Antineutrophil Cytoplasmic Antibodies In Patients Research Articles

Frequency of anti-neutrophil cytoplasmic antibodies in patients with systemic lupus erythematosus

IntroductionSystemic lupus erythematosus (SLE) is a multisystem autoimmune disease. Patients with SLE exhibit multiple serum autoantibodies, including anti-neutrophil cytoplasmic antibodies (ANCAs). There are two main techniques to detect ANCAs: indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA). In this study, an attempt was made to determine the frequency and clinical associations of ANCAs in patients with SLE. MethodsA cross-sectional study was conducted in a tertiary care hospital in Colombia that included 74 patients with SLE. The presence of ANCAs was assessed using IIF with ethanol-fixed slides, and ELISA was used to detect antibody specificities for myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA. ResultsOf the 74 patients with SLE evaluated, 60 (81.1%) of them were ANCA-positive by IIF. By contrast, only one patient showed specificity for PR3-ANCA by ELISA. The relevance of ANCA positivity by IIF and clinical and serological features was significant for renal involvement (p=.0174), and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) (p=.0308). ConclusionANCAs are common in the serum of patients with SLE, as detected by ethanol-fixed slides with IIF staining. However, detection of specificity to PR3 and/or MPO is rare, thus highlighting the importance of detecting these autoantibodies by different techniques.

Antineutrophil Cytoplasmic Antibodies in Patients Treated With Methimazole

Abstract Introduction: Antithyroid drugs (ATDs) are widely used for the treatment of hyperthyroidism. Most side effects of these medications are mild and emerge within the first months of treatment. In contrast, antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis is a severe adverse event whose occurrence increases with increasing time of treatment. Vasculitis is more frequently associated with propylthiouracil than with methimazole, but the latter has also been related to the occurrence of ANCA and even to clinically manifest vasculitis. Many patients develop ANCA during treatment with methimazole but do not exhibit signs/symptoms of vasculitis. Objective: We previously reported a relatively high frequency (20%) of ANCA in patients exposed to methimazole but none of them exhibited clinical manifestations of vasculitis on that occasion. We continued to follow up these patients with ANCA and report here their evolution after 2 years. Methods: Seventeen patients exposed to methimazole were followed for 2 years after antibodies detection (ANCA). Results: Eight patients had ANCA but had not used methimazole for at least 6 months. During the following 24 months, continuing without ATD, none of the patients developed clinically apparent vasculitis. In the last assessment, five patients no longer had ANCA, while these antibodies persisted in three. Nine patients had ANCA and had been on methimazole for at least 6 months. The medication was not immediately discontinued in these patients when the antibodies were detected. After this detection, treatment with methimazole was continued in these patients for more 3 months (n = 1), 6 months (n = 2), 9 months (n = 1), 12 months (n = 2), 18 months (n = 2), and 24 months (n = 1). During the 2 years of follow-up after the detection of ANCA, none of the 9 patients developed signs/symptoms of vasculitis. In the last assessment, ANCA were negative in two patients who had received methimazole for more 3 and 6 months and who were therefore without receiving the drug for 21 and 18 months, respectively. The other 7 patients remained ANCA positive. Conclusion: Although vasculitis is necessarily associated with the presence of ANCA, the inverse frequency is undefined and appears to be low. Thus, measurement of ANCA would not be recommended in asymptomatic patients during methimazole treatment and immediate discontinuation of this drug, if these antibodies are detected eventually, may not be required. Reference: Antineutrophil cytoplasmic antibodies in patients treated with methimazole: a prospective Brazilian study. Andrade GC, Maia FCP, Mourão GF, Rosario PW, Calsolari MR. Braz J Otorhinolaryngol. 2019; 85:636-41.

Frequency of anti-neutrophil cytoplasmic antibodies in patients with systemic lupus erythematosus

IntroductionSystemic lupus erythematosus (SLE) is a multisystem autoimmune disease. Patients with SLE exhibit multiple serum autoantibodies, including anti-neutrophil cytoplasmic antibodies (ANCAs). There are two main techniques to detect ANCAs: indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA). In this study, an attempt was made to determine the frequency and clinical associations of ANCAs in patients with SLE. MethodsA cross-sectional study was conducted in a tertiary care hospital in Colombia that included 74 patients with SLE. The presence of ANCAs was assessed using IIF with ethanol-fixed slides, and ELISA was used to detect antibody specificities for myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA. ResultsOf the 74 patients with SLE evaluated, 60 (81.1%) of them were ANCA-positive by IIF. By contrast, only one patient showed specificity for PR3-ANCA by ELISA. The relevance of ANCA positivity by IIF and clinical and serological features was significant for renal involvement (p=.0174), and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) (p=.0308). ConclusionANCAs are common in the serum of patients with SLE, as detected by ethanol-fixed slides with IIF staining. However, detection of specificity to PR3 and/or MPO is rare, thus highlighting the importance of detecting these autoantibodies by different techniques.

Antineutrophil cytoplasmic antibodies in patients treated with methimazole: a prospective Brazilian study

IntroductionThe side effects of antithyroid drugs are well known. Antineutrophil cytoplasmic antibody-associated vasculitis is a severe adverse reaction. Most studies evaluating antineutrophil cytoplasmic antibodies related to antithyroid drugs have been carried out with patients treated with propylthiouracil, but less information is available for methimazole. Furthermore, most studies that investigated antineutrophil cytoplasmic antibodies related to antithyroid drugs were conducted on Asian populations. ObjectiveTo evaluate the frequency of antineutrophil cytoplasmic antibodies and antineutrophil cytoplasmic antibodies-positive vasculitis in an adult population of Brazilian patients treated with methimazole. MethodsThis was a prospective study. We evaluated patients ≥18 years with Graves’ disease who have been using methimazole for at least 6 months (Group A, n=36); with Grave's disease who had been previously treated with methimazole but no longer used this medication for at least 6 months (Group B, n=33), and with nodular disease who have been using methimazole for at least 6 months (Group C, n=13). ResultsANCA were detected in 17 patients (20.7%). Four patients (4.9%) had a strong antineutrophil cytoplasmic antibodies-positive test. The frequency of antineutrophil cytoplasmic antibodies was similar in the groups. When Groups A and B were pooled and compared to Group C to evaluate the influence of Grave's disease, and when Groups A and C were pooled and compared to Group B to evaluate the influence of methimazole discontinuation, no difference was found in the frequency of antineutrophil cytoplasmic antibodies. No difference was observed in sex, age, etiology of hyperthyroidism, anti-TSH receptor antibodies, dose or time of methimazole use between patients with versus without antineutrophil cytoplasmic antibodies. The titers of these antibodies were not correlated with the dose or time of methimazole use. None of the antineutrophil cytoplasmic antibodies-positive patient had clinical event that could potentially result from vasculitis. ConclusionThis clinical study of a Brazilian population shows a considerable frequency of antineutrophil cytoplasmic antibodies in patients treated with methimazole but the clinical repercussion of these findings remains undefined.

Anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus.

BackgroundThe clinical significance of anti-neutrophil cytoplasmic antibodies in patients with new-onset systemic lupus erythematosus, especially in systemic disease accompanied by interstitial lung disease remains to be elucidated.ObjectivesThis study was designed to investigate the role of anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus patients.MethodsA hundred and seven patients with new-onset SLE were enrolled. Presence of anti-neutrophil cytoplasmic antibodies in the sera was assessed by indirect immunofluorescence as well as enzyme linked immunosorbent assay against proteinase-3 and myeloperoxidase. Clinical features and laboratory parameters of patients were also recorded. All patients were subjected to chest X-ray, chest high-resolution computed tomography and pulmonary function test.ResultsForty-five systemic lupus erythematosus patients (45/107, 42%) were seropositive for anti-neutrophil cytoplasmic antibodies. Compared with anti-neutrophil cytoplasmic antibodies-negative patients, the anti-neutrophil cytoplasmic antibodies-positive patients had significantly higher incidence of renal involvement, anemia, and Raynaud's phenomenon as well as decreased serum level of complement 3/complement 4 and elevated erythrocyte sedimentation rate. In addition, there was a positive correlation between serum anti-neutrophil cytoplasmic antibodies level and disease activity of systemic lupus erythematosus. Furthermore, prevalence of interstitial lung disease in the anti-neutrophil cytoplasmic antibodies -positive patients (25/45, 55.6%) was obviously higher than that in the anti-neutrophil cytoplasmic antibodies-negative patients (15/62, 24.2%).Study limitationsThe sample size was limited and the criteria for screening new-onset systemic lupus erythematosus patients might produce bias.ConclusionsThe level of anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus patients correlates positively with the disease activity and the prevalence of interstitial lung disease.

Antineutrophil Cytoplasmic Antibodies in Patients with Idiopathic Inflammatory-Demyelinating Diseases

Objective: We assessed the clinical significance of antineutrophil cytoplasm antibodies (ANCA) in patients with idiopathic inflammatory-demyelinating disease (IIDD). Methods: A consecutive cohort of 269 subjects with IIDD and 595 controls was analyzed retrospectively. Results: Among all subjects, ANCA positivity rates were low [9.5% in a perinuclear pattern (pANCA) and 2.3% in a cytoplasmic pattern (cANCA)]. One of the 117 patients with multiple sclerosis (MS) had cANCA and 2 had pANCA. Ten patients with neuromyelitis optica (NMO; 13.9%) had pANCA and 3 (4.2%) had cANCA. Four patients with recurrent longitudinal extensive transverse myelitis (RLETM; 19.0%) had pANCA and 1 (4.8%) had cANCA. In monophasic TM, 22.9% were pANCA seropositive. Among patients with brainstem syndromes, 14.3% were pANCA seropositive. Patients with NMO, RLETM or monophasic TM had higher pANCA levels than patients with MS. There was a positive association between spinal cord (SC) lesions and ANCA, and especially between longitudinal extensive transverse myelitis and ANCA. Among anti-aquaporin 4 antibody-positive patients, ANCA-positive patients (n = 16) were older and had higher Expanded Disability Status Scale scores, more antinuclear antibodies, longer SC lesions and fewer brain abnormalities than the ANCA-negative patients (n = 68). In the NMO subgroup, ANCA-positive patients were older and had more antinuclear antibodies and longer SC lesions than ANCA-negative patients. Conclusion: Among the IIDDs, we found a higher occurrence of ANCA in patients with NMO spectrum disorders than in patients with MS. Therefore, ANCA is another interesting marker of autoimmunity in IIDD patients, especially those with anti-aquaporin 4 antibody.

Clinical significance of detection of anti-neutrophil cytoplasmic antibodies in patients with autoimmune hepatitis

Clinical significance of detection of anti-neutrophil cytoplasmic antibodies in patients with autoimmune hepatitis

Antineutrophil cytoplasmic antibodies in patients with pulmonary tuberculosis.

Mycobacterium tuberculosis is a major cause of mortality and morbidity worldwide. Infection with this bacterium is known to induce the development of autoantibodies of which a few are also known to be diagnostic markers for some other diseases. Antineutrophil Cytoplasmic Antibodies (ANCA's) are among those autoantibodies used in clinical setting for diagnosing systemic vasculitic syndromes. Multiple studies investigated ANCA positivity in diseases other than small vessel vasculitis. This study was performed to determine the prevalence of ANCA in pulmonary tuberculosis (TB) which may lead to the false diagnosis of Wegener's granulomatosis (WG) or vice versa. In a case-control study, 32 consecutive smear positive pulmonary TB patients and 32 normal individuals were studied. All cases and controls were screened for ANCA by indirect immunofluorescent assay (IIF), and MPO and PR3 were also tested by ELISA. A prenuclear pattern (P-ANCA) was detected in 25% of the cases and 6.25% of the controls and a cytoplasmic pattern (C-ANCA) was deserved in 3.1% of both the cases and the controls by IIF assay. ANCA specificities tested by ELISA in cases revealed that 75% of the cases had anti-MPO and 12.5% had anti-PR3, while in the in controls, 3.12% had anti-MPO and none had anti-PR3. The positive ANCA significantly correlated with TB (p<0.01). ANCA's may be observed in both TB and systemic vasculitic syndromes such as WG. Tuberculosis and WG share some clinical features. Therefore, in countries with a high prevalence of TB, one has to distinguish between these two diseases especially when no sign of extrapulmonary involvement is observed.

Epitope shift of proteinase-3 anti-neutrophil cytoplasmic antibodies in patients with small vessel vasculitis

Anti-neutrophil cytoplasmic antibodies against proteinase 3 (PR3-ANCA) are used as diagnostic tools for patients with small vessel vasculitis (AASV). We have produced chimeric mouse/human PR3 molecules and investigate changes in reactivity over time and the possible relationship between epitope specificity and clinical course. Thirty-eight PR3-ANCA-positive patients diagnosed between 1990 and 2003 were followed until December 2005. Plasma was collected at each out-patient visit and older samples were retrieved retrospectively. Patients reacted with multiple epitopes at the time of diagnosis. At subsequent relapses 12 patients shifted reactivity, in 11 cases from epitopes located in the C-terminal towards epitopes in the N-terminal. Patients with reactivity against N-terminal parts of PR3 at diagnosis had a significantly lower relapse rate, 30% compared to 78% in the group with predominantly C-terminal reactivity (P = 0.04). The reactivity pattern did not correlate to outcome measured as death, end-stage renal disease or vasculitis activity index score (VDI) at 5 years. Further research is necessary to conclude if this is a general phenomenon.

Diagnostic value of antineutrophil cytoplasmic antibodies in patients with ulcerative colitis: a meta-analysis

To evaluate the diagnostic value of antineutrophil cytoplasmic antibodies (ANCA) in patients with ulcerative colitis (UC). Articles related to diagnosis of UC by ANCA test, published before November 2007, were retrieved in the databanks such as Chinese BioMedical Disc, Chinese Medical Current Contents, China National Knowledge Infrastructure, and VIP databank. Related journals were searched manually. Meta-analysis was performed by summary receiver operating characteristic curve recommended by Diagnostic and Screening Group of the Cochrane Collaboration Web with the parameters such as sensitivity, specificity, accuracy, predictive values and likelihood ratio. Totally 10 studies including 381 patients met the inclusion criteria. Meta-analysis showed that the sensitivity and specificity of ANCA to the diagnosis of UC were 52.2% and 99.0% respectively. The positive and negative predictive values (PPV and NPV) were 98.0% and 68.7% respectively. Meanwhile, the positive and negative likelihood ratio (+LR and -LR) were 52.2 and 0.5, respectively. ANCA is an immunological index related to UC. Positive ANCA helps diagnose UC, but is not sensible enough to screen UC.

Functional characterization of antineutrophil cytoplasmic antibodies in patients with cocaine‐induced midline destructive lesions

Antineutrophil cytoplasmic antibodies (ANCA) binding to neutrophil elastase (NE) and proteinase 3 (PR3) are detectable in most patients with cocaine-induced midline destructive lesions (CIMDL), but the pathogenic role and antigen specificity of these antibodies are unknown. This study was undertaken to assess the effects of NE ANCA on the enzymatic activity of NE, to determine whether these antibodies interfere with the physiologic effect of secretory leukoprotease inhibitor (SLPI), and to investigate the antigen specificity of both NE and PR3 ANCA in patients with CIMDL. We also compared the binding of PR3 ANCA in patients with CIMDL with that in patients with Wegener's granulomatosis (WG). PR3 ANCA and NE ANCA were detected by capture enzyme-linked immunosorbent assays (ELISAs) and by indirect immunofluorescence. IgG was purified from the patients' sera, and the influence of NE ANCA on the enzymatic activity of NE and on the inhibitory activity of SLPI was investigated by determining the hydrolysis of N-methoxysuccinyl-Ala-Ala-Pro-Val p-nitroanilide by NE. IgG from NE ANCA-positive sera of patients with CIMDL inhibited the enzymatic activity of NE and did not interfere with the activity of SLPI. In contrast to the findings in WG sera, measurement of PR3 ANCA in CIMDL sera showed only fair to moderate concordance between the 2 different capture ELISAs. Cross-inhibition experiments demonstrated that NE ANCA and PR3 ANCA represent distinct autoantibodies in patients with CIMDL. The functional effects of NE ANCA on the enzymatic activity of NE or on the activity of SLPI cannot be implicated in the pathogenesis of CIMDL. The autoimmune reaction that targets neutrophil serine proteases in patients with CIMDL is frequently directed against more than one antigen. The ANCA response, including the reactivity of PR3 ANCA, in patients with CIMDL differs from what has been described in patients with WG.

Anti-neutrophil cytoplasmic antibodies in patients with pulmonary tuberculosis

Anti-neutrophil cytoplasmic antibodies in patients with pulmonary tuberculosis

Detection of antineutrophil cytoplasmic antibodies in patients with inflammatory bowel diseases

Detection of antineutrophil cytoplasmic antibodies in patients with inflammatory bowel diseases

The role of antineutrophil cytoplasmic antibodies in patients with systemic lupus erthematosus

the role of antineutrophil cytoplasmic antibodies in patients with systemic lupus erthematosus

Anticorps anticytoplasme des polynucléaires neutrophiles au cours de la mucoviscidose. Fréquence et signification

Some immune system abnormalities have been reported in cystic fibrosis, particularly the presence of antineutrophil cytoplasmic antibodies (ANCAs). The purpose of this study was to determine the frequency of these antibodies in a population of patients with cystic fibrosis and to assess their relationship with the disease progression. Population and methods. – This retrospective study looked for the presence of these antibodies in sera from 64 patients (30 boys and 34 girls) aged one to 29 years. All patients were followed up within the Cystic Fibrosis Center of the University Hospital of Angers. The serum samples were collected in 2001 during the yearly check-up to evaluate disease status. Results. – Seven of the 64 patients presented the antibodies. Univariate analysis showed that these patients were significantly older and more often chronically infected with Pseudomonas aeruginosa than the other patients. They also scored significantly more poorly on pulmonary radiography and showed significantly higher IgG and CRP. Multivariate analysis revealed that the two following independent factors were associated with the presence of ANCAs: chronic P. aeruginosa infection and high IgG level. Conclusion. – This work confirms the abnormally high frequency of antineutrophil cytoplasmic antibodies in patients with cystic fibrosis. These antibodies were observed in the sickest patients with severe infection status. They reflect the impact of inflammatory processes in the pathogenesis of the disease. Detection of these antibodies might be an indication for intensified treatment of bronchial infections.

Antineutrophil cytoplasmic antibodies in patients with Graves? disease: association of antimyeloperoxidase autoantibodies with propylthiouracil therapy

Antineutrophil cytoplasmic antibodies in patients with Graves? disease: association of antimyeloperoxidase autoantibodies with propylthiouracil therapy

Antineutrophil cytoplasmic antibodies in patients with Graves’ disease: association of antimyeloperoxidase autoantibodies with propylthiouracil therapy

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitic disorders have been reported in patients with Graves’ disease during propylthiouracil (PTU) therapy. To investigate whether ANCA are found in serum samples from patients with Graves’ disease, and whether PTU therapy is associated with ANCA positivity, levels of serum ANCA were examined in Graves’-disease patients receiving either PTU (n = 49) or 1-methyl-2-mercaptoimidazole (methimazole, MMI) (n = 50), and in untreated Graves’-disease patients (n = 32) by enzyme-linked immunosorbent assay (ELISA). Serum samples from patients with Hashimoto’s thyroiditis (n = 46) were also analyzed. Antimyeloperoxidase (MPO) autoantibodies (MPO-ANCA) were present in 10 (20.4%) of 49 Graves’-disease patients receiving PTU therapy, whereas MPO-ANCA were not detected in Graves’-disease patients receiving MMI, in untreated Graves’-disease patients, or in Hashimoto’s thyroiditis patients. The MPO-ANCA-positive sera showed a perinuclear staining pattern which was detected by indirect immunofluorescence microscopy using a human polymorphonuclear leukocyte–cytospin preparation. Furthermore, Western blot analysis revealed that MPO-ANCA in the Graves’-disease patients, as well as MPO-ANCA in patients with idiopathic pauci-immune necrotizing and crescentic glomerulonephritis, recognize the 105-kD protein of native MPO. These results indicate that MPO-ANCA in Graves’-disease patients are strongly associated with PTU therapy, and not simply related to the autoimmune thyroid disease. This study also suggests that the presence of MPO-ANCA alone may not be sufficient for the development of vasculitic disorders.

Anti-neutrophil cytoplasmic antibodies in patients with rheumatoid arthritis: clinical, biological, and radiological correlations

Objectives. – To determine the prevalence and the associations of anti-neutrophil cytoplasmic antibodies (ANCA) and subtypes with clinical, biological, and radiological findings in patients with rheumatoid arthritis (RA). Materials and methods. – This is a transversal study of 85 patients with RA (followed in Ibn-i Sina Hospital, Ankara University School of Medicine) with disease duration of 8.7 ± 6.4 years. Besides clinical, biological, and radiological disease activity parameters, ANCA and ANCA against myeloperoxidase (MPO) and proteinase 3 (PR3) were examined. Results. – The prevalence of ANCA, perinuclear ANCA (p-ANCA) and atypical ANCA (a-ANCA) were 18% (15/85 patients), 6% and 12%, respectively. Anti-MPO was found in six patients while anti-PR3 was not found. No significant association could be found between clinical, biological, and radiological disease activity assessments and ANCA (including indirect immunoflorescence subtypes). Similarly, ANCA were not associated with features suggestive of underlying vasculitis (noticed in 11/85 patients), and/or other extra-articular features. Conclusions. – Our results confirm that ANCA of various specificities (mainly a-ANCA) occur in a minority of RA. However, those ANCA were not associated with more severe RA, including the 6/85 patients positive for MPO (who were all free from vasculitis). The over-representation in RA sera of a-ANCA, as compared to p-ANCA, should be further studied.

Antineutrophil cytoplasmic antibody in patients with ulcerative colitis: Relation to clinical course

Antineutrophil cytoplasmic antibody in patients with ulcerative colitis: Relation to clinical course

Diagnostic role of anti-Saccharomyces cerevisiae mannan antibodies combined with antineutrophil cytoplasmic antibodies in patients with inflammatory bowel disease.

Perinuclear antineutrophil cytoplasmic autoantibody is known to be a marker for ulcerative colitis, and anti-Saccharomyces cerevisiae Mannan antibody is a serologic marker associated with Crohn's disease. The aim of this study was to assess the value of detecting perinuclear antineutrophil cytoplasmic autoantibody and/or anti-Saccharomyces cerevisiae Mannan antibody for the diagnosis of ulcerative colitis, Crohn's disease, Behçet's colitis, and tuberculous colitis. Serum samples were obtained from 85 patients with Crohn's disease, 77 with ulcerative colitis, 36 with Behçet's colitis, 14 with tuberculous colitis, 20 healthy controls, and 21 first-degree relatives of patients with Crohn's disease. Determination of perinuclear antineutrophil cytoplasmic autoantibody and anti-Saccharomyces cerevisiae Mannan antibody was performed with the standardized indirect immunofluorescence technique and an enzyme-linked immunosorbent assay, respectively. A relatively high percentage of patients with Crohn's disease (49.4 percent), relatives of Crohn's disease patients (61.9 percent), and patients with Behçet's disease (41.7 percent) tested seropositive for anti-Saccharomyces cerevisiae Mannan antibody compared with normal controls (10 percent). In cases of ulcerative colitis, 44.2 percent tested seropositive for perinuclear antineutrophil cytoplasmic autoantibody, whereas the controls showed 0 percent positivity. The combination of a positive anti-Saccharomyces cerevisiae Mannan antibody test and a negative perinuclear antineutrophil cytoplasmic autoantibody yielded a sensitivity and specificity of 48.2 and 87 percent, respectively, for Crohn's disease. The combination of a positive perinuclear antineutrophil cytoplasmic autoantibody test and a negative anti-Saccharomyces cerevisiae Mannan antibody test yielded a sensitivity and specificity of 36.4 and 97.6 percent, respectively, for ulcerative colitis. Anti-Saccharomyces cerevisiae Mannan antibody may be associated with Crohn's disease and Behçet's disease and perinuclear antineutrophil cytoplasmic autoantibody with ulcerative colitis. A combination of both tests may aid the differential diagnosis of inflammatory bowel disease.