Anti-flagellin (CBir1) phenotypic and genetic Crohn's disease associations

BACKGROUND: Antibody reactivity to microbial antigens correlates with distinct Crohn's disease (CD) phenotypes such as fistulizing or fibrostenosing disease. We examined the association between anti-CBir1 and clinical phenotypes and NOD2 variants in a large cohort of adult CD patients. METHODS: Sera and genomic DNA were collected from 731 patients with CD and tested for immune responses to I2, CBir1, oligomannan, and outer membrane porin C (OmpC) and the 3 most common CD-associated NOD2 variants. RESULTS: Anti-CBir1 reactivity was significantly associated with fibrostenosis (FS), internal penetrating (IP) disease phenotypes, small bowel (SB) involvement, and SB surgery but negatively associated with ulcerative colitis (UC)-like CD. Multivariate logistic regression analysis showed that anti-CBir1 was independently associated with FS and UC-like CD irrespective of the antibody reactivity to I2, oligomannan, or OmpC, but not with SB involvement or SB surgery. The magnitude of anti-CBir1 reactivity, when added to the quantitative response toward the other 3 CD-associated antigens, enhances the discrimination of FS, IP, UC-like CD, and SB involvement, but not SB surgery. Finally, although the frequency of anti-CBir1 was similar in patients with none versus at least 1 NOD2 variant, the quantitative response to CBir1 flagellin was significantly higher in patients with CD carrying at least 1 NOD2 variant versus those carrying no variants (median anti-CBir1 titer 33.39 versus 28.36, respectively; P = 0.01). CONCLUSIONS: Anti-CBir1 serum reactivity in CD patients is independently associated with FS and complicated SB CD. Quantitative, but not qualitative, response to CBir1 is also significantly associated with the CD-associated NOD2 variants.     

Association of antibody responses to microbial antigens and complications of small bowel Crohn's disease

BACKGROUND & AIMS: Crohn's disease patients can be characterized by antibody responses against Crohn's disease-related bacterial sequence, Escherichia coli outer membrane porin C, Saccharomyces cerevisiae (oligomannan), and neutrophil nuclear antigens. Our aim was to determine whether expression of antibodies against Crohn's disease-related bacterial sequence and Escherichia coli outer membrane porin C is associated with distinct phenotypic manifestations. METHODS: Sera from 303 patients were tested for antibodies to the Crohn's disease-related bacterial sequence (I2), anti-Escherichia coli outer membrane porin C, anti-Saccharomyces cerevisiae, and perinuclear antineutrophil cytoplasmic antibodies and for 3 Crohn's disease-associated variants of the NOD2 gene (R702W, G908R, and 1007fs) and compared with clinical data. RESULTS: Patients expressing I2 were more likely to have fibrostenosing Crohn's disease (64.4% vs. 40.7%; P < 0.001) and to require small bowel surgery (62.2% vs. 37.4%; P < 0.001). Patients with anti-Escherichia coli outer membrane porin C were more likely to have internal perforating disease (50.0% vs. 30.7%; P = 0.001) and to require small bowel surgery (61.4% vs. 44.2%; P = 0.003). Anti-Crohn's disease-related bacterial sequence was independently associated with fibrostenosis (P = 0.027) and small bowel surgery (P = 0.01), whereas anti-Escherichia coli outer membrane porin C was independently associated with internal perforations (P < 0.006). Patients positive for I2, anti-Escherichia coli outer membrane porin C, and anti-Saccharomyces cerevisiae were the most likely to have undergone small bowel surgery (72.0%; odds ratio, 8.6; P < 0.001) compared with patients without reactivity (23.0%). When the presence and magnitude of antibody responses were considered, 90% of patients with small bowel disease who required surgery had high levels of I2, Escherichia coli outer membrane porin C, and oligomannan antibodies, compared with only 18.2% with low-titer responses (P < 0.001). CONCLUSIONS: I2 and anti-Escherichia coli outer membrane porin C are associated with Crohn's disease phenotypes, and patients with the highest level of serum reactivity toward an increasing number of microbiota have the greatest frequency of strictures, internal perforations, and small bowel surgery.     

The value of serologic markers in indeterminate colitis: a prospective follow-up study

BACKGROUND & AIMS: In the absence of pathognomonic markers for Crohn's disease (CD) and ulcerative colitis (UC), the diagnosis of inflammatory bowel disease depends on a compendium of clinical, radiographic, endoscopic, and histologic criteria that bears imperfect specificity to the individual disorders. In 10% of cases of colitis, no differentiation can be made between CD and UC; these patients are diagnosed with indeterminate colitis (IC). We evaluated the value of anti-Saccharomyces cerevisiae antibodies (ASCA) and perinuclear antineutrophil cytoplasmic antibodies (pANCA) to increase diagnostic accuracy in categorizing IC. METHODS: Since 1996, 97 patients with IC from 3 centers (Leuven, Lille, and Vienna) were enrolled, analyzed for pANCA and ASCA, and followed up prospectively. RESULTS: A definitive diagnosis has been reached for 31 of 97 patients (32%). In these patients, ASCA+/pANCA- correlated with CD in 8 of 10 patients, whereas ASCA-/pANCA+ correlated with UC in 7 of 11 patients. The remaining 4 cases became CD, clinically behaving as UC-like CD. Almost half of the patients (47 of 97 [48.5%]) were negative for ASCA and pANCA, and 40 remain diagnosed with IC to date. Only 7 seronegative cases (14.9%) became CD or UC compared with 48% (24 of 50) of seropositive patients (P < 0.001). CONCLUSIONS: Results so far show that ASCA+/pANCA- predicts CD in 80% of patients with IC and ASCA-/pANCA+ predicts UC in 63.6%. Interestingly, 48.5% of patients do not show antibodies against ASCA or pANCA. Most of these patients remain diagnosed with IC during their further clinical course, perhaps reflecting a distinct clinicoserological entity.     

炎症性肠病患者血清中自身抗体检测的临床意义

目的研究抗酿酒酵母抗体(ASCA)和抗中性粒细胞胞浆抗体(pANCA)在炎症性肠病诊断与鉴别诊断中的意义。方法间接免疫荧光生物薄片法检测29例溃疡性结肠炎(UC)、34例克罗恩病(CD)及25例正常对照者血清中ASCA和pANCA的表达。结果pANCA在CD组、UC组和正常对照组中的阳性率分别为47.1%、69.0%和16.0%,UC组显著高于CD组(P<0.05)和正常对照组(P<0.05)。ASCA在上述3组中的阳性率分别为11.8%、58.6%和8.0%,UC组亦显著高于CD组(P<0.05)和正常对照组(P<0.05)。ASCA /pANCA-诊断CD的敏感性、特异性、阳性预测值分别是0、89.7%和0;pANCA /ASCA-诊断UC的敏感性、特异性和阳性预测值分别是20.7%、64.7%和33.3%。结论ASCA和pANCA阳性有利于炎症性肠病的诊断却不能敏感地筛选患者;ASCA和pANCA联合检测不能作为汉族UC和CD鉴别诊断的指标。     

pANCA and ASCA in the diagnosis of different subtypes of inflammatory bowel disease

BACKGROUND/AIMS: The measurement of perinuclear antineutrophil cytoplasmic (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) has recently been suggested as a valuable and noninvasive diagnostic approach in the differentiation of ulcerative colitis (UC), Crohn's disease (CD) and indeterminate colitis (IC). The aim of the study was to determine the prevalence of pANCA and ASCA in patients with inflammatory bowel disease (IBD) subgroups of different clinical course and to assess their accuracy in differential diagnosis. METHODOLOGY: The study was performed in 109 patients: 50 patients with UC, 17 with CD, 18 with IC and 24 non-IBD controls. Antibodies status has been measured with ELISA, using commercial antibody panel by MedTek kits, confirmed by IIF technique using Euroimmun panels. RESULTS: Sensitivity and specificity of pANCA+/ ASCA- pattern for UC diagnosis was 36% and 98%; pANCA-/ASCA+ for CD: 35% and 88%, pANCA/ASCA- for IC: 72% and 63%, respectively. In addition the significant positive correlation between antibodies profiles: pANCA+/ASCA- and active disease; pANCA-/ASCA+ and number of operations, as well as the negative correlation between pANCA-/ASCA- and patient's age has been found. CONCLUSIONS: Our study lends further support to the opinions that serologic assessment identifies a large subset of different subtypes of IBD patients.     

抗酿酒酵母抗体和抗中性粒细胞胞质抗体对炎症性肠病的诊断价值

目的 了解抗酿酒酵母抗体(ASCA)和核周型抗中性粒细胞胞质抗体(pANCA)的分布,观察其在炎症性肠病(IBD)诊断及鉴别诊断中的意义.方法 选择2002年9月至2007年7月在北京协和医院就诊并行ASCA、pANCA检查的IBD患者175例,其中克罗恩病(CD)62例、溃疡性结肠炎(UC)97例、未定型16例.另取对照者167例.采用酶联免疫吸附法测定血清ASCA水平,间接免疫荧光法测定血清pANCA水平.结果 在CD、UC、未定型者、对照者中,ASCA的阳性率分别为45.2%、14.4%、11/16、29.3%,pANCA的阳性率分别为4.8%、56.7 0A、1/16、4.8%.对照者中,ASCA在恶性肿瘤、嗜酸性粒细胞增多症、自身免疫性肝病、弥漫性结缔组织病及肠结核中的阳性率较高(分别为42.1%、2/5、4/10、4/19、4/14).ASCA诊断CD的敏感性、特异性及阳性预测值分别为45.2%、85.6%、66.7%.pANCA诊断UC的敏感性、特异性及阳性预测值分别为56.7%、95.2%、94.8%.联合检测ASCA+/pANCA-诊断CD的敏感性、特异性及阳性预测值分别为41.9%、93.8%,81.3%.联合检测ASCA-/pANCA+诊断UC的敏感性、特异性和阳性预测值分别为48.5%、98.4%、97.9%.结论 ASCA和pANCA不适于作为IBD筛查指标,联合检测有利于UC与CD的鉴别诊断.     

NOD2 variants and antibody response to microbial antigens in Crohn's disease patients and their unaffected relatives

BACKGROUND & AIMS: The Cdcs1 locus of the C3Bir mouse confers severe colitis associated with a decrease in innate immune function and an increase in adaptive T-cell responses to commensal bacterial products. The aim of our study was to determine if defects in innate immunity are similarly associated with increased adaptive immune responses to microbial antigens in Crohn's disease patients. METHODS: Sera from 732 patients, 220 unaffected relatives, and 200 healthy controls were tested for antibodies to oligomannan, the Pseudomonas fluorescens-related protein, Escherichia coli outer membrane porin C, CBir1 flagellin, and DNA from the same subjects was tested for 3 Crohn's disease-associated variants of the NOD2 gene, and 5 toll-like receptor (TLR) 2, 2 TLR4, and 2 TLR9 variants. The magnitude of responses to microbial antigens was examined according to variant status. RESULTS: NOD2 variant carriage increased in frequency with increasing number of positive antibodies and increasing cumulative quantitative response as measured by quartile sum (P for trend, .0008 and .0003, respectively). Mean antibody and quartile sums were higher for patients carrying any NOD2 variant versus those carrying none (2.24 vs 1.92 and 10.60 vs 9.72; P = .0008 and P = 0.0003, respectively). The mean quartile sum was higher for unaffected relatives carrying any NOD2 variant versus those carrying none (10.67 vs 9.75, respectively; P = .02). No association was found between any TLR variant and the magnitude of response. CONCLUSIONS: Patients with Crohn's disease and unaffected relatives carrying variants of the NOD2 gene have increased adaptive immune responses to microbial antigens.     

Antineutrophil cytoplasmic autoantibodies and anti-Saccharomyces cerevisiae antibodies in inflammatory bowel diseases.

BACKGROUND/AIMS: Perinuclear antineutrophil cytoplasmic autoantibody is a marker for ulcerative colitis, and anti-Saccharomyces cerevisiae antibody is known to be associated with Crohn's disease. The purpose of this study was to search the value of detecting perinuclear antineutrophil cytoplasmic autoantibody and anti-Saccharomyces cerevisiae antibody for the diagnosis of Turkish inflammatory bowel disease patients. METHODS: Serum samples were obtained from 80 patients with ulcerative colitis, 61 patients with Crohn's disease and 40 healthy controls. Determination of both anti-Saccharomyces cerevisiae antibody and antineutrophil cytoplasmic autoantibody was performed with the standardized enzyme-linked immunosorbent assay. RESULTS: In cases with ulcerative colitis, 65% tested seropositive for antineutrophil cytoplasmic autoantibody, whereas the controls showed 2.5% positivity. In cases with Crohn's disease, 63.9% tested seropositive for anti-Saccharomyces cerevisiae antibody, whereas the controls showed 2.5% seropositivity. The combination of a positive anti-Saccharomyces cerevisiae antibody test and a negative antineutrophil cytoplasmic autoantibody yielded a sensitivity and specificity of 32.0% and 97.5%, respectively. The combination of a positive perinuclear antineutrophil cytoplasmic autoantibody and a negative anti-Saccharomyces cerevisiae antibody test yielded a sensitivity and specificity of 44.2% and 97.5%, respectively. CONCLUSIONS: Both serologic tests may aid in the differential diagnosis of inflammatory bowel disease.     

Serum immune responses predict rapid disease progression among children with Crohn's disease: immune responses predict disease progression

BACKGROUND AND AIM: Crohn's disease (CD) is a heterogeneous disorder characterized by diverse clinical phenotypes. Childhood-onset CD has been described as a more aggressive phenotype. Genetic and immune factors may influence disease phenotype and clinical course. We examined the association of immune responses to microbial antigens with disease behavior and prospectively determined the influence of immune reactivity on disease progression in pediatric CD patients. METHODS: Sera were collected from 196 pediatric CD cases and tested for immune responses: anti-I2, anti-outer membrane protein C (anti-OmpC), anti-CBir1 flagellin (anti-CBir1), and anti-Saccharomyces-cerevisiae (ASCA) using ELISA. Associations between immune responses and clinical phenotype were evaluated. RESULTS: Fifty-eight patients (28%) developed internal penetrating and/or stricturing (IP/S) disease after a median follow-up of 18 months. Both anti-OmpC (p < 0.0006) and anti-I2 (p < 0.003) were associated with IP/S disease. The frequency of IP/S disease increased with increasing number of immune responses (p trend = 0.002). The odds of developing IP/S disease were highest in patients positive for all four immune responses (OR (95% CI): 11 (1.5-80.4); p = 0.03). Pediatric CD patients positive for > or =1 immune response progressed to IP/S disease sooner after diagnosis as compared to those negative for all immune responses (p < 0.03). CONCLUSIONS: The presence and magnitude of immune responses to microbial antigens are significantly associated with more aggressive disease phenotypes among children with CD. This is the first study to prospectively demonstrate that the time to develop a disease complication in children is significantly faster in the presence of immune reactivity, thereby predicting disease progression to more aggressive disease phenotypes among pediatric CD patients.     

Serological markers for prediction of response to anti-tumor necrosis factor treatment in Crohn's disease

OBJECTIVES: The use of monoclonal anti-tumor necrosis factor (TNF) antibodies (infliximab, Remicade) is a new therapeutic approach for severe refractory luminal or fistulizing, Crohn's disease (CD). However, up to 30% of patients do not respond to this treatment. So far, no parameters predictive of response to anti-TNF have been identified. Our aim was to determine whether serological markers ASCA (anti-Saccharomyces cerevisiae antibodies) or pANCA (perinuclear antineutrophil cytoplasmic antibodies) could identify Crohn's patients likely to benefit from anti-TNF therapy. METHODS: Serum samples of 279 CD patients were analyzed for ASCA and pANCA before anti-TNF therapy. A blinded physician determined clinical response at week 4 (refractory luminal CD) or week 10 (fistulizing CD) after the first infusion of infliximab (5 mg/kg). RESULTS: Overall, there was no relationship between ASCA or pANCA and response to therapy. However, lower response rates were observed for patients with refractory intestinal disease carrying the pANCA+/ASCA- combination, although this lacked significance (p = 0.067). CONCLUSIONS: In this cohort of infliximab-treated patients, neither ASCA nor pANCA could predict response to treatment. However, the combination pANCA+/ASCA- might warrant further investigation for its value in predicting nonresponse in patients with refractory luminal disease.     

Anti-Saccharomyces cerevisiae mannan antibodies and antineutrophil cytoplasmic autoantibodies in Greek patients with inflammatory bowel disease

OBJECTIVES: The combined measurement of perinuclear antineutrophil cytoplasmic autoantibodies (pANCA) and anti-Saccharomyces cerevisiae mannan antibodies (ASCA) has recently been suggested as a valuable diagnostic approach in inflammatory bowel disease (IBD). The aim of this study was to assess the value of detecting pANCA and ASCA in the differentiation between ulcerative colitis (UC) and Crohn's disease (CD) in a Greek population with IBD. METHODS: Sera were collected from 157 patients with IBD (97 with UC, 56 with CD, and four with indeterminate colitis) and 150 healthy controls. Determination of pANCA was performed by a standard indirect immunofluorescence technique on ethanol-fixed granulocytes and ASCA by an ELISA assay. RESULTS: In patients with UC, sensitivity, specificity, positive predictive value, and negative predictive value of the pANCA test was 67%, 84%, 93%, and 46% respectively. These values did not change significantly when the combination of positive pANCA and negative ASCA was used. ASCA test in diagnosing CD yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 39%, 89%, 54%, and 81%. The combination of pANCA negative and ASCA positive increased the positive predictive value to 77% and it was associated with small bowel disease. CONCLUSIONS: A positive pANCA test in Greek patients has a diagnostic value in confirming a diagnosis of UC. Measurement of pANCA and ASCA together has a rather limited value in the differential diagnosis between UC and CD but may be of help in studying disease heterogeneity.     

A comparative study of goblet cell and pancreatic exocine autoantibodies combined with ASCA and pANCA in Chinese and Caucasian patients with IBD

BACKGROUND: The incidence of Crohn's disease (CD) and ulcerative colitis (UC) is increasing, but differentiating between them is often extremely difficult. Pancreatic (PAB) and goblet cell autoantibodies (GAB) are specific for CD and UC, respectively, but with low sensitivity. In combination with anti-Saccharomyces cerevisiae (ASCA) and anti-neutrophil cytoplasmic antibodies (pANCA) testing, these antibodies may improve differentiation between the diseases. This study determined the sensitivity, specificity, and positive and negative predictive values (PPV and NPV) of PAB and GAB +/- ASCA and pANCA testing in Chinese and Caucasian IBD populations. RESULTS: Patients were recruited from Caucasian and Chinese populations (CD, n = 100; UC, n = 99; controls, n = 100). PAB was highly specific for CD, and detection was greater in patients less than 35 years old and in Chinese compared with Caucasian patients with CD (CD, 46% versus 22%, P = 0.018; UC, 2% versus 6%; controls, 0% versus 2%). GAB detection was poor in all groups (<2%). PAB showed a PPV of 93% to differentiate all patients with CD from patients with UC, but only 62% for those with isolated colonic disease. The PPV of PAB increased to 100%, specificity was 100%, and sensitivity was 21% for isolated colonic disease when combined with pANCA and ASCA. PAB expression was not associated with stricturing or perforating CD. CONCLUSIONS: This study identified that GAB was not useful in our patients with IBD. PAB expression was highly specific for CD and more sensitive in Chinese than Caucasian patients with CD. The combination of PAB, pANCA, and ASCA testing improved the differentiation between UC and CD, particularly in isolated colonic disease, compared with pANCA and ASCA testing alone.     

Serologic testing with ANCA, ASCA, and anti-OmpC in children and young adults with Crohn's disease and ulcerative colitis: diagnostic value and correlation with disease phenotype

OBJECTIVES: Serologic testing is increasingly being utilized to evaluate children with suspected inflammatory bowel disease (IBD). The aim of this paper was to evaluate the sensitivity and specificity of a currently available panel involving four antibodies: deoxyribonuclease (DNase)-sensitive perinuclear antineutrophil cytoplasmic antibody (DNase-sensitive pANCA), IgA and IgG antibodies to Saccharomyces cerevisiae (IgA and IgG ASCA), and antibody to Escherichia coli outer membrane porin (anti-OmpC). We also wished to determine whether antibody levels correlated with disease activity, and whether a specific antibody pattern correlated with location and outcome of disease in children. METHODS: We studied sera from 81 children with Crohn's disease (CD), 54 with ulcerative colitis (UC), and 63 controls. Clinical data, disease activity, and disease diagnosis were gathered at the time of serum sampling, and charts were re-reviewed at time of the study to determine long-term outcome. Enzyme-linked immunosorbent assay was utilized to determine titers of antibodies to ASCA, DNase-sensitive pANCA, and anti-OmpC; the presence of perinuclear staining for ANCA was confirmed by immunofluorescence. RESULTS: We identified ASCA antibodies in 44% of CD patients, 0% of UC patients, and 1 control patient. DNase-sensitive pANCA antibodies were found in 70% of patients with UC, 18% of CD patients (predominantly Crohn's colitis), and 3% of controls. Anti-OmpC as an isolated assay had low sensitivity for both CD (24%) and UC (11%), and displayed a 5% false-positive rate. However, anti-OmpC did identify a small number of IBD patients not detected by the other assays. If any one or more of the four antibodies was positive, the overall sensitivity of the four antibody panel was 65% for CD and 76% for UC, with a specificity of 94%. Patients who were ASCA-positive were more likely to have disease of the ileum or ileum and right colon than patients who were ASCA-negative (58%vs 18%, p < 0.001). Patients with ASCA-positive were also more likely to require ileocecal resection (36%vs 13%, p < 0.05). CONCLUSIONS: A currently available commercial antibody panel has good sensitivity and excellent specificity for CD and UC. The ASCA antibodies, while highly specific for CD, identify predominantly the subset of children with disease of the ileum and ascending colon who may be at increased risk of surgery.     

Antibodies to I2 predict clinical response to fecal diversion in Crohn's disease

OBJECTIVES: Fecal diversion is occasionally indicated in patients with advanced perianal or colorectal Crohn's disease (CD). Because CD may result from an aberrant immunologic response to bacteria within the gut lumen, fecal diversion should be effective in managing these complications. However, not all patients achieve a clinical response after fecal diversion. CD patients can be characterized by their antibody responses against Pseudomonas fluorescens (I2), E.coli outer membrane porin C (OmpC), oligomannan (anti-Saccharomyces cerevisiae antibodies [ASCA]), and antinuclear antigens (perinuclear antineutrophil cytoplasmic antibodies [pANCA]). This study examines the association between clinical features and seroreactivity to these microbial and auto-antigens in predicting a clinical response to fecal diversion. METHODS: Twenty-seven consecutive CD patients undergoing fecal diversion were included. Sera were drawn and tested for anti-I2, anti-OmpC, ASCA, and pANCA in a blinded fashion. Response was assessed using clinical parameters. RESULTS: Seventeen (63%) patients underwent fecal diversion for medically resistant proctocolitis and 10 (37%) for severe perianal disease. Median follow-up was 41 months. Seventeen (63%) patients achieved a clinical response. No preoperative clinical or surgical factor predicted response to diversion. Clinical response after fecal diversion was seen in 15 of 16 (94%) patients who were I2 positive compared with only 2 of 11 (18%) patients who were I2 negative (P = 0.0001). Seroreactivity to OmpC, ASCA, or pANCA was not associated with a clinical response to diversion. CONCLUSION: Expression of I2 antibodies against a bacterial antigen of Pseudomonas fluorescens was highly associated with clinical response to fecal diversion in CD patients.     

Clinical significance of anti-Saccharomyces cerevisiae antibody (ASCA) in Korean patients with Crohn''s disease and its relationship to the disease clinical course

BACKGROUNDS/AIMS: The implications of anti-Saccharomyces cerevisiae antibody for the diagnosis and the clinical course of Crohn's disease have been reported in Western countries, but rarely in Korea with its very different environmental and genetic backgrounds. We aimed to evaluate whether anti-S. cerevisiae antibody expression is associated with diagnostic findings, stratified Vienna classification phenotypes, disease activity and clinical course in Korean patients with Crohn's disease. MATERIALS/METHODS: One hundred and fifteen patients with Crohn's disease, diagnosed and treated between 1990 and 2004 at Severance Hospital, Yonsei University and followed for at least 2 years, were included in this study. Anti-S. cerevisiae antibody was detected by an indirect immunofluorescence assay using EUROIMMUN kits. Information collected during treatment included demography, Vienna classification phenotype, clinical manifestation, laboratory tests, treatment modality and surgery rate. Disease activity was measured monthly using the Harvey-Bradshaw index. RESULTS: The anti-S. cerevisiae antibody prevalence was 38.3% in Crohn's disease patients. There was no difference in anti-S. cerevisiae antibody expression between genders. The mean age at diagnosis was younger for the anti-S. cerevisiae antibody positive group than the negative group (25.3 years versus 29.7 years, p<0.05). Clinical manifestations and laboratory tests at diagnosis did not differ between the groups. The anti-S. cerevisiae antibody positive group had increased fibrostenosis (B2) and penetration (B3) compared to negative group, as determined by the Vienna classification (75.0% versus 53.5%, p<0.05). Anti-S. cerevisiae antibody positive patients were admitted to the hospital more frequently than anti-S. cerevisiae antibody negative patients (p<0.05). The yearly cumulative Harvey-Bradshaw index score was higher in the anti-S. cerevisiae antibody positive group than in the negative group during the follow-up period (p<0.05). In addition, steroid (72.7% versus 52.1%, p<0.05) and immunosuppressive (45.5% versus 23.9%, p<0.05) treatments were more frequently given to the anti-S. cerevisiae antibody positive group. CONCLUSIONS: Our data demonstrate that anti-S. cerevisiae antibody positive Crohn's disease patients had a more severe clinical course and thus often required more aggressive medical treatment.     

New serological markers in inflammatory bowel disease are associated with complicated disease behaviour

BACKGROUND AND AIMS: Several antibodies have been associated with Crohn's disease and are associated with distinct clinical phenotypes. The aim of this study was to determine whether a panel of new antibodies against bacterial peptides and glycans could help in differentiating inflammatory bowel disease (IBD), and whether they were associated with particular clinical manifestations. METHODS: Antibodies against a mannan epitope of Saccharomyces cerevisiae (gASCA), laminaribioside (ALCA), chitobioside (ACCA), mannobioside (AMCA), outer membrane porins (Omp) and the atypical perinuclear antineutrophilic cytoplasmic antibody (pANCA) were tested in serum samples of 1225 IBD patients, 200 healthy controls and 113 patients with non-IBD gastrointestinal inflammation. Antibody responses were correlated with the type of disease and clinical characteristics. RESULTS: 76% of Crohn's disease patients had at least one of the tested antibodies. For differentiation between Crohn's disease and ulcerative colitis, the combination of gASCA and pANCA was most accurate. For differentiation between IBD, healthy controls and non-IBD gastrointestinal inflammation, the combination of gASCA, pANCA and ALCA had the best accuracy. Increasing amounts and levels of antibody responses against gASCA, ALCA, ACCA, AMCA and Omp were associated with more complicated disease behaviour (44.7% versus 53.6% versus 71.1% versus 82.0%, p < 0.001), and a higher frequency of Crohn's disease-related abdominal surgery (38.5% versus 48.8% versus 60.7% versus 75.4%, p < 0.001). CONCLUSIONS: Using this new panel of serological markers, the number and magnitude of immune responses to different microbial antigens were shown to be associated with the severity of the disease. With regard to the predictive role of serological markers, further prospective longitudinal studies are necessary.     

New serologic markers for inflammatory bowel disease diagnosis

Inflammatory bowel diseases (IBD) are chronic intestinal disorders where, in genetically susceptible hosts, an intestinal microorganism triggers an over-reactive immune response. Antibodies against luminal antigens are specifically associated with Crohn's disease (CD). In addition to the previously described antibodies antineutrophil cytoplasmic (auto)antibodies (ANCA), anti-Saccharomyces cerevisiae antibodies (ASCA), OmpC, I2 and CBir1 Flagellin, new anti-glycan antibodies were recently added to the armamentarium of serologic markers in IBD. Glycans are sugars associated with proteins, abundant on many living cells. The anti-glycan antibodies are directed against laminaribioside, chitobioside, mannobioside and mannan residues and are designated anti-laminaribioside carbohydrate antibodies (ALCA), anti-chitobioside carbohydrate antibodies (ACCA), anti-mannobioside carbohydrate antibodies (AMCA) and gASCA, respectively. Anti-laminarin IgA (Anti-L), and anti-chitin IgA (Anti-C) are new members of this family. Laminarin and chitobioside are capable of stimulating the innate immune system, thus the finding of antibodies against these glycans suggests a connection between the adaptive and innate arms of the immune response in CD patients. The contribution of serologic markers, specifically the anti-glycan antibodies, to IBD diagnosis may be in differentiating IBD from other gastrointestinal diseases, and between CD and ulcerative colitis (UC), in better classifying undetermined colitis and for decision-making prior to proctocolectmy in UC patients. The anti-glycan antibodies are specifically important in ASCA-negative CD patients. Correlation between serologic markers and genetic variations may contribute to reclassifying IBD into new and more homogeneous subclasses. Their significance in diagnosing populations at risk, such as unaffected relatives of IBD patients and CD patients prior to diagnosis, is under current investigation.     

Detection of anti-Saccharomyces cerevisiae antibodies in Crohn''s disease: is it a reliable diagnostic and prognostic marker?

Background. In the past few years, serologic markers have been proposed in inflammatory bowel disease. Anti-Saccharomyces cerevisiae antibodies showed high specificity for Crohn's disease. A prognostic role for serology has also been hypothesised.

Aims To evaluate anti-Saccharomyces cerevisiae antibody distribution in an unselected Italian inflammatory bowel disease population. To analyse whether anti-Saccharomyces cerevisiae antibody status (positive/negative) and/or anti-Saccharomyces cerevisiae antibody titres are associated with clinical variables and outcome measures in Crohn's disease patients.

Patients and Methods. A series of 299 inflammatory bowel disease patients were evaluated; serum samples were taken and a short clinical history was recorded. anti-Saccharomyces cerevisiae antibodies IgG enzyme-linked immunosorbent assay Medilab® (Milan, Italy) kit was used in order to determine anti-Saccharomyces cerevisiae antibody status.

Results. Sensitivity, specificity and likelihood ratio for positive test in the differential diagnosis of inflammatory bowel disease was 59%, 89%, 8.1, respectively. Clinical variables significantly associated with anti-Saccharomyces cerevisiae antibody status in logistic regression were found to be ileal location (p =0.01) and earlier age at diagnosis (p<0.01). Among ileal Crohn's disease patients, there was a trend in concordance between anti-Saccharomyces cerevisiae antibody titres and higher number of surgical procedures which was not statistically significant applying more complex statistics.

Conclusions. In an Italian inflammatory bowel disease population, anti-Saccharomyces cerevisiae antibodies status showed characteristics similar to those previously reported. Anti-Saccharomyces cerevisiae antibody positivity is associated with ileal involvement and with earlier onset of Crohn's disease.     

Anti-Saccharomyces cerevisiae mannan antibodies combined with antineutrophil cytoplasmic autoantibodies in inflammatory bowel disease: prevalence and diagnostic role

^a Service d'Hépato-Gastroentérologie, Hôpital Huriez, ^b Laboratoire de Parasitologie-Mycologie, ^c Service d'Epidémiologie et de Santé Publique, CH et U Lille, ^d Département d'Hématologie-Immunologie-Cytogénétique, CH Valenciennes, France, ^e Division of Gastroenterology and the UCLA Inflammatory Bowel Disease Center, Department of Medicine, UCLA School of Medicine, Los Angeles, California, USA

Correspondence to: Dr J-FColombel, Clinique des Maladies de l'Appareil Digestif et de la Nutrition, Hôpital Huriez, CH et U Lille, 59037 Lille, France.

Accepted for publication 19 January 1998

Background—Perinuclear antineutrophil cytoplasmic autoantibodies (pANCA) are a well recognised marker for ulcerative colitis. Antibodies to oligomannosidic epitopes of the yeast Saccharomyces cerevisiae (ASCA) are a new marker associated with Crohn's disease.
Aims—To assess the value of detecting pANCA and/or ASCA for the diagnosis of ulcerative colitis and Crohn's disease.
Methods—Serum samples were obtained from 100 patients with Crohn's disease, 101 patients with ulcerative colitis, 27 patients with other miscellaneous diarrhoeal illnesses, and 163 healthy controls. Determination of pANCA and ASCA was performed using the standardised indirect immunofluorescence technique and an ELISA, respectively.
Results—The combination of a positive pANCA test and a negative ASCA test yielded a sensitivity, specificity, and positive predictive value of 57%, 97%, and 92.5% respectively for ulcerative colitis. The combination of a positive ASCA test and a negative pANCA test yielded a sensitivity, specificity, and positive predictive value of 49%, 97%, and 96% respectively for Crohn's disease. Among patients with miscellaneous non-inflammatory bowel disorders, three were ASCA positive and two were pANCA positive. One control was ASCA positive. The presence of ASCA in patients with Crohn's disease was associated with small bowel involvement.
Conclusion—ASCA and pANCA are strongly associated with Crohn's disease and ulcerative colitis, respectively. Combination of both tests could help the diagnosis of inflammatory bowel disease.
(GUT 1998;:788-791)

Keywords: Crohn's disease;  ulcerative colitis;  antineutrophil cytoplasmic autoantibodies;  anti-Saccharomyces cerevisiae mannan antibodies