Bronchoalveolar Lavage Fluid Cytology of Deployed Military Personnel with Chronic Respiratory Symptoms from the STAMPEDE III Study

Abstract

Abstract Background:Deployed military personnel may be at risk for developing acute and chronic lung disease. Prior studies of this patient population have revealed that unexplained exertional dyspnea is the most common diagnosis despite an extensive evaluation. There is concern that an occult disorder may be affecting this population. This study evaluated the role for bronchoalveolar lavage (BAL) fluid analysis in the evaluation of chronic deployment associated dyspnea. Methods: Military personnel who reported chronic respiratory symptoms were evaluated as part of the STAMPEDE III study. Participants underwent bronchoscopy with BAL as part of a standardized evaluation. Results: 308 patients with a mean age of 38 ± 8.6 years underwent bronchoscopy with BAL. BAL cell count percentages of macrophages, lymphocytes, neutrophils, and eosinophils respectively were: 76.2 ± 17.0%, 16.3 ± 13.4%, 6.6 ± 8.9%, and 0.9 ± 3.2%. There was no clear differentiation between groups based on increases in lymphocyte counts (p = 0.640) although lymphocyte values were more elevated (21.4 ± 12.1%) in the interstitial lung disease category. Neutrophil counts (6.6 ± 8.9%) were elevated compared to the reported normal reference values and were increased in the isolated pulmonary function test (PFT) abnormality (9.4 ± 11.6%), large airway disorder (10.0 ± 7.5%), miscellaneous (10.9 ± 20.2%), and obstructive lung disease (11.0 ± 15.6%) groups. Eosinophil counts were within normal limits (0.9 ± 3.2%) and showed no differences between groups (p = 0.545); asthma patients trended higher (1.6 ± 5.7%). BAL counts for the exertional dyspnea group were within normal reference values and showed no differences from the entire cohort. Conclusion:The addition of BAL cytology did not help differentiate those patients with unexplained dyspnea from other etiologies.