TNFalpha genotype influences development of IgA-ASCA antibodies in Crohn's disease patients with CARD15 wild type

Familial Association of Granulocyte-Macrophage Colony-Stimulating Factor Autoantibodies in Inflammatory Bowel Disease

OBJECTIVES

Elevated granulocyte-macrophage colony-stimulating factor auto-antibodies (GM-CSF Ab) are associated with increased intestinal permeability and stricturing behavior in Crohn disease (CD). We tested for familial association of serum GM-CSF Ab level in CD and ulcerative colitis (UC) families.

METHODS

Serum GM-CSF Ab concentration was determined in 230 pediatric CD probands and 404 of their unaffected parents and siblings, and 45 UC probands and 71 of their unaffected parents and siblings. A linear mixed effects model was used to test for familial association. The intra-class correlation coefficient (ICC) was used to determine the degree of association of the serum GM-CSF Ab level within families in comparison with the degree of association among families.

RESULTS

The median (IQR) serum GM-CSF Ab concentration was higher in CD probands than in UC probands (1.5 [0.5,5.4] μg/mL vs 0.7 [0.3, 1.6] μg/mL, P = 0.0002). The frequency of elevated serum GM-CSF Ab concentration ≥1.6 μg/mL was increased in unaffected siblings of CD probands with elevated GM-CSF Ab, compared with unaffected siblings of CD probands without elevated GM-CSF Ab (33% vs 13%, respectively, P = 0.04). A similar result was observed within UC families. In families of CD patients, the mean (95th CI) ICC was equal to 0.153 (0.036, 0.275), P = 0.001, whereas in families of UC patients, the mean (95th CI) ICC was equal to 0.27 (0.24, 0.31), P = 0.047.

CONCLUSIONS

These data confirmed familial association of serum GM-CSF Ab levels. This could be accounted for by either genetic or environmental factors shared within the family.

Significant association of the KIR2DL3/HLA-C1 genotype with susceptibility to Crohn's disease

We aimed to analyze the possible association of KIR/HLA-C genotypes with the susceptibility to Crohn's disease (CD) in a Spanish population. A total of 125 patients with CD and 339 healthy controls were selected for this study. KIR and HLA-C typing were developed by sequence-specific oligonucleotide probing. We found that the centromeric A/A genotype and HLA-C1 combination was significantly increased in CD patients (P<10(-3)). The KIR2DL3/2DL3 genotype was significantly increased in CD patients (P<0.0005). Moreover, we also observed a highly significant increase of KIR2DL3-HLA-C1 homozygosis in CD patients (P<0.0005). Our results confirm the relevance of the KIR2DL2/KIR2DL3 genes and their interaction with HLA-C to CD. We show that the contribution of the KIR genes to CD susceptibility extends beyond the association with individual KIRs, with an imbalance between activating and inhibitory KIR genes seeming to influence the susceptibility to CD.

Pancreatic autoantibodies are associated with reactivity to microbial antibodies, penetrating disease behavior, perianal disease, and extraintestinal manifestations, but not with NOD2/CARD15 or TLR4 genotype in a Hungarian IBD cohort

BACKGROUND

Pancreatic autoantibodies (PAB) and goblet cell autoantibodies (GAB) are specific for Crohn's disease (CD) and ulcerative colitis (UC), but the sensitivity alone is low. Conventional antibodies and carbohydrates (glycans) are associated with disease phenotype and may be of diagnostic importance in inflammatory bowel disease (IBD). Our aim was to determine the accuracy of PAB and GAB autoantibodies as well as to study relevant phenotype-serotype associations.

METHODS

A Hungarian study cohort of 1092 subjects, including 689 well-characterized, unrelated IBD patients (CD: 579, m/f ratio: 274/305, duration: 7.9 +/- 11.2 years; UC: 110, m/f ratio: 53/57, duration: 8.9 +/- 9.8 years), 139 celiac patients, 100 healthy, and 64 non-IBD gastrointestinal controls were investigated. Sera were assayed for PAB-GAB IgA/IgG, anti-Omp, anti-Saccharomyces cerevisiae antibodies (ASCA), and anti-glycans. TLR4 and NOD2/CARD15 was tested by polymerase chain reaction / restriction fragment length polymorphism (PCR-RFLP). Detailed clinical phenotypes were determined.

RESULTS

The prevalence of PAB was significantly more frequent in CD (41.1%) versus UC (22.7%), celiac (22.3%), and controls (8% and 4.6%, P < 0.01 for each), while GAB detection was poor in all groups except UC (15.4%). In CD the combination of PAB and/or anti-glycans/ASCA increased the sensitivity to 72% and 59%, respectively, for isolated colonic disease. PAB was associated to gylcans (odds ratio [OR] 1.74,P = 0.002), ASCA IgG/IgA (OR 1.75, P = 0.002), Omp (OR 1.86, P = 0.001) as well as perforating, perianal disease, arthritis, ocular, and cutaneous manifestations (P = 0.002-0.032). In contrast, PAB and GAB antibodies were not associated with NOD2/CARD15 or TLR4, response to medical therapy, or need for surgery. No associations were found in UC.

CONCLUSIONS

PAB autoantibodies in combination with ASCA or anti-glycan antibodies increase the sensitivity for detecting CD, especially isolated colonic CD. Antibody response to PAB was associated with complicated disease phenotype and extraintestinal manifestations in this Eastern European IBD cohort.

Current understanding of fungal microflora in inflammatory bowel disease pathogenesis

Inflammatory bowel diseases are a current and growing public health problem, with a prevalence that appears to be increasing in most countries and cultures. While most research into the triggering phenomenon has focused on the interaction between commensal bacteria and inflammatory bowel disease, enteric fungi may also be important in determining disease susceptibility. Herein we review what is known about enteric fungi and the mechanisms by which they and their dysregulation might be involved in triggering inflammatory diseases of the bowel.