The relationship of serum interleukin-13 to asthma control in a sample of nigerian asthmatics

Abstract

Title: The relationship of serum interleukin-13 to asthma control in a sample of Nigerian asthmatics. Background: Asthma control is the main goal of asthma management and interleukin-13 (IL-13) has a major role in Th2 response that is characteristic of allergic asthma. Aim: We aimed to investigate the correlation between serum IL-13 and asthma control as measured by asthma control test (ACT) scores, hypothesizing that serum IL-13 would correlate inversely with ACT scores. Methods: It was a cross-sectional study in which 82 consecutive stable asthmatics ( mean age 44.3±16.3 years, 59 females) in a tertiary hospital in Nigeria were recruited. All subjects had assessment of asthma control by ACT, spirometry, skin prick test and serum IL-13 assay by a commercial ELISA kit. Correlation between ACT scores and serum IL-13 was assessed by spearman’s correlation coefficient. Results: The median (IQR) ACT score was 18(13-22) and median serum IL-13 was 4.0(3.3-4.4) pg/ml. Out of the 82 subjects, 49(59.8%) had uncontrolled asthma (ACT≤20). Serum IL-13 correlated inversely with ACT, rho= -0.218, p=0.025. The serum IL -13 median (IQR) concentration did not differ significantly between non atopic 4.1(3.7-4.4)pg/ml and atopic 3.8(3.2-4.4)pg/ml; p=0.159 asthmatics as measured by skin prick test. Conclusion: Serum IL-13 may be a useful biomarker to assess asthma control in Nigerian asthmatics.