Journal Information
Journal ID (publisher-id): BM
Journal ID (nlm-ta): Biochem Med (Zagreb)
Title: Biochemia Medica
Abbreviated Title: Biochem. Med. (Zagreb)
ISSN (print): 1330-0962
ISSN (electronic): 1846-7482
Publisher: Croatian Society of Medical Biochemistry and Laboratory Medicine
Article Information
Copyright statement: Croatian Society of Medical Biochemistry and Laboratory Medicine.
Copyright: 2021, Croatian Society of Medical Biochemistry
License (open-access):
This is an Open Access article distributed under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Date received: 20 March 2021
Date accepted: 02 June 2021
Publication date (print and electronic): 15 October 2021
Volume: 31
Issue: 3
Electronic Location Identifier: 030901
Publisher ID: bm-31-3-030901
DOI: 10.11613/BM.2021.030901
Seroprevalence of SARS-CoV-2 in Croatian solid-organ transplant recipients
Željka Jureković[3]
Jadranka Pavičić-Šarić[3]
Vladimir Stevanović[4]
Irena Tabain[5]
Željka Hruškar[5]
Danko Mikulić[3]
Ljubo Barbić[4]
[1] Department of Gastroenterology and Hepatology, University Hospital Center Zagreb, Zagreb, Croatia
[2] School of Medicine, University of Zagreb, Zagreb, Croatia
[3] Transplant Centre, Merkur University Hospital, Zagreb, Croatia
[4] Department of Microbiology and Infectious Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
[5] Department of Virology, Croatian Institute of Public Health, Zagreb, Croatia
Author notes:
[*] Corresponding author: anna.mrzljak@gmail.com
Introduction
The data on the coronavirus disease (COVID-19) in solid-organ transplant recipients (SOTRs) in Croatia is unknown. The aim of this study was to analyze the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Croatian SOTRs.
Materials and methods
From 7 September to 27 November 2020 (beginning of the second COVID-19 pandemic wave), a cross-sectional screening for COVID-19 was performed in the adult outpatient liver (LTRs; N = 280) and kidney transplant recipients (KTRs; N = 232). Serum samples were initially tested for SARS-CoV-2 IgG antibodies using a commercial enzyme-linked immunosorbent assay (ELISA; Vircell Microbiologists, Granada, Spain). All positive samples were confirmed using a virus neutralization test (VNT). Data on risk exposure and COVID-19 related symptoms were collected using a questionnaire.
Results
The transplanted cohort’s seroprevalence detected by ELISA and VNT was 20.1% and 3.1%, respectively. Neutralizing (NT) antibodies developed in 15.6% of anti-SARS-CoV-2 ELISA IgG positive SOTRs. The difference in seropositivity rates between LTRs and KTRs was not statistically significant (ELISA 21.1% vs. 19.0%, P = 0.554; VNT 3.6% vs. 2.6%, P = 0.082). Overall VNT positivity rates were higher in patients who reported participation in large community events (5.9% vs. 1.0%; P = 0.027) as well as in patients who reported COVID-19 related symptoms in the past six months. In addition, symptomatic VNT positive patients showed significantly higher (P = 0.031) NT antibody titers (median 128, interquartile range (IQR) = 32-128) compared to asymptomatic patients (median 16, IQR = 16-48).
Conclusions
This study showed that 15.6% of anti-SARS-CoV-2 ELISA positive Croatian SOTRs developed NT antibodies indicating protective immunity. Further studies are needed to determine the dynamic of NT antibodies and COVID-19 immunity duration in immunocompromised populations such as LTRs and KTRs.
Keywords: COVID-19; seroprevalence; solid-organ transplant recipients; SARS-CoV-2 antibodies
