Objectives: Up- and down-regulation of inflammatory response was described in blood cells from septic patients, according to the stage of sepsis and the cells evaluated. This study aimed to evaluate the Toll-like receptor (TLR) signaling pathway gene expression in peripheral blood mononuclear cells (PBMC) and neutrophils in patients throughout the different stages of sepsis.
Design: Prospective, observational study.
Settings: Two emergency rooms and two intensive care units in one university and one teaching hospital.
Patients and controls: A total of 15 septic patients, five with sepsis, five with severe sepsis, and five with septic shock, in addition to five healthy volunteers were enrolled.
Interventions: None.
Measurements and main results: The Human-TLR Signaling Pathway, which comprises 84 genes related to TLR-mediated signal transduction, was evaluated by real time polymerase chain reaction in PBMC and neutrophils obtained from patients and controls. The fold change for each gene (2(-Delta DeltaCt)) was compared between the groups. Genes with fold changes greater than 2 and significant changes in DeltaCT are reported as differently expressed. The fold change ratios in PBMC gene expression between septic patients and healthy controls revealed a dynamic process according to the stage of sepsis, tending toward down-regulation of the TLR signaling pathway in PBMC in the more severe forms of the disease. However, the differential gene expression was restricted to five down-regulated genes in septic shock patients, which are found in the effector and downstream pathways. Neutrophils showed a different pattern of adaptation. Patients with sepsis, severe sepsis, and septic shock presented a broad gene up-regulation, which included all functional groups evaluated and persisted throughout the stages of the disease.
Conclusions: TLR-signaling pathway genes are differently regulated in PBMC and neutrophils of septic patients, and are dynamically modulated throughout the different stages of sepsis.