Related Experiment Video
Updated: Jun 19, 2026

Murine Oropharyngeal Aspiration Model of Ventilator-associated and Hospital-acquired Bacterial Pneumonia
Published on: June 28, 2018
Decrease of CD4-lymphocytes and apoptosis of CD14-monocytes are characteristic alterations in sepsis caused by
Aimilia Pelekanou1, Iraklis Tsangaris, Antigoni Kotsaki
14th Department of Internal Medicine, ATTIKON University Hospital, 1 Rimini Str, Athens 124 62, Greece. aimpelekanou@yahoo.gr
Introduction:
The present study aimed to investigate changes of the immune response between sepsis due to ventilator-associated pneumonia (VAP) and sepsis due to other types of infections.
Methods:
Peripheral venous blood was sampled from 68 patients with sepsis within 24 hours of diagnosis; 36 suffered from VAP; 32 from other nosocomial infections, all well-matched for severity, age and sex. Blood monocytes were isolated and cultured with/without purified endotoxin (lipopolysaccharide (LPS)). Estimation of tumour necrosis factor alpha (TNFalpha) and interleukin-6 (IL-6) in cultures' supernatants was done by an enzyme immunoassay. Flow cytometry was used to determine subpopulations of mononuclear cells and apoptosis. To mimic pathogenesis of VAP, mononuclear cells of healthy volunteers were progressively stimulated with increased inocula of pathogens; apoptosis was determined.
Results:
In patients with VAP, the absolute number of CD3(+)/CD4(+) lymphocytes was significantly lower (P = 0.034) and apoptosis of isolated monocytes was increased (P = 0.007) compared to other infections. TNFalpha and IL-6 production from LPS-stimulated monocytes was lower in patients with VAP-related sepsis than with sepsis due to other infections. Apoptosis of monocytes was induced after in vitro stimulation of mononuclear cells by a mechanism mimicking VAP.
Conclusions:
Decrease of CD4-lymphocytes and immunoparalysis of monocytes are characteristic alterations of sepsis arising in the field of VAP.
Related Concept Videos
Pneumonia II: Pathophysiology
Pneumonia I: Introduction
Pneumonia I: Introduction
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
Pneumonia III: Complications and Assessment
Pneumonia IV: Management
Bacterial Pneumonia Treatment
For bacterial pneumonia, antibiotics serve as the cornerstone of therapy. Initial treatment often begins with empirical antibiotics, tailored to the anticipated causative organism and adjusted based on culture results. Key antibiotic choices include:
Atypical Pneumonia