SARS-CoV-2 seroprevalence,seroconversion and neutralizing antibodies in a systemic lupus erythematosus cohort and comparison to controls

Abstract

Sir,

At the outset of the SARS-CoV-2 pandemic, it was speculated that systemic lupus erythematosus (SLE) patients may be at significant risk of COVID-19 due to underlying immune dysregulation and immunosuppressive therapies (reviewed in¹). It was unclear how these factors would alter B/T cell responses, risk of infection, and/or development of neutralizing antibodies.^2,3 In this study, we examined the prevalence of SARS-CoV-2 antibodies using multiple assays, RT-PCR positivity, and neutralizing antibodies in 173 SLE patients (94.8% female, mean age 48.5 years, mean disease duration 11.7 years, 42.8% non-White race/ethnicity, 83.2% prescribed hydroxychloroquine, 28.9% corticosteroids, and 43.9% other immunomodulators) prior to vaccination compared to controls.

Pre-pandemic serum samples biobanked prior to 01/01/2020 and intra-pandemic samples collected from 03/15/2020–01/31/2021 were tested for SARS-CoV-2 antibodies using an ELISA measuring IgA and IgG anti-spike 1 (S1) protein (Euroimmun AG, Lübeck, Germany) and an assay detecting IgG antibodies to nucleocapsid (N), S1 receptor binding domain (RBD), and S1 (XMAP®: Luminex Corporation, Austin, TX) and conventional SLE autoantibodies (anti-Ro52, -SSA/Ro60, -SSB/La, -Sm, -U1RNP, -ribosomal P, and -dsDNA). One hundred pre-pandemic and 148 intra-pandemic sera (i.e., 248 unique individuals) from unselected ambulatory individuals undergoing autoantibody testing served as controls. RT-PCR tests were performed on the SLE cohort if clinically indicated and results retrospectively collected until 01/31/2021. Pre-pandemic and intra-pandemic SLE and control samples with antibodies to at least one SARS-CoV-2 antigen were tested for neutralizing antibodies using the Surrogate Virus Neutralization Test (GenScript Biotech Corporation, Piscataway, NJ, USA).⁴

None of the SLE patients had pre-pandemic SARS-CoV-2 antibodies versus 6% of controls (difference −6.0%, 95% CI: −10.7%, −1.4%; Table 1). Comparable proportions of SLE patients and controls had at least one intra-pandemic SARS-CoV-2 antibody (3.5% versus 4.7%, difference −1.2%, 95% CI: −5.6%, 3.2%). A sensitivity analysis age and sex-matching controls to SLE patients (2:1) yielded similar results. Intra-pandemic seroprevalence of IgG antibodies to the N protein in SLE patients was lower than in the general population (Calgary, AB Canada) over a similar observation interval⁵ (0.6% vs 2.9%, difference −2.3%, 95% CI: −3.6%, −1.0%). 7.5% (6/80) of SLE patients had a positive RT-PCR. None of the 173 SLE patients in the cohort, including the nine SLE patients with either intra-pandemic SARS-CoV-2 antibodies and/or a positive RT-PCR (Supplementary Table 1) were hospitalized for SARS-CoV-2 infection.

Table 1.

SLE cohort patients and controls with pre- and/or intra-pandemic SARS-CoV-2 antibodies.^a

			SLE, n (%) (n = 173)	Controls, n (%) (pre-pandemic, n = 100; intra-pandemic, n = 148)	Difference between cohort and controls, % (95% CI)
Pre-pandemic	ELISA	Anti-S1 IgA ^b	0 (0.0)	3 (3.0)	−3.0 (−6.3, 0.3)
	ELISA	Anti-S1 IgG ^c	0 (0.0)	4 (4.0)	−4.0 (−7.8, 0.1)
	xMAP®	Anti-N IgG ^d	0 (0.0)	2 (2.0)	−2 (−4.7, 0.7)
		Anti-RBD IgG ^d	0 (0.0)	0 (0.0)	0. (0.0, 0)
		Anti-S1 IgG ^d	0 (0.0)	0 (0.0)	0. (0.0, 0)
	Patients with at least one antibody^e		0 (0.0)	6 (6.0)	−6.0 (-10.7, -1.4)
	Neutralizing antibodies^f		0 (0.0^g)	0 (0.0^g)	NA
Intra-pandemic	ELISA	Anti-S1 IgA ^b	1 (0.6)	3 (2.0)	−1.4 (−3.9, 1.1)
	ELISA	Anti-S1 IgG ^c	5 (2.9)	5 (3.4)	−0.5 (−4.3, 3.3)
	xMAP®	Anti-N IgG ^d	1 (0.6)	5 (3.4)	−2.8 (−5.9, 0.3)
		Anti-RBD IgG ^d	2 (1.2)	3 (2.0)	−0.8 (−3.6, 2.0)
		Anti-S1 IgG ^d	0 (0.0)	1 (0.7)	−0.7 (-11.1, -2.9)
	Patients with at least one antibody^e		6 (3.5)	7(4.7)	−1.2 (−5.6, 3.2)
	Neutralizing antibodies^f		2 (33.3)	4 (57.1)	Not done^h
	RT-PCR (+/−)		6 (7.5ⁱ)	NA

Bolded differences indicate statistical significance.

ELISA: enzyme-linked immunosorbent assay; IgA: immunoglobulin A; IgG: immunoglobulin G; N: nucleocapsid; NA: not applicable; RBD: receptor binding domain; RT-PCR: reverse transcription-polymerase chain reaction; S1: spike 1 protein; SLE: systemic lupus erythematosus; XMAP: Luminex addressable laser bead imunoassay.

^aNone of the SLE patients received a COVID vaccination prior to intra-pandemic testing. None of the controls received a COVID vaccination prior to pre-pandemic sampling. We were unable to verify the vaccination status of the intra-pandemic control samples, but there was very limited vaccine available in Canada prior to 31 January 2021.

^bCut-off for positivity: 1.9 OD ratio.

^cCut-off for positivity: 0.8 OD ratio.

^dCut-off for positivity: 700 MFI.

^eidentified by either ELISA or xMAP® assays.

^fCut-off for positivity: 20%.

^gOnly patients positive for SARS-CoV-2 antibodies pre- and/or intra-pandemic were assessed for neutralizing antibodies (pre-pandemic, n = 6 controls, n = 0 SLE; intra-pandemic, n = 7 controls, n = 6 SLE).

^hStatistical testing not done due to low n.

ⁱ80 patients had a RT-PCR performed.

Two of six SLE patients with at least one SARS-CoV-2 intra-pandemic antibody developed neutralizing antibodies (medication profiles in Supplementary Table 1); both had IgG antibodies to the RBD of SARS-CoV-2 (Supplementary Table 2). None of six controls with at least one pre-pandemic antibody to SARS-CoV-2 had neutralizing antibodies, whereas 4/7 controls with at least one intra-pandemic SARS-CoV-2 antibody had neutralizing antibodies, three of which had IgG antibodies to RBD. As shown in Supplementary Table 3, there was no statistical difference (chi-squared test) in frequency of any pre- or intra-pandemic SLE-related autoantibodies between SLE patients with and without SARS-CoV2 positivity. This and the absence of SARS-CoV2 antibodies in pre-pandemic sera suggests that molecular mimicry is an unlikely explanation for SARS-CoV-2 seropositivity.⁶

Like other reports,^3,7,8 our SLE cohort had a lower rate of seropositivity pre-pandemic and a slightly lower to similar rate of seropositivity intra-pandemic compared to contemporaneous controls. In contrast, over a similar observation period, others reported that 4% (4/100) SLE patients had PCR-confirmed infection, but 36% showed SARS-CoV-2 antibodies of at least one isotype, particularly IgA and IgM.² However, these antibodies were also detected in pre-pandemic samples and had low neutralizing activity. We also measured IgM antibodies but found them to be an unreliable indicator of SARS-CoV-2 exposure and IgA cut-offs needed to be increased according to local controls. Although there is emerging evidence of higher rates of SARS-CoV2 infections and increased odds of mortality in rheumatic disease patients,⁹ it is unclear which factors influence SARS-CoV-2 infection in SLE,^2,3,7,8. However, as no pre-pandemic SARS-CoV2- IgG antibodies were observed in our SLE cohort, this seems an unlikely explanation for protection against COVID-19. Current efforts are focusing on vaccine responses in SLE.^10,11

Supplemental Material

sj-pdf-1-lup-10.1177_09612033211063793 – Supplemental Material for SARS-CoV-2 seroprevalence, seroconversion and neutralizing antibodies in a systemic lupus erythematosus cohort and comparison to controls

Supplemental Material, sj-pdf-1-lup-10.1177_09612033211063793 for anSARS-CoV-2 seroprevalence, seroconversion and neutralizing antibodies in a systemic lupus erythematosus cohort and comparison to controls by Hannah R Mathew, May Y Choi, Katherine Buhler, Xenia Gukova, Francesca S Cardwell, Heather Waldhauser, Ann E Clarke, and Marvin J Fritzler in Lupus

Footnotes

Acknowledgements

The authors acknowledge the laboratory technical assistance of Haiyan Hou, Emily Walker, Meifeng Zhang and Dr. Paul Sciore (University of Calgary).

Declaration of conflicting interests

The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: MJF is a consultant to and has received honoraria and/or travel support from Werfen (Barcelona, Spain, San Diego, CA). MJF is also Medical Director of Mitogen Diagnostics Corporation. All other author(s) declare no conflict of interest.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: No private funding was used for this study. AEC holds The Arthritis Society Chair in Rheumatic Diseases at the University of Calgary and some of these funds were used to support HW and FSC.

Ethics

Anonymized data was used and presented. The study was performed in accord with the World Medical Association Declaration of Helsinki.

ORCID iD

Marvin J Fritzler

Supplemental material

Underlying research materials related to this manuscript (data, samples or models) are in Supplemental Tables published online or can be accessed by contacting the corresponding author.

References

Sakthiswary

Chuah

Chiang

, et al. COVID-19 in systemic lupus erythematosus: a pooled analysis and systematic review of case reports and series. Lupus 2021; 30: 1946–1954. Online ahead of print. DOI: 10.1177/09612033211045057.

Sjöwall

Azharuddin

Frodlund

, et al. SARS-CoV-2 antibody isotypes in systemic lupus erythematosus patients prior to vaccination: associations with disease activity, antinuclear antibodies, and immunomodulatory drugs during the first year of the pandemic. Front Immunol 2021; 12: 724047. DOI: 10.3389/fimmu.2021.724047.

Aringer

. Systemic lupus erythematosus does not prevent antibody responses to SARS-CoV-2. Lancet Rheumatol 2021; 3(8): e538–e540. DOI: 10.1016/S2665-9913(21)00153-3.

Valcourt

Manguiat

Robinson

, et al. Evaluation of a commercially-available surrogate virus neutralization test for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Diagn Microbiol Infect Dis 2020; 99: 115294. DOI: 10.1016/j.diagmicrobio.2020.115294.

Canadian Blood

Services.

COVID-19 seroprevalence report august 2021. Canadian Blood Service Reports, 2021; Report #11, pp. 1–41. http://dx.doi.org/10.2139/ssrn.3903944

Kanduc

. From Anti-SARS-CoV-2 immune responses to COVID-19 via molecular mimicry. Antibodies (Basel) 2020; 9(3): 33. DOI: 10.3390/antib9030033.

Saxena

Guttmann

Masson

, et al. Evaluation of SARS-CoV-2 IgG antibody reactivity in patients with systemic lupus erythematosus: analysis of a multi-racial and multi-ethnic cohort. Lancet Rheumatol 2021; 3(8): e585–e594. DOI: 10.1016/S2665-9913(21)00114.

Ammitzbøll

Andersen

Vils

, et al. Isolation, behavioral changes and low seroprevalence of SARS-CoV-2 antibodies in patients with systemic lupus erythematosus or rheumatoid arthritis. Arthritis Care Res (Hoboken ) 2021. Online ahead of print. DOI: 10.1002/acr.24716.

Conway

Grimshaw

Konig

, et al. SARS-CoV-2 Infection and COVID-19 Outcomes in Rheumatic Disease: A Systematic Literature Review And Meta-Analysis. Arthritis Rheumatol 2021. Online ahead of print. doi: 10.1002/art.42030.

10.

Sattui

Liew

Kennedy

, et al. Early experience of COVID-19 vaccination in adults with systemic rheumatic diseases: results from the COVID-19 global rheumatology alliance vaccine survey. RMD Open 2021; 7: e001814. DOI: 10.1136/rmdopen-2021-001814.

11.

Connolly

Boyarsky

Ruddy

, et al. Absence of humoral response after two-dose SARS-CoV-2 messenger RNA Vaccination in patients with rheumatic and musculoskeletal diseases: a case series. Ann Intern Med 2021; 174: 1332–1334.

Supplementary Material

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