Anti-Saccharomyces cerevisiae antibodies in autoimmune liver disease

Prevalence of Anti- Saccharomyces Cerevisiae Antibodies (ASCA) in Patients With Irritable Bowel Syndrome (IBS). A Case-control Study

BACKGROUND

Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction that affects patients' quality. Recent research has shown variations in the mycobiome of individuals with IBS, particularly involving Saccharomyces cerevisiae , and its association with dysbiosis and visceral hypersensitivity. However, the role of Anti-Saccharomyces cerevisiae antibodies (ASCA) in IBS remains unclear, despite their significance as markers of disease severity in inflammatory bowel disease.

OBJECTIVE

This study aimed to investigate the role of ASCA in Mexican IBS patients compared with healthy controls (HCs) and determine whether these antibodies could help differentiate between IBS patients and healthy individuals.

METHODS

Serum samples from 400 IBS patients and 400 HC were analyzed. ASCA IgG levels were measured using enzyme-linked immunosorbent assay (ELISA). The IBS patients were further categorized into subtypes: constipation predominant (IBS-C), diarrhea predominant (IBS-D), and mixed (IBS-M).

RESULTS

Among the participants, 66 IBS patients (16.5%) and 63 HC (15.75%) tested positive for ASCA IgG. No significant difference was observed in ASCA IgG levels between the 2 groups ( P value: 0.8451). The prevalence of ASCA IgG positivity was 14.5% in IBS-C, 17.8% in IBS-D, and 15.9% in IBS-M.

CONCLUSION

Surprisingly, a high prevalence of ASCA IgG was found in the HC group in Mexico. Furthermore, there was no significant difference in ASCA IgG levels between IBS patients and controls. These findings suggest that ASCA is not useful as a discriminatory biomarker for distinguishing IBS patients from healthy individuals and cannot serve as a surrogate marker for visceral hypersensitivity.

Autologous Haematopoietic Stem Cell Transplantation (AHSCT) in Severe Crohn's Disease: A Review on Behalf of ECCO and EBMT

Despite the major recent progress in the treatment of Crohn's disease [CD], there is a subset of patients in whom the disease runs an aggressive course with progressive tissue damage requiring early and repeated surgical management. Increasing evidence supports sustained and profound improvement in gastrointestinal parameters and quality of life following high-dose immunosuppressive therapy and autologous haematopoietic stem cell transplantation [AHSCT] compared to standard therapy in this context. In addition, international transplant registry data reflect the use of AHSCT in CD outside of trials in selected patients. However, AHSCT may be associated with significant treatment-related complications with risk of transplant-related mortality. In a joint initiative, the European Crohn's and Colitis Organisation [ECCO] and the European Society for Blood and Marrow Transplantation [EBMT] have produced a state-of-the-art review of the rationale, evaluation, patient selection, stem cell mobilization and transplant procedures and long-term follow up. Given the unique spectrum of issues, we recommend that AHSCT should only be performed in experienced centres with expertise in both haematological and gastroenterological aspects of the procedure. Where possible, patients should be enrolled on clinical trials and data registered centrally. Future development should be coordinated at both national and international levels.

Anti Saccharomyces cerevisiae Antibodies in Patients With Anti-β2 Glycoprotein I Antibodies

BACKGROUND

In this study, cross-reactive epitopes on β2 glycoprotein I and Saccharomyces cerevisiae have been described. The objective of our study was to determine the frequency of anti S. cerevisiae antibodies (ASCA) in patients with anti-β2 glycoprotein I antibodies (aβ2GPI).

METHODS

A retrospective study was conducted in 77 patients with aβ2GPI (aβ2GPI-IgG or aβ2GPI-IgA). Eighty blood donors were used as a control group. ASCA IgG and ASCA IgA were determined by Enzyme Linked Immunosorbent Assay (ELISA).

RESULTS

Thirteen patients among 77 had ASCA. ASCA (IgA or IgG) was significantly more frequent in patients than in healthy subjects (16.9% vs. 3.7%, P = 0.01). The positivity of both ASCA IgG and ASCA IgA is higher in patients than in control group (6.5% vs. 0%, P = 0.02). The frequency of ASCA IgG was significantly higher in patients than in the control group (15.6% vs. 2.5%, P = 0.009). In females, the frequency of ASCA IgG was significantly higher in patients than in control group (17.5% vs. 3.7%, P = 0.03). The average titer of ASCA IgG was significantly higher in patients than in the control group (9.7 ± 23 U/ml vs. 2.2 ± 2.8 U/ml; P = 0.004). ASCA IgG was significantly more frequent than ASCA IgA in all patients (15.6% vs. 7.8%, P = 0.04).

CONCLUSION

The frequency of ASCA was significantly higher in patients with aβ2GPI than in the control group.

Serologic antiglycan antibodies in inflammatory bowel disease

At diagnosis, the clinical presentation of both entities of inflammatory bowel disease (IBD), Crohn's disease (CD) and ulcerative colitis (UC), can be highly heterogeneous, leading to a delay in correct identification or differentiation between CD and UC in a subgroup of patients. In addition, the natural history of IBD patients is strikingly variable. During the life of a CD patient, in the majority of instances, stricturing or perforating complications occur, leading to surgery. Serologic antiglycan antibodies directed against various microbial carbohydrate epitopes are useful in differentiation of CD vs. UC and are a promising tool for identification of CD patients at risk for rapid progression and need for surgical intervention. Instruments for prediction of CD behavior are critical, as the use of immunomodulators and/or biologicals early in the disease course might be justified for patients with a high hazard for complicated disease behavior.

Anti-Saccaromyces Cerevisiae antibodies (ASCA) are elevated in autoimmune thyroid disease ASCA in autoimmune thyroid disease

Environmental factors have been implicated in the development of autoimmune thyroid disease (AITD). Anti-Saccaromyces Cerevisiae Antibodies (ASCA) were shown to be elevated in several autoimmune diseases. The aim of the study was to determine ASCA levels and their relationship with thyroid autoantibodies in patients with AITD. One-hundred and twelve patients with AITD (age 41.1±12.8 years; F/M:96/16) and 103 healthy controls (38.5±10.3 years; F/M:82/21) were included. Twenty-four patients had Graves disease (GD), and 88 had Hashimoto's thyroiditis (HT). ASCA IgA and IgG, TSH, free T4, anti-thyroglobulin, and anti-thyroid peroxidase antibody concentrations were determined. ASCA IgA positivity in patients with GD (16.6%) was similar to patients with HT (13.6%) and was higher than controls (5.8%). No significant difference was present between the frequencies of IgG positivity among GD (12.5%), HT (7.9%), and control groups (5.8%). The mean levels of ASCA IgA and IgG were comparable within the groups. No correlation of ASCA and anti-thyroglobulin and anti-thyroid peroxidase levels was observed. Increased IgA ASCA positivity is observed in patients with GD, suggesting a role of environmental stimuli in its pathogenesis. The role of ASCA in the etiology of AITD needs to be further examined.

Presence of anti-microbial antibodies in liver cirrhosis--a tell-tale sign of compromised immunity?

Background

Bacterial translocation plays important role in the complications of liver cirrhosis. Antibody formation against various microbial antigens is common in Crohn's disease and considered to be caused by sustained exposure to gut microflora constituents. We hypothesized that anti-microbial antibodies are present in patients with liver cirrhosis and may be associated with the development of bacterial infections.

Methodology/Principal Findings

Sera of 676 patients with various chronic liver diseases (autoimmune diseases:266, viral hepatitis C:124, and liver cirrhosis of different etiology:286) and 100 controls were assayed for antibodies to Saccharomyces cerevisiae(ASCA) and to antigens derived from two intestinal bacterial isolates (one gram positive, one gram negative, neither is Escherichia coli). In patients with liver cirrhosis, we also prospectively recorded the development of severe episodes of bacterial infection. ASCA and anti-OMP Plus™ antibodies were present in 38.5% and 62.6% of patients with cirrhosis and in 16% and 20% of controls, respectively (p<0.001). Occurrence of these antibodies was more frequent in cases of advanced cirrhosis (according to Child-Pugh and MELD score; p<0.001) or in the presence of ascites (p<0.001). During the median follow-up of 425 days, 81 patients (28.3%) presented with severe bacterial infections. Anti-microbial antibody titers (p = 0.003), as well as multiple seroreactivity (p = 0.036), was associated with infectious events. In logistic regression analysis, the presence of ascites (OR:1.62, 95%CI:1.16–2.25), co-morbidities (OR:2.22, 95%CI:1.27–3.86), and ASCA positivity (OR:1.59, 95%CI:1.07–2.36) were independent risk factors for severe infections. A shorter time period until the first infection was associated with the presence of ASCA (p = 0.03) and multiple seropositivity (p = 0.037) by Kaplan-Meier analysis, and with Child-Pugh stage (p = 0.018, OR:1.85) and co-morbidities (p<0.001, OR:2.02) by Cox-regression analysis.

Conclusions/Significance

The present study suggests that systemic reactivity to microbial components reflects compromised mucosal immunity in patients with liver cirrhosis, further supporting the possible role of bacterial translocation in the formation of anti-microbial antibodies.

Anti-Saccharomyces cerevisiae antibodies in primary biliary cirrhosis

AIM

The aim of this study was to evaluate, retrospectively, the frequency of anti-Saccharomyces cerevisiae antibodies (ASCA) in patients with primary biliary cirrhosis (PBC).

METHODS

ASCA, IgG, and IgA, were determined by ELISA in sera of 95 PBC patients; 80 healthy blood donors served as controls.

RESULTS

The frequency of ASCA (IgG or IgA) was significantly higher in PBC patients than in the control group (24.2% vs 3.7%, P = 0.0001). The frequency of ASCA IgG and ASCA IgA in PBC patients was also significantly higher than that found in the control group (18.9% vs 2.5%, P = 0.0006 and 11.6% vs 1.2%, P = 0.007, respectively). Six patients out of 95 (6.3%) had both ASCA IgG and ASCA IgA; in contrast, none of the control group had both isotypes (P = 0.02). There was no correlation between ASCA levels and mitochondrial autoantibodies (AMA) titres in PBC patients.

CONCLUSION

We conclude that ASCA are common in patients with PBC.

Cross-reactive epitopes on beta2-glycoprotein-I and Saccharomyces cerevisiae in patients with the antiphospholipid syndrome

Anti-Saccharomyces cerevisiae antibodies (ASCA), directed against the phosphopeptidomannan (PPM) part of the cell wall of the yeast, have been identified as an important and specific serological marker for Crohn's disease. We evaluated the prevalence and properties of ASCA in APS patients. Thirty-one out of 155 APS patients tested positive for ASCA (20.0%), compared to 5.0% in healthy controls (P < 0.05). The presence of ASCA was not associated with any specific manifestation of APS. The ASCA found to be the population of anti-beta2GPI antibodies (Abs). Affinity purified anti-beta2GPI from ASCA-positive sera on a beta2GPI column, bound specifically the PPM, as shown by direct binding and competition assays (95-98%). The PPM inhibited differentially the anti-beta2GPI binding to beta2GPI. Since the anti-beta2GPI anti-PPM could bind only native form of beta2GPI and not the recombinant form, we assume that these specific anti-beta2GPI subpopulations of Abs are directed to the glycosylated site of the molecule. In conclusion, a subpopulation of anti-beta2GPI is specific to the glycosylated site of the beta2GPI molecule that cross-reacts with PPM.

Utility of serological markers in inflammatory bowel diseases: Gadget or magic?

The panel of serologic markers for inflammatory bowel diseases (IBD) is rapidly expanding. Although anti-Saccharomyces cerevisiae antibodies (ASCA) and atypical perinuclear antineutrophil cytoplasmic antibodies (P-ANCA) remain the most widely investigated, an increasing amount of experimental data is available on newly discovered antibodies directed against various microbial antigens. The role of the assessment of various antibodies in the current IBD diagnostic algorithm is often questionable due to their limited sensitivity. In contrast, the association of serologic markers with disease behavior and phenotype is becoming increasingly well-established. An increasing number of observations confirms that patients with Crohn’s disease expressing multiple serologic markers at high titers are more likely to have complicated small bowel disease (e.g. stricture and/or perforation) and are at higher risk for surgery than those without, or with low titers of antibodies. Creating homogenous disease sub-groups based on serologic response may help develop more standardized therapeutic approaches and may help in a better understanding of the pathomechanism of IBD. Further prospective clinical studies are needed to establish the clinical role of serologic tests in IBD.

Anti-Saccharomyces cerevisiae antibody in intestinal Behçet's disease patients: relation to clinical course

PURPOSE

This study was designed to assess anti-Saccharomyces cerevisiae antibody positive rate in Behçet's disease and intestinal Behçet's disease and to evaluate whether anti-Saccharomyces cerevisiae antibody expression is associated with clinical findings at diagnosis and clinical course of intestinal Behçet's disease.

METHODS

One hundred six patients with intestinal Behçet's disease, 30 patients with Behçet's disease, and 45 healthy control subjects were included. Anti-Saccharomyces cerevisiae antibody was detected by indirect immunofluorescence assay. According to anti-Saccharomyces cerevisiae antibody expression, the various parameters at diagnosis, cumulative relapse rates, and cumulative probabilities of operation were analyzed.

RESULTS

Anti-Saccharomyces cerevisiae antibody positive rate was 44.3 percent in intestinal Behçet's disease, 3.3 percent in Behçet's disease, and 8.8 percent in healthy control subjects. In patients with intestinal Behçet's disease, age, gender, distribution of Behçet's disease subtype, symptoms, laboratory tests, and colonoscopic findings at diagnosis were not different according to anti-Saccharomyces cerevisiae antibody expression. Cumulative probability of a first operation was significantly higher in anti-Saccharomyces cerevisiae antibody (+) intestinal Behçet's disease than in anti-Saccharomyces cerevisiae antibody (-) intestinal Behçet's disease: 44.8 and 17.2 percent at one year, and 53 and 24.3 percent at two years after diagnosis, respectively (P=0.006). The number of patients who underwent two or more operations was higher in anti-Saccharomyces cerevisiae antibody (+) intestinal Behçet's disease than in anti-Saccharomyces cerevisiae antibody (-) intestinal Behçet's disease (21.3 vs. 8.5 percent). The cumulative relapse rates were not different between the two groups.

CONCLUSIONS

Anti-Saccharomyces cerevisiae antibody positive rate was 44.3 percent in intestinal Behçet's disease. Clinical findings at diagnosis and cumulative relapse rates of intestinal Behçet's disease were not found to be associated with anti-Saccharomyces cerevisiae antibody expression. However, patients with anti-Saccharomyces cerevisiae antibody (+) intestinal Behçet's disease were more likely to receive surgical treatment.

Patients with primary biliary cirrhosis react against a ubiquitous xenobiotic-metabolizing bacterium

Infectious and environmental agents have been proposed as immunologic triggers for primary biliary cirrhosis (PBC). Recently, a ubiquitous organism that metabolizes organic compounds and estrogens, Novosphingobium aromaticivorans, has been defined. Importantly, 2 bacterial proteins have homology with the E2 component of the pyruvate dehydrogenase complex (PDC-E2). Sera from 97 patients with PBC, 46 first-degree relatives, 10 spouses, and 195 controls were studied for reactivity against N. aromaticivorans and Escherichia coli. The reactivity was defined by absorption, affinity purification, and using monoclonal antibodies to PDC-E2. Stool samples from 20 patients with PBC and 34 controls were analyzed by polymerase chain reaction (PCR) for the presence of N. aromaticivorans. Sera from 100% of anti-PDC-E2 positive (77/77), 33% of anti-BCOADC E2 positive (1/3), and 12% of antimitochondrial antibody (AMA) negative patients with PBC (2/17) reacted with titers up to 10(-6) against two known lipoylated bacterial proteins (47 and 50 kd) from N. aromaticivorans, including patients with early disease. This titer was approximately 100- to 1,000-fold higher than against E. coli and verified by absorption, use of affinity-purified sera, and monoclonal antibody reagents. Moreover, 78 of 80 AMA-positive and 5 of 17 AMA-negative patients with PBC had antibodies against 3 other N. aromaticivorans proteins. In contrast, 0 of 195 control sera reacted against N. aromaticivorans. Approximately 25% of patients and controls had N. aromaticivorans in their fecal specimens. In conclusion, based on protein homology, capacity to metabolize xenobiotics as well as modulate estrogens, its presence in feces, and specific immunologic response, we propose that N. aromaticivorans is a candidate for the induction of PBC.

Autoantibodies in the diagnosis and management of liver disease

Autoantibodies are nonpathogenic manifestations of immune reactivity, and they may occur in acute and chronic liver diseases. Autoantibodies may be consequences rather than causes of the liver injury, and they should be regarded as diagnostic clues rather than etiologic markers. Conventional autoantibodies used in the categorization of autoimmune liver disease are antinuclear antibodies, smooth muscle antibodies, antibodies to liver/kidney microsome type 1, antimitochondrial antibodies, and atypical perinuclear anti-neutrophil cytoplasmic antibodies. Ancillary autoantibodies that enhance diagnostic specificity, have prognostic connotation, or direct treatment are antibodies to endomysium, tissue transglutaminase, histones, doubled-stranded DNA, and actin. Autoantibodies that have an emerging diagnostic and prognostic significance are antibodies to soluble liver antigen/liver pancreas, asialoglycoprotein receptor, liver cytosol type 1, and nuclear pore complex antigens. Autoantibodies of uncertain clinical value that remain under investigation are antibodies to chromatin, lactoferrin, and Saccharomyces cervisiae. Continued recognition and characterization of autoantibodies should improve diagnostic precision, provide prognostic indices, and elucidate target autoantigens. These advances may in turn clarify pathogenic mechanisms, facilitate the development of animal models, and generate novel site-specific therapies.

Anti-Saccharomyces cerevisiae antibodies (ASCA) and autoimmune liver diseases

Antibodies to the baker's yeast Saccharomyces cerevisiae (ASCA), recently proposed as a serological marker of Crohn's disease, have also been detected in other autoimmune disorders. The aim of this study was to determine prevalence and clinical significance of ASCA in autoimmune liver disease. The presence of IgG and IgA ASCA was evaluated using a commercially available immunoassay in 215 patients with autoimmune liver disease (primary biliary cirrhosis, PBC, 123 cases; autoimmune hepatitis, AIH, 67 cases; primary sclerosing cholangitis, PSC, 25 cases), 48 with inflammatory bowel disease and 19 healthy blood donors. Anti neutrophil cytoplasmic antibodies with the perinuclear pattern (p-ANCA) were assessed by indirect immunofluorescence in PSC patients. The main clinical and biochemical parameters between ASCA-positive and negative patients were analysed and compared. ASCA are predominant in Crohn's disease (70%); among liver patients, PSC and AMA-negative PBC show the highest ASCA prevalence (53% and 44%). In PBC ASCA correlate with higher levels of circulating IgA (P < 0.05). In PSC the detection of either ASCA or p-ANCA is neither associated with any clinical or biochemical feature, nor with an underlying inflammatory bowel disease. ASCA can not be considered an additional serological marker of autoimmune liver disease, but the possibility of detecting such a reactivity in autoimmune liver disorders should be considered; their correlation with elevated IgA in PBC suggests that ASCA may be an indirect sign of enhanced mucosal immunity; in PSC patients neither ASCA nor p-ANCA predict the occurrence of a concomitant inflammatory bowel disease.

Serological markers in inflammatory bowel diseases

This chapter is an overview of the literature on serological markers of inflammatory bowel diseases (IBD), focusing on anti-neutrophil cytoplasm autoantibodies (ANCA) and anti- Saccharomyces cerevisiae mannan antibodies (ASCA). The methodology for ANCA and ASCA testing is first introduced. The value of these markers as diagnostic tools is then discussed. Other chapters are devoted to the potential role of ANCA and ASCA in disease monitoring, disease stratification and as subclinical markers in families. Finally reviewed are other antibodies recently tested in clinical trials such as pancreatic antibodies and antibodies directed against bacterial antigens. The role of these antibodies in the pathophysiology of IBD still needs to be assessed. We also need to identify the ASCA immunogen(s) eliciting the antibody response.

New autoantibodies and autoantigens in autoimmune hepatitis

The molecular characterization of the autoreactivities associated with autoimmune liver disease will improve their diagnosis and enhance understanding of their pathogenic mechanisms. Surprisingly, little is known about the nature of the major autoreactivities associated with type 1 AIH, including homogeneous ANA and antibodies to microfilaments [3]. Type 1 AIH is, however, the prototype of autoimmune liver disease [103].

Pediatric inflammatory bowel disease: clinical and therapeutic aspects

Epidemiologic data suggest that the incidences of pediatric ulcerative colitis and Crohn disease continue to evolve with geographic variations. One study suggests that children with autism have a unique inflammatory bowel disorder that is associated with gastrointestinal symptoms. The appropriate use of new diagnostic tests and novel treatments for inflammatory bowel disease (IBD) needs to be clarified in the pediatric population. Because of concerns regarding sensitivity and specificity, serologic markers measuring anti-Saccharomyces cerevisiae antibodies and perinuclear antineutrophil cytoplasmic antibodies cannot yet replace conventional diagnostic testing for screening or diagnosis of pediatric IBD. Large, prospective, pediatric population-based studies still need to be performed to ascertain their use as a noninvasive screening tool. Genetic studies using thiopurine methyl transferase and measurement of 6-mercaptopurine metabolites appear to be valuable for management of pediatric patients with IBD, in assisting clinicians in optimizing therapeutic response to 6-mercaptopurine, and in identifying individuals at increased risk for drug-induced toxicity. Newer immunomodulatory agents also are being explored in pediatric IBD. Open pilot trials of infliximab (Remicade; Centocor, Malvern, PA) for the treatment of children with Crohn disease that does not respond to conventional management have demonstrated short-term efficacy and safety. Trials of tacrolimus for treatment of fulminant colitis in children have been disappointing.