Figure legends
Figure 1 , The comparisons in the duration of hospitalization and the time of negative conversion of RT-PCR assays for SARS-CoV-2 nucleic acid, respectively, between the following COVID-19 subgroups: (A, B), allergic and non-allergic patients; (C, D), no pneumonia and mild pneumonia patients; (E, F), patients aged < 10 years and ≥ 10 years. In each graph, the dots denote each of numerical values, the middle long lines denote medians, and bilateral short lines denote interquartile ranges. In particular, the black dots denote the numerical values of three severe/critical cases, and the hollow black dot denotes that of one dead case. Details of these four severe or critically ill patients were presented in Table 7. All of the comparisons were not significantly different (p > 0.05). RT-PCR, real-time reverse transcription polymerase chain reaction. (+), positive.
Figure 2 , Typical chest CT images of pediatric COVID-19 patients. (A) a 11-month-old non-allergic female, with chest CT showing ground-glass opacity in left lower lobe; (B) a 1-year-old non-allergic male, with chest CT showing bilateral ground-glass opacities and subpleural nodular consolidation; (C) a 4-year-old male with a history of allergic rhinitis, and his chest CT showed patchy opacities in left lower lobe; (D) a 3-year-old male with a history of allergic rhinitis and recurrent wheezing, and his chest CT showed patchy opacity distributed around the bronchovascular bundle in right lower lobe.
Figure 3 , Heatmap of correlation matrix between duration of hospitalization (DH), duration of RT-PCR conversion (DP, time from first positive to first negative RT-PCR results), blood cell counts and immunological parameters of pediatric patients with COVID-19 in (A) total cases (n = 182), (B) allergic cases (n = 43), and (C) mild pneumonia cases (n = 124), respectively. Analyzed variables included numbers of immune cells, serum levels of immunoglobulins (Igs), complements and cytokines: NEU (neutrophils count, ×10^9/L), EOS (eosinophils count, ×10^9/L), LYM (lymphocytes count, ×10^9/L), T (T cells count, /μl), CD4+ and CD 8+ T (CD4+ and CD8+ T cells count, /μl), B (B cells count, /μl), NK (natural killer cells count, /μl), IgG, IgA and IgM (concentration, g/L), IgE (concentration, IU/ml), C3 and C4 (complements C3 and C4 concentration, g/L), IL-2, 4, 6 and 10 (interleukins concentration, pg/ml), TNF-α (tumor necrosis factor-α concentration, pg/ml), and IFN-γ (interferon-γ, pg/ml). The values of Spearman’s correlation coefficients are shown in each cell of the graph. Red and blue backgrounds stand for positive and negative correlations, respectively, and the shades of color reflect the strength of correlation.
Figure 4 , Correlations between the duration of hospitalization and the time of RT-PCR conversion in pediatric COVID-19 patients: (A) all patients, (B) allergic patients, (C) patients with pneumonia, (D) the significantly negative correlation between the duration of hospitalization and the level of IFN-γin patients with pneumonia. Spearman’s correlation test was used, with a calculation of correlation coefficient (r ). The red dots denote the numerical values of three severe/critical cases, and the hollow red dot denotes that of one dead case. RT-PCR, real-time reverse transcription polymerase chain reaction. (+), positive; (-), negative.