Evidence for SARS-CoV-2 Spike Protein in the Urine of COVID-19 Patients

This article has been Reviewed by the following groups

Read the full article See related articles

Discuss this preprint

Start a discussion What are Sciety discussions?

Abstract

Key Points

  • Using an antigen capture assay to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike S1 protein, we found that the protein is present in the urine of 25% of patients with coronavirus disease 2019 (COVID-19).

  • Further, we found that 24% and 21% of adult patients with COVID-19 have high levels of urine albumin and cystatin C, respectively.

  • The presence of SARS-CoV-2 spike protein in the urine suggests renal abnormalities resulting from COVID-19.

Background

SARS-CoV-2 infection has, as of April 2021, affected >133 million people worldwide, causing >2.5 million deaths. Because the large majority of individuals infected with SARS-CoV-2 are asymptomatic, major concerns have been raised about possible long-term consequences of the infection.

Methods

Wedeveloped an antigen capture assay to detect SARS-CoV-2 spike protein in urine samples from patients with COVID-19whose diagnosis was confirmed by positive PCR results from nasopharyngeal swabs (NP-PCR+) forSARS-CoV-2. We used a collection of 233 urine samples from 132 participants from Yale New Haven Hospital and the Children’s Hospital of Philadelphia that were obtained during the pandemic (106 NP-PCR+ and 26 NP-PCR−), and a collection of 20 urine samples from 20 individuals collected before the pandemic.

Results

Our analysis identified 23 out of 91 (25%) NP-PCR+ adult participants with SARS-CoV-2 spike S1 protein in urine (Ur-S+). Interestingly, although all NP-PCR+ children were Ur-S−, one child who was NP-PCR− was found to be positive for spike protein in their urine. Of the 23 adults who were Ur-S+, only one individual showed detectable viral RNA in urine. Our analysis further showed that 24% and 21% of adults who were NP-PCR+ had high levels of albumin and cystatin C, respectively, in their urine. Among individuals with albuminuria (>0.3 mg/mg of creatinine), statistical correlation could be found between albumin and spike protein in urine.

Conclusions

Together, our data showed that one of four individuals infected with SARS-CoV-2 develop renal abnormalities, such as albuminuria. Awareness about the long-term effect of these findings is warranted.

Article activity feed

  1. SciScore for 10.1101/2021.01.27.21250637: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Rabbit polyclonal anti-spike protein antibody purified using Protein G immunoaffinity chromatography was purchased from MyBioSource (MBS434243; 2µg/µL) and used as capture antibody in the capture ELISA.
    Rabbit polyclonal anti-spike protein antibody
    suggested: None
    anti-spike protein
    suggested: None
    After 15-16 hours, the wells were washed four times with PBST, biotinylated polyclonal anti-COVID-19 antibodies (spike protein) were added at a concentration of 5µg/mL, and plates were incubated for 1 hour at room temperature.
    anti-COVID-19
    suggested: None
    In addition, to determine the specificity of polyclonal SARS-CoV-2 anti-spike antibodies (MyBioSource; MBS434243; 2µg/µL), different concentrations (0.1µg, 0.5µg and 1µg) of purified recombinant SARS-CoV-2 S1 (GenScript; Cat No Z03501) were probed using a Western blot (Figure 1E).
    anti-spike
    suggested: None
    The membrane was blocked with 5% milk (American Bio Cat No AB10109-00100) in PBST followed by treatment with polyclonal antibody against SARS-CoV-2 spike (S1+S2) protein raised in rabbit (MyBioSource MBS434243) and used at 1:1000 dilution in PBST
    S1+S2 ) protein
    suggested: None
    Goat anti-rabbit IgG horse radish peroxidase (HRP) conjugate (Thermofisher Scientific, USA, Cat No 31466) was used as the secondary antibody at 1:5000 dilution.
    anti-rabbit IgG
    suggested: None

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).


    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: We did not find any issues relating to colormaps.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.