Expression of inflammatory cytokines and its correlation with peptide YY and claudin-1 in patients with irritable bowel syndrome / 中华消化杂志

ABSTRACT

Objective To explore the pathogenesis of irritable bowel syndrome (IBS) by detecting serum levels and the colonic mucosa expression of inflammatory cytokines,peptide YY (PYY),and claudin-1,and to analyze their correlation.Methods From April 2013 to April 2015,50 outpatients with IBS and 20 healthy controls were selected.Serum levels of PYY,interleukin (IL)-10,tumor necrosis factor (TNF)-α and claudin-1 were detected by enzyme-linked immunosorbent assay (ELISA).The expression of IL-10,TNF-α,PYY and claudin-1 in colonic mucosa was determined by immunohistochemistry.Single factor analysis of variance,least significant difference (LSD) method,chi-square test,and Pearson correlation analysis were performed for statistical analysis.Results Among the 50 patients with IBS,27 cases were diarrhea-type irritable bowel syndrome (D-IBS),and 23 cases were constipated-type irritable bowel syndrome (C-IBS).The serum level and the positive expression rate of PYY in colonic mucosa of D-IBS group were significantly higher than those of healthy control group ((16.28± 2.75) ng/L vs (10.12± 1.55) ng/L;66.7 ％ (18/27) vs 30.0 ％ (6/20)),and the differences were statistically significant (LSD-t=10.19,x2 =6.182,both P＜0.05).The serum level and the positive expression rate of IL-10 in colonic mucosa of D-IBS group were both significantly lower than those of healthy control group ((2.95 ±0.24) ng/L vs (3.58±0.35) ng/L;22.2％(6/27) vs 50.0％ (10/20)),and the differences were statistically significant (LSD-t =4.52,x2=3.948,both P＜0.05).The serum level and the positive expression rate of TNF-α in colonic mucosa of D-IBS group were both significantly higher than those of healthy control group ((8.73±0.41) ng/L vs (7.73±0.51) ng/L;66.7％(18/27) vs 30.0％(6/20)),and the differences were statistically significant (LSD-t=8.43,x2 =6.182,both P＜0.05).There was no statistically significant difference between C-IBS group and healthy control group in the serum levels of PYY ((10.24±1.34) ng/L vs (10.12± 1.55) ng/L),IL-10 ((3.43 ± 0.71) ng/L vs (3.58 ± 0.35) ng/L),TNF-α ((7.81±0.26) ng/L vs (7.73 ±0.51) ng/L),and thus the positive expression rate in colonic mucosa (39.1％(9/23) vs 30.0％(6/20),56.5％(13/23) vs 50.0％(10/20),34.8％ (8/23) vs 30.0％(6/20);all P＞0.05).The serum level of claudin-1 and its positive expression rate of PYY,IL-10,TNF-α in colonic mucosa in D-IBS group were both lower than those of healthy control group ((94.44 ± 6.61) ng/Lvs (103.64 ± 5.47) ng/L;11.1％ (3/27) vs 40.0％ (8/20)),and the differences were statistically significant (LSD-t=5.76,x2 =5.349;both P＜0.05).However,the serum level of claudin-1 and its positive expression rate in colonic mucosa in C-IBS group were both higher than those of healthy control group ((115.54±3.42) ng/L vs (103.64±5.47) ng/L;73.9％ (17/23) vs 40.0％(8/20)),and the differences were statistically significant (LSD-t=5.56,x2 =5.055;both P＜0.05).The serum levels of IL-10 and PYY,TNF-α and claudin-1 were negatively correlated in the D-IBS group (r=-0.874 and -0.863,both P＜0.05).While the serum levels of TNF-α and PYY,IL-10 and claudin-1 were positively correlated (r =0.865 and 0.876,both P＜ 0.05).Conclusions There may be the imbalance of proinflammatory factors and anti-inflammatory factors in IBS patients.PYY may decrease the expression of claudin-1 by promoting IL-10 and inhibiting TNF-α,and thus ameliorate the inflammation reaction of IBS patients.