[Changes of serum interleukin (IL)-12 and IL-13 in asthmatic patients and regulatory effects of glucocorticoids on them].

OBJECTIVE: To observe the changes of serum interleukin (IL)-12, IL-13 and lung function in asthmatic patients and to evaluate the influence of glucocorticoid on them. METHODS: The serum samples were obtained from (1) 25 asthmatic patients with acute asthma attack before and after one week course of oral prednisone, (2) 20 asthmatic patients in remission stage, and (3) 15 healthy volunteers. Serum IL-12 and IL-13 were determined with sandwich ELISA. Lung ventilatory function forced expiratory volume in one second (FEV(1)) and respiratory impedance airway resistance (R(5)) were measured in all patients. RESULTS: (1) Serum level of IL-12 in asthma attack group was significantly lower than that in asthma remission group (P < 0.05); both were significantly lower than that in normal control group (P < 0.01); in asthma attack group IL-12 level after prednisone treatment was significantly higher than that before treatment (P < 0.01). (2) Serum level of IL-13 in asthma attack group was significantly higher than that in asthma remission group (P < 0.01); both were significantly higher than that in normal control group (P < 0.01); in asthma attack group IL-13 level after prednisone treatment was significantly lower than that before treatment (P < 0.01). Correlation analysis showed that the serum level of IL-12 was positively correlated to FEV(1) and negatively correlated to R(5) and to serum level of IL-13 (r(1) = 0.458, r(2) = -0.516, and r(3) = -0.549, respectively; P < 0.05 and P < 0.01); the serum level of IL-13 was negatively correlated to FEV(1) and positively correlated to R(5) (r(1) = -0.493, and r(2) = 0.528, respectively; P < 0.05). CONCLUSION: The secretion of IL-12 and IL-13 was impaired in asthma with a significant increase in serum level of IL-13 and decrease in serum level of IL-12. Glucocorticoid could downregulate the serum level of IL-13 and upregulate the serum level of IL-12, redress the imbalance of IL-12/IL-13, and improve lung function in asthmatic patients.