Association of serum-soluble CD26 and CD30 levels with asthma, lung function and bronchial hyper-responsiveness at school age

Aim: There is a need for markers of Th1 and Th2 imbalance in diseases such as asthma. CD30 is an activation marker of Th2 cells, and importance of Th1 marker CD26 was recently found in adult asthma. We studied whether serum-soluble CD30 (sCD30) or serum-soluble CD26 (sCD26) could support early diagnosis of asthma in children at school age. Methods: sCD26 and sCD30 were measured in 34 children with clinically confirmed asthma, 31 with possible asthma and in 147 controls. In addition, the associations of flow volume spirometry, methacholine inhalation challenge and free running test results with serum sCD26 or sCD30 were analysed. Results: Serum sCD30 was significantly higher in children with confirmed asthma (mean 91.5 IU/mL, SD 23.0) than in the controls (78.8 IU/mL, 25.9; p = 0.042). No significant differences were found in serum sCD26 levels between the groups. There was a negative correlation of mean mid expiratory flow values with serum sCD26 (r = -0.22, p = 0.0018). Neither methacholine inhalation challenge nor free running test results were associated with serum sCD26 or sCD30. Conclusion: Serum sCD30 was higher in children with asthma. However, marked overlap in serum sCD30 between asthmatic and healthy children limits the usefulness of sCD30 as a diagnostic marker of asthma.