Postdeployment Respiratory Syndrome in Soldiers With Chronic Exertional Dyspnea

Area of Science:

• Pulmonary Medicine
• Military Health
• Pathology

Background:

• Soldiers deployed to Southwest Asia often report persistent respiratory symptoms.
• Exertional dyspnea and exercise intolerance are common complaints post-deployment.

Purpose of the Study:

• To investigate the lung pathology in soldiers with unexplained dyspnea after deployment.
• To characterize the histomorphometric changes in lung tissue.

Main Methods:

• Surgical lung biopsies were performed on 50 soldiers with unexplained dyspnea.
• Quantitative histomorphometry analyzed inflammation and remodeling in small airways, vasculature, and pleura.
• Comparison was made with 17 age-matched, non-smoking control subjects.

Main Results:

• Affected soldiers showed increased airway wall thickness, smooth muscle hypertrophy, and collagen deposition.
• Pulmonary vasculature exhibited smooth muscle hypertrophy and increased wall-to-lumen ratio.
• Reduced capillary density and increased collagen/elastin in alveolar parenchyma were observed.
• Pleural inflammation or fibrosis was present in 92% of soldiers.

Conclusions:

• A distinct postdeployment respiratory syndrome is identified in susceptible soldiers.
• This syndrome is characterized by exertional dyspnea and complex pathological changes in the distal lungs.
• Long-term follow-up revealed persistent symptoms and declining lung capacity.