ABO histo-blood group might modulate predisposition to Crohn's disease and affect disease behavior

Associations Between ABO Blood Groups and Diseases in the Digestive System and Vein

Purpose

The ABO blood type system is crucial for human blood transfusions. However, the relationships between ABO blood groups and diseases in the digestive system and vein have not been elucidated. We investigated the relationships between ABO blood groups and diseases in the digestive system and vein in this study.

Patients and Methods

A retrospective study on a Chinese population, including 1432 Crohn's disease (CD), 416 ulcerative colitis (UC), 1140 stomach cancer (SC), 841 colorectal cancer (CRC), 384 pancreatic cancer (PC), 520 liver cancer (LC), and 563 venous thrombosis (VT) patients, was performed. Furthermore, 896 healthy subjects were enrolled as normal controls (NC) in this study. The demographic characteristics of patients and NC were compared using the unpaired t-test and χ2 test. Multivariate logistic regression model was used to evaluate the association between ABO blood groups and CD and VT.

Results

ABO blood groups distributions in UC, SC, CRC, PC, and LC patients did not differ from that of NC, but CD and VT patients had significant difference of ABO blood group distribution from that of NC (p = 0.015 and p = 0.002, respectively). Patients with CD and VT had considerably lower rates of type O blood (p = 0.011 and p = 0.001, respectively) and significantly higher rates of type AB blood (p = 0.013 and p = 0.022, respectively) than those with NC. Multivariate logistic regression analysis showed the association of CD and VT with non-O blood types was still significant with a higher risk than with blood group O after adjusting for age and gender (OR = 1.355, 95% CI = 1.100-1.670, p = 0.004 and OR = 1.465, 95% CI = 1.131-1.903, p = 0.004, respectively).

Conclusion

ABO blood groups distributions in CD and VT patients significantly differed from that of NC. Non-O blood group could be a new predictor for CD and VT.

Blood group as a novel predictor of postoperative atrial fibrillation after off-pump coronary artery bypass grafting

OBJECTIVE

The objective of this study was to reveal whether there was a possible relationship between the blood group and postoperative atrial fibrillation after off-pump coronary artery bypass grafting.

METHODS

Between January 2020 and January 2022, 452 patients undergoing off-pump coronary artery bypass grafting surgery consisted of the research population. Patients were divided into two groups based on the occurrence of new-onset atrial fibrillation from the time of operation until discharge. Group 1 (atrial fibrillation group) had 122 patients, whereas group 2 (non-atrial fibrillation group) contained 350 patients. Patients' baseline clinical characteristics and operative and postoperative data were recorded and then compared between the groups. Moreover, a multivariate logistic regression analysis was also conducted to identify the predictors of postoperative atrial fibrillation.

RESULTS

Non-O blood groups were substantially more common in the atrial fibrillation group than in the non-atrial fibrillation group. Patient age differences between the atrial fibrillation and non-atrial fibrillation groups were statistically significant, and patients in the atrial fibrillation group were detected to be older. Mean left atrial diameter, rates of obesity and prior percutaneous coronary intervention history, and perioperative intraaortic balloon pump requirement were significantly greater in the atrial fibrillation group than in the non-atrial fibrillation group. According to logistic regression analysis, blood group, age, left atrial diameter, obesity, and prior percutaneous coronary intervention were identified as predictors of postoperative atrial fibrillation.

CONCLUSION

We demonstrated for the first time in the literature that ABO blood type was a novel and significant predictor of new-onset atrial fibrillation after off-pump coronary artery bypass grafting.

ABO Blood Group and the Risk and Prognosis of Lymphoma

ABO blood group antigens exhibit alternative phenotypes and genetically derived structures that are located on the red cell surface. The role of ABO blood group in cancer biology has been intensely reported by several studies, and it is now widely recognized that ABO antigens are associated with the risk and prognosis of several types of tumors, namely gastric cancer and pancreatic cancer. However, there have been contentious limited issues with the association between the ABO blood group and lymphoma. In this narrative review, based on literature data, we discuss the role of ABO blood group in the risk and prognosis of lymphoma and summarize the current knowledge of the underlying pathogenic mechanisms of the association. The possible association of ABO blood group with racial disparities and pathological classification in lymphoma patients is also discussed.

Microbiota-induced regulatory T cells associate with FUT2-dependent susceptibility to rotavirus gastroenteritis

The FUT2 α1,2fucosyltransferase contributes to the synthesis of fucosylated glycans used as attachment factors by several pathogens, including noroviruses and rotaviruses, that can induce life-threatening gastroenteritis in young children. FUT2 genetic polymorphisms impairing fucosylation are strongly associated with resistance to dominant strains of both noroviruses and rotaviruses. Interestingly, the wild-type allele associated with viral gastroenteritis susceptibility inversely appears to be protective against several inflammatory or autoimmune diseases for yet unclear reasons, although a FUT2 influence on microbiota composition has been observed. Here, we studied a cohort of young healthy adults and showed that the wild-type FUT2 allele was associated with the presence of anti-RVA antibodies, either neutralizing antibodies or serum IgA, confirming its association with the risk of RVA gastroenteritis. Strikingly, it was also associated with the frequency of gut microbiota-induced regulatory T cells (Tregs), so-called DP8α Tregs, albeit only in individuals who had anti-RVA neutralizing antibodies or high titers of anti-RVA IgAs. DP8α Tregs specifically recognize the human symbiont Faecalibacterium prausnitzii, which strongly supports their induction by this anti-inflammatory bacterium. The proportion of F. prausnitzii in feces was also associated with the FUT2 wild-type allele. These observations link the FUT2 genotype with the risk of RVA gastroenteritis, the microbiota and microbiota-induced DP8α Treg cells, suggesting that the anti-RVA immune response might involve an induction/expansion of these T lymphocytes later providing a balanced immunological state that confers protection against inflammatory diseases.

Inflammatory bowel disease-associated intestinal fibrosis

Fibrosis is characterized by a proliferation of fibroblasts and excessive extracellular matrix following chronic inflammation, and this replacement of organ tissue with fibrotic tissue causes a loss of function. Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal tract, and intestinal fibrosis is common in IBD patients, resulting in several complications that require surgery, such as a stricture or penetration. This review describes the pathogenesis and various factors involved in intestinal fibrosis in IBD, including cytokines, growth factors, epithelial-mesenchymal and endothelial-mesenchymal transitions, and gut microbiota. Furthermore, histopathologic findings and scoring systems used for stenosis in IBD are discussed, and differences in the fibrosis patterns of ulcerative colitis and Crohn's disease are compared. Biomarkers and therapeutic agents targeting intestinal fibrosis are briefly mentioned at the end.

Intestinal Norovirus Binding Patterns in Nonsecretor Individuals

Human norovirus (HuNoV) infection is associated with an active FUT2 gene, which characterizes the secretor phenotype. However, nonsecretor individuals are also affected by HuNoV infection although in a lesser proportion. Here, we studied GII.3, GII.4, and GII.17 HuNoV interactions in nonsecretor individuals using virus-like particles (VLPs). Only GII.4 HuNoV specifically interacted with nonsecretor saliva. Competition experiments using histo-blood group antigen (HBGA)-specific monoclonal antibodies (MAbs) demonstrate that GII.4 VLPs recognized the Lewis a (Le^a) antigen. We also analyzed HuNoV VLP interactions on duodenum tissue blocks from healthy nonsecretor individuals. VLP binding was observed for the three HuNoV genotypes in 10 of the 13 individuals, and competition experiments demonstrated that VLP recognition was driven by an interaction with the Le^a antigen. In 3 individuals, binding was restricted to either GII.4 alone or GII.3 and GII.17. Finally, we performed a VLP binding assay on proximal and distal colon tissue blocks from a nonsecretor patient with Crohn's disease. VLP binding to inflammatory tissues was genotype specific since GII.4 and GII.17 VLPs were able to interact with regenerative mucosa, whereas GII.3 VLP was not. The binding of GII.4 and GII.17 HuNoV VLPs was linked to Le^a in regenerative mucosae from the proximal and distal colon. Overall, our data clearly showed that Le^a has a pivotal role in the recognition of HuNoV in nonsecretors. We also showed that Le^a is expressed in inflammatory/regenerative tissues and interacts with HuNoV in a nonsecretor individual. The physiological and immunological consequences of such interactions in nonsecretors have yet to be elucidated. IMPORTANCE Human norovirus (HuNoV) is the main etiological agent of viral gastroenteritis in all age classes. HuNoV infection affects mainly secretor individuals where ABO(H) and Lewis histo-blood group antigens (HBGAs) are present in the small intestine. Nonsecretor individuals, who only express Lewis (Le) antigens, are less susceptible to HuNoV infection. Here, we studied the interaction of common HuNoV genotypes (GII.3, GII.4, and GII.17) in nonsecretor individuals using synthetic viral particles. Saliva binding assays showed that only GII.4 interacted with nonsecretor saliva via the Lewis a (Le^a) antigen Surprisingly, the three genotypes interacted with nonsecretor enterocytes via the Le^a antigen on duodenal tissue blocks, which were more relevant for HuNoV/HBGA studies. The Le^a antigen also played a pivotal role in the recognition of GII.4 and GII.17 particles by inflammatory colon tissue from a nonsecretor Crohn's disease patient. The implications of HuNoV binding in nonsecretors remain to be elucidated in physiological and pathological conditions encountered in other intestinal diseases.

Fucosyltransferase 2: A Genetic Risk Factor for Intestinal Diseases

The fucosyltransferase 2 gene (FUT2) mediates the synthesis of histoblood group antigens (HBGA) that occur in vivo from multiple organs, particularly on the surface of intestinal epithelial cells and body fluids. To date, many studies have demonstrated that the interaction of HBGA with the host microbiota is the cause of pathogenesis of intestinal diseases, making FUT2 non-secretor a risk factor for inflammatory bowel disease (IBD) due to the lack of HBGA. As HBGA also acts as an attachment site for norovirus (NoV) and rotavirus (RV), the non-secretor becomes a protective factor for both viral infections. In addition, the interaction of norovirus and rotavirus with symbiotic bacteria has been found to play an important role in regulating enteroviral infection in IBD. Given the current incomplete understanding of the complex phenomenon and the underlying pathogenesis of intestinal diseases such as IBD, it has recently been hypothesized that the FUT2 gene regulates intestinal bacteria through attachment sites, may help to unravel the role of FUT2 and intestinal flora in the mechanism of intestinal diseases in the future, and provide new ideas for the prevention and treatment of intestinal diseases through more in-depth studies.

ABO blood type and clinical characteristics of patients with ulcerative colitis: A hospital-based study in central Taiwan

BACKGROUND

The variations in ABO blood groups are reported to be associated with multiple disorders, including ulcerative colitis (UC). We aimed to investigate the distribution of ABO blood groups in UC patients and explore its impact on disease severity.

METHODS

We retrospectively collected 129 UC patients diagnosed at our hospital between January 2000 and November 2019. Clinical characteristics, ABO blood groups, and operation rates were analyzed.

RESULTS

The mean diagnostic age of patients was 38.97 years. Males accounted for the majority of all patients (62.8%). Of 129 patients, 43 (33.3%) were blood type O, 41 (31.8%) were blood type A, 38 (29.5%) were blood type B, and 7 (5.4%) were blood type AB. Although our patients had higher ratio of blood type A comparing our general population, there was no statistically significant association of ABO blood types distribution between these two groups (p = 0.1906). In the subgroup analysis, there were no significant difference of disease locations and operation rates between different ABO blood groups. Furthermore, blood type A patients had higher serum hemoglobin (Hb) levels compared to blood type O patients (13.31 g/dL vs. 12.30 g/dL, p = 0.0347). Blood type A patients had lower serum erythrocyte sedimentation rate (ESR) levels compared to blood type O patients (12.46 mm/hour vs. 21.5 mm/hour, p = 0.0288). Blood type O had higher serum ESR levels compared to non-O groups (p = 0.0228). In the ABO blood groups and mean diagnostic age (≤ 40 years or > 40 years), there were no statistically significant difference between these two age groups, p = 0.5515.

CONCLUSIONS

Our results showed ABO blood groups are not associated with UC in spite of a higher ratio of blood type A in our patients. Blood type O patients had higher serum ESR levels; however, blood type A patients had higher Hb levels.

Association between ABO blood group and risk of Crohn's disease: A case-control study in the Chinese Han population

BACKGROUND

Blood group O has been reported to be a potentially protective factor for Crohn's disease (CD) susceptibility in Caucasian and Korean populations, but a similar conclusion was not found in a Chinese study. The present study investigated the potential association in the Chinese Han population.

METHODS

We included 275 CD patients, 132 ulcerative colitis (UC) patients and 1201 healthy individuals in this case-control study. The demographic characteristics and ABO blood group were compared among the three groups. The clinical characteristics and treatment of CD were further investigated according to the blood group distribution.

RESULTS

The blood group distribution in CD patients was significantly different from healthy controls, and the frequency of O blood in CD patients was significantly lower compared to healthy controls. After adjusting for age and gender, the non-O blood groups remained significantly associated with CD susceptibility in propensity score-adjusted and propensity score-matched analyses. Compared to CD patients with non-O blood groups, patients with O blood were at a lower risk of developing penetrating disease, more likely to receive immunosuppressant treatment and less likely to receive biological treatment.

CONCLUSION

Our results confirmed that non-O blood groups were significantly associated with an increased risk of CD in the Chinese Han population.

Characterization of the human ABO genotypes and their association to common inflammatory and cardiovascular diseases in the UK Biobank

The ABO gene contains three major alleles that encodes different antigens; A, B, and O, which determine an individual's blood group. Previous studies have primarily focused on identifying associations between ABO blood groups and diseases risk. Here, we sought to test for association between ABO genotypes (OO, OA, AA; OB, BB, and AB) and a large set of common inflammatory and cardiovascular diseases in UK Biobank as well as disease-related protein biomarkers in NSPHS. We first tested for association by conducting a likelihood ratio test, testing whether ABO contributed significantly to the risk for 24 diseases, and 438 plasma proteins. For phenotypes with FDR < 0.05, we tested for pair-wise differences between genetically determined ABO genotypes using logistic or linear regression. Our study confirmed previous findings of a strong association between ABO and cardiovascular disease, identified associations for both type 1 and type 2 diabetes, and provide additional evidence of significant differences between heterozygous and homozygous allele carriers for pulmonary embolism, deep vein thrombosis, but also for von Willebrand factor levels. Furthermore, the results indicated an additive effect between genotypes, even between the two most common A subgroups, A1 and A2. Additionally, we found that ABO contributed significantly to 39 plasma proteins, of which 23 have never been linked to the ABO locus before. These results show the need of incorporating ABO genotype information in the consultation and management of patients at risk, rather than classifying patients into blood groups.

Crohn's disease-related single nucleotide polymorphisms are associated with ileal pouch afferent limb stenosis

BACKGROUND

Ileal pouch-anal anastomosis (IPAA) is a common surgical treatment for ulcerative colitis. Afferent limb stenosis is an infrequent complication following IPAA, suggesting underlying Crohn's disease (CD). We hypothesized that CD-related single nucleotide polymorphisms (SNPs) are associated with afferent limb stenosis.

METHODS

Afferent limb stenosis and CD control group patients were recruited from a prospective institutional inflammatory bowel disease database and associated biobank. Patient demographics, Montreal classification, and medication use were recorded. Ten SNPs associated with stricturing Crohn's disease were examined in genomic DNA and compared among afferent limb stenosis, stricturing CD, and non-stricturing CD controls.

RESULTS

Twenty-seven afferent limb stenosis and 162 CD control group patients (108 stricturing, 54 non-stricturing) were identified. Patients were gender and race matched. Afferent limb stenosis and stricturing CD controls were younger at diagnosis (Montreal A1/A2 vs. A3) compared to non-stricturing CD controls (both p < 0.05). The majority of afferent limb stenosis patients were non-smokers compared to CD controls (74% vs. 36%, p < 0.01) and did not use biologic therapies (4% vs. 37%, p < 0.001). The FUT2 G allele was more frequent in afferent limb stenosis and stricturing CD controls compared to non-stricturing CD controls (both p < 0.05). The NOD2 T allele was more frequent in stricturing CD controls compared to afferent limb stenosis and non-stricturing CD controls (both p < 0.05).

CONCLUSION

Afferent limb stenosis patients are phenotypically similar to stricturing CD controls, but differ with lower smoking rates and lower NOD2 allele frequency. Such differences could contribute to the presentation delay with a stricturing phenotype. Selective SNP assessment may help categorize patients likely to develop afferent limb stenosis.

Specific Norovirus Interaction with Lewis x and Lewis a on Human Intestinal Inflammatory Mucosa during Refractory Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are progressive diseases affecting millions of people each year. Flare-ups during IBD result in severe mucosal alterations of the small intestine (in CD) and in the colon and rectum (in CD and UC).

Inflammatory bowel disease (IBD), which includes Crohn’s disease (CD) and ulcerative colitis (UC), is related to immunological and microbial factors, with the possible implication of enteric viruses. We characterized the interaction between human noroviruses (HuNoVs) and blood group antigens in refractory CD and UC using HuNoV virus-like particles (VLPs) and histological tissues. Immunohistochemistry was conducted on inflammatory tissue samples from the small intestine, colon, and rectum in 15 CD and 9 UC patients. Analysis of the regenerative mucosa of the colon and rectum revealed strong expression of sialylated Lewis a (sLe^a) and Lewis x (sLe^x) antigens and HuNoV VLP binding in the absence of ABO antigen expression in both UC and CD. Competition experiments using sialidase, lectins, and monoclonal antibodies demonstrated that HuNoV attachment mostly involved Le^a and, to a lesser extent, Le^x moieties on regenerative mucosa in both UC and CD. Further studies will be required to understand the implications of specific HuNoV binding to regenerative mucosa in refractory IBD.

IMPORTANCE Inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are progressive diseases affecting millions of people each year. Flare-ups during IBD result in severe mucosal alterations of the small intestine (in CD) and in the colon and rectum (in CD and UC). Immunohistochemical analysis of CD and UC samples showed strong expression of known tumoral markers sialyl Lewis a (CA19.9) and sialyl Lewis x (CD15s) antigens on colonic and rectal regenerative mucosa, concurrent with strong human norovirus (HuNov) VLP GII.4 affinity. Sialidase treatment and competition experiments using histo-blood group antigen (HBGA)-specific monoclonal antibodies and lectins clearly demonstrated the implication of the Lewis a moiety and, to a lesser extent, the Lewis x moiety in HuNov recognition in regenerative mucosa of CD and UC tissues. Further studies are required to explore the possible implications of enteric viruses in the impairment of epithelial repair and dysregulation of inflammatory pathways during severe IBD.

Can the FUT2 Non-secretor Phenotype Associated With Gut Microbiota Increase the Children Susceptibility for Type 1 Diabetes? A Mini Review

The global toll of type 1 diabetes (T1D) has steadily increased over the last decades. It is now widely acknowledged that T1D pathophysiology is more complex than expected. Indeed, a multifaceted interplay between genetic, metabolic, inflammatory and environmental factors exists that leads to heterogeneous clinical manifestations across individuals. Children with non-secretor phenotype and those affected by T1D share low abundance of bifidobacteria, low content of short-chain fatty acids, intestinal phosphatase alkaline and a high incidence of inflammatory bowel diseases. In this context, host-gut microbiota dyad may represent a relevant contributor to T1D development and progression due to its crucial role in shaping host immunity and susceptibility to autoimmune conditions. The FUT2 gene is responsible for the composition and functional properties of glycans in mucosal tissues and bodily secretions, including human milk. FUT2 polymorphisms may profoundly influence gut microbiota composition and host susceptibility to viral infections and chronic inflammatory disease. In this minireview, the possible interplay between mothers' phenotype, host FUT2 genetic background and gut microbiota composition will be discussed in perspective of the T1D onset. The study of FUT2-gut microbiota interaction may add a new piece on the puzzling T1D etiology and unveil novel targets of intervention to contrast T1D development and progression. Dietary interventions, including the intake of α-(1, 2)-fucosyl oligosaccharides in formula milk and the use of specific prebiotics and probiotics, could be hypothesized.

The potential use of ABO blood group system for risk stratification of COVID-19

ABO blood groups is a cheap and affordable test that can be immediately retrieved from COVID-19 patients at the diagnosis. There is increasing evidence that non-O blood groups have both higher susceptibility and higher severity of COVID-19 infections. The reason behind such relationship seems elusive. Regarding susceptibility, Non-O individuals have Anti-A antibodies which can prevent viral entry across ACE-2 receptors, moreover, Non-O individuals are at higher risk of autoimmunity, hypercoagulable state, and dysbiosis resulting in an augmented tendency for vascular inflammatory sequelae of COVID-19. We can conclude, on the diagnostic level, that ABO blood groups can be potentially used for risk stratification of affected COVID-19 patients, to anticipate the deterioration of patients at higher risk for complications. On a therapeutic level, plasma from normal O blood group individuals might potentially replace the use of convalescent serum for the treatment of COVID-19.

Association of FUT2 and ABO with Crohn's disease in Koreans

BACKGROUND AND AIM

Fucosyltransferase 2 (FUT2) at 19q13 is a well-established susceptibility locus for Crohn's disease (CD) in Caucasians. FUT2 encodes α-1,2-fucosyltransferase that regulates the secretion of the α-1-2-N-acetylgalactosaminyltransferase and α-1-3-galactosyltransferase (ABO) antigens in both the gastrointestinal mucosa and secretory glands. Given that CD is thought to arise from dysregulated mucosal immune responses to the gut flora and both the ABO blood group and the FUT2 secretor status affect the composition of the gut microbiota, the goal of this study was to evaluate the associations of variants of FUT2 and ABO with CD in Koreans.

METHODS

Three single-nucleotide polymorphisms from the FUT2 and ABO genes were genotyped in 1735 patients with CD and 8074 healthy controls.

RESULTS

The FUT2 non-secretor allele showed genome-wide significant association with CD in Koreans (rs1047781, odds ratio [OR] = 1.30, Pcombined  = 3.52 × 10-12 ). The ABO locus showed genome-wide significant association with CD in Asians (Pmeta  = 2.35 × 10-8 ). A moderate association was observed with the A and B groups (OR = 1.40, P = 2.26 × 10-6 ; and OR = 1.32, P = 1.92 × 10-4 , respectively) compared with the O group. Following stratification on the basis of FUT2 genotype, carriers of the secretor O blood group were significantly protective against CD than were those of the secretor non-O blood group (OR = 0.63, 95% confidence interval = 0.54-0.73, P = 2.86 × 10-9 ).

CONCLUSIONS

These are the first results indicating that the O blood group and FUT2 secretor status are protective factors against CD in Asians.

How the gut microbiome regulates host immune responses to viral vaccines

The co-evolution of the microbiota and immune system has forged a mutually beneficial relationship. This relationship allows the host to maintain the balance between active immunity to pathogens and vaccines and tolerance to self-antigens and food antigens. In children living in low-income and middle-income countries, undernourishment and repetitive gastrointestinal infections are associated with the failure of oral vaccines. Intestinal dysbiosis associated with these environmental influences, as well as some host-related factors, compromises immune responses and negatively impacts vaccine efficacy. To understand how immune responses to viral vaccines can be optimally modulated, mechanistic studies of the relationship between the microbiome, host genetics, viral infections and the development and function of the immune system are needed. We discuss the potential role of the microbiome in modulating vaccine responses in the context of a growing understanding of the relationship between the gastrointestinal microbiota, host related factors (including histo-blood group antigens) and resident immune cell populations.

Association of Fucosyltransferase 2 Gene Polymorphisms with Inflammatory Bowel Disease in Patients from Southeast China

Aims. Fucosyltransferase 2 (FUT2) gene potentially affects the constituent of intestinal microbiota, which play a crucial role in the pathogenesis of inflammatory bowel disease (IBD). This study investigated the association of FUT2 gene polymorphisms with IBD in southeast China. Methods. We collected 671 IBD patients and 502 healthy controls. FUT2 gene polymorphisms (C357T, A385T, and G428A) were determined by SNaPshot. Frequencies of the FUT2 genotypes, alleles, and haplotype between groups were compared by χ² test. Results. The allele and genotype frequencies of FUT2 did not differ between ulcerative colitis patients and controls (all P > 0.05). However, mutant allele and genotype of FUT2 (A385T) were significantly increased in Crohn's disease (CD) patients (P = 0.024, OR = 1.271, and 95% CI = 1.031–1.565; P < 0.001, OR = 1.927, and 95% CI = 1.353–2.747, resp.). The same conclusion was drawn from FUT2 (G428A) (P = 0.023, OR = 3.324, and 95% CI = 1.108–9.968; P = 0.044, OR = 1.116–10.137, and 95% CI = 1.116–10.137, resp.). The haplotype TT formed with “C357T and A385T” was more prevalent in CD patients than in controls (P = 0.020, OR = 1.277, and 95% CI = 1.036–1.573). Besides, frequencies of mutant allele and genotype of FUT2 (A385T) were significantly lower in patients with ileocolonic CD than in those with colonic CD (P = 0.001 and 0.002, resp.) and ileal CD (P = 0.007 and 0.004, resp.). Conclusions. FUT2 gene polymorphisms and haplotypes were associated with the susceptibility to CD but not UC.

Associations of fucosyltransferase 2 gene polymorphism with susceptibility to inflammatory bowel disease: A meta-analysis

AIM

To explore the relationship between fucosyltransferase 2 (FUT2) A385T and G428A gene polymorphisms and susceptibility to inflammatory bowel disease(IBD).

METHODS

Databases including Embase, PubMed, EBM Reviews, Ovid, Springer, CNKI, and WanFang were searched for articles evaluating the relationship between FUT2 gene polymorphism and susceptibility to IBD. Available data were extracted and quality of the included studies was evaluated. Meta-analysis was conducted by using Review Manager 5.3 and Stata 12.0. Begg's funnel plot was used to assess the published bias of articles.

RESULTS

Totally 10 articles were included, including 3682 cases and 5470 controls. Each genetic model in ulcerative colitis (UC) was as follows: dominant model [(AA + AT) vs TT: OR = 0.60 (95%CI: 0.43-0.85); (GG + GA) vs AA: OR = 0.51 (95%CI: 0.38-0.70)]; recessive model [(AT + TT) vs AA: OR = 0.96 (95%CI: 0.73-1.25); (GA + AA) vs GG: OR = 0.70 (95%CI: 0.36-1.36)]; codominant model [AA vs TT: OR = 1.02 (95%CI: 0.82-1.27); GG vs AA: OR = 1.23 (95%CI: 0.93-1.63)]; allele genetic model [A vs T: OR = 1.06 (95%CI: 0.95-1.17); G vs A: OR = 1.18 (95%CI: 0.68-2.04)]. Each genetic model in Crohn's disease (CD) was as follows: dominant model [(AA + AT) vs TT: OR = 0.60 (95%CI: 0.43-0.85); (GG + GA) vs AA: OR = 0.51 (95%CI: 0.38-0.70)]; recessive model [(AT + TT) vs AA]: OR = 0.99 (95%CI: 0.73-1.35); (GA + AA) vs GG: OR = 1.49 (95%CI: 1.17-1.91)]; codominant model [AA vs TT: OR = 1.37 (95%CI: 0.95-1.98); GG vs AA: OR = 0.46 (95%CI: 0.33-0.65)]; allele genetic model [G vs A: OR = 0.67 (95%CI: 0.57-0.79); G vs A: OR = 0.67 (95%CI: 0.57-0.79)].

CONCLUSION

FUT2 A385T and G428A polymorphisms are not significantly related with IBD. In Asians, the TT on A385T confers a significant risk for developing CD. FUT2 G428A polymorphism is related with CD, and the allele gene A confers a risk for developing CD.

Genetic Influences on the Development of Fibrosis in Crohn's Disease

Fibrostenotic strictures are an important complication in patients with Crohn’s disease (CD), very often necessitating surgery. This fibrotic process develops in a genetically susceptible individual and is influenced by an interplay with environmental, immunological, and disease-related factors. A deeper understanding of the genetic factors driving this fibrostenotic process might help to unravel the pathogenesis, and ultimately lead to development of new, anti-fibrotic therapy. Here, we review the genetic factors that have been associated with the development of fibrosis in patients with CD, as well as their potential pathophysiological mechanism(s). We also hypothesize on clinical implications, if any, and future research directions.

The role of ABO blood groups in Crohn's disease and in monitoring response to infliximab treatment

BACKGROUND

The variation in ABO blood groups is reported to be associated with multiple diseases. Infliximab (IFX) has been widely used in the treatment of Crohn's disease (CD). We aim to investigate the distribution of ABO blood groups in Chinese patients with CD and to explore its impact on response to IFX.

MATERIALS AND METHODS

Patients with CD were consecutively recruited to the study between 2007 and 2014. CD patients receiving IFX therapy were followed for at least two years.

RESULTS

In 293 patients with CD, most patients (40.6%) had blood type O (119/293). The odds ratio (OR) of CD in blood type O patients was 1.06 (95%CI: 0.6-1.86; p=0.84) compared to all other blood types. Among those CD patients, 107 patients received IFX treatment. One year after the first course of IFX, a significant association was found between the overall ABO system and outcomes of IFX treatment (p<0.001). CD patients with blood type AB (OR=4.42, 95% CI: 1.04-18.76; p=0.044) were more likely to achieve mucosal healing, while CD patients with blood type A had a high risk of losing response (OR=0.38, 95% CI: 0.15-0.96; p=0.040).

DISCUSSION

ABO blood groups are not associated with prevalence of CD. Patients with blood type AB had a better response to IFX while those with blood type A appeared to have a risk of losing response to IFX.

Association of Ulcerative Colitis with FUT2 and FUT3 Polymorphisms in Patients from Southeast China

OBJECTIVES

Dysbiosis of intestinal microbiota has been implicated in ulcerative colitis (UC). Fucosyltransferase (FUT) 2 and FUT3 determine expression of histo-blood group antigens in the gut and may affect the intestinal microbiota. We investigated the association between FUT2 and FUT3 polymorphisms and UC in Chinese patients.

METHODS

We genotyped FUT2 (rs281377, rs1047781 and rs601338) and FUT3 (rs28362459, rs3745635 and rs3894326) in 485 UC patients and 580 healthy controls using SNaPshot. We also evaluated expression of Lewis a and b antigens in the sigmoid colon of 7 UC patients and 7 patients with benign colonic polyps.

RESULTS

The frequencies of mutant allele (A) and genotype (GA+AA) in FUT3 (rs3745635) were higher in UC patients than controls (P = 0.016, 95%CI: 1.339-1.699; P = 0.038, 95%CI: 1.330-1.742, respectively). Stratified analyses revealed that the frequencies of mutant allele (G) and genotype (TG+GG) of FUT3 (rs28362459) were significantly lower in patients with extensive colitis than those with distal colitis (P<0.001, 95%CI: 0.503-0.742; P = 0.001, 95%CI: 0.567-0.786, respectively). Similar conclusions were drawn for the mutant allele (A) and genotype (GA+AA) of FUT3 (rs3745635) in patients with extensive colitis compared to those with distal colitis (P = 0.006, 95%CI: 0.553-0.845; P = 0.011, 95%CI: 0.621-0.900, respectively). Although expression of Lewis b antigen in the sigmoid colon did not differ between UC patients and controls, Lewis a antigen expression was higher in the cryptic epithelium of both inflammatory and non-inflammatory sigmoid colon of UC patients than controls (P = 0.028).

CONCLUSIONS

Our findings indicated that polymorphisms in FUT3 and its intestinal expression might be associated with UC pathogenesis.

Mucin glycan foraging in the human gut microbiome

The availability of host and dietary carbohydrates in the gastrointestinal (GI) tract plays a key role in shaping the structure-function of the microbiota. In particular, some gut bacteria have the ability to forage on glycans provided by the mucus layer covering the GI tract. The O-glycan structures present in mucin are diverse and complex, consisting predominantly of core 1-4 mucin-type O-glycans containing α- and β- linked N-acetyl-galactosamine, galactose and N-acetyl-glucosamine. These core structures are further elongated and frequently modified by fucose and sialic acid sugar residues via α1,2/3/4 and α2,3/6 linkages, respectively. The ability to metabolize these mucin O-linked oligosaccharides is likely to be a key factor in determining which bacterial species colonize the mucosal surface. Due to their proximity to the immune system, mucin-degrading bacteria are in a prime location to influence the host response. However, despite the growing number of bacterial genome sequences available from mucin degraders, our knowledge on the structural requirements for mucin degradation by gut bacteria remains fragmented. This is largely due to the limited number of functionally characterized enzymes and the lack of studies correlating the specificity of these enzymes with the ability of the strain to degrade and utilize mucin and mucin glycans. This review focuses on recent findings unraveling the molecular strategies used by mucin-degrading bacteria to utilize host glycans, adapt to the mucosal environment, and influence human health.

Distribution of ABO and Rh Blood Groups in Patients With Keratoconus: A Case-Control Study

Association of keratoconus (KC) with genetic predisposition and environmental factors has been well documented. However, no single study has investigated the possible relationship between ABO and Rh blood groups and KC.

METHODS

A case-control study was designed in a university hospital enrolling 214 patients with KC in the case group and equal number of age- and sex-matched healthy subjects in the control group. Primary characteristics, ABO blood group, and Rh factors were compared between the two groups. Topographic findings of KC eyes and the severity of the diseases were investigated according to the distribution of the blood groups.

RESULTS

Blood group O and Rh(+) phenotype were most frequent in both groups. There was no significant difference between the two groups in terms of ABO blood groups or Rh factors. Mean keratometery (K), central corneal thickness, thinnest corneal thickness, flat K, steep K, sphere and cylinder, spherical equivalent, and uncorrected visual acuity were all similar between ABO blood groups and Rh(+) and Rh(-) groups. However, the best spectacle-corrected visual acuity (BCVA) had the highest value in AB blood group (0.35 ± 0.22 logMAR, P=0.005). Moreover, the blood group AB revealed the highest frequency for grade 3 KC, followed by grades 1, 2, and 4 (P=0.003).

CONCLUSION

We observed no significant excess of any particular blood group among KC cases compared with healthy subjects. Except BCVA, none of the keratometric or topographic findings was significantly different between blood groups.