Introduction:
Pneumonia is an infection of the lungs caused by bacteria, viruses,
fungi, and parasites that impose significant costs for the health care
system and exhibit the most common reason for the death of infectious
origin1. In this disease, polymorphonuclear
neutrophils and macrophages fight with microorganisms by using reactive
oxygen species (ROSs) and lysosomal enzymes2. As a
consequence of pulmonary defense mechanism in inflammatory diseases such
as pneumonia and asthma, Oxidative stress (OS) at the systemic level may
have a central role with adverse clinical outcomes of these diseases,
such as the endothelial dysfunction (ED), exacerbation of inflammation,
and shortness of breath, and ultimately acute respiratory distress
syndrome (ARDS), and death 3-5.
ED causes pulmonary edema due to an increase in endothelial
permeability. The activated endothelium mediates leukocyte binding to
express the adhesion molecules such as vascular cell adhesion molecule-1
(VCAM-1) and intercellular adhesion molecule 1 (ICAM-1)
that mediate leukocyte binding. Upon leukocyte binding, these adhesion
molecules activate endothelial cell signal transduction and then alter
endothelial cell shape for the opening of passageways, through which
leukocytes can migrate 6-7.
Characterized by chronic inflammation in the airway wall, asthma is the
most common chronic respiratory disease in children, which is prevalent
in developing countries. Although it cannot be considered a direct cause
of pneumonia, children with asthma are more prone to develop pneumonia
due to previous lung damage. As a result, a child with asthma may have
more severe symptoms and complications from pneumonia. Asthma may
exacerbate the clinical consequences of pneumonia, such as ED8-11.
We are not aware of any studies on assessing the changes in OS,
inflammation, and ED biomarkers in children with asthma and pneumonia
together compared with children with pneumonia only. Therefore, the
current study assessed the alterations in OS, TNF-α, and ED biomarkers
in children with asthma and pneumonia, children with pneumonia only, and
healthy children.