Long-term use of ICS influence TLR2 expression on induced sputum from severe COPD patients

Objection: To evaluate the influence of long-term use of inhaled corticosteroid on TLR2 expression on and in macrophages from induced sputum in severe COPD patients. Methods: Severe stable smoking male COPD patients treated in OPD of Respirology were divided into2 groups: long-term ICS group (ICS≥500/day futicasone propionate, ≥1 year)(n=21) and ICS naive group(n=29). With flow cytometry, we tested TLR2 expression on macrophages from induced sputum in these COPD patients. We also examined the mRNA expression in the induced sputum. Result: The TLR2 extracellular expression on the macrophages from induced sputum in long-term ICS treatment group were lower than the ICS naive group(13.69±1.17 vs 20.12±4.37,p=0.019). The TLR2 intracellular expression (5.35±1.67 vs 12.81±4.89), the TLR2mRNAand TNFαmRNA expression also showed decreased trends in ICS long-term treatment group. There were positive relationship between the expression of TLR2 extracellular and intracellular expression. Conclusion: Long-term use of ICS may have negative influence on TLR2 expression in the airway of COPD patients, which may increase the pneumonia susceptibility in severe COPD patients.