Percentage of eosinophils with surface CD44 and levels of eosinophil cationic protein in the peripheral blood in children with bronchial asthma and their changes after montelukast therapy.

Bronchial asthma (BA) is chronic inflammation of the respiratory tract with a role played by a variety of cells, particularly mast cells, eosinophils (Eo), and T lymphocytes. The serum levels of Eo cationic protein (S-ECP) reflect the severity of bronchial inflammation and the level of bronchial hyperreactivity in asthma patients. One of the most important adhesion molecules is CD44. We examined S-ECP, the percentage of Eo with surface CD44 expression (EoCD44), and Eo count in the peripheral blood of newly diagnosed pediatric atopic patients with intermittent and persistent mild BA according to the Global Iniative for Asthma 2002, in a proportion of patients 3 months after initiation of montelukast therapy. Ninety-seven children with BA had their medical history taken, and S-ECP, with the percentage of EoCD44 determined by direct fluorescence from whole blood using flow cytometry with a Coulter EPICS XL cytometer, and Eo count, total serum immunoglobulin E levels (S-IgE) were determined. Therapy with montelukast (5 mg daily) was started in 23 children. Three months after the first collection, a second S-ECP level and EoCD44 count determinations were made. An inverse correlation between S-ECP and EoCD44 (-0.602; p < 0.0001) was found in the 97 children with BA. In the 23 children receiving montelukast we documented inverse correlation of fluctuation on S-ECP and EoCD44 after 3 months. These results were not significant. An inverse correlation between S-ECP and percent of EoCD44 was established in the 97 children with asthma before therapy initiation. The lower percentage of EoCD44 in peripheral blood in asthmatic children is due to Eo inflammation activity and attests to massive Eo invasion into the airways. Determination of the percentage proportion of EoCD44 is another potential indirect marker of the multiple features of Eo inflammation.