[The clinical characteristics of intra-acinar pulmonary artery inflammation and its effect on clinical parameters in smokers with normal lung function and patients with chronic obstructive pulmonary disease]

Abstract

Objective: To study the pathological characteristics of intra-acinar pulmonary artery inflammation and its correlation with smoking index and disease progression in smokers with normal lung function and smokers with chronic obstructive pulmonary disease (COPD).

Methods: Patients requiring lung resection for peripheral lung cancer were divided into group A (nonsmokers with normal lung function, n = 10), group B (smokers with normal lung function, n = 13), and group C (smokers with stable COPD, n = 10). The lung tissue far away from tumor were resected to compare the pathological changes of intra-acinar pulmonary arteries and infiltration level of inflammatory cell in pulmonary non-muscularized arteries (NMA), pulmonary partially muscularized arteries (PMA) and muscularized arteries (MA) among the three groups. The correlation analysis was made among infiltration level, smoking index, percentage of predicted value of forced expiratory volume in one second (FEV(1)%Pred), six-minute-walk distance (6MWD) and BODE index.

Results: (1) Both group B and group C showed the intima and media thickness of MA was significantly higher, the lumen area of MA was narrower and the proportion of MA was higher, and collagenous fiber of MA adventitial proliferated and area increased in group C (P < 0.05 or P < 0.01). (2) In group B and group C, the percentage of the intra-acinar pulmonary arteries that contained leukocytes, T lymphocytes, CD(8)(+)T lymphocytes and the number of these positive cells infiltrating the intra-acinar pulmonary arteries were increased, especially an increased number of CD(8)(+)T lymphocytes infiltrating in the arterial adventitia as compared with group A, moreover there were significant difference between group C and group B (P < 0.05 or P < 0.01). In group B and group C, the degree of these positive cells infiltrating NMA, PMA and MA presented a decreasing sequence (P < 0.05 or P < 0.01). Among the intima, media and adventitia of MA, the infiltration of these positive cells was the highest in the adventitia. Among group A, group B and group C, infiltration degree of CD(4)(+)T lymphocyte, B lymphocyte, macrophage and neutrophil demonstrated no significant difference, also among NMA, PMA and MA (P > 0.05). (3) The number of leukocytes, T lymphocytes, CD(8)(+)T lymphocytes infiltrating MA showed a positive correlation with the thickness of MA (r = 0.563, 0.627, 0.589, P < 0.01, respectively) and smoking index (r = 0.551, 0.665, 0.600, P < 0.01, respectively), moreover the degree of these cells infiltrating MA demonstrated negative correlation with FEV(1)%Pred (r = -0.763, -0.703, -0.767, P < 0.01, respectively). Also infiltrating degree of T lymphocytes and CD(8)(+)T lymphocytes was positively correlated with BODE (r = 0.390, 0.476, P < 0.05, respectively). Furthermore the infiltrating degree of CD(8)(+)T lymphocytes had negative correlation with 6MWD (r = -0.356, P < 0.05).

Conclusions: (1) Pulmonary arterial inflammation appears in smokers with normal lung function and smokers with COPD patients. It involves in all types of intra-acinar pulmonary arteries especially NMA and infiltrates whole layer of MA with a characteristic of CD(8)(+)T lymphocytes infiltrating in the adventitia of intra-acinar pulmonary arteries. (2) Pulmonary inflammation is closely correlated to cigarette smoking and clinical parameters such as BODE index, FEV(1)% pred and 6MWD. It is one of the key factors affecting the progression of COPD.