Tobacco smoking associated with the increases of the bronchoalveolar levels of interleukin-5 and interleukin-1 receptor antagonist in acute eosinophilic pneumonia.

BACKGROUND There is a strong association between tobacco smoking and acute eosinophilic pneumonia (AEP) and tobacco smoking has been related to onset of AEP, but the mechanisms for causing AEP are largely unknown. AEP is characterized by locally high levels of interleukin-5 (IL-5) and interleukin-1 receptor antagonist (IL-1RA). Thus, tobacco smoking may relate to the high levels of IL-5 and IL-1RA in AEP. AIM We aimed to determine whether the rate of tobacco smoking positively related to the high levels of IL-5 and IL-1RA. PATIENTS AND METHODS In the study, 155 AEP patients and 135 control healthy subjects were recruited by the Clinical Research Center at General Hospital of Shenyang Military Area Command (Shenyang, China). All the subjects were interviewed regarding for the tobacco smoking rate. The number of eosinophils was counted in all subjects. The relative expressive levels of IL-5 and IL-1RA were measured with ELISA in Bronchoalveolar lavage (BAL) and serum. RESULTS The BAL levels of IL-5, IL-1ra, eosinophils and lymphocytes positively correlates with the rate of tobacco smoking in AEP patients (p < 0.005) comparing with those in healthy control groups. No significant association was observed between the serum levels IL-5 and IL-1ra and the rate of tobacco smoking in AEP patients (p > 0.05) comparing with those in healthy control groups. CONCLUSIONS Smoking increases the BAL levels of IL-5 and IL-1RA, which is associated with the onset of AEP.