Clinical significance of measurement of interleukin 4 and interleukin 5 serum concentrations in bronchial asthma

Cytokines IL-4 and IL-5 participate in the chronic inflammation process in the atopic airway diseases. Our study is aimed at determining correlation between IL-4 and IL-5 serum concentrations and severity of the disease in patients with bronchial asthma. The total of 65 patients with asthma is classified into three groups: 1. patients with mild, 2. moderate and 3. severe asthma. The control group comprised 10 healthy individuals. Measurement of IL-4 and IL-5 serum concentrations was performed according to ELISA method. Minimal detectable concentrations of IL-4 and IL-5 were 0.27 pg/mL and 4 pg/mL, respectively. IL-4 (Z = 2.245, p = 0.025) and IL-5 (Z = 2.139, p = 0.032) serum concentrations are significantly lower in healthy individuals in comparison to the individuals with asthma. Comparison of the study results between the groups (mild, moderate and severe asthma) evidenced that IL-4 serum concentrations in the group with moderate (Z = 2.604, p = 0.009) and severe asthma (Z= 2.658, p = 0.008) were statistically significantly higher in comparison to the group with mild asthma. IL-5 serum concentrations in the group with moderate (Z = 3.910, p = 0.000) and severe asthma (Z = 4.037, p = 0.000) were statistically significantly higher in comparison to the group with mild asthma. Further studies on the role of IL-4 and IL-5 in the process of chronic inflammation in asthma are needed.