Effect of allergen immunotherapy on soluble adhesion molecules

The level of soluble adhesion molecules in the serum reflects the degree of systemic inflammation but the dynamics of these molecules in the pathogenesis of allergic diseases and their evolution during treatment, remains to be established.

To determine the evolution of the levels of soluble forms of serum intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) during immunotherapy to Dermatophagoides pteronyssinus in patients with allergic rhinitis and/or asthma.

We included in this study 23 patients with perennial allergic rhinitis and/or asthma to Dermatophogoides pteronyssinus. 17 patients (6 males, 11 females, 13-48 years; mean: 27.2 years) were treated for one year with specific immunotherapy using standardized slow-release D. pteronyssinus extract (Lofarma, Milan, Italy). The other 6 patients (control group; 2 males, 4 females, 20-37 years; mean: 26.5 years) received only symptomatic treatment.

Serum sICAM-1 and sVCAM-1 were measured by ELISA method (R&D system). Blood samples were collected from each immunotherapy-treated patient at two timings: before immunotherapy (T0) and after one year of immunotherapy (T1). The two blood samples from each control patient (T0 and T1) were also collected one year apart.

Before Immunotherapy (T0), the mean serum level of sICAM-1 was 336.0 ng/ml. After one year of immunotherapy (T1) it decreased to 325.2 ng/ml but this difference was not statistically significant. Mean serum level of sVCAM-1 was 655.5 ng/ml before immunotherapy (T0), decreasing significantly (p < 0.05) to 568.2 ng/ml (T1). In the control group both sICAM-1 and sVCAM-1 had no significant changes (sICAM-1: 363.1 ng/ml (T0) and 374.7 ng/ml (T1); sVCAM-1: 611.5 ng/ml (T0) and 649.8 ng/ml (T1).

These results suggest that specific immunotherapy with D. pteronyssinus induces a decrease in serum sVCAM-1 but not in sICAM-1 levels. The decreased expression of sVCAM-1 after immunotherapy is probably related to a decrease in the inflammatory reactions.