Objective To determine the number of goblet cells

the change of MUC5AC expression in chronic obstructive pul- monary disease （COPD） patients and the relationship of smoking with goblet cell

MUC5AC

and lung function. Methods Eighteen patients undergoing lung resections for a solitary peripheral carcinoma were classified by lung function as having COPD. Twenty patients with normal lung function served as the control group. Normal lobe bronchioles far away from the lesion site were taken for paraffin section. Goblet cells were identified by AB/PAS staining and the ex- pression of MUC5AC in the paraffin’s section was tested by immunohistochemistry. Results Goblet cell hyperplasia was observed in the COPD group. The positive rate of goblet cell in COPD group （0.20% ± 0.10%） was significantly higher than that in the normal lung function group （0.13% ± 0.06%

P < 0.05）. The posi- tive rate of MUC5AC expression in the COPD group （0.27% ± 0.09%） was higher than that in the normal lung function group （0.20% ± 0.10%

P < 0.05）. The positive rate of goblet cell in smokers （27.93% ± 9.00%） of the COPD group and normal lung function group was higher than that in non-smokers （17.70% ± 9.37%

P < 0.05）

while MUC5AC expression had no significant difference between smokers and non-smokers （17.88% ± 6.44% and 10.88% ± 7.10%

respectively）. Conclusion For COPD patients with declined lung function

there were goblet cell hyperplasia and increased expres- sion of MUC5AC. MUC5AC expression up-regulation may due to goblet cell hyperplasia. Smoking may be an important factor for goblet cell hyperplasia.