Anna Mrzljak, Željka Jureković, Jadranka Pavičić-Šarić, Vladimir Stevanović, Irena Tabain, Željka Hruškar, Danko Mikulić, Ljubo Barbić, Tatjana Vilibić-Čavlek
{"title":"Seroprevalence of SARS-CoV-2 in Croatian solid-organ transplant recipients.","authors":"Anna Mrzljak, Željka Jureković, Jadranka Pavičić-Šarić, Vladimir Stevanović, Irena Tabain, Željka Hruškar, Danko Mikulić, Ljubo Barbić, Tatjana Vilibić-Čavlek","doi":"10.11613/BM.2021.030901","DOIUrl":null,"url":null,"abstract":"<p><strong>Introduction: </strong>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.</p><p><strong>Materials and methods: </strong>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.</p><p><strong>Results: </strong>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% <i>vs</i>. 19.0%, P = 0.554; VNT 3.6% <i>vs</i>. 2.6%, P = 0.082). Overall VNT positivity rates were higher in patients who reported participation in large community events (5.9% <i>vs</i>. 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).</p><p><strong>Conclusions: </strong>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.</p>","PeriodicalId":9021,"journal":{"name":"Biochemia Medica","volume":null,"pages":null},"PeriodicalIF":3.8000,"publicationDate":"2021-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8495621/pdf/","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biochemia Medica","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.11613/BM.2021.030901","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MEDICAL LABORATORY TECHNOLOGY","Score":null,"Total":0}
引用次数: 2
Abstract
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.
期刊介绍:
Biochemia Medica is the official peer-reviewed journal of the Croatian Society of Medical Biochemistry and Laboratory Medicine. Journal provides a wide coverage of research in all aspects of clinical chemistry and laboratory medicine. Following categories fit into the scope of the Journal: general clinical chemistry, haematology and haemostasis, molecular diagnostics and endocrinology. Development, validation and verification of analytical techniques and methods applicable to clinical chemistry and laboratory medicine are welcome as well as studies dealing with laboratory organization, automation and quality control. Journal publishes on a regular basis educative preanalytical case reports (Preanalytical mysteries), articles dealing with applied biostatistics (Lessons in biostatistics) and research integrity (Research integrity corner).