Combined Treatment Cuts Inflammatory Cells in Chronic Obstructive Pulmonary Disease
The combination of two existing clinical treatments, salmeterol and fluticasone propionate, can significantly reduce inflammatory cells in the airways of current and former smokers being treated for moderate to severe chronic obstructive pulmonary disease (COPD).
These findings appear in the first issue for April 2006 of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.
Neil Barnes, M.D., Professor of Respiratory Medicine at London Chest Hospital in United Kingdom, and nine colleagues, performed a randomized, double-blind, placebo-controlled, parallel-group, multi-center study on 140 COPD patients. Of this total, 67 patients (average age 65) were treated with salmeterol/fluticasone propionate, while 73 individuals received a placebo medication. Both treatment groups were matched for demographics, smoking history, and baseline lung function.
"This is the first demonstration that a currently available treatment can reduce the exaggerated bronchial inflammation in COPD," said Dr. Barnes. He adds that this therapy decreased inflammation by 36 percent.
After conducting a biopsy examination, the researchers conclude that the combination therapy significantly reduced the absolute numbers of certain inflammatory cells, including leukocytes, CD8+ cells and CD4+ cells, and caused a reduction in cells expressing genes for certain pro-inflammatory mediators in the lung.
"Inflammation in COPD is distinct from that in asthma and is characterized by a predominance of CD8+ cells at all airway levels, including the functional part of the lung, or parenchyma," explained Dr. Barnes.
According to the authors, this broad spectrum of anti-inflammatory effects was also accompanied by a significant improvement in lung function.
"The magnitude of the improvement in the standard lung function test was similar to or greater than that seen in other studies of anti-inflammatory treatments used in COPD," said Dr. Barnes.
Using a bronchoscope, the investigators examined each participant's lung passages one week before the study began and after 12 weeks of treatment. Only four patients experienced adverse reactions to the bronchoscopy, such as nose bleed, cough, sore throat, etc.
The researchers gave six patients in the treatment group and eight in the control cohort an antibiotic to reduce worsening COPD symptoms. One patient from the treatment group also was hospitalized to treat worsening symptoms.
"As designed, our research represents the largest biopsy study ever to be completed in COPD," said Dr. Barnes.
He noted that these findings support the premise that the combination treatment could be applied earlier than currently proposed in existing COPD guidelines.