Effect of vitamin D3 supplementation on TNF-α serum level and disease activity index in Iranian IBD patients.

AIM: The aim of the study was to assess the effectiveness of vitamin D3 [1, 25(OH)2D3] treatment in IBD with regard to tumor necrosis factor-alpha (TNF-α) serum level and clinical disease activity index (CDAI). BACKGROUND: Vitamin D has immune-regulatory functions in experimental inflammatory bowel disease (IBD) and vitamin D deficiency is common in IBD patients. PATIENTS AND METHODS: This was a randomized clinical trial on 108 IBD patients with serum 25-OHD levels less than 30ng/ml, which divided into vitamin D and control groups. Vitamin D group received 50000 IU vitamin D3 for 12 weeks. Before and after the study, TNF-α and 25-OHD serum levels were measured by ELISA method. Data were analyzed using paired t-test, chi-square test and Spearman correlation coefficient. P-values ​​less than 0.05 were considered statistically significant. RESULTS: Before the intervention no significant difference was found between baseline characteristics and TNF-α serum level of two groups. After intervention TNF-α serum level reduced but this reduction was not statistically significant (p= 0.07, 95% CI: -0.45 to 8.14). The mean serum 25-OHD level of vitamin D increased from 15.54 to 67.89, which was statistically significant (p= 0.00, 95% CI: -61.40 to -43.30). TNF-α level was also associated significantly with CDAI before (Spearman's rho: 0.3, p<0.0001) and after (Spearman's rho: 0.27, P=0.01) intervention. CONCLUSION: Oral supplementation vitamin D3 significantly increased serum vitamin D levels and insignificantly reduced serum TNF-α level. More studies with larger samples would be beneficial to assess vitamin D3 supplementation efficient effect in IBD.

Association of Tumor Necrosis Factor Alpha Gene Polymorphisms with Inflammatory Bowel Disease in Iran.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic disease of unknown etiology, in which genetic factors, seem to play an important role in the disease predisposition and course. Assessment of tumor necrosis factor (TNF-α) gene polymorphisms in many populations showed a possible association with IBD. Considering the genetic variety in different ethnic groups, the aim of the present study was to investigate the association of five important single nucleo-tide polymorphisms (SNPs) in the promoter region of (TNF-α) gene with IBD in Iran. METHODS: In this case-control study, 156 Ulcerative colitis (UC) patients, 50 Crohn's disease (CD) patients and 200 sex and age matched healthy controls of Iranian origin were enrolled. The study was performed during a two year period (2008-2010) at Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. DNA samples were evaluated for (TNF-α) gene polymorphisms (including -1031, -863, -857, -308 and -238) by PCR and RFLP methods. RESULTS: The frequency of the mutant allele of -1031 polymorphism was significantly higher in Iranian patients with Crohn's disease compared to healthy controls (P=0.01, OR=1.92; 95% CI: 1.14-3.23). None of the other evaluated polymorphisms demonstrated a significant higher frequency of mutant alleles in Iranian IBD patients compared to controls. CONCLUSION: Among the five assessed (SNPs), only -1031 polymorphism of (TNF-α) gene may play a role in disease susceptibility for Crohn's disease in Iran. This pattern of distribution of (TNF-α) gene polymorphisms could be specific in this population.