Comparative Analysis of the Host Response to Community-acquired and Hospital-acquired Pneumonia in Critically Ill Patients.
Am J Respir Crit Care Med. 2016 Jun 6;
Authors: van Vught LA, Scicluna BP, Wiewel MA, Hoogendijk AJ, Klein Klouwenberg PM, Franitza M, Toliat MR, Nürnberg P, Cremer OL, Horn J, Schultz MJ, Bonten MM, van der Poll T
RATIONALE: Preclinical studies suggest that hospitalized patients are susceptible to infections caused by nosocomial respiratory pathogens at least in part due to immune suppression caused by the condition for which they were admitted.
OBJECTIVES: We aimed to characterize the systemic host response in hospital-acquired pneumonia (HAP) when compared with community-acquired pneumonia (CAP).
METHODS: We performed a prospective study in two intensive care units (ICU) in 453 patients with HAP (n=222) or CAP (n=231). Immune responses were determined on ICU admission by measuring 19 plasma biomarkers reflecting organ systems implicated in infection pathogenesis (in 192 HAP and 183 CAP patients) and by applying genome-wide blood gene expression profiling (in 111 HAP and 110 CAP patients).
MEASUREMENTS AND MAIN RESULTS: HAP and CAP patients presented with similar disease severities and mortality rates did not differ up to one year after admission. Plasma proteome analysis revealed largely similar responses, including systemic inflammatory and cytokine responses, and activation of coagulation and the vascular endothelium. The blood leukocyte genomic response was >75% common in HAP and CAP patients, comprising pro-inflammatory, anti-inflammatory, T cell signaling and metabolic pathway gene sets. HAP patients showed over-expression of genes involved in cell-cell junction remodeling, adhesion and diapedesis, which corresponded with lower plasma levels of matrix metalloproteinase-8 and soluble E-selectin. In addition, HAP patients demonstrated under-expression of a type-I interferon signaling gene signature.
CONCLUSIONS: HAP and CAP patients present with a largely similar host response at ICU admission.
PMID: 27267747 [PubMed - as supplied by publisher]