Possible diagnostic role of antibodies to Crohn's disease peptide (ACP): results of a multicenter study in a Japanese cohort

Diagnostic utility, disease activity, and disease phenotype correlation of serum ASCA, pANCA, and PR3-ANCA in pediatric inflammatory bowel disease

OBJECTIVE

This study aimed to evaluate the diagnostic utility, disease activity, and phenotypic association of serum anti-Saccharomyces cerevisiae antibody (ASCA), perinuclear anti-neutrophil cytoplasmic antibody (pANCA), PR3-ANCA, and MPO-ANCA in pediatric patients with inflammatory bowel disease (IBD).

METHODS

Pediatric patients diagnosed with IBD were recruited and classified as Crohn's disease (CD), ulcerative colitis (UC), and IBD-unclassified (IBD-U) through full investigation. The Paris classification was used to evaluate disease phenotypes of pediatric CD and UC.

RESULTS

In all, 229 pediatric patients with IBD (CD 147, UC 53, IBD-U 29) were included. The ASCA IgG seropositivity significantly differed among the three groups (CD 75.4%, UC 17.5%, and IBD-U 60.0%; p < 0.001). PR3-ANCA positive rates were the highest in UC (24.0%), followed by IBD-U (17.6%), and none in CD (p = 0.002); pANCA-positive rates were higher in IBD-U (33.6%), followed by UC (28.0%) than in CD (1.4%) (p < 0.001). Regarding disease phenotype, perianal disease revealed higher serum ASCA IgG titers (median 36.7 U/mL in P1 vs. 25.2 U/mL in P0, p = 0.019). Serum ASCA IgG and IgA cutoff values to distinguish CD were 32.7 (U/mL) and 11.9 (U/mL), respectively, with a specificity of 80.0%.

CONCLUSION

Serological biomarkers of ASCA IgG and IgA were effective for differentiating CD in pediatric IBD patients, and serum pANCA and PR3-ANCA, but not MPO-ANCA, were effective in distinguishing UC and IBD-U. Furthermore, measuring serological titers of ASCA IgG and IgA may help differentiate CD and evaluate the disease activity and phenotype of pediatric IBD in practice.

Role of Serum Proteinase 3 Antineutrophil Cytoplasmic Antibodies in the Diagnosis, Evaluation of Disease Severity, and Clinical Course of Ulcerative Colitis

Background/Aims

Proteinase 3 antineutrophil cytoplasmic antibody (PR3-ANCA) is a serologic marker for granulomatosis with polyangiitis. However, recent studies have also shown their role as diagnostic markers for ulcerative colitis (UC). This study was performed to investigate the clinical roles of PR3-ANCAs in the disease severity, disease extension, and clinical course of UC.

Methods

Serum PR3-ANCAs were measured in 173 UC patients including 77 patients with new-onset patients UC diagnosed within 1 month, 110 patients with Crohn’s disease, 48 patients with other intestinal diseases, and 71 healthy controls. Associations between the PR3-ANCA titer and clinical data, such as disease severity, disease extension, and clinical course, were assessed. The clinical utility of PR3-ANCA measurement was evaluated by receiver operating characteristic (ROC) analysis.

Results

PR3-ANCA ≥3.5 U/mL demonstrated 44.5% sensitivity and 95.6% specificity for the diagnosis of UC in all patients. PR3-ANCA positivity was more prevalent in the 77 new-onset UC patients (58.4%). In this group, the disease severity and extension were more severe in PR3-ANCA positive patients than in PR3-ANCA negative group (p<0.001). After treatment, the partial Mayo scores were significantly decreased with the PR3-ANCA titers. The proportion of patients who required steroids for induction therapy was significantly higher among PR3-ANCA positive than negative group. ROC analysis revealed that PR3-ANCA ≥3.5 U/mL had 75% sensitivity and 69.0% specificity for steroid requirement in new-onset UC patients.

Conclusions

Our results indicate that PR3-ANCA measurement is useful not only for diagnosing UC but also for evaluating disease severity and extension and predicting the clinical course.

Diagnostic accuracy of serum proteinase 3 antineutrophil cytoplasmic antibodies in children with ulcerative colitis

BACKGROUND AND AIM

Serologic markers such as myeloperoxidase (MPO) antineutrophil cytoplasmic antibodies (ANCA) (MPO-ANCA) have been used to screen patients for ulcerative colitis (UC). However, MPO-ANCA shows limited accuracy in Asians. Proteinase 3 ANCA (PR3-ANCA) has performed better at UC diagnosis in Japanese adults than MPO-ANCA. The present study aimed to evaluate usefulness of PR3-ANCA for diagnosis of UC in Japanese pediatric practice.

METHODS

Patients under 17 years old undergoing assessment at 12 Japanese pediatric centers between November 2016 and February 2018 were prospectively enrolled and divided into groups with UC, Crohn's disease (CD), intestinal disease control (IC), and healthy control (HC). Serum PR3-ANCA and MPO-ANCA were analyzed using chemiluminescence enzyme immunoassay kits.

RESULTS

Sera from 367 patients (148 with UC at a median age of 12 years; 120 with CD, 13 years; 56 with IC, 10.5 years; and 43 with HC, 10 years) were examined. Median PR3-ANCA values in UC (1.6 U/mL) were greater than in CD (0.2; P < 0.001), IC (0.15; P < 0.001), and HC (0.1; P < 0.001). In receiver operating characteristic curve analyses, the area under the curve for PR3-ANCA was 0.79, significantly greater than for MPO-ANCA (0.58; P < 0.001). Using a cut-off value of 0.8 U/mL determined from the receiver operating characteristic analyses, PR3-ANCA showed significantly greater sensitivity (64.9%) than MPO-ANCA (cut-off, 0.2 U/mL; sensitivity, 19.6%; P < 0.001) and good specificity (83.6%).

CONCLUSIONS

In Japanese children and adolescents, PR3-ANCA performed better as a serologic marker for diagnosis of UC than MPO-ANCA. To our knowledge, this is the first report of such a comparison.

Antibodies to Crohn's disease peptide 353 as a diagnostic marker for pediatric Crohn's disease: a prospective multicenter study in Japan

BACKGROUND

Various serologic markers such as anti-glycoprotein 2 antibodies and anti-Saccharomyces cerevisiae antibodies have been reported to be diagnostically useful in Crohn's disease. Mitsuyama et al. reported that antibodies to Crohn's disease peptide 353, a newly proposed serologic marker, were more useful in Japanese adults than anti-Saccharomyces. We addressed the same issue in Japanese children and adolescents.

METHODS

Prospectively enrolled subjects under 17 years old assessed and treated at 12 pediatric centers in Japan included groups with Crohn's disease, ulcerative colitis, other intestinal diseases, or good health. The 3 serum markers were analyzed by enzyme-linked immunosorbent assays.

RESULTS

Enrolled subjects, numbering 367, included 120 with Crohn's disease, 148 with ulcerative colitis, 56 with other intestinal diseases, and 43 healthy subjects. In Crohn's disease, anti-Crohn's disease peptide 353, anti-glycoprotein 2, and anti-Saccharomyces concentrations (median, 2.25, 3.0, and 8.9 U/mL) were significantly greater than in ulcerative colitis (1.1, 1.9, and 3.4; all P < 0.001), other intestinal diseases (1.1, 1.85, and 2.95; all P < 0.001), and healthy controls (1.1, 1.7, and 2.8; all P < 0.001), respectively. At 95% specificity, sensitivity of anti-Crohn's disease peptide (45.0%) was significantly higher than for anti-glycoprotein 2 (30.8%; P < 0.05) or anti-Saccharomyces (26.7%; P < 0.01).

CONCLUSIONS

Anti-Crohn's disease peptide 353 proved more useful for diagnosis of Crohn's disease in Japanese children than the other 2 markers. To our knowledge, this is the first pediatric report to that effect.

Diagnostic and clinical role of serum proteinase 3 antineutrophil cytoplasmic antibodies in inflammatory bowel disease

BACKGROUND AND AIM

Proteinase 3 antineutrophil cytoplasmic antibodies (PR3-ANCAs) are well-known serological markers for granulomatosis with polyangiitis, but their role as serological markers for inflammatory bowel disease remains uncertain. The present study aimed to evaluate the diagnostic and clinical role of PR3-ANCAs as markers for inflammatory bowel disease.

METHODS

Using a new methodology with chemiluminescence enzyme immunoassay, serum PR3-ANCA titers were assessed in 102 patients with ulcerative colitis (UC), 67 patients with Crohn's disease (CD), 44 controls with other intestinal diseases, and 66 healthy controls. Associations with clinical data were investigated. The diagnostic role of PR3-ANCAs was evaluated by receiver operating characteristic analysis.

RESULTS

Proteinase 3 antineutrophil cytoplasmic antibody titers were significantly higher in patients with UC than in those with CD patients, patients with intestinal diseases (intestinal controls), and healthy controls (all P < 0.001). Receiver operating characteristic analysis demonstrated an area under the curve of 0.85 (95% confidence interval: 0.83-0.87) and showed that the manufacturer's cutoff value (3.5 U/mL) had a sensitivity of 39.2% and specificity of 96.6% for UC. There was a significant difference between PR3-ANCA-positive and PR3-ANCA-negative patients with regard to disease duration (P < 0.05) and disease severity (P < 0.01).

CONCLUSIONS

Proteinase 3 antineutrophil cytoplasmic antibodies were significantly more prevalent in patients with UC than in those with CD and controls. Our results suggested the role of PR3-ANCAs as serological markers for aiding in diagnosing UC and evaluating disease severity. Further prospective studies are needed across multiple populations of patients and ethnic groups.

Overcoming difficulty in diagnosis and differential diagnosis of Crohn's disease: the potential role of serological and genetic tests

Crohn's disease (CD) represents a heterogeneous group of chronic inflammatory disorders with various phenotypes. Establishing a definite diagnosis of CD should be based upon a combined assessment of clinical, endoscopic, radiological and pathological features. Although segmental disease distribution, transmural inflammation and non-caseating epithelioid granulomas have been considered as a 'hallmarks' for CD, clear diagnosis of CD in some patients has been challenging, due to overlapping endoscopic, radiographic and histologic features with other inflammatory bowel disease-like conditions. Laboratory markers (serological and genetic tests) may provide additional clues for the diagnosis and differential diagnosis of CD. This review focuses on the application of the currently available serological and genomic markers and in diagnosis and differential diagnosis of CD.

Loss and Gain of Tolerance to Pancreatic Glycoprotein 2 in Celiac Disease

BACKGROUND

Autoantibodies against pancreatic secretory-granule membrane glycoprotein 2 (GP2) have been demonstrated in patients with Crohn's disease but recently also with celiac disease (CD). Both entities are characterized by intestinal barrier impairment with increased gut permeability. Pathophysiological hallmark of CD is a permanent loss of tolerance to alimentary gliadin and a transient loss of tolerance to the autoantigen human tissue transglutaminase (tTG). Therefore, we explored the behavior of loss of tolerance to GP2 reported in CD.

METHODS

We assessed prevalences and levels of autoantibodies against GP2, CD-specific antibodies to endomysial antigens and tTG as well as Crohn's disease-specific anti-Saccharomyces cerevisiae antibodies in sera of 174 patients with active CD, 84 patients under gluten-free diet (GFD) and 129 controls. Furthermore, we looked for an association between anti-GP2 antibody positivity and degree of mucosal damage in CD.

RESULTS

We found significantly elevated anti-GP2 IgA positivity in active CD patients (19.5%) compared to CD patients under GFD (0.0%) and controls (5.4%, p < 0.001, respectively). Anti-GP2 IgA levels correlated significantly with CD-specific antibodies (p < 0.001). Anti-GP2 autoantibody positivity disappeared under GFD similarly to CD-specific autoantibodies against tTG and endomysial antigens. For the first time, IgA antibody levels to GP2 are demonstrated to be associated with degree of villous atrophy according to Marsh classification.

CONCLUSIONS

Anti-GP2 IgA seems to be associated with disease activity in a distinct subgroup of patients with CD. The observed loss of tolerance to GP2 in a subset of patients with CD is transient and disappears under GFD.