【Objective】 To explore changes and significance of serum interleukin-35 concentration in patients with bronchial asthma. 【Method】 Forty-five subjects were divided into two groups: bronchial asthma group with 25 patients and control group with 20 healthy subjects. To detect serum IL-35 concentrations of those uncontrolled

partly controlled and controlled after a week in the asthma group and their main pulmonary function indicators (including FEV1/FEV1 predicted value

FVC/FVC predicted value

FEV1/FVC

PEF/PEF predicted value) and PC20-FEV1 during uncontrolled period

and detect the serum IL-35 concentration of control group

and then analyze the difference of serum IL-35 concentration between both groups and the relevance of serum IL-35 concentration with asthma controlled level and airway reactivity. 【Result】 Serum IL-35 concentrations (pg/mL) during uncontrolled period

partly controlled period and controlled period were 141 ± 45

260 ± 84

366 ± 94. Serum IL-35 concentration (pg/mL) in control group was 396 ± 120. Serum IL-35 concentrations of asthma group during uncontrolled and partly controlled periods are lower than control group (t were respectively -9.427 and -4.458

P < 0.001). There exists no significance difference between serum IL-35 concentrations in asthma group during controlled period and control group (P = 0.36). Serum IL-35 concentration during uncontrolled period is lower than that during partly controlled period (95% Confidence Interval: -163.10~ -73.65

P < 0.001)

and serum IL-35 concentration during partly controlled period is lower than that during controlled period (95% Confidence Interval: -151.41 ~ -61.97

P < 0.001). IL-35 level of asthma patients shows positive correlation with asthma controlled level and shows no correlation with PC20-FEV1. 【Conclusion】 There expresses IL-35 in serum of asthma patients and healthy persons. Serum IL-35 concentration may be used as index to test asthma controlled level.