Markers of Systemic and Lung Inflammation in Childhood Asthma

Abstract

Aim. To compare different biomarkers of inflammation in children with controlled and uncontrolled asthma and to investigate their relationship with other clinical indices of asthma control (symptoms, lung function, serum IgE, and prn beta-agonist use). Materials and Methods. A total of 62 consecutive asthmatic children (age 11 ± 3.3 years, 32 girls) with controlled ([C], n = 19) and uncontrolled asthma ([NC], n = 43) were studied. Measured lung function and inflammatory biomarkers included: spirometry, exhaled NO (F_ENO), high-sensitivity C-reactive protein (hs-CRP), peripheral blood white blood cells (WBC) counts, and differentials. Results. Hs-CRP was significantly higher in uncontrolled than in controlled asthma (hs-CRP, median [IQR], mg/L; 0.56 [0.60] vs 0.25 [0.34], p = 0.008). Discriminant analysis (backward stepwise) depicted hs-CRP and lymphocytes (as Z-score for absolute count) as significant discriminative factors for asthma control (F = 8.319, p = 0.0007) with 82.3% diagnostic accuracy. Divided into quartiles hs-CRP showed the significant inverse association with F_ENO (F = 7.359, p = 0.003, ANOVA) with no significant difference for asthma control (F = 1.032, p = 0.386). Post-hoc analysis revealed that F_ENO values were significantly lower in the third and the fourth quartile of hs-CRP in comparison to the first and the second one (p < 0.05 for all). Conclusion. In asthmatic children with uncontrolled asthma serum hs-CRP was increased compared to children with controlled asthma. Although F_ENO values were also increased (insignificantly) and inversely correlated with hs-CRP they were probably reflecting different etiology underlying the loss of control. The role of peripheral blood biomarkers in asthmatics is still poorly investigated so new studies are required.

Keywords:

• asthma
• biomarkers
• C-reactive protein
• exhaled nitric oxide
• inflammation