Expressions of serum 25 (OH)D, vitamin D receptor and vitamin Dl-α hydroxylase in intestinal mucosa tissues of patients with inflammatory bowel disease / 中华消化杂志

ABSTRACT

Objective To investigate the expression of serum 25(OH)D,vitamin D receptor (VDR)and vitamin D1-α hydroxylase (CYP27B1) in intestinal mucosa tissues of patients with inflammatory bowel disease (IBD).Methods From January 1st to December 31st in 2014,105 patients with IBD were enrolled,among them there were 49 cases of ulcerative colitis (UC) and 56 cases of Crohn's disease (CD);there were 20 cases in remission,26 cases in mild active phase,37 cases in moderate active phase and 22 cases in severe active phase;and 50 cases with lesions located in the left colon and 55 cases with lesions located in the right colon.At the same period,45 healthy individuals were also recruited as controls,whom were suspected as IBD but at last proved healthy.The lactulose and mannitol absorption ratio (LMR),serum endotoxin,tumor necrosis factor-α (TNF-α) and 25(OH)D levels,and the expressions of VDR and CYP27B1 in the intestinal mucosa tissues were detected in all the subjects.T test,one-way analysis of variance and chi square test were used for statistical analysis.Results The LMR,endotoxin and TNF-α levels of UC group were (63.2 ± 13.9)％,(118.9 ± 19.7) EU/mL,and (109.6 ± 18.4) ng/L,respectively,which were higher than those of the healthy control group ((3.3 ± 1.2)％,(34.2 ±5.6) EU/mL,and (0.6±0.3) ng/L);the level of 25 (OH)D was (36.6± 9.7) nmol/L,which was lower than that of healthy control group ((49.6± 10.9) nmol/L),and all the differences were statistically significant (t =28.796,29.284,27.817 and 6.118,all P＜0.05).LMR,endotoxin and TNF-α levels of CD group were (52.9±11.3)％,(96.4±10.6) EU/mL and (83.0±16.1) ng/L,respectively,which were higher than those of the healthy control group,25(OH)D level was (44.4±9.4) nmol/L,which was lower than that of healthy control group,and all the differences were statistically significant (t=34.555,39.716,34.293 and 0.012,all P＜0.05).The differences in LMR,endotoxin,TNF-α and 25 (OH)D levels among healthy control group,remission group,mild active group,moderate active group and severe active group were statistically significant (F=286.731,385.690,657.830 and 18.932,all P＜0.01) which was dependent on the disease activity.Compared with those of the healthy controls,the levels of LMR,endotoxin and TNF-α of the left colon group and the right colon group increased,and 25(OH)D levels decreased.The high expression rates of VDR in UC group and CD group were 36.7％ (18/49) and 55.4％ (31/ 56),respectively,which were both lower than that of healthy control group (80.0％ (36/45)),and the differences were statistically significant (x2 =38.574 and 13.837,both P＜0.05).The high expression rates of CYP27B1 of UC group and CD group were 26.5％ (13/49) and 35.7％ (20/56),respectively,which were both higher than that of healthy control group (22.2％ (10/45)),and the differences were statistically significant (x2=6.499 and 4.430,both P＜0.05).The differences in the high expression rates of VDR and CYP27B1 among healthy control group,remission group,mild active group,moderate active group and severe active group were statistically significant (F=33.470 and 27.142,both P＜0.01),which was dependent on the disease activity.Compared with that of the healthy control group,the high expression rates of VDR of the left colon group and the right colon group decreased,and the high expression rates of CYP27B1 increased.Conclusion There is vitamin D metabolic imbalance in IBD patients,as well as low serum 25(OH)D level,low rate of high VDR expression in colonic mucosa tissues and high rate of high CYP27B1.