Patients with asthma had significantly higher plasma levels of IL-5 (0.92 ± 0.22 vs. 0.45 ± 0.07 pg/mL, p = 0.009) and IL-10 (2.13 ± 0.32 vs. 1.88 ± 0.56 pg/mL, p = 0.026), and patients with allergic rhinitis also showed elevated IL-5 levels (0.77 ± 0.17 vs. 0.42 ± 0.04 pg/mL, p = 0.026) and IL-10 concentrations (3.14 ± 0.91 vs. 1.05 ± 0.16, p = 0.013). This evidence concerns the gene IL10 and asthma.