJASN
    • Kidney360
    • Kidney News Online
    • American Society of Nephrology

User menu

  • Subscribe
  • My alerts
  • Log in
  • My Cart

Search

  • Advanced search
American Society of Nephrology
  • Other
    • CJASN
    • Kidney360
    • Kidney News Online
    • American Society of Nephrology
  • Subscribe
  • My alerts
  • Log in
  • My Cart
Advertisement
American Society of Nephrology

Advanced Search

  • Home
  • Content
    • Published Ahead of Print
    • Current Issue
    • Subject Collections
    • JASN Podcasts
    • Archives
    • Saved Searches
    • ASN Meeting Abstracts
  • Authors
    • Submit a Manuscript
    • Author Resources
  • Editorial Team
  • Subscriptions
  • More
    • About JASN
    • Alerts
    • Advertising
    • Editorial Fellowship Program
    • Feedback
    • Reprints
    • Impact Factor
  • ASN Kidney News
  • Follow JASN on Twitter
  • Visit ASN on Facebook
  • Follow JASN on RSS
  • Community Forum
Research Letter
Open Access

Detection of SARS-CoV-2 Antibodies in Kidney Transplant Recipients

Maria Prendecki, Candice Clarke, Sarah Gleeson, Louise Greathead, Eva Santos, Adam McLean, Paul Randell, Luke S.P. Moore, Nabeela Mughal, Mary Guckian, Peter Kelleher, Stephen P. Mcadoo and Michelle Willicombe
JASN December 2020, 31 (12) 2753-2756; DOI: https://doi.org/10.1681/ASN.2020081152
Maria Prendecki
1Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, London, United Kingdom
2Imperial College Renal and Transplant Centre, Imperial College Healthcare National Health Service (NHS) Trust, Hammersmith Hospital, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Candice Clarke
1Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, London, United Kingdom
2Imperial College Renal and Transplant Centre, Imperial College Healthcare National Health Service (NHS) Trust, Hammersmith Hospital, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Sarah Gleeson
2Imperial College Renal and Transplant Centre, Imperial College Healthcare National Health Service (NHS) Trust, Hammersmith Hospital, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Sarah Gleeson
Louise Greathead
3Department of Infection and Immunity, North West London Pathology, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Eva Santos
3Department of Infection and Immunity, North West London Pathology, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Adam McLean
2Imperial College Renal and Transplant Centre, Imperial College Healthcare National Health Service (NHS) Trust, Hammersmith Hospital, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Paul Randell
3Department of Infection and Immunity, North West London Pathology, London, United Kingdom
4Immunology of Infection Group, Department of Infectious Diseases, Imperial College London, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Luke S.P. Moore
4Immunology of Infection Group, Department of Infectious Diseases, Imperial College London, London, United Kingdom
5Infectious Diseases and Microbiology Department, Chelsea and Westminster Hospital NHS Foundation Trust, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Nabeela Mughal
4Immunology of Infection Group, Department of Infectious Diseases, Imperial College London, London, United Kingdom
5Infectious Diseases and Microbiology Department, Chelsea and Westminster Hospital NHS Foundation Trust, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Mary Guckian
3Department of Infection and Immunity, North West London Pathology, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Peter Kelleher
3Department of Infection and Immunity, North West London Pathology, London, United Kingdom
4Immunology of Infection Group, Department of Infectious Diseases, Imperial College London, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Stephen P. Mcadoo
1Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, London, United Kingdom
2Imperial College Renal and Transplant Centre, Imperial College Healthcare National Health Service (NHS) Trust, Hammersmith Hospital, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Michelle Willicombe
1Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, London, United Kingdom
2Imperial College Renal and Transplant Centre, Imperial College Healthcare National Health Service (NHS) Trust, Hammersmith Hospital, London, United Kingdom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Michelle Willicombe
  • Article
  • Figures & Data Supps
  • Info & Metrics
  • View PDF
Loading
  • immunosuppression
  • immunology
  • virology
  • kidney transplantation
  • COVID-19

Kidney transplant recipients and other patient groups receiving immunosuppression have a poor prognosis following presentation with symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.1 The immune response to SARS-CoV-2 in an immunocompromised population has not been systematically reported. Recognition that humoral immune responses against common viral infections are blunted in such patients has led to their exclusion from validation studies of serologic assays for SARS-CoV-2.2,3 In this study, we analyze the seroprevalence of SARS-CoV-2 antibodies in a transplant population. In order to ensure the accuracy of the seroprevalence rate, we also evaluate the performance of different serologic assays within this patient cohort.

We investigated 855 consecutive kidney transplant recipients who attended the phlebotomy service at the Imperial College Renal and Transplant Centre (ICTRC) London in June 2020 for SARS-CoV-2 antibodies. Patient demographics were obtained from the ICRTC transplant registry (Table 1). The study was approved by the Health Research Authority, Research Ethics Committee (reference: 20/WA/0123).

View this table:
  • View inline
  • View popup
Table 1.

Patient characteristics

Sera from all patients were tested for the presence of nucleocapsid protein (NP) antibodies using the Abbott SARS-CoV-2 IgG assay on the Abbott Architect system. Samples were interpreted as positive or negative according to the manufacturer’s instructions with a cutoff index of 1.4.4 All samples with an index value of >0.25 (Supplemental Material) were run on a second assay, the Fortress Diagnostics COVID-19 Total Antibody assay, which is a nonquantitative two-step antigen sandwich ELISA that detects total Ig against the receptor binding domain (RBD). Samples are interpreted as positive on the basis of a cutoff value from negative controls assayed on the sample microplate. Samples showing discordant results on the Abbott and Fortress assays were additionally tested using a commercially available lateral flow immunoassay (LFIA; Biomedomics Inc.), which detects both IgM and IgG to the recombinant antigen MK201027 of the RBD.5 The assay was used as per the manufacturer’s instructions, results were assessed by two independent blinded observers, and only IgG results were considered. Serologic samples taken from 85 health care workers (HCWs) with RT-PCR–confirmed infection were used to compare assay performance in an immunocompetent population.

Statistical and graphical analyses were performed with MedCalc v19.2.1. The two-sided level of significance was set at P<0.05. The 95% confidence interval (95% CI) of the seroprevalence was calculated from binomial probabilities using Wilson methods. Concordance between assays was analyzed using Cohen κ coefficient of qualitative results.

Sixty-nine of 855 patients tested positive for SARS-CoV-2 IgG using the Abbott assay, giving a seroprevalence of 8.1% (95% CI, 6.4 to 10.1). However, it was noted that 33 of 855 (3.9%) study patients had prior infection confirmed by RT-PCR, of whom 11 of 33 (33.3%) were serologically negative for IgG using the Abbott assay at a median time of testing of 36 (28–58) days postdiagnosis.

To investigate the lack of seroconversion versus inadequate assay sensitivity in an immunocompromised population, we tested samples from 38 transplant recipients (including 33 from our screening cohort) with PCR-confirmed infection across three assays. Patients were tested at a median time of 35 (22–53) days postdiagnosis. All paired historical control samples, which had been taken and stored from our study patients prior to July 2019, were negative for IgG across all three assays. The numbers of patients with antibodies detected by the Abbott, Fortress, and LFIA assays were 26 of 38 (68.4%), 35 of 38 (92.1%), and 31 of 38 (81.6%), respectively (Table 2). Patient characteristics by antibody status are shown in Table 3. Three of 38 (7.9%) patients did not have detectable antibodies on any assay, and these patients may represent true failure to seroconvert.

View this table:
  • View inline
  • View popup
Table 2.

Test characteristics as determined by sampling historic and current sera from 38 patients who were SARS-CoV-2 RT-PCR positive

View this table:
  • View inline
  • View popup
Table 3.

Patient characteristics by antibody status and assay in patients who were RT-PCR positive

To compare assay performance in an immunocompetent population, we tested 85 HCWs with RT-PCR–confirmed infection. At a median time of 31 (19–45) days postdiagnosis, three of 85 (3.5%) HCWs had no detectable antibodies by either the Abbott or Fortress assay, and an additional five of 82 (6.1%) HCWs had no antibodies detected by the Abbott assay. The sensitivity values of the Abbott and Fortress assays in HCWs were 90.6% (95% CI, 82.5 to 95.2) and 96.5% (95% CI, 90.1 to 98.8), respectively. Although there was no difference in the proportion of detectable antibody between the immunosuppressed patients and HCWs using the Fortress assay (P=0.30), immunosuppressed patients were less likely to have a positive serologic test using the Abbott assay compared with HCWs (P=0.002).

To investigate potential missed cases of patients who were SARS-CoV-2 IgG positive in our overall cohort screened by the Abbott assay alone, we re-examined the 822 study patients without confirmed infection; 147 of 822 (17.9%) patients had an antibody index value of >0.25 by the Abbott assay, of which 100 had a value between 0.25 and 1.4 and 47 patients had a value ≥1.4. All but four patients were retested using the Fortress assay, and discordant results were seen in 18 of 143 (12.6%) patients. Twelve (12%) of 100 patients negative on the Abbott assay were positive on the Fortress assay, whereas six positive patients by the Abbott assay were negative on the Fortress assay. When these 18 samples were tested by the LFIA, agreement was seen with the Fortress assay in 14 of 18 (77.8%) patients (Supplemental Material). Analyzing the concordance of the assays, we found only a moderate agreement between the Abbott and Fortress assays (κ=0.73 [0.64–0.82]) and between the Abbott and LFIA assays (κ=0.60 [0.46–0.74]), whereas concordance between the Fortress and LFIA assays was strong (κ=0.86 [0.77–0.95]).

On amalgamating the results of the Fortress and Abbott assays, the overall seroprevalence in our transplant cohort increased to 10.4% (95% CI, 8.5 to 12.6).

The finding of a seroprevalence of 10.4% (95% CI, 8.5 to 12.6) in a cohort of shielded patients with kidney transplants was higher than expected, albeit in patients from a region with a community seroprevalence rate of 13% (Ward H, Atchison CJ, Whitaker M, Ainslie KCE, Elliott J, Okell LC, et al.: Antibody prevalence for SARS-CoV-2 in England following first peak of the pandemic: REACT2 study in 100,000 adults. medRxiv, 2020 10.1101/2020.08.12.20173690). Notably, our study demonstrates the influence of the assay utilized to detect SARS-CoV-2 antibodies and hence, estimate seroprevalence in an immunosuppressed cohort.

Our results indicate that the Fortress ELISA and LFIA are more sensitive than the Abbott test at detecting SARS-CoV-2 antibodies in kidney transplant recipients. We also showed that there was better concordance between the Fortress and LFIA assays compared with the Fortress and Abbott assays, which also suggests the potential importance of the target antigen in the serologic assays. The LFIA and Fortress assays share the RBD as their target antigen, whereas the Abbott assay utilizes the NP. It may be proposed that the RBD is more immunogenic than the NP, making it a better stimulus for an immune response in patients who are immunosuppressed. Recently published evaluation studies from Public Health England support this, suggesting that assays targeting NP are less sensitive in immunocompetent populations too.6 Further, we have demonstrated that the Abbott assay was significantly less likely to detect antibody in the immunosuppressed population compared with HCWs. In addition to the greater sensitivity of RBD assays, there is evidence that RBD antibodies may provide information on functional immunity given reported correlations between RBD antibodies and neutralizing antibodies.7,8 It, therefore, follows that assays utilizing the RBD, rather than the NP, may be clinically more relevant for immunosuppressed patients.

Our study would have been strengthened by analyzing larger numbers of patients who were RT-PCR positive, incorporating serial sampling, and including demographic data on our HCWs, and we acknowledge that we have not been able to exclude discordance related to the detection of IgM or IgA by the Fortress assay. However, to our knowledge, this is the first SARS-CoV-2 seroprevalence study in patients with transplants, and we have shown that immunoassays that incorporate the RBD as their antigenic target may be superior in testing for SARS-CoV-2 antibodies, without compromising specificity (Table 2). This finding may be seen in immunocompetent people but seems to have a greater effect in an immunosuppressed transplant population.6

Disclosures

P. Kelleher reports scientific advisor or membership as an editorial board member for HIV medicine. S. McAdoo reports consultancy agreements with GSK; and honoraria from Rigel Pharmaceuticals, ThermoFisher Scientific, and Celltrion. L. Moore reports research funding from the Chelsea and Westminster Hospital Charity and National Institute of Health Research; honoraria from Eumedica and Profile Pharma; scientific advisor or membership with bioMerieux, Pfizer, and Umovis Lab; and speakers bureau for bioMerieux, Pfizer, and Umovis Lab. N. Mughal reports honoraria from Baxter, Eudmedica, and Pfizer. M. Willicombe reports research funding from Chiesi Pharmaceuticals. All remaining authors have nothing to disclose.

Funding

This research is supported by the National Institute for Health Research (NIHR) NIHR Imperial Biomedical Research Centre based at Imperial College Healthcare National Health Service Trust and Imperial College London.

Data Sharing Statement

Data are available from the corresponding author upon reasonable request.

Acknowledgments

The authors would like to recognize the contribution of the West London Kidney Patient Association, all the patients, staff within the North West London Pathology laboratories, and senior clinical staff at Imperial looking after renal patients throughout the pandemic (M. Appelbe, D. Ashby, E. Brown, T. Cairns, R. Charif, C. Clerkin, M. Condon, R.W. Corbett, J. Crane, F. Dor, N. Duncan, C. Edwards, F. Fernandes da Costa, A. Frankel, D. Goodall, J. Harris, S. Harris, P. Hebert, P. Hill, A. Kousios, J.B. Levy, L. Liu, M. Loucaidou, K. Lynch, N. Medjeral-Thomas, D. Moabi, A. Muthusamy, M. Nevin, A. Palmer, V. Papalois, D. Parsons, V. Prout, S. Punzalan, E. Salisbury, E. Sandhu, C. Smith, R. Storey, A. Tanna, K. Tansey, D. Thomas, J. Tomlinson, P. Webster, and D. Yang).

C. Clarke, S. Mcadoo, M. Prendecki, and M. Willicombe conceived the project; S. Gleeson, E. Santos, and M. Willicombe obtained samples; C. Clarke, L. Greathead, M. Guckian, S. Mcadoo, L. Moore, N. Mughal, M. Prendecki, and E. Santos processed the samples; S. Gleeson, L. Greathead, and M. Willicombe obtained data; P. Kelleher and P. Randell supervised research; M. Prendecki and M. Willicombe analyzed the data; C. Clarke, S. Mcadoo, M. Prendecki, and M. Willicombe wrote the first draft of paper; and all authors reviewed and approved the final manuscript.

Supplemental Material

This article contains supplemental material online at http://jasn.asnjournals.org/lookup/suppl/doi:10.1681/ASN.2020081152/-/DCSupplemental.

Supplemental Table 1. SARS CoV-2 antibody detection in PCR-positive healthcare workers and historic control.

Supplemental Table 2.Comparison of SARS CoV-2 antibody detection by the Fortress and Abbott Assays.

Supplemental Figure 1. ROC curve analysis of the Abbott and Fortress serology tests for diagnosis of previous SARS-CoV-2 infection.

Supplemental Table 3. Comparison of assay results.

Footnotes

  • M.P. and C.C. contributed equally to this work.

  • Published online ahead of print. Publication date available at www.jasn.org.

  • Copyright © 2020 by the American Society of Nephrology

References

  1. ↵
    1. Williamson EJ,
    2. Walker AJ,
    3. Bhaskaran K,
    4. Bacon S,
    5. Bates C,
    6. Morton CE, et al
    .: Factors associated with COVID-19-related death using OpenSAFELY. Nature 584: 430–436, 2020, In press doi:10.1038/s41586-020-2521-4 pmid:32640463
    OpenUrlCrossRefPubMed
  2. ↵
    1. Gangappa S,
    2. Wrammert J,
    3. Wang D,
    4. Li ZN,
    5. Liepkalns JS,
    6. Cao W, et al
    .: Kinetics of antibody response to influenza vaccination in renal transplant recipients. Transpl Immunol 53: 51–60, 2019pmid:30664927
    OpenUrlCrossRefPubMed
  3. ↵
    1. Public Health England
    : Evaluation of the Abbott SARS-CoV-2 IgG for the detection of anti-SARSCoV-2 antibodies, 2020. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/890566/Evaluation_of_Abbott_SARS_CoV_2_IgG_PHE.pdf. Accessed June 5, 2020
  4. ↵
    1. Bryan A,
    2. Pepper G,
    3. Wener MH,
    4. Fink SL,
    5. Morishima C,
    6. Chaudhary A, et al
    .: Performance characteristics of the Abbott Architect SARS-CoV-2 IgG assay and seroprevalence in Boise, Idaho. J Clin Microbiol 58: e00941-20, 2020pmid:32381641
    OpenUrlAbstract/FREE Full Text
  5. ↵
    1. Li Z,
    2. Yi Y,
    3. Luo X,
    4. Xiong N,
    5. Liu Y,
    6. Li S, et al
    .: Development and clinical application of a rapid IgM-IgG combined antibody test for SARS-CoV-2 infection diagnosis [published online ahead of print February 27, 2020]. J Med Virol doi:10.1002/jmv.25727pmid:32104917
    OpenUrlCrossRefPubMed
  6. ↵
    Public Health England: Evaluation of sensitivity and specificity of four commercially available SARS-CoV-2 antibody immunoassay, 2020. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/898437/Evaluation__of_sensitivity_and_specificity_of_4_commercially_available_SARS-CoV-2_antibody_immunoassays.pdf. Accessed July 13, 2020
  7. ↵
    1. Amanat F,
    2. Stadlbauer D,
    3. Strohmeier S,
    4. Nguyen THO,
    5. Chromikova V,
    6. McMahon M, et al
    .: A serological assay to detect SARS-CoV-2 seroconversion in humans. Nat Med 26: 1033–1036, 2020pmid:32398876
    OpenUrlCrossRefPubMed
  8. ↵
    1. Premkumar L,
    2. Segovia-Chumbez B,
    3. Jadi R,
    4. Martinez DR,
    5. Raut R,
    6. Markmann A, 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 5: eabc8413, 2020
    OpenUrlAbstract/FREE Full Text
PreviousNext
Back to top

In this issue

Journal of the American Society of Nephrology: 31 (12)
Journal of the American Society of Nephrology
Vol. 31, Issue 12
December 2020
  • Table of Contents
  • Table of Contents (PDF)
  • About the Cover
  • Index by author
View Selected Citations (0)
Print
Download PDF
Sign up for Alerts
Email Article
Thank you for your help in sharing the high-quality science in JASN.
Enter multiple addresses on separate lines or separate them with commas.
Detection of SARS-CoV-2 Antibodies in Kidney Transplant Recipients
(Your Name) has sent you a message from American Society of Nephrology
(Your Name) thought you would like to see the American Society of Nephrology web site.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Detection of SARS-CoV-2 Antibodies in Kidney Transplant Recipients
Maria Prendecki, Candice Clarke, Sarah Gleeson, Louise Greathead, Eva Santos, Adam McLean, Paul Randell, Luke S.P. Moore, Nabeela Mughal, Mary Guckian, Peter Kelleher, Stephen P. Mcadoo, Michelle Willicombe
JASN Dec 2020, 31 (12) 2753-2756; DOI: 10.1681/ASN.2020081152

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Request Permissions
Share
Detection of SARS-CoV-2 Antibodies in Kidney Transplant Recipients
Maria Prendecki, Candice Clarke, Sarah Gleeson, Louise Greathead, Eva Santos, Adam McLean, Paul Randell, Luke S.P. Moore, Nabeela Mughal, Mary Guckian, Peter Kelleher, Stephen P. Mcadoo, Michelle Willicombe
JASN Dec 2020, 31 (12) 2753-2756; DOI: 10.1681/ASN.2020081152
del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like

Jump to section

  • Article
    • Disclosures
    • Funding
    • Data Sharing Statement
    • Acknowledgments
    • Supplemental Material
    • Footnotes
    • References
  • Figures & Data Supps
  • Info & Metrics
  • View PDF

More in this TOC Section

  • Acute Start Peritoneal Dialysis during the COVID-19 Pandemic: Outcomes and Experiences
Show more Research Letter

Cited By...

  • No citing articles found.
  • Google Scholar

Similar Articles

Related Articles

  • PubMed
  • Google Scholar

Keywords

  • immunosuppression
  • immunology
  • virology
  • kidney transplantation
  • COVID-19

Articles

  • Current Issue
  • Early Access
  • Subject Collections
  • Article Archive
  • ASN Annual Meeting Abstracts

Information for Authors

  • Submit a Manuscript
  • Author Resources
  • Editorial Fellowship Program
  • ASN Journal Policies
  • Reuse/Reprint Policy

About

  • JASN
  • ASN
  • ASN Journals
  • ASN Kidney News

Journal Information

  • About JASN
  • JASN Email Alerts
  • JASN Key Impact Information
  • JASN Podcasts
  • JASN RSS Feeds
  • Editorial Board

More Information

  • Advertise
  • ASN Podcasts
  • ASN Publications
  • Become an ASN Member
  • Feedback
  • Follow on Twitter
  • Password/Email Address Changes
  • Subscribe

© 2021 American Society of Nephrology

Print ISSN - 1046-6673 Online ISSN - 1533-3450

Powered by HighWire