Department of Microbiology, Parasitology and Immunology, Medical Science Faculty (FCM), Rio de Janeiro State University (UERJ), Rio de Janeiro, RJ, Brazil.
Laboratory of Clinical Research on STD/AIDS, National Institute of Infectology Evandro Chagas, Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, RJ, Brazil.
PLoS One. 2023 Apr 5;18(4):e0283983. doi: 10.1371/journal.pone.0283983. eCollection 2023.
Cytokines induced by SARS-CoV-2 infection play a crucial role in the pathophysiology of COVID-19 and hyperinflammatory responses have been associated with poor clinical outcomes, with progression to severe conditions or long-term subacute complications named as long-COVID-19.
In this cross-sectional study, we aimed to evaluate a set of antigen-specific inflammatory cytokines in blood from recovered COVID-19 individuals or who suffered a post-acute phase of SARS-CoV-2 infection compared to healthy individuals with no history of COVID-19 exposition or infection. Interferon-gamma (IFN-γ), IFN-γ-induced protein 10 (IP-10), tumor necrosis factor (TNF), IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, and IL-17A were quantified by multiplex cytometric bead assay and enzyme-linked immunosorbent assay after stimulation of whole blood with recombinant Spike protein from SARS-CoV-2. Additionally, all participants have evaluated for anti-(S) protein-specific IgG antibodies. Clinical specimens were collected within two months of COVID-19 diagnosis.
A total of 47 individuals were enrolled in the study, a median age of 43 years (IQR = 14.5), grouped into healthy individuals with no history of infection or exposure to SARS-CoV-2 (unexposed group; N = 21); and patients from the Health Complex of the Rio de Janeiro State University (UERJ), Brazil, who were SARS-CoV-2 positive by RT-PCR (COVID-19 group)-categorized as recovered COVID-19 (N = 11) or long-COVID-19 (N = 15). All COVID-19 patients presented at least one signal or symptom during the first two weeks of infection. Six patients were hospitalized and required invasive mechanical ventilation. Our results showed that COVID-19 patients had significantly higher levels of IFN-γ, TNF, IL-1β, IL-2, IL-6, IL-8, and IP-10 than the unexposed group. The long-COVID-19 group has presented significantly high levels of IL-1β and IL-6 compared to unexposed individuals, but not from recovered COVID-19. A principal-component analysis demonstrated 84.3% of the total variance of inflammatory-SARS-CoV-2 response in the first two components, and it was possible to stratify IL-6, TNF, IL-1β, IL-10, and IL-2 as the top-five cytokines which are candidates to discriminate COVID-19 group (including long-COVID-19 subgroup) and healthy unexposed individuals.
We revealed important S protein-specific differential biomarkers in individuals affected by COVID-19, bringing new insights into the inflammatory status or SARS-CoV-2 exposition determination.
SARS-CoV-2 感染诱导的细胞因子在 COVID-19 的病理生理学中起着至关重要的作用，过度炎症反应与不良临床结局相关，进展为严重疾病或长期亚急性并发症称为长 COVID-19。
在这项横断面研究中，我们旨在评估一组来自 COVID-19 恢复期个体或经历 SARS-CoV-2 急性后期感染的个体的血液中与健康个体（无 COVID-19 暴露或感染史）相比的一组抗原特异性炎症细胞因子。使用 SARS-CoV-2 的重组 Spike 蛋白刺激全血后，通过多重流式细胞术 bead 测定和酶联免疫吸附试验定量检测干扰素-γ (IFN-γ)、干扰素-γ 诱导蛋白 10 (IP-10)、肿瘤坏死因子 (TNF)、IL-1β、IL-2、IL-4、IL-6、IL-8、IL-10、IL-12 和 IL-17A。此外，所有参与者均评估了抗（S）蛋白特异性 IgG 抗体。临床标本在 COVID-19 诊断后两个月内采集。
共有 47 名个体入组研究，中位年龄为 43 岁（IQR=14.5），分为无 SARS-CoV-2 感染或暴露史的健康个体（未暴露组；N=21）和来自巴西里约热内卢州立大学健康综合体（UERJ）的 SARS-CoV-2 阳性个体（COVID-19 组）-分为 COVID-19 恢复期（N=11）和长 COVID-19 组（N=15）。所有 COVID-19 患者在感染的前两周内至少出现一种信号或症状。六名患者住院并需要有创机械通气。我们的结果表明，COVID-19 患者的 IFN-γ、TNF、IL-1β、IL-2、IL-6 和 IP-10 水平明显高于未暴露组。长 COVID-19 组的 IL-1β 和 IL-6 水平明显高于未暴露个体，但与 COVID-19 恢复期患者无差异。主成分分析表明，前两个成分中 SARS-CoV-2 炎症反应的总方差为 84.3%，可以将 IL-6、TNF、IL-1β、IL-10 和 IL-2 分层为区分 COVID-19 组（包括长 COVID-19 亚组）和健康未暴露个体的前五名候选细胞因子。
我们揭示了 COVID-19 个体中重要的 S 蛋白特异性差异生物标志物，为炎症状态或 SARS-CoV-2 暴露的确定提供了新的见解。
