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.

[Assessment of antibodies anti-saccharomyces cerevisiae (ASCA) and autoantibodies in patients with inflammatory bowel disease]

The incidence of inflammatory bowel disease (IBD) has been increasing worldwide, and despite the advances regarding their pathogenesis and therapeutics, the differential diagnosis between Crohn's Disease (CD) and Ulcerative Colitis (UC) is mainly based on clinically invasive tests. Recent studies have identified new serological markers with a potential value for the diagnosis of these pathologies, in particular the anti-Saccharomyces cerevisiae antibodies (ASCA) and anti-neutrophil cytoplasmic antibodies (ANCA). Also of note are the anti-goblet cells antibodies (anti-CCI) and the anti-pancreatic exocrine autoantibodies that react with the pancreatic acinus (anti-AP). We assessed these new serological markers and compared the efficiency between immune enzymatic (ELISA) and indirect immunofluorescence tests in the identification of ASCA of IgG or IgA class. We studied a set of 81 serum samples (with an initial diagnosis of IBD) and 33 control samples from healthy blood donors. The laboratory tests were correlated with the diagnosis of each patient, established in the Gastroenterology outpatient unit based on conventional methods. The agreement between the two laboratory methods employed in the identification of the ASCA was excellent (k = 0.63) for the IgG antibodies and good (k = 0.56) for the IgA antibodies. We found a weak agreement (k = 0.137) between ELISA (MPO and PR3 purified antigens) and the IFA test for ANCA. Regarding the serologic markers ANCA, anti-AP and anti-CCI, only the later showed no differences in the distribution of positive results between the studied groups. Positive ASCA IgG and IgA were significantly associated with diagnosis of DC, with both laboratorial methods tested. The identification of ANCA with the available solidphase tests does not seem appropriate for the screening of the autoantibodies with the atypical p-ANCA pattern of IBD. The combination between anti-AP and ASCA antibodies seems a good option for the laboratorial diagnosis of CD. This study shows that these serologic markers in spite of being non invasive laboratory tests, also have a considerable overlapping in the different IBD. Nevertheless, further prospective studies based on larger populations are required to clarify the relationship between these antibodies, the diagnosis and clinical evolution of inflammatory bowel disease.

The application of Montreal classification in different clinical and serological IBD subtypes

BACKGROUND/AIMS

Inflammatory bowel disease (IBD) represents the heterogeneous group of disorders with a wide variety of clinical manifestations. The Montreal classification has been developed recently and its accuracy in categorizing of IBD phenotypes needs to be investigated. The aim of the study was to assess the usefulness of the Montreal classification compared to CAI and CDAI in various disease activity, serological and clinical manifestations of IBD.

METHODOLOGY

The study was performed in 125 IBD patients: 71 patients with ulcerative colitis, 31 with Crohn's disease and 23 with IBD unclassified (indeterminate colitis). Disease activity and clinical course were assessed using Montreal classification, Clinical Activity Index and Crohn's Disease Activity Index. pANCA and ASCA were measured with ELISA, using widely used, commercial antibody panel (Cogent Diagnostics and Genesis Diagnostics and MedTek kits).

RESULTS

No significant correlation has been found between pANCA/ASCA presence and disease activity using CAI and CDAI. ASCA and pANCA-/ASCA+ antibodies pattern had been detected more often in patients with Crohn's disease after surgery, with localization in small or small and large intestine, without perianal lesions and with early disease onset.

CONCLUSIONS

Correlations between serotype and certain clinical phenotype are present, which could potentially be of value in the classification of patients particular treatment regimen. We have noticed that clinical course assessment using Montreal classification shows precisely real CD patients state.

The prevalence and diagnostic value of perinuclear antineutrophil cytoplasmic antibodies and anti-Saccharomyces cerevisiae antibodies in patients with inflammatory bowel disease in mainland China

BACKGROUND

Perinuclear anti-neutrophil cytoplasmic (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) have been studied extensively in Western countries. We determined the prevalence of pANCA and ASCA in the mainland Chinese population and the ability of pANCA and ASCA to discriminate between ulcerative colitis (UC) and Crohn's disease (CD).

METHODS

Two hundred-six unrelated patients with IBD (UC, n=152; CD, n=54), 60 patients with other gastrointestinal diseases, and 80 healthy controls were included. Sera pANCA and ASCA titers were determined by a standardized indirect immunofluorescence technique.

RESULTS

The sensitivity, specificity, positive and negative predictive values, and positive likelihood ratio of pANCA were calculated for differentiating UC from healthy controls (43.4%, 96.3%, 95.7%, 47.2%, and 11.7, respectively) and ASCA for differentiating CD from healthy controls and (46.3%, 96.3%, 89.3%, 72.6%, and 12.5, respectively). The combination of pANCA and ASCA did not result in greater diagnostic efficiency than either test alone. pANCA was more frequent in UC with extensive or severe phenotype than others. ASCA was associated with severe CD disease activity.

CONCLUSIONS

pANCA and ASCA are useful in confirming the diagnosis of IBD and differentiating between UC and CD in an IBD cohort in central China.

Anti-Saccharomyces cerevisiae antibodies are frequent in type 1 diabetes

Anti-Saccharomyces cerevisiae antibodies (ASCA) have been described in many autoimmune diseases in which there is an increased intestinal permeability. Also in type 1 diabetes (T1D), there is an increased intestinal permeability. Since no data are available about ASCA in T1D, we evaluated, retrospectively, the frequency of ASCA in this disease. ASCA, IgG, and IgA, were determined by ELISA in sera of 224 T1D patients in which coeliac disease has been excluded and 157 healthy control group. The frequency of ASCA (IgG or IgA) was significantly higher in T1D patients than in the control group (24.5% vs. 2.5%, p < 10(-7)). The same observation was found in children and in adult patients when we compare them to healthy children and blood donors group respectively. Compared to children, adult patients with T1D showed significantly higher frequencies of ASCA of any isotype (38% vs. 13.7%, p < 10(-4)), both ASCA IgG and IgA (12% vs. 1.6%, p = 0.002), ASCA IgG (35% vs. 9.8%, p < 10(-5)) and ASCA IgA (15% vs. 5.6%, p = 0.001). The frequency of ASCA was statistically higher in females of all T1D than in males (30.8% vs.17.7%, p = 0.03), in girls than in boys (22% vs.6.2%, p = 0.017), and significantly higher in men than in boys (35.7% vs. 6.2%, p < 10(-4)). The frequency of ASCA IgG was significantly higher than that of ASCA IgA in all T1D patients (21% vs. 9.8%, p < 0.002), in all females (26.5% vs. 10.2%, p < 0.002), in women (37.9% vs. 12%, p < 0.001). The frequency of ASCA was significantly higher in all long-term T1D than in an inaugural T1D (29% vs. 14.5%, p = 0.019). The same observation was found in adults (45.8% vs. 17.8%, p = 0.01). In long-term T1D patients, ASCA were significantly more frequent in adults than children (45.8% vs. 14.5%, p < 10(-4)). The frequency of ASCA IgG was significantly higher in long-term T1D than in an inaugural T1D (25.2% vs. 11.6%, p = 0.03). Patients with T1D had a high frequency of ASCA.

The production, characterisation and enhanced pharmacokinetics of scFv-albumin fusions expressed in Saccharomyces cerevisiae

An expression system is described for the production of monomeric scFvs and scFv antibody fragments genetically fused to human albumin (at either the N- or C-terminus or both). Based upon strains of Saccharomyces cerevisiae originally developed for the production of a recombinant human albumin (Recombumin) this system has delivered high levels of secreted product into the supernatant of shake flask and high cell density fed-batch fermentations. Specific binding to the corresponding ligand was demonstrated for each of the scFvs and scFv-albumin fusions and pharmacokinetic studies showed that the fusion products had greatly extended circulatory half-lives. The system described provides an attractive alternative to other microbial systems for the manufacture of this type of product.

[Expression of hepatitis B virus core antigen gene region in yeast cell]

In this study, the core antigen (HBcAg) gene region of hepatitis B virus (HBV) was transformed and expressed into an eukaryotic expression vector by recombinant DNA technology in order to obtain the protein used in anti-HBc tests which is being one of the most important marker for the serodiagnosis of HBV infections. For this purpose, HBV-DNA positive patient sera were used as the source of viral nucleic acids, and the primers coding HBcAg gene region have been designed. After the amplification of HBcAg gene region by polymerase chain reaction (PCR), the amplicons purified by Invisorb Spin Rapid PCR Kit" (Invitek, Germany), were cloned to pYES2.1 plasmid via the TOPO TA expression kit (Invitrogen, USA) and this plasmid was transformed to competent bacteria (TOPO 10F' Escherichia coli) by CaCl2 method. After competent bacteria were grown on LB (Lysogeny Broth) agar media supplemented with ampicillin, the plasmid "pYES2.1 + HBcAg" were isolated and transformed to Saccaromyces cerevisiae via the "S.c. EasyComp Transformation Kit" (Invitrogen, USA). Finally, the expression of HBcAg by the yeast was confirmed with the use of in house ELISA method. Since the diagnostic kits used in our country for hepatitis B serology are usually imported products, this creates a great economical burden. Thus, the experience and knowledge that builds up following such studies will help to produce our own diagnostic products using our equity.

NOD2 mutations and anti-Saccharomyces cerevisiae antibodies are risk factors for Crohn's disease in African Americans

OBJECTIVES

NOD2 mutations and anti-Saccharomyces cerevisiae antibodies (ASCAs) are established risk factors of Crohn's disease (CD) in whites but have not been assessed in African-American (AA) adults with CD.

METHODS

AAs with CD and controls were recruited by the Mid-Atlantic African-American IBD Study as part of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) IBD Genetics Consortium. Genotyping for the three common CD NOD2 mutations (Leu1007fsinsC, G908R/2722g>c, and R702W/2104c>t) and ASCA enzyme-linked immunosorbent assays were performed in 183 AA CD patients and in 143 controls. Logistic regression was used to calculate adjusted odds ratios (ORs) for the association between ASCA and disease phenotype.

RESULTS

ASCA sensitivity and specificity values were 70.5 and 70.4%, respectively. On univariate analysis, ASCA was significantly associated with younger age at diagnosis, ileal involvement, and complicated (stricturing/penetrating) behavior. On multivariate analysis, ASCA titer (per 25 Units) was associated with ileal involvement (OR 1.18, 95% confidence interval (CI): 1.04-1.34), complicated behavior (OR 1.13, 95% CI: 1.01-1.28), and surgery (hazard ratio: 1.11, 95% CI: 1.02-1.21). Cigarette smoking and CD family history were also significantly associated with surgery. NOD2 carriers (all heterozygotes) were more common among CD cases than controls (8.2 vs. 2.1%; OR 4.17%, 95% CI: 1.18-14.69). The NOD2 mutation population attributable risk was 6.2%.

CONCLUSIONS

In comparison with whites, ASCA in AAs has a similar sensitivity but a lower specificity for CD. ASCA is associated with ileal involvement, complicated behavior, and surgery in AAs with CD. NOD2 is a risk gene for AA CD, although mutation frequency and population attributable risk are much lower than in whites.

Effect of Brewer's yeast-induced pyrexia on aminophylline-elicited convulsions in mice

Theophylline-associated convulsions have been observed most frequently in children with fever, but the mechanism is not fully understood. In this study, we investigated the basic mechanism of aminophylline [theophylline-2-ethylenediamine]-induced convulsions and the effects of Brewer's yeast-induced pyrexia in mice. Diazepam (5-10mg/kg, i.p.), a benzodiazepine receptor agonist, significantly prolonged the onset and significantly decreased the incidence of convulsions induced by aminophylline (350 mg/kg, i.p.). However, the gamma aminobutyric acid (GABA)A receptor agonist muscimol (1-4 mg/kg, i.p.), the GABAB receptor agonist baclofen (2-4 mg/kg, i.p.) and the N-methyl-D-aspartic acid receptor antagonist dizocilpine (0.1-0.3 mg/kg, i.p.) failed to protect against the convulsions. 20% Brewer's yeast (0.02 ml/g, s.c.) increased body temperature by 1.03, and also significantly shortened the onset and significantly increased the incidence of convulsions induced by aminophylline. The anticonvulsant action of diazepam (2.5-10mg/kg, i.p.) on the convulsions induced by aminophylline was reduced by Brewer's yeast-induced pyrexia. The proconvulsant actions of the GABAA receptor antagonists picrotoxin (3-4 mg/kg, i.p.) and pentylenetetrazol (40-60 mg/kg, i.p.) were enhanced by Brewer's yeast. These results suggest that the anticonvulsant action of diazepam against aminophylline is reduced by Brewer's yeast-induced pyrexia, and that GABAA receptors are involved in the aggravation of the convulsions by Brewer's yeast in mice.

Normal Human Plasma Anti-β-Glucoside Antibody Has Markedly Elevated IgA Content and Binds Fungal and Yeast Polysaccharides

Normal human plasma antibody that recognizes beta-linked glucoside moiety was purified by affinity chromatography on cellulose. The anti-beta-glucoside antibody had three times higher IgA to IgG ratio and substantially higher polymeric IgA content than total serum immunoglobulins. Cellobiose and other beta-glucosides were best inhibitors of its binding to polystyrene microwell-coated polysaccharides. In synthetic glycoproteins made by conjugating disaccharides to hemoglobin or bovine serum albumin, cellobiose, unlike lactose or maltose, was sugar-specifically recognized by the antibody. It also recognized polystyrene well-coated beta1-->3 linked glycans of Saccharomyces cerevisiae, Candida albicans and of barley in decreasing order of affinity. Its sugar-binding site could thus accommodate beta-glucoside with or without substitution at C4 and C3. High IgA content along with the capacity to bind common microbial and dietary antigens pointed to the immune inflammatory potential of the antibody.

Diagnostic value of antineutrophil cytoplasmic antibodies and anti-Saccharomyces cerevisiae antibody in Iranian patients with inflammatory bowel disease

BACKGROUND AND STUDY AIMS

Perinuclear antineutrophil cytoplasmic autoantibodies (pANCA) and anti-Saccharomyces Cerevisiae antibody (ASCA) are potential markers for diagnosis of inflammatory bowel disease (IBD). The aim of the present study was to evaluate the diagnostic value of pANCA and ASCA in Iranian patients with IBD.

PATIENTS AND METHODS

Serum samples were collected from 144 patients with IBD (113 ulcerative colitis and 31 Crohn's disease) and patients with non-IBD problems were assayed for ASCA by Enzyme-Linked Immunosorbent Assay (ELISA) and for pANCA by indirect immunofluorescence assay.

RESULTS

Sensitivity and specificity of pANCA in UC were 39.8% and 82.1%, respectively. For CD, pASCA test provided the sensitivity of 58% and specificity of 70%. A combination of pANCA+/ASCA- for diagnosis of UC showed a sensitivity of 31.9% and specificity of 89.1%. In addition the combination of pANCA-/ASCA+ showed a sensitivity of 35.5% and specificity of 79.8% for diagnosis of CD.

CONCLUSION

Due to low sensitivity of pANCA and ASCA alone or in combination, they are not valuable serological markers for diagnosis of UC or CD.

Anti-Saccharomyces cerevisiae as unusual antibodies in autoimmune hepatitis

Autoantibodies are disease markers of autoimmune hepatitis (AIH). Antinuclear antibodies, smooth muscle antibodies, antibodies to liver/kidney microsome type 1, and perinuclear antibodies to neutrophil cytoplasm constitute the ''conventional'' battery of autoantibodies, while an emerging interest to evaluate new autoantibodies as diagnostic or prognostic markers, such as the anti-Saccharomyces cerevisiae antibodies, is detectable (ASCA). This paper focuses mainly on the findings and the potential role of ASCA in AIH. These antibodies are present in 5-6.3% of blood donors and in the gastrointestinal setting, ASCA have been found most often in Crohn's disease and with lower frequency in the course of ulcerative colitis and celiac disease. Furthermore, they have been described, to a lesser extent, in patients with primary sclerosing cholangitis and primary biliary cirrhosis and in AIH. ASCA occur in 20-30% of patients suffering from AIH with a statistically significant increase observed only for IgG ASCA in type 1 AIH. This probably indicates collateral immune reactivities to the primary pathogenic process. The outcome of hepatitis is not influenced by the presence of ASCA. In conclusion, ASCA positivity does not imply that there exists a distinct subgroup of patients with AIH and these autoantibodies are not involved in the pathogenetic mechanism of AIH.

Human dendritic cell maturation and activation by a heat-killed recombinant yeast (Saccharomyces cerevisiae) vector encoding carcinoembryonic antigen

Tumor-associated antigens are weakly immunogenic. Human carcinoembryonic antigen (CEA) is overexpressed on a wide range of human carcinomas and represents an attractive target for cancer immunotherapy. This study analyzes the ability of a Saccharomyces cerevisiae vector containing the transgene encoding CEA (yeast-CEA) to activate human dendritic cells (DCs) and stimulate CEA-specific T-cell responses. We demonstrate for the first time that treatment with yeast-CEA can activate human DCs, resulting in increases in surface expression of CD80, CD83, CD54, CD58, and MHC class II, and increased production by DCs of IL-12p70, TNF-alpha, IFN-gamma, IL-8, IL-2, IL-13, IL-10, and IL-1beta. We also show that human DCs treated with yeast-CEA can activate CEA-specific T-cell lines and can act as antigen-presenting cells (APCs) to generate CEA-specific T-cell lines capable of lysing CEA(+) human tumor cells. Gene expression profiles of human DCs treated with yeast-CEA show increased expression of numerous genes involved in the production of chemokines and cytokines and their receptors, and genes related to antigen uptake, antigen presentation, and signal transduction.

Clinical utility of serological markers in inflammatory bowel disease

BACKGROUND/AIMS

The role of perinuclear antineutrophil cytoplasmic antibodies (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) assessment in inflammatory bowel disease (IBD) diagnosis and differentiating is still imprecise and controversial. The aim of the study was to determine the accuracy of pANCA and ASCA in patients with IBD subgroups.

METHODOLOGY

The study was performed in 125 patients: 71 patients with ulcerative colitis (UC), 31 with Crohn's disease (CD) and 23 with indeterminate Colitis (IC). Control group consists of 45 patients with functional intestinal disorders. pANCA and ASCA (IgA and IgG) were measured with ELISA, using commercial antibody panel.

RESULTS

In UC patients the prevalence of pANCA was 68%, which was significantly higher than in CD-29%. ASCA were found significantly more often in CD-80.6% than in UC patients-26.8%. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of pANCA for UC diagnosis was 68%, 84%, 75% and 78%; and ASCA for CD: 81%, 78%, 45,5% and 95%, respectively. The combined use of these two markers gave changes in diagnostic accuracy: pANCA+/ASCA- in UC: 42%, 100%, 100% and 43%, and for pANCA-/ASCA+ in CD: 52%, 98.6% 94% and 82%, respectively.

CONCLUSIONS

The specificity of these combined markers tends to be higher than sensitivity, what made them more useful in the differentiation of the IBD subtypes rather than population screening. The characteristic IC serotype pANCA(-)ASCA(-) leads to further controversies about origin of this IBD subtype.

MAGI2 genetic variation and inflammatory bowel disease

BACKGROUND

Despite recent advances the majority of inflammatory bowel disease (IBD) susceptibility 'genes' remain undiscovered. Recent data suggest that autoimmune conditions may 'share' susceptibility loci. Epidemiological evidence indicates an association between celiac disease and IBD and both conditions demonstrate increased gut permeability. MAGI2, recently implicated in ulcerative colitis (UC) and celiac disease, encodes a scaffolding protein involved in epithelial integrity. Our aim was to test MAGI2 variants for association with IBD and also their role in determining intermediate hereditary phenotypes defined by antibody production to microbial antigens.

METHODS

We genotyped 113 MAGI2 single nucleotide polymorphisms (SNPs) in 681 cases of Crohn's disease (CD), 259 UC cases, and 195 controls.

RESULTS

The most significant IBD association was in intron 6 (rs2160322, P = 0.009) and both UC (P = 0.006) and CD (P = 0.03) contributed to this association. The most significant CD association was with an intron 2 haplotype (rs7785088/rs323149/rs13246026, P = 0.002). We observed highly significant associations with UC in intron 6 (rs7803276/rs7803705, P = 0.002) and also significant associations in introns 2, 6, and 20. Significant associations were seen with: immunoglobulin G (IgG) anti-Saccharomyces cerevisiae antibodies (ASCA)-positive CD in intron 3 (P = 0.003), intron 6 (P = 0.003), and intron 20 (P = 0.001); anti-CBir1-positive CD in intron 3 (P = 0.0001) and intron 6 (P = 0.008); and anti-outer membrane porin C (OmpC)-positive CD in intron 3 (P = 0.0009), and intron 9 (P = 0.007). Quantitative antibody levels were also associated with variants in intron 4 (anti-IgA ASCA, P = 0.0003 and anti-IgG ASCA, P = 0.0002).

CONCLUSIONS

These findings support the significance of the epithelial barrier in IBD pathogenesis.

Serum antibodies against Saccharomyces cerevisiae: a new prognostic indicator in metastatic renal-cell carcinoma

PURPOSE

A recent study reported that a diet rich in bread and refined cereals might have an unfavorable role in the development of renal cell carcinoma (RCC). To test whether an underlying intolerance of bread ingredients is responsible for the unfavorable influence of bread on RCC, we examined patient sera for the presence of food-specific IgG.

EXPERIMENTAL DESIGN

A commercial test was used to detect food-specific IgG directed against a panel of 113 food antigens in sera of 54 patients with metastatic RCC. Kaplan-Meier estimates were used for univariate survival analysis, and differences in survival curves were assessed with the log-rank test. Multivariate survival analysis was done using a Cox regression model.

RESULTS

We found that RCC patients with elevated serum levels of IgG antibodies against S. cerevisiae, commonly known as baker's yeast and yet another bread component, have an unfavorable clinical course. Median survival of patients with high levels of S. cerevisiae IgG was only 17.8 months, whereas median survival of patients with low S. cerevisiae IgG was 43.8 months (P = 0.0022; log-rank). Multivariate survival analysis identified high levels of S. cerevisiae IgG as a strong and independent prognostic risk factor (risk ratio 4.6, P = 0.001; 95% CI 1.61-13.08).

CONCLUSIONS

Our findings indicate that serum levels of IgG against S. cerevisiae may predict survival in patients with metastatic RCC. The data suggest not cereals but baker's yeast being the critical component of bread that may cause immune deviation and impaired immunosurveillance in predisposed RCC patients.

Anti-Saccharomyces cerevisiae antibody is not useful to differentiate between Crohn's disease and intestinal tuberculosis in India

CONTEXT

Clinical, endoscopic, radiological and histological parameters of intestinal tuberculosis (IT) and Crohn's disease (CD) are so similar that differentiation between these two diseases, which require different treatment, is difficult. Anti- Saccharomyces cerevisiae antibody (ASCA), which is often present in the sera of patients with CD, may be potentially useful to differentiate CD from IT.

AIM

To evaluate the role of enzyme-linked immunosorbent assay test for ASCA in serum in differentiating CD from intestinal tuberculosis.

SETTINGS AND DESIGN

Prospective case-control study.

MATERIALS AND METHODS

Sixteen patients with IT, 16 CD, 36 UC diagnosed using standard parameters and 12 controls (11 healthy subjects and one with colonic carcinoma) were tested for IgG ASCA in serum.

STATISTICAL ANALYSIS USED

Categorical variables were analyzed using Chi-square test with Yates' correction, as applicable. Continuous variables were analyzed using Mann-Whitney U test.

RESULTS

Eight of 16 (50%) patients with IT, 10 of 16 with CD (62%), nine of 35 with UC (26%) and one of 12 controls tested positive for ASCA in serum. Though the frequency of ASCA in serum was comparable among patients with IT and CD (8/16 vs. 10/16, P = ns), IT and UC (8/16 vs. 9/35, P =ns), CD and UC (10/16 vs. 9/35, P =ns), its frequency in CD or IT but not in UC was higher than healthy controls (P Conclusions: Serum ASCA is unlikely to be useful to differentiate between CD and IT in India.

Elevated serum anti-Saccharomyces cerevisiae, anti-I2 and anti-OmpW antibody levels in patients with suspicion of celiac disease

OBJECTIVES

Expression of anti-Saccharomyces cerevisiae antibodies (ASCA) identifies patients and individuals at risk for Crohn's disease and has also been reported in 40-60% of celiac disease (CD) cases, suggesting a role of host response to enteric microbiota in the development of inflammatory lesions. In this prospective study in patients with suspicion of CD, we evaluate the frequency and association of ASCA to serological responses for other host microbial targets formally associated with Crohn's disease, including the Pseudomonas fluorescens associated sequence I2 and a Bacteroides caccae TonB-linked outer membrane protein, OmpW.

METHODS

Small bowel mucosal biopsies were taken from 242 patients with suspicion of CD, their sera were tested for antibodies to tissue transglutaminase (tTG), ASCA, I2, and OmpW. Eighty adult healthy blood donors were used as controls.

RESULTS

The diagnosis of CD was confirmed on biopsy in 134 cases. The occurrence of ASCA and I2 positivity was significantly higher in adult CD patients than in patients with non-CD disease. Anti-I2 levels in the sera were significantly higher in adult CD patients than in non-CD disease or the controls and anti-OmpW levels in CD and non-CD patients when compared to controls. Positive seroreactivity to OmpW seemed to increase with age. Of the CD patients, 90% were seropositive for at least one microbial antigen tested.

CONCLUSIONS

This study demonstrates a mosaic of disease-related serological responses to microbial antigens in patients with CD. Immune responses to commensal enteric bacteria may play a role in the small intestine mucosal damage in CD.

Antiglycan antibodies as serological markers in the differential diagnosis of inflammatory bowel disease

BACKGROUND

The objective of the study was to evaluate the diagnostic accuracy of recently developed antiglycan serological tests in clinical practice for the diagnosis of Crohn's disease.

METHODS

This study was a cohort analysis of both clinical and biochemical parameters of patients with diagnosed inflammatory bowel disease compared with those in a control population. Antiglycan antibodies were determined using commercially available enzyme immunoassays. The setting was the outpatient unit of the gastroenterology department of a large, tertiary-care referral academic hospital. Participants were 214 consecutive patients, enrolled over a 5-month period, including 116 with Crohn's disease and 53 with ulcerative colitis, as well as 45 with other gastrointestinal diseases and 51 healthy controls.

RESULTS

Anti-Saccharomyces cerevisiae antibodies showed the best performance (54% sensitivity and 88%-95% specificity for Crohn's disease). Among patients with negative anti-Saccharomyces antibodies, 19 (34%) had high titers of at least another tested antiglycan antibody. Anti-Saccharomyces and anti-laminaribioside antibodies were associated with disease involving the small bowel and with penetrating or stricturing phenotype. Anti-laminaribioside was significantly higher in patients with a familial history of inflammatory bowel disease.

CONCLUSIONS

The new proposed serological markers are significantly associated with Crohn's disease, with low sensitivity but good specificity. About one third of anti-Saccharomyces-negative patients may be positive for at least 1 of those markers. Antiglycan antibodies appear to be associated with characteristic localization and phenotype of the disease.

Anti-Saccharomyces cerevisiae antibodies (ASCA) in spondyloarthropathies: a reassessment

OBJECTIVES

Seronegative spondyloarthropathies, especially ankylosing spondylitis (AS), is shown to be associated with inflammatory bowel disease. Anti-Saccharomyces cerevisiae antibodies (ASCA) is a valid serological marker for Crohn's disease. Presence of ASCA is controversial in AS. In this study, we aimed to investigate the prevalence of ASCA in spondyloarthropathies and its relationship with disease activity and severity.

METHODS

One hundred and seventy-five patients with AS, 47 patients with undifferentiated spondyloarthropathy (uSpA) and 103 healthy controls (HCs) were studied. All patients were questioned for demographic features and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores. Radiological damage is assessed by Bath Ankylosing Spondylitis Radiology Index (BASRI) and modified Stroke Ankylosing Spondylitis Spinal Score (mSASSS). ASCA levels were measured with standard ELISA kits.

RESULTS

There was an overall increased prevalence of ASCA IgA in AS and uSpA compared with HCs (20.6 and 19.1% vs 5.8%, P = 0.0008 and P = 0.02, respectively). No association was observed between ASCA positivity and erythrocyte sedimentation rate, C-reactive protein levels and BASDAI scores. However, ASCA-positive patients had higher BASRI scores [median BASRI: 7 (2-12) vs 6 (2-12); P = 0.037]. Although not reaching significance, they also had reduced chest expansion and higher Bath Ankylosing Spondylitis Functional Index (BASFI) scores. ASCA-positive AS patients also required anti-tumour necrosis factor therapy more frequently (P = 0.006).

CONCLUSIONS

ASCA IgA seems to be more prevalent in AS and uSpA. ASCA can also be a marker of radiological damage and a more severe course in AS.

Anti-Saccharomyces cerevisiae mannan antibodies (ASCA) of Crohn's patients crossreact with mannan from other yeast strains, and murine ASCA IgM can be experimentally induced with Candida albicans

BACKGROUND

Anti-Saccharomyces cerevisiae antibodies (ASCA) present in a subgroup of Crohn's disease (CD) patients indicate loss of tolerance against commensal antigens. ASCA can be induced in Candida albicans-infected rabbits, suggesting their potential crossreactive nature. The present study aimed to determine crossreactivities of ASCA with cell wall mannans from other yeasts, including the opportunistic pathogen C. albicans, and to define the requirements for (crossreactive) ASCA in experimental mice.

METHODS

ASCA were determined by enzyme-linked immunosorbent assay (ELISA). ASCA were neutralized by preincubating sera with purified mannans. Binding of ASCA was visualized by Western blot. Mice were immunized with live yeasts and experimental colitis was induced with dextran sodium sulfate (DSS).

RESULTS

Seroreactivity of ASCA-positive CD patients against S. cerevisiae mannan significantly correlates with that against mannans from 5 other yeast species, including C. albicans. This correlation is due to crossreactive IgG, demonstrated by the loss of reactivity after preincubation of sera with mannans from the other yeasts. Immunization of mice with S. cerevisiae or C. albicans fails to induce (crossreactive) ASCA IgM or IgG antibodies. Subsequent chronic experimental colitis concomitant with feeding live yeasts promotes ASCA IgM but not IgG generation, while titers remain modest compared to those in ASCA-positive CD patients.

CONCLUSIONS

Correlations of ASCA reactivities against mannans from different yeasts are due to crossreactive IgGs. The inability of mice to readily generate ASCA is in line with the current opinion that genetic predisposition is a prerequisite for the development of this and other unusual immune reactivities in CD.

[Comparison of five techniques to detect anti-Saccharomyces cerevisiae antibodies (ASCA) in serum for diagnosing Crohn's disease]

OBJECTIVE

the anti-Saccharomyces cerevisiae antibodies (ASCA) are diagnostic markers found in Crohn's disease patients. The aim of this study was to compare three Elisa (enzyme linked immunosorbent assay) kits with the indirect immunofluorescence (IFI) technique and an immunodot for ASCA detection.

MATERIALS AND METHODS

we compared the results obtained using IFI (IgA and IgG) and Elisa (IgA and IgG) in 139 patients (37 Crohn's disease). An immunodot (IgA+IgG) was tested in a sub-group of 24 patients (18 Crohn's disease).

RESULTS AND DISCUSSION

for the different techniques by Elisa (IgA or IgG), the sensitivity ranged from 65% to 76%, the specificity from 88% to 98%, the positive predictive value (PPV) from 84% to 94% and the negative predictive value (NPV) from 88% to 93%. For IFI, the sensitivity was 81%, the specificity 100%, the PPV 100% and the NPV 93%. The immunodot showed a specificity and PPV of 100% and NPV of 33%.

CONCLUSION

the detection of the ASCA is useful in the diagnosis of Crohn's disease. IFI appears as the method of choice for its excellent sensitivity and specificity, and affordable costs.