Alterations in serum levels of selected markers of oxidative imbalance in adult celiac patients with extraintestinal manifestations: a pilot study.

INTRODUCTION    Oxidative stress is considered to be one of the mechanisms responsible for gluten toxicity, but its role in celiac disease (CD) remains unclear. OBJECTIVES    The aim of the study was to evaluate oxidative imbalance in the pathomechanism of CD by determining the concentrations of nitric oxide (NO) and selected antioxidant parameters. PATIENTS AND METHODS    The study involved 197 adult patients: 53 patients with untreated active CD, 92 celiac patients on gluten‑free diet (GFD), and 52 controls. The serum levels of antioxidants (uric acid, bilirubin, ferritin, albumin), celiac antibodies, NO, glutathione peroxidase 3 (GPx3), and vitamin E were measured. A histopathological study of duodenal biopsy was performed. RESULTS    Celiac patients had higher uric acid concentrations than controls (P <0.001). NO levels were higher in patients with active CD than in controls (P <0.01) and were correlated with the degree of mucosal damage (r2 = 0.04; P = 0.01). Vitamin E levels were decreased in celiac patients (P <0.01), and GPx3 activity was reduced in patients with active CD compared with controls (P <0.001). CONCLUSIONS    Oxidative imbalance may be involved in the pathomechanism of CD in adults. GFD only partially reduces oxidative stress. Serum NO levels seem to be a marker of the effectiveness of treatment. Uric acid may act as an antioxidant in CD.