Meningococcal sepsis remains an important cause of childhood morbidity and mortality. Largely due to logistic complexities of research in young children with acute life-threatening disease, very little is known regarding differential expression kinetics and molecular regulation of immune response genes in leukocyte subsets.

In this prospective case-control study, six children with meningococcal sepsis were included. Blood was drawn at four time points (t=0, t=8, t=24 and t=72 h after admission to the paediatric intensive care unit). Blood was also collected from matched controls. Detailed immunophenotyping of leukocytes was performed; RNA isolated from whole blood, lymphocytes, monocytes, and granulocytes was used to perform Affymetrix micro-array gene expression analysis.No replicates were performed.Table 4. Results of between-subject analyses.Source Time (h) ca co/ca at t=TBlood t0: ca:2 3, co: a b c; t8: 2; t24 :ca:1 2 3; t72: ca:1 2.Lym t0: ca:2 3, co:a b c d;t8: ca:1 3 4;t24: ca:1 2 3 4 6; t72: ca: 1 2.Mono t0:ca: 1 3 4 6, co: a b d; t8: ca:1 2 3; t24:ca: 1 2 3; t72: ca:1.Numbers represent the patient identification numbers.Characters represent the individual controls.

Meningococcal sepsis (2021 ICD-10-CM code* = A41.9-A39.4)

Micro-array analysis. Background was removed using robust multichip analysis (RMA) and probe intensity levels were quantile normalized. Array groups were compared based on the perfect match (PM) probe intensity levels only, by performing a per-probeset two-way analysis of variance (ANOVA, with factors “probe” and “group”). This results in average expression levels for each probeset in each group, as well as raw p-values for the significance of the difference between the groups. The latter were adjusted for multiple testing using ¬Šidák step-up adjustment to control the family-wise error rate (FWER), i.e. the probability of incorrectly calling at least one probeset differentially expressed. All differences with adjusted p-values < 0.05 were considered significant. The Ingenuity program was used to analyse what pathophysiological pathways were differentially expressed between patients at t=0 and controls (Ingenuity Pathway Analysis; 5.5.1-1002).