Abnormal rheological properties of red blood cells as a potential marker of Gulf War Illness: A preliminary study.

BACKGROUND: Veterans with Gulf War Illness (GWI) experience chronic symptoms that include fatigue, pain, and cognitive impairment. This symptom cluster may be the consequence of impaired tissue oxygen delivery due to red blood cell (RBC) dysfunction. OBJECTIVE: The purpose of this preliminary study was to determine whether the microrheological behavior of RBCs is altered in GWI. METHODS: We recruited 17 cases of GWI (GWI+) and 10 age matched controls (GWI-), and examined RBC deformability and aggregation via ektacytometry along with measurement of complete blood counts. RESULTS: RBCs were more deformable in GWI+, as indicated by higher elongation indices particularly at higher shear stress values (5.33, 9.49, and 16.89) when compared to GWI-. Aggregation formation, stability and kinetics were similar between GWI+and GWI-. Complete blood counts were also similar, with the exception of mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and RBC distribution width (RDW) which was elevated in GWI+. CONCLUSIONS: In this preliminary study, we observed increased deformability along with increased MCH, MCHC and RDW in veterans with GWI+, which may contribute to the symptomatology of GWI. Further research is required to confirm our findings and the role of RBC microrheology in GWI.

Isolated diffusing capacity reduction is a common clinical presentation in deployed Iraq and Afghanistan veterans with deployment-related environmental exposures.

Following deployment to Iraq and Afghanistan ("post-9/11"), a spectrum of respiratory conditions has been reported; however, there are few published reports of objective physiologic data or later experience of symptoms and function. To better understand the post-deployment clinical presentation, we conducted a retrospective review of pulmonary function testing in 143 veterans referred to our tertiary care clinic for post-deployment health concerns. More than 75% of our sample had normal lung volumes and spirometry on pulmonary function testing; however, an isolated reduction in lung diffusing capacity (DLCO) was observed in 30% of our sample of post-9/11 veterans. An isolated reduction in DLCO is a rare pattern in primary-care seeking dyspneic patients, but is commonly associated with underlying pulmonary disease. Post-9/11 veterans with respiratory complaints and an isolated reduction in DLCO should undergo further evaluation.

Role of mitochondrial DNA damage and dysfunction in veterans with Gulf War Illness.

Gulf War Illness (GWI) is a chronic multi-symptom illness not currently diagnosed by standard medical or laboratory test that affects 30% of veterans who served during the 1990-1991 Gulf War. The clinical presentation of GWI is comparable to that of patients with certain mitochondrial disorders-i.e., clinically heterogeneous multisystem symptoms. Therefore, we hypothesized that mitochondrial dysfunction may contribute to both the symptoms of GWI as well as its persistence over time. We recruited 21 cases of GWI (CDC and Kansas criteria) and 7 controls to participate in this study. Peripheral blood samples were obtained in all participants and a quantitative polymerase chain reaction (QPCR) based assay was performed to quantify mitochondrial and nuclear DNA lesion frequency and mitochondrial DNA (mtDNA) copy number (mtDNAcn) from peripheral blood mononuclear cells. Samples were also used to analyze nuclear DNA lesion frequency and enzyme activity for mitochondrial complexes I and IV. Both mtDNA lesion frequency (p = 0.015, d = 1.13) and mtDNAcn (p = 0.001; d = 1.69) were elevated in veterans with GWI relative to controls. Nuclear DNA lesion frequency was also elevated in veterans with GWI (p = 0.344; d = 1.41), but did not reach statistical significance. Complex I and IV activity (p > 0.05) were similar between groups and greater mtDNA lesion frequency was associated with reduced complex I (r2 = -0.35, p = 0.007) and IV (r2 = -0.28, p < 0.01) enzyme activity. In conclusion, veterans with GWI exhibit greater mtDNA damage which is consistent with mitochondrial dysfunction.

Correction: Role of mitochondrial DNA damage and dysfunction in veterans with Gulf War Illness.

[This corrects the article DOI: 10.1371/journal.pone.0184832.].

Bronchodilator Responsiveness and Airflow Limitation Are Associated With Deployment Length in Iraq and Afghanistan Veterans.

OBJECTIVE: The aim of this study was to determine the relationship between deployment length and indices of airflow obstruction in Iraq and Afghanistan veterans with airborne hazards exposure. METHODS: One hundred twenty-four post-9/11 veterans completed pulmonary function testing and questionnaires. We examined the association of airflow limitation [forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC)] and bronchodilator responsiveness (ΔFEV1 and ΔFVC) with deployment length, adjusting for smoking. RESULTS: Longer deployment length was associated with lower FEV1/FVC [ß = -0.19; 95% confidence interval (95% CI), -0.39 to 0.01], greater ΔFEV1 (ß = 0.27; 95% CI, 0.09 to 0.45) and ΔFVC (ß = 0.19; 95% CI, 0.05 to 0.33). In our model adjusted for smoking history, longer deployment length remained associated with greater ΔFEV1 and ΔFVC (P < 0.01), but not with FEV1/FVC (P = 0.059). CONCLUSION: In our sample of post-9/11 veterans, longer deployment lengths were associated with significant bronchodilator responsiveness and a trend toward airflow limitation independent of tobacco use.