High levels of pro-inflammatory SARS-CoV-2-specific biomarkers revealed by in vitro whole blood cytokine release assay (CRA) in recovered and long-COVID-19 patients

Abstract

Background 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. Methods 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. Results 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. Conclusion 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.

The Angiopoietin Signaling Pathway Is Involved in Inflammatory Processes in Hospitalized COVID-19 Patients

“…In accordance with published findings, in our study, the IL-6 and IgG antibody levels were higher in patients with severe clinical presentation and in those patients with adverse outcomes (death or >30 days hospitalization). The increase in antibody levels is believed to be a response to an elevated viral load and may potentially be the culprit of uncontrolled systemic inflammatory response in critically ill patients [25,26]. IL-6 is known to induce defective angiogenesis via the activation of the Ang2 pathway [2].…”

COVID-19 in patients with anemia and haematological malignancies: risk factors, clinical guidelines, and emerging therapeutic approaches

“…A diverse range of the most common haematological manifestations, including lymphopenia, anemia, thrombocytopenia, hyperferritinemia, coagulopathy, and high D-dimer levels, can be closely related to COVID-19 [ 18 , 19 ]. The pathogenesis of this condition is mostly attributed to the severe increase of pro-inflammatory markers such as interleukin-1 beta (IL-1β), IL-2, IL-4, IL-6, IL-10, tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ) which cause an exaggerated immune response [ 20 ]. The inflammatory response also causes disturbances in iron metabolism, contributing to high hepcidin levels, decreased iron utilization, hyperferritinemia, and anemia [ 21 ] ( Fig.…”

Neurological Sequelae of COVID-19: A Biochemical Perspective

“…Immunological memory is derived from an adaptive immune system, including CD4 T cells, CD8 T cells, B cells, and enduring antibody responses. Altered immunity in long COVID enhances inflammatory process and impacts the release of cytokines . − According to a limited examination, many cytokines do share sequence features with those in long COVID factors, such as relatively high content of valine plus glycine, basic amino acids, or both, consequently reinforcing symptoms of COVID sequel by augmenting the formation of aggregates. Cytokine storm damages tissues which can lead to long COVID .…”