Absent pleocytosis in infant viral central nervous system infections reflects lymphocyte depletion and cytokine activation

Figures

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  Fig. 1. Host plasma proteome response to EV and PeV CNS infection. A, B Volcano plots of differentially expressed proteins (FDR 0.05) between infant groups from the Olink cohort: A EV-positive CSF infants (n = 49) and viral negative CSF infants (n = 76), B PeV-positive CSF infants (n = 6) and viral negative CSF infants (n = 76). Statistical comparisons were performed using two-tailed Welch’s two-sample t-tests with Benjamini–Hochberg correction for multiple testing, as implemented in the OlinkAnalyze R package. Colour coding indicating fold change and statistical significance is defined within the figure key. C Hierarchical clustering displayed as a heatmap of the Olink cohort (n = 131) by significantly differentiated proteins (FDR < 0.05) with a fold change of > 1.0 between EV vs viral negative CSF and PeV vs viral negative CSF. Both proteins and samples were clustered using Euclidean distance and complete linkage. Coloured by protein expression values as defined within the figure key. All data points are from distinct participants. EV enterovirus, PeV parechovirus, CSF cerebrospinal fluid, FDR false discovery rate.

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  Fig. 2. Plasma proteome response, CSF pleocytosis and peripheral lymphocyte count. A, B Volcano plot showing the correlation in CSF virus-positive samples between plasma protein expression and: A Peripheral lymphocyte count (n = 54), infants without data on peripheral lymphocyte count were excluded (n = 1), B CSF WBC count (n = 49), infants without data on CSF WBCs were excluded (n = 6). Statistical comparisons were performed using two-sided Pearson correlation tests with Benjamini–Hochberg correction for multiple testing. Colour coding indicating statistical significance is defined within the figure key. (C&D) Volcano plots of differentially expressed proteins (FDR 0.05) between: C EV-positive CSF infants with CSF pleocytosis (n = 21) and virus-negative CSF (n = 76), D EV-positive CSF infants without CSF pleocytosis (n = 23) and virus-negative CSF (n = 76). EV-positive infants without CSF WBCs were excluded (n = 5). Statistical comparisons were performed using two-tailed Welch’s two-sample t-tests with Benjamini–Hochberg correction for multiple testing, as implemented in the OlinkAnalyze R package. Colour coding indicating fold change and statistical significance is defined within the…

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  Fig. 3. Plasma proteome clusters and functional analysis of EV/PeV CNS infection. A Hierarchical clustering displayed as a heatmap of all infants with EV or PeV positive CSF from the Olink cohort (n = 55) by proteins significantly correlated with CSF WBC count or peripheral lymphocyte count (FDR < 0.05). Proteins and samples were clustered using Euclidean distance and complete linkage, and the sample dendrogram was partitioned into three clusters. Coloured by protein expression values as defined within the figure key. The hierarchical clustering results are descriptive only and were not subjected to formal stability or resampling analyses. B–D Bar charts of enriched terms from proteins upregulated in heatmap clusters 1 (B), 2 (C), and 3 (D), generated using Metascape. Enrichment analysis was performed using a hypergeometric test with Benjamini–Hochberg correction for multiple comparisons. Enriched terms were clustered based on Kappa similarity, and the most significant term from each cluster is shown. Bars are coloured according to enrichment p-values (LogP). All data points are from distinct participants. EV enterovirus, PeV parechovirus, CSF cerebrospinal fluid, WBC white blood cells,…

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  Fig. 4. The effect of fever duration of plasma proteome response and WBC counts. A Volcano plot of differentially expressed proteins (FDR 0.05) between virus-positive CSF infants in the Olink cohort, presenting <6 h (n = 37) vs >6 h (n = 14) from first recorded fever. Infants without information on fever duration were excluded (n = 4). Statistical comparisons were performed using two-tailed Welch’s two-sample t-tests with Benjamini–Hochberg correction for multiple testing, as implemented in the OlinkAnalyze R package. Colour coding indicating statistical significance is defined within the figure key. B Box plot showing CSF WBC count by fever duration category for all participants in clinical data cohort with EV or PeV positive CSF (n = 166; <6 h n = 102, 6–12 h n = 31, 12–24 h n = 26, >24 h n = 7). Infants without data on fever duration or CSF WBC were excluded (n = 28). Lines represent median and interquartile ranges. Zero CSF WBC values were set to 0.1 for visualisation on the log-scale axis only. Statistical comparisons were performed using the Kruskal–Wallis test. C Box plot showing peripheral lymphocyte count by fever duration category for all participants with EV or PeV positive…