Cytokine levels associated with favorable clinical outcome in the CAPSID randomized trial of convalescent plasma in patients with severe COVID-19.

Objectives: To determine the profile of cytokines in patients with severe COVID-19 who were enrolled in a trial of COVID-19 convalescent plasma (CCP). Methods: Patients were randomized to receive standard treatment and 3 CCP units or standard treatment alone (CAPSID trial, ClinicalTrials.gov NCT04433910). The primary outcome was a dichotomous composite outcome (survival and no longer severe COVID-19 on day 21). Time to clinical improvement was a key secondary endpoint. The concentrations of 27 cytokines were measured (baseline, day 7). We analyzed the change and the correlation between serum cytokine levels over time in different subgroups and the prediction of outcome in receiver operating characteristics (ROC) analyses and in multivariate models. Results: The majority of cytokines showed significant changes from baseline to day 7. Some were strongly correlated amongst each other (at baseline the cluster IL-1ß, IL-2, IL-6, IL-8, G-CSF, MIP-1α, the cluster PDGF-BB, RANTES or the cluster IL-4, IL-17, Eotaxin, bFGF, TNF-α). The correlation matrix substantially changed from baseline to day 7. The heatmaps of the absolute values of the correlation matrix indicated an association of CCP treatment and clinical outcome with the cytokine pattern. Low levels of IP-10, IFN-γ, MCP-1 and IL-1ß on day 0 were predictive of treatment success in a ROC analysis. In multivariate models, low levels of IL-1ß, IFN-γ and MCP-1 on day 0 were significantly associated with both treatment success and shorter time to clinical improvement. Low levels of IP-10, IL-1RA, IL-6, MCP-1 and IFN-γ on day 7 and high levels of IL-9, PDGF and RANTES on day 7 were predictive of treatment success in ROC analyses. Low levels of IP-10, MCP-1 and high levels of RANTES, on day 7 were associated with both treatment success and shorter time to clinical improvement in multivariate models. Conclusion: This analysis demonstrates a considerable dynamic of cytokines over time, which is influenced by both treatment and clinical course of COVID-19. Levels of IL-1ß and MCP-1 at baseline and MCP-1, IP-10 and RANTES on day 7 were associated with a favorable outcome across several endpoints. These cytokines should be included in future trials for further evaluation as predictive factors.

Interleukin-9-secreting CD4+ T cells regulate CD8+ T cells cytotoxicity in patients with acute coronary syndromes.

T cells play vital roles in the development and progression of acute coronary syndromes (ACS), including cytotoxicity mediated by CD8+ T cells and immunoregulatory activity mediated by CD4+ T cells. Interleukin (IL)-9-secreting CD4+ T cells (Th9 cells) were recently found to be involved in the onset of ACS. We investigated regulatory role of Th9 cells to CD8+ T cells in patients with stable angina pectoris, unstable angina pectoris, and acute myocardial infarction (AMI). Circulating Th9 cells percentage, plasma IL-9 level, and PU.1 mRNA relative level was up-regulated in AMI patients compared with controls. There was no significant difference of IL-9-secreting CD8+ T cells percentage among groups. CD8+ T cells from AMI patients revealed increased cytotoxicity than those from controls, which presented as enhanced cytotolytic activity to target cells, increased interferon-γ and tumor necrosis factor-α secretion, elevated perforin and granzyme B production, and reduced programmed death-1 and cytotoxic T lymphocyte-associated protein 4. IL-9 stimulation did not affect proliferation, but promoted CD8+ T-cell cytotoxicity from both controls and AMI patients. IL-9-secreting CD4+ T cells were enriched in CD4+ CCR4- CCR6- CXCR3- cells. The enhancement of CD8+ T-cell cytotoxicity induced by CD4+ CCR4- CCR6- CXCR3- cells was dependent on IL-9 secretion. The present results indicated that up-regulation of IL-9-secreting CD4+ T cells may contribute to pathogenesis of AMI through enhancement of CD8+ T-cell cytotoxicity.

Cytokine profile and disease severity in patients with COVID-19.

Cytokine dysregulation is the proposed mechanism for Coronavirus disease 2019 (COVID-19). The aim of this study was to evaluate the serum levels of interferon (IFN)-γ, interleukin (IL)-5, IL-8, Il-9, IL-17, TGF-ß and IFN-γ in patients infected with SARS-CoV-2. The study was conducted between 63 adult patients with COVID-19 and compared with 33 age and gender-matched healthy subjects as controls. The age range in both groups was 50-70 years. The patients were classified into mild group (33 patients) and severe group (30 patients). Serum samples were collected from all participants and tested for the cytokine levels by ELISA (enzyme-linked immunosorbent assay) method. Statistical analysis was performed using the one-way ANOVA. The mean serum levels of IFN-γ, TGF-ß, IL-17 and IL-8 in the COVID-19 patients were significantly higher than those observed in the control group. A comparison of between the mild and severe groups showed significant differences in TGF-ß levels. The mean concentration of serum IL-5 and IL-9 in patients with COVID-19 did not differ from those in the control group. Systemic IL-17 levels correlated positively and significantly with TGF-ß in patients with COVID-19. Th1 (IFN-γ), Treg (TGF-ß), and Th17 (IL-17) cytokines concentration were increased in COVID-19 patients. Interferon-γ and IL-17 are involved in inducing and mediating proinflammatory responses. Our data suggest that TGF-ß can be used as a predictive factor of disease severity in patients with COVID-19.