Aim: To evaluate selected intestinal parameters of oxidative stress, and antioxidant capacity in adult celiac disease patients with extraintestinal manifestations.
Methods: The study involved 85 adult patients divided into the following subgroups: (1) patients with newly diagnosed celiac disease (CD) (n = 7); (2) celiac patients not adhering to a gluten-free diet (GFD) (n = 22); (3) patients with CD on the GFD (n = 31); and (4) patients with functional disorders of the gastrointestinal tract, serving as controls (n = 25). Celiac patients presented with non-classic symptoms or extraintestinal manifestations. Standard blood tests including serum antioxidant levels (uric acid, bilirubin, and vitamin D), celiac antibody levels, and histopathological status of duodenal biopsy specimens have been determined. The expression of mRNA for tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), interleukin 10 (IL-10), superoxide dismutase (SOD), heat-shock protein 70 (HSP-70), hypoxia-inducible factor 1 (HIF-1α), and BAX in the duodenal mucosa of patients was analyzed by reverse transcriptase-polymerase chain reaction.
Results: The mean plasma uric acid level in patients with active CD (newly diagnosed and nonadherent patients) and treated celiac patients was significantly higher than in controls (260.17 ± 53.65 vs 190.8 ± 22.98, P < 0.001, and 261.7 ± 51.79 vs 190.8 ± 22.98, P < 0.001, respectively). The mean bilirubin concentration in active and treated celiac patients was significantly lower than in controls (8.23 ± 5.04 vs 10.48 ± 4.08, P < 0.05 and 8.06 ± 3.31 vs 10.48 ± 4.08, P < 0.05, respectively). The mean plasma vitamin D level was significantly lower in active celiac patients than in treated celiac patients and controls (19.37 ± 9.03 vs 25.15 ± 11.2, P < 0.05 and 19.37 ± 9.03 vs 29.67 ± 5.12, P < 0.001, respectively). The expression of TNF-α, IL-10, and HSP-70 mRNAs was significantly elevated in the celiac groups regardless of the diet when compared with controls. Patients on the GFD presented a significantly lower mRNA expression of TNF-α and IL-10 than in newly diagnosed and nonadherent patients (P < 0.05). The expression of SOD mRNA was significantly elevated in celiac patients compared with controls (P < 0.05), with a significant difference between treated and untreated patients (P < 0.05). The expression of HIF-1α mRNA and BAX mRNA was significantly higher in patients with active CD compared with controls and patients on GFD, while no difference was observed between the latter two groups.
Conclusion: Increased intestinal expression of HSP-70 despite GFD indicates that GFD only partially reduced oxidative stress. CD patients exhibited an oxidative imbalance and inflammatory response despite GFD. Uric acid may act as an important antioxidant in CD.
Keywords: Apoptosis; Celiac disease; Heat-shock protein 70; Hypoxia-inducible factor; Oxidative stress; Superoxide dismutase; Tumor necrosis factor alpha; Uric acid; Vitamin D.