Hot Topics from the Assemblies

Rhinovirus detection in symptomatic and asymptomatic children: value of host transcriptome analysis Authors: Heinonen S, Jartti T, Garcia C, et al. Am J Respir Crit Care Med 2015; [In press DOI: 10.1164/rccm.201504-0749OC] Summary: The “transcriptome” represents the set of RNA expressed by genes in one cell or a population of cells. Transcriptome analysis could facilitate our understanding of how the body reacts to environmental and infectious triggers. This study used transcriptome analysis to evaluate the effects of rhinovirus infection on the blood transcriptome. In particular, the authors investigated whether a transcriptional pattern exists that could allow differentiation between individuals acutely infected with rhinovirus (active infection) and those who are rhinovirus-positive but have no symptoms (incidental detection). The authors included 151 previously healthy children aged <2 years and divided them into four subgroups: 37 control rhinovirus-negative children, 14 asymptomatic rhinovirus-positive children, 30 outpatient rhinovirus-positive children with respiratory infection and 70 inpatient rhinovirus-positive children with respiratory infection. The analysis of the transcriptional profiles was made on blood samples and focused on the activation of the immune response: the results show that active rhinovirus infection is characterised by a strong and reproducible transcriptional pattern, with a clear change in the expression of genes involved in the immune response (overexpression of innate immunity and underexpression of adaptive immunity genes), while no significant change was found in asymptomatic rhinovirus-positive children. Specifically, overexpressed transcripts included genes related mostly to interferon (IFITM3 and IFI27; the latter being the most overexpressed transcript), but also to neutrophil function (DEFA1, 3 and 4, BPI, GPR84, FCGR1) and apoptosis (MMP9). This study raises preliminary speculation that transcriptomic analyses could provide a useful clinical tool to differentiate between active infection and incidental pathogen detection. Further studies are now needed. Reviewed by: Maria Di Cicco (Italy, Assembly 7)