In-silico immune cell deconvolution of the airway proteomes of infants with pneumonia reveals a link between reduced airway eosinophils and an increased risk of mortality

Charles J Sande; Jacqueline M Waeni; James M Njunge; Martin N Mutunga; Elijah Gicheru; Nelson K Kibinge; Agnes Gwela

The difference in the immunological response to pneumonia between children who succumb to infection and those who survive it is not clear. An improved understanding of the immunobiology of this elevated post infection mortality risk will be crucial in identifying prognostic biomarkers of poor outcome, which will be critical in guiding care decisions in the first critical hours after admission. Most studies on the mechanisms of severe pneumonia in infants have been done using blood samples 6 , and whist these studies have provided significant insights into disease pathology, they might not fully recapitulate the immune response to infection in the airway. In the case of RSV, there has only been one study in the last 60 years that examined the lung samples of children who died from pneumonia. Archived post-mortem lung tissue from three children who died in the pre-intensivist era in the USA in the 1930s and 1940s was evaluated and airway obstruction with necrotic cells, fibrin, mucus, and fluid identified as a prominent feature in RSV lung infection 7 . Staining for immune cell populations was not technically feasible in these long term archival samples.