ABSTRACT
Background. Cytokines play a major role in the immune response to viral infections, contributing to viral clearance but also mediating immunopathology following infection. We sought to define and compare systemic cytokine responses in infants hospitalized with COVID-19 versus RSV infection (RSVi). Methods. Prospective study of convenience cohort of infants hospitalized with PCR confirmed SARS-CoV-2 or RSVi, as well as pre-pandemic healthy controls (HC). Blood samples were obtained at enrollment and cytokine analysis performed using a 92-cytokine inflammation panel (Olink platform). Statistical analyses were performed in R environment. Results. We enrolled 26 infants with COVID-19, 77 with RSVi, and 18 healthy infants as a comparator control group. Oxygen requirement was significantly more frequent in infants with RSVi (p=0.02), while presence of comorbidities was significantly more common in infants with COVID-19 (p=0.01). No statistical differences were identified in terms of length of stay, admission to pediatric intensive care unit, need for mechanical ventilation, and lymphocyte counts (Table 1). Principal component analysis (PCA) revealed clustering of the global cytokine profiles differentiating HC from infants with COVID-19 and RSVi (Figure 1A). Multiple comparison analysis among the three groups yielded 49 significantly different cytokines clustered in three groups. A first cluster that included cytokines such as CCL11, CCL19 and TNFSF12 were lower in both COVID-19 and RSVi compared to HC;a second cluster with CCL8, CXCL8 and CASP8 that were mildly increased in both COVID-19 and RSVi;and a third cluster that included IL6, IL17C and IFN-gamma were markedly increased in both viral groups compared with HC (ANOVA padj< 0.05) (Figure 1B). Direct comparison between COVID-19 and RSVi (padj< 0.05 and FC >1.5) identified 7 statistically different cytokines. CCL8, CXCL1, CCL20 concentrations were increased in COVID-19, while SIRT2, STAMBP, MMP10 and EIF4EBP1 concentrations were increased in RSVi (Figure 1C-D). Conclusion. Analysis of systemic cytokine profiles identified shared but also distinct cytokine responses in infants with SARS-CoV-2 and RSVi suggesting important differences in the pathogenesis of these viral infections. (Figure Presented).
ABSTRACT
Background. The factors associated with severe COVID-19 in pediatric patients remain poorly understood. We sought to determine whether mucosal innate immunity cytokines were associated with disease severity in children and adolescents with acute COVID-19. Methods. Single-center, prospective study including children and adolescents < 21 years of age hospitalized because of symptomatic COVID-19 from 3/2020 to 1/ 2021, and age, sex and race matched pre-pandemic (2016-2019) healthy controls. Nasopharyngeal (NP) samples were obtained at enrollment for measurement of SARS-CoV-2 viral loads by rt-PCR and cytokine concentrations using a 92-plex inflammation/ antiviral panel (Olink). Disease severity was assessed by the need for supplemental oxygen or PICU admission, and patients classified as severe and non-severe based on these two parameters. Statistical analyses were performed in R studio and Benjamini-Hochberg applied to adjust for multiple comparisons. Results. Of the 75 children with acute COVID-19 (median IQR age: 3.4 [0.2-15.3] years), 28 (37%) were classified as severe COVID-19 (19 PICU;25 supplemental oxygen) and 47 (63%) were non-severe. Children with severe COVID-19 were predominantly male and had an underlying condition more frequently than those with non-severe disease (79% vs 49% respectively;p< 0.01, Table 1). SARS-CoV-2 viral loads were comparable between groups, yet patients with severe COVID-19 had significantly higher concentrations of C-reactive protein (p=0.04), more frequent lymphopenia (p=0.03) and cardiac involvement (p=0.04), and received COVID-19 directed therapies more commonly (p< 0.001). Comparative analyses identified 24 cytokines that were significantly different between children with acute COVID-19 versus 45 healthy controls. Of those, concentrations of IFN-gamma (p=0.004), CXCL10 (p=0.01), CXCL11 (p=0.02) and CCL19 (p=0.02) were significantly lower in children with severe versus those with non-severe COVID-19 (Fig 1). Conclusion. Mucosal concentrations of antiviral/regulatory cytokines were decreased in children with severe COVID-19. These findings suggest that impaired mucosal innate immune responses might favor SARS-CoV-2 disease progression and severity in children. (Figure Presented).
ABSTRACT
Background. The mechanisms associated with COVID-19 in children are not well understood. We sought to define the differences in nasopharyngeal (NP) cytokine profiles according to clinical presentation in children with COVID-19. Methods. Single-center, prospective study in 137 children and adolescents < 21 years of age hospitalized with COVID-19, and 35 age, sex and race matched pre-pandemic (2016-2019) healthy controls. Children with COVID-19 were categorized according to their clinical presentation in: COVID-19-symptomatic;COVID-19-screening, and multisystem inflammatory syndrome (MIS-C). NP swabs were obtained within 24 hours of admission to measure SARS-CoV-2 loads by rt-PCR, and a 92-cytokine panel. Unsupervised and supervised analysis adjusted for multiple comparisons were performed. Results. From 3/2020 to 1/2021, we enrolled 76 COVID-19-symptomatic children (3.5 [0.2-15.75] years);45 COVID-19-screening (11.1 [4.2-16.1] years), and 16 MIS-C (11.2 [5.9-14.6] years). Median NP SARS-CoV-2 loads were higher in COVID-19-symptomatic versus screening and MIS-C (6.8 vs 3.5 vs 2.82 log10 copies/mL;p< 0.001). Statistical group comparisons identified 15 cytokines that consistently differed between groups and were clustered in three functional categories: (1) antiviral/regulatory, (2) pro-inflammatory/chemotactic, and (3) a combination of (1) and (2);(Fig 1). All 15 cytokines were higher in COVID-19-symptomatic versus controls (p< 0.05). Similarly, and except for TNF, CCL3, CCL4 and CCL23, which were comparable in COVID-19-symptomatic and screening patients, the remaining cytokines were higher in symptomatic children (p< 0.05). PDL-1 (p=0.01) and CCL3 (p=0.03) were the only cytokines significantly decreased in children with MIS-C versus symptomatic COVID-19 children. The 15 cytokines identified by multiple comparisons were correlated using Person's in R software. Red reflects a positive correlation and blue a negative correlation with the intensity of the color indicating the strength of the association. Conclusion. Children with symptomatic COVID-19 demonstrated higher viral loads and greater mucosal cytokines concentrations than those identified via screening, whereas in MIS-C concentrations of regulatory cytokines were decreased. Simultaneous evaluation of viral loads and mucosal immune responses using non-invasive sampling could aid with the stratification of children and adolescents with COVID-19 in the clinical setting.