The latest edition of the New England Journal of Medicine describes the results of an interesting series of cases of respiratory symptoms in a group of soldiers returning from deployment to Iraq and Afghanistan.
Eighty soldiers at Fort Campbell, Kentucky, were referred for medical evaluation due to respiratory symptoms between 2004-2009. All were unable to meet US Army fitness standards upon return from duty in the Middle East, suffering exercise intolerance and failure to attain the fitness standard for the 2 mile run – despite having met it prior to deployment. They were otherwise apparently healthy.
Of the 80 soldiers evaluated, 49 of them underwent lung biopsy. Within the group that received biopsies, 38 soldiers were diagnosed with constrictive bronchiolitis – a condition that involves narrowing of the airways as a result of increased amounts of associated fibrous tissue and smooth muscle. Many of these biopsy sections also demonstrated the presence of foreign material in the airways – suggestive of some type of inhalational exposure.
The authors discussed the characteristics of these 38 soldiers with constrictive bronchiolitis:
- Median age at enrollment was 33 years old
- Various service positions within the Army
- Normal cardiopulmonary exams, pulmonary function tests, chest x-rays, and CT scans
Many of the soldiers had been deployed to Iraq in 2003, and discussed having been exposed to smoke from sulfur-mine fire, dust storms, and incinerated human waste. So although all had been exposed to something, there was no single exposure that linked them all. Additionally, the constrictive bronchiolitis was not limited just to these soldiers who had been exposed to something.
Constrictive bronchiolitis, a rare finding in healthy adults, is most typically described in patients with rheumatologic diseases, or in organ transplant patients. It has additionally been associated with inhalational exposure to inorganic dust, and a variety of chemical compounds.
Respiratory problems have frequently been reported in soldiers returning from duty in the Middle East, and although a possible link with some kind of exposure has been suggested, the exact cause remains unknown. This study unveils a key issue – the fact that so many soldiers suffered this problem after deployment raises the question of not just what is causing the problem, but just how many soldiers actually could become affected with by this condition, since no single cause has been identified. The exact nature of the particulate, foreign material found in the airways at lung biopsy also remains unknown, and will require further studies for evaluation.
Importantly too, the soldiers apparently continued to have respiratory symptoms as the study was being followed. Additionally, by 2010, most suffered continued dyspnea after climbing a flight of stairs. Half of the soldiers had even left the Army as a result of disability.
King et al: “Constrictive Bronchiolitis in Soldiers Returning from Iraq and Afghanistan” NEJM 2011; 365:222-230.