Comparison of Serum Total Antioxidant Status Between Patients with Community Acquired Pneumonia and Severe Asthma Exacerbation.

Background: Oxidant/antioxidant imbalance has been reported in various respiratory diseases including pneumonia and asthma. However the role of blood antioxidants has not been fully discussed. Objectives:  The aim of this exploratory study was the measurement and comparison of serum Total Antioxidant Status (TAS) in patients with community-acquired pneumonia (CAP) or asthma exacerbation during hospitalization. Methods: Forty five patients (41 men – 4 women, with a mean age of 48.95±22.06 years) admitted to hospital for community-acquired pneumonia and thirty patients with severe asthma exacerbation (22 men – 8 women, with a mean age of 41.27±20.73 years) as well as eighteen normal subjects (40.22±9.96 years of age) were included in the study. On admission and on the 7th day serum TAS was measured using a colorimetric method in 600nm. Results: In both groups TAS on admission was decreased compared with normal    subjects (0.83±0.13 vs. 1.19±0.09 mmol/L, p<0.001 and 0.98±0.08 vs. 1.19±0.09 mmol/L, p<0.001 respectively). In patients with CAP, but not in asthmatics, TAS on discharge was still decreased compared with normals (1.00 ±0.18 vs. 1.19±0.09 mmol/L, p<0.001). Change of TAS between 1st and 7th day was not different between the two groups of patients. Comparison between TAS on admission and TAS on discharge revealed statistically significant difference in both groups of patients (asthma: 0.98±0.08 vs. 1.13±0.18 mmol/L, p<0.001, pneumonia: 0.83±0.13 vs. 1.00±0.18 mmol/L, p<0.001). Comparison of TAS on admission and TAS on discharge between the two groups of patients showed that both measurements were statistically significantly decreased in patients with pneumonia compared with asthmatics (0.83±0.13 vs. 0.98±0.08 mmol/L, p<0.001 and 1.00±0.18 vs. 1.13±0.18 mmol/L, p=0.003 respectively). Decreased TAS on admission was found in smokers with pneumonia compared with smokers asthmatics but on discharge this difference was obscured. Non smokers with pneumonia had decreased TAS both on admission and discharge compared with non smokers asthmatics. Conclusions: It is concluded that serum TAS is decreased in patients with CAP or asthma exacerbation suggesting the presence of oxidative stress. Although TAS change during the course of the disease is similar, this decrement is more profound in CAP patients on admission as well as on discharge