Sensitivities of a Rapid Test Versus an ELISA Kit for Detecting Anti-SARS-CoV-2 IgM/IgG in Sera from an Egyptian Cohort.

This study aimed to compare diagnostic sensitivities of a rapid test (Rt) and an ELISA kit for detecting anti-SARS-CoV-2 IgM/IgG in virus-RT-PCR-positive (VPP) and virus-RT-PCR-unchecked (VPU) subjects in an Egyptian cohort during the first wave of SARS-CoV-2 infection. The results revealed higher sensitivity of the Rt for detecting IgM/IgG in the VPP subjects. Both the Rt and ELISA showed identical sensitivities for IgM detection in the VPU subjects. The ELISA was more sensitive for detecting IgG in the VPU subjects. Generally, within both the VPP and the VPU groups, Rt was more sensitive for detecting IgM/IgG among the symptomatic (S) compared to asymptomatic (AS) subjects than ELISA. Within the VPP group, the Rt was more sensitive for detecting both IgM/IgG among the AS subjects than ELISA. In the VPU group, the Rt was more sensitive for detecting IgM among the S subjects than ELISA. The ELISA was more sensitive for detecting IgM/IgG among AS subjects than the Rt. From these results we concluded that, despite the limitation of sample size, this study indicates suitability of the used Rt for detecting anti-SARS-CoV-2 IgM/IgG among S subjects and sheds light on possibility of relying on the used ELISA for IgG detection among AS human subjects.

Proinflammatory Cytokine Profiles in Both Mild Symptomatic and Asymptomatic SARS-CoV-2-Infected Egyptian Individuals and a Proposed Relationship to Post-COVID-19 Sequela.

Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection is associated with proinflammatory cytokine release as mediators of host antiviral response to the infection. Cytokine persistent elevation leads to post-Coronavirus disease-2019 (COVID-19) post-COVID-19 sequela (PCS) reported in about 60% of patients affecting individual's normal life after recovery. This study evaluates relationship of cytokines and chemokines pattern during and postinfection to PCS events. Serum samples collected from 82 individuals with symptomatic, asymptomatic, or no SARS-CoV-2 infection were classified as recently or formerly infected groups according to levels of anti-2019nCoV Immunoglobulin G/Immunoglobulin M. Levels of interleukin (IL)-1α, IL-1ß, IL-6, IL-8, interferon alpha (IFN-α), tumor necrosis factor alpha (TNF-α), granulocyte macrophage colony-stimulating factor (GM-CSF), and monocyte chemoattractant protein-1 were assessed via ELISA for each individual. All asymptomatic groups showed nonsignificant differences in cytokines' levels than control group. Significant elevation of IFN-α, TNF-α, and GM-CSF levels were observed in recent symptomatic, while IFN-α and TNF-α levels were significant in former symptomatic groups. We observed an association between fever with IL-1α and IFN-α levels, fatigue with TNF-α and GM-CSF, dyspnea with IFN-α, TNF-α, and GM-CSF, and chest-wheezing with GM-CSF. Individuals were surveyed 12 months postsampling for PCS events. Among 35 responders to survey, 8 (22.8%) reported PCS events, 6 of which were females. Upon studying PCS events, IL-8, IFN-α, TNF-α, and GM-CSF levels showed significant elevation in active infection, that was not seen in a resolved state of infection. Cytokines patterns suggest that either a persistent elevation in levels or damage caused during infection contributes to PCS. Although with the limited sample size, our study emphasizes the importance to conduct medical approaches targeting the associated cytokines to improve the PCS symptoms.