Dynamic changes of apoptotic rate of peripheral blood polymorphonuclear neutrophils in the patients with chronic obstructive pulmonary disease

Guoqiang CAO; Guisheng QIAN; Ren LIU

ABSTRACT

BACKGROUND:

Chronic obstructive pulmonary disease(COPD) is characterized of chronic inflammation in airway, pulmonary parenchyma and pulmonary vessels. The mechanism of the increment and activity changes of these inflammatory cells is unclear at present.

OBJECTIVE:

To study the apoptotic character of peripheral blood polymorphonuclear neutrophils(PMNs) and its relationship with COPD to provide a reference for early intervention and function surveillance for COPD patients.

DESIGN:

An observatory comparative study based on COPD patients and healthy population as controls.

SETTING:

Department of pulmonary medicine in a military medical university of Chinese PLA affiliated hospital.

PARTICIPANTS:

Totally 98 COPD patients were admitted by the Department of Pulmonary Medicine, Research Institute of Surgery, Daping Hospital, Third Military Medical University of Chinese PLA between February 2003 and December 2003 due to COPD acute attack. Eighteen patients including 12 males and 6 females aged between 48 and 70 years old [mean of(56 ± 7) years old]were randomly selected into COPD group according to random number table.Totally 14 healthy adults including 10 males and 4 females aged between 50 and 70 years old [mean of (59 ± 8) years old] who were individuals came for physical check up in our hospital were selected in control group.

METHODS:

PMNs were separated from peripheral blood by density gradient centrifugation. The dynamic changes of PMNs apoptosis in peripheral blood was observed by flow cytometer and TUNEL method.MAIN OUTCOME

MEASURES:

Comparison of PMNs apoptotic rate in peripheral blood among groups

RESULTS:

As indicated by flow cytometric analysis, PMNs apoptotic rate at early apoptotic phase in COPD patients at paracmasis was(8.5 ± 1.3)%,which was significantly lower than(12.5 ± 1.8)% of normal control group( t=6.25, P ＜ 0. 01); PMNs apoptotic rate was(5.1 ±0.6)% at acute aggravation stage, which was significantly lower than that of paracmasis group ( t =5.66, P ＜001). As indicated by TUNEL analysis, PMNs apoptotic rate at paracmasis was(12.42 ±2.7)% , which was significantly lower than (21.5±4.8)% of normal control group(t=5.76, P ＜ 0.01); PMNs apoptotic rate was(4. 9 ±0.4)% at acute aggravation stage, which was significantly lower than that of paracmasis group( t = 6. 12, P ＜ 0. 01 ) . PMNs changes at the late phase of apoptosis/necrosis had a contrary tendency, i. e.,PMNs rate at late apoptotic phase/necrosis was(2. 8 ± 0.5)% in COPD patients at paracmasis, which was significantly higher than(1. 3 ±0.4)% of normal control group ( t= 6. 37, P ＜ 0. 01 ); PMNs rate was (3.7 ± 0. 3) % at acute aggravation stage, which was significantly higher than that of paracmasis group(t=5.81, P ＜0.01).

CONCLUSION:

PMNs abnormal apoptosis might be an important reason that induces PMNs aggregation in airway and lung tissues in COPD. This process might have an important significance in the generation and development of chronic airway inflammation, which provides an etiologic basis for the primary rehabilitative intervention of COPD.