Serum prolidase activity and oxidative status in patients with bronchial asthma.

Asthma is a disease where there is an accumulation of collagen in the reticular basal membrane of the airway leading to chronic inflammation. The enzyme prolidase plays an important role in the breakdown of collagen and the breakdown of intracellular protein especially in the final stage when peptides and dipeptides contain a high level of proline. To evaluate the relationship between prolidase activity and oxidative status in asthma patients. Comparison was made between 42 patients diagnosed with bronchial asthma and 32 healthy children of similar age and gender. Serum prolidase activity was measured spectrophotometrically. Oxidative status was determined using total antioxidant capacity (TAC) and total oxidant status (TOS) measurement. The prolidase activity of the asthma patient group was statistically significant compared with the control group (P< or =0.001). TAC and TOS levels in the asthma patient group were higher than the control group (P< or =0.001, P< or =0.002, respectively). No correlation was found between the prolidase and oxidative levels of the two groups. A positive correlation was determined between the prolidase activity and TAC in the asthma patient group (P< or =0.001, r=0.501). The prolidase enzyme activity, which plays a role in the collagen turnover, was low in the asthma patients; therefore, their collagen metabolism had undergone a change and this indicates that there may be an effect on the accumulation of collagen in the reticular basal membrane. Moreover, the high level of TOS indicates that these patients were exposed to severe oxidative stress with an increased TAC response.