Small nucleolar RNA networks are up‐regulated during human anaphylaxis

Background Anaphylaxis is a severe, potentially life‐threatening allergic reaction driven primarily by the activation of mast cells. We still fail to understand factors underlying reaction severity. Furthermore, there is currently no reliable diagnostic test to confirm anaphylaxis in the emergency department (ED). Objective This study sought to explore gene expression changes associated with anaphylaxis severity in peripheral blood leucocytes and evaluate biomarker potential. Methods Microarray analysis (total RNA) was performed using peripheral blood samples from ED patients with moderate (n = 6) or severe (n = 12) anaphylaxis and sepsis (n = 20) at presentation (T0) and one hour later (T1). Results were compared between groups and healthy controls (n = 10 and n = 11 matched to anaphylaxis and sepsis patients, respectively). Changes in gene expression were determined using R programming language, and pathway analysis applied to explore biological processes and pathways associated with genes. Differentially expressed genes were validated in an independent cohort of anaphylaxis (n = 30) and sepsis (n = 20) patients, and healthy controls (n = 10), using quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR). Results Significant up‐regulation of small nucleolar RNAs (snoRNAs) was demonstrated in anaphylaxis compared to sepsis patients in the microarray cohort, at T0 and T1. qRT‐PCR analysis of the validation cohort showed five genes: SNORD61, SNORD8, SNORD69, SNORD119 and HIST1H1D to be significantly up‐regulated (adjusted p