Increased apoptosis of neutrophils in induced sputum of COPD patients

Makris, Demosthenes; Vrekoussis, Thomas; Izoldi, Mbouloukaki; Alexandra, Kalogeraki; Katerina, Darivianaki; Dimitris, Tamiolakis; Michalis, Alexandrakis; Tzortzaki, Eleni; Siafakas, Nikos M.; Tzanakis, Nikos

doi:10.1016/j.rmed.2009.03.002

« Previous Next »Respiratory Medicine
Volume 103, Issue 8 , Pages 1130-1135, August 2009

Increased apoptosis of neutrophils in induced sputum of COPD patients

Demosthenes Makris
- Department of Thoracic Medicine, University of Crete, Medical School, Heraklion, Crete, Greece
- Corresponding author. Tel.: +30 2810 392433/2410 681267.
Thomas Vrekoussis
- Laboratory of Pathology, University of Crete, Medical School, Heraklion, Crete, Greece
Mbouloukaki Izoldi
- Department of Thoracic Medicine, University of Crete, Medical School, Heraklion, Crete, Greece
Kalogeraki Alexandra
- Laboratory of Pathology, University of Crete, Medical School, Heraklion, Crete, Greece
Darivianaki Katerina
- Laboratory of Pathology, University of Crete, Medical School, Heraklion, Crete, Greece
Tamiolakis Dimitris
- Laboratory of Pathology, University of Crete, Medical School, Heraklion, Crete, Greece
Alexandrakis Michalis
- Department of Hematology, University of Crete, Medical School, Heraklion, Crete, Greece
Eleni Tzortzaki
- Department of Thoracic Medicine, University of Crete, Medical School, Heraklion, Crete, Greece
Nikos M. Siafakas
- Department of Thoracic Medicine, University of Crete, Medical School, Heraklion, Crete, Greece
Nikos Tzanakis
- Department of Thoracic Medicine, University of Crete, Medical School, Heraklion, Crete, Greece
- Department of Epidemiology, Social Medicine, Medical School, University of Crete, Heraklion, Crete, Greece

Received 9 July 2008; accepted 2 March 2009. published online 31 March 2009.

Summary

Aim

The aim of the current study was to evaluate apoptosis in induced sputum neutrophils and to investigate the relationship between the number of apoptotic cells and clinical parameters in COPD patients.

Methods

Twenty-four COPD ex-smoker patients and 10 healthy controls were included in the study. All subjects underwent clinical evaluation and sputum induction. Sputum cell in situ apoptosis was identified using white light microscopy and TUNEL assay technique. Apoptosis of neutrophils obtained by sputum induction was expressed as apoptotic rate (AR=percentage of apoptotic neutrophils over the number of neutrophils measured).

Results

TUNEL assay revealed statistically significant higher AR in COPD patients than controls (p=0.004). Patients with FEV₁<50%pred had significantly higher median (IQR) AR (%) compared to patients with FEV₁≥50% [26.3 (16–29) vs 13.1 (8.6–21), p=0.01]. No significant association was found between the number of apoptotic cells and age, symptoms or medication used.

Conclusion

The significantly increased apoptotic rate of neutrophils that were found in COPD patients with advanced disease compared to controls might reflect either a deregulation of apoptosis of neutrophils or, a reduced clearance of apoptotic neutrophils from the airways. The pathophysiologic significance of the observed phenomenon has to be further explored.

Keywords: Apoptosis, Chronic obstructive pulmonary disease, Induced sputum, Neutrophil