Total antioxidant status and severity of community-acquired pneumonia: are they correlated?

Background: Oxidant/antioxidant imbalance has been reported in various respiratory diseases including pneumonia. However, the role of blood antioxidants has not been fully discussed.

Objectives: The aim of this exploratory study was to assess serum total antioxidant status (TAS) in patients with community-acquired pneumonia (CAP) and the probable correlation with the severity of the disease.

Methods: Thirty patients (22 men, 8 women; mean age of 48 +/- 21 years) and 10 healthy nonsmokers (mean age 44 +/- 16 years) were studied. Clinical, laboratory and radiological findings were recorded on the day of admission and on the 7th day. A severity score was calculated using the Fine scale. Serum TAS was measured at the same time points using a colorimetric method.

Results: On admission, TAS (TAS1) was significantly lower than on the 7th day (TAS2) (0.84 +/- 0.13 mmo/l vs. 1.00 +/- 0.17 mmo/l; p = 0.0001) and compared with the healthy subjects (0.84 +/- 0.13 vs. 1.19 +/- 0.09 mmol/l; p < 0.001). TAS change (TAS2 - TAS1) was statistically significantly more marked in smokers (0.17 vs. 0.28, p = 0.001), in patients with factors predisposing to CAP (0.12 vs. 0.37; p = 0.000) and in patients with gram-negative pneumonia (0.16 vs. 0.35; p = 0.000). On the other hand, change in TAS was statistically significantly less marked in patients with lobar pneumonia (0.27 vs. 0.17; p = 0.001). Additionally, TAS change was positively correlated to white blood count on admission (r = 0.39; p = 0.029).

Conclusions: It is concluded that serum TAS is decreased in patients with CAP, suggesting the presence of oxidative stress, and that change in TAS seems to be influenced by disease severity. TAS measurement may be useful in estimating the severity of CAP and is a probable indication for the administration of antioxidants in the management of the disease.