Elevation of serum soluble vascular cell adhesion molecule-1 (sVCAM-1) levels in bronchial asthma

We have previously shown the elevation of serum soluble intercellular adhesion molecule-1 (sICAM-1) and soluble E-selectin( sE-selectin) in patients with bronchial asthma during asthma attacks. In the present study, we extended our earlier study by measuring serum sVCAM-1 levels by ELISA in 45 patients with bronchial asthma (23 atopic and 22 non-atopic) during asthma attacksand in stable conditions in order to assess further the state of adhesion molecules in allergic inflammationof bronchial asthma. The levels of sVCAM-1 in sera obtained during bronchial asthma attackswere higher than those in sera obtained in stable conditions. These findings were observed regardless of atopic status. To examine the regulatory mechanism in the elevation of serum sVCAM-1 levels, serum tumor necrosis factor-alpha (TNF-alpha) levels were measured by ELISA. TNF-alpha levels in sera obtained during bronchial asthma attackswere higher than those in sera obtained in stable conditions. The nature of change in serum TNF-alpha levels correlated with the nature of change in serum sVCAM-1 levels, but serum TNF-alpha levels did not correlate with serum sVCAM-1 levels. These results suggest that higher levels of sVCAM-1 during asthma attacksmay reflect the up-regulation of VCAM-1expression in allergic inflammation, and that a soluble form of VCAM-1molecules may be useful markers for the presence of allergic inflammation. TNF-alpha is shown to enhance the expression and release of VCAM-1in vitro, however; the regulatory mechanism in the elevation of serum sVCAM-1 levels remains to be clarified.