Circulating Exosomes and Ambient Air Pollution Exposure in COPD.

Background: Chronic obstructive pulmonary disease (COPD) is characterized by progressive obstruction of airways due to chronic inflammation. Both genetic and environmental components are risk factors for COPD. The most common cause of COPD is smoking. However, evidence suggests that 17% to 38% of COPD patients are nonsmokers, so other factors like air pollution may also play a role. Objective: The relationship between serum exosomes and exposure to particulate matter (PM) <2.5 and 10 micrometers (µm) in the residing environment of COPD patients and healthy groups was investigated. The correlation between inflammatory cytokine levels with exosome count was also studied. Methods: Peripheral blood samples were taken from 20 COPD patients without a smoking history or a family history of COPD, along with 20 nonsmoker healthy controls. The serum exosomes were counted by flow cytometry using a CD81 marker. The exposure to PM2.5 and PM10 was measured in daily, weekly, and monthly intervals based on the longitudinal measurements of the monitoring stations, and the correlation between exosome count and air pollutants was analyzed. Results: The serum CD81+ exosome count in COPD patients was significantly elevated compared to the healthy controls and this was correlated with daily PM10 (P-value=0.02) and monthly PM2.5 (P-value=0.02) exposure. Although interferon-gamma levels of COPD patients were higher than healthy controls, there was no correlation between exosome count and cytokine level. Conclusions: Considering the significant relationship between air pollutants and the count of serum exosomes demonstrated in the present study, air pollution might be a considerable risk factor in the progression of airway inflammation.

Applying bio-impedance vector analysis (BIVA) to adjust ultrafiltration rate in critically ill patients on continuous renal replacement therapy: A randomized controlled trial.

BACKGROUND: Bioimpedance vector analysis (BIVA) has been suggested as a valuable tool in assessing volume status in critically ill patients. However, its effectiveness in guiding fluid removal by continuous renal replacement therapy (CRRT) has not been evaluated. METHODS: In this randomized controlled trial, 65 critically ill patients receiving CRRT were allocated on a 1:1 ratio to have UF prescribed and adjusted using BIVA fluid assessment in the intervention group (32 patients) or conventional clinical parameters (33 patients). The primary outcome was the lean body mass (LBM) water content at CRRT discontinuation, and the secondary outcomes included the mortality rate, urinary output, the duration of ventilation support, and ICU stay. RESULTS: The study group was associated with a lower water content of LBM (80.7 ± 9.4 vs. 85.9 ± 10.4%; p < 0.05), and a higher mean UF-rate and urinary output (1.5 ± 0.8 vs. 1.2 ± 0.5 ml/kg/h and 0.9 ± 0.9 vs 0.5 ± 0.6 ml/kg/h, both: p < 0.05). The mortality rate, the length of ICU stay, and ventilation support duration were similar. CONCLUSION: BIVA guided UF prescription may be associated with a lower rate of fluid overload. Larger studies are required to evaluate its impact on patients' outcomes.