Diagnostic role and clinical association of ASCA and ANCA in Brazilian patients with inflammatory bowel disease

Serum ANCA as Disease Biomarkers: Clinical Implications Beyond Vasculitis

Usually associated with autoimmune diseases, anti-neutrophil cytoplasmic antibodies are also detected in other conditions, such as infections, malignancies, and after intake of certain drugs. Even if the mechanisms of production and their pathogenic role have not been fully elucidated yet, ANCA are widely recognized as a clinically alarming finding due to their association with various disorders. While ANCA target several autoantigens, proteinase-3, and myeloperoxidase are the ones proved to be most frequently related to chronic inflammation and tissue damage in murine models. Albeit these autoantibodies could be present as an isolated observation without any implications, ANCA are frequently used in clinical practice to guide the diagnosis in a suspect of small vessel vasculitis. Conditions that should prompt the clinician to test ANCA status range from various forms of lung disease to renal or peripheral nervous system impairment. ANCA positivity in the presence of an autoimmune disease, especially rheumatoid arthritis, or connective tissue diseases, is frequently correlated with more clinical complications and treatment inefficacy, even in the absence of signs of vasculitis. For this reason, it has been postulated that ANCA could represent the final expression of an immune dysregulation rather than a pathogenic event responsible for organs damage. Recently, it has also been proposed that ANCA specificity (PR3 or MPO) could possibly define ANCA-associated vasculitides better than clinical phenotype. This review aims at summarizing the latest advancements in the field of ANCA study and clinical interpretation.

CLASSICAL SEROLOGICAL MARKERS IN PEDIATRIC INFLAMMATORY BOWEL DISEASE IN BRAZIL

BACKGROUND

Perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) and anti-Saccharomyces cerevisiae antibodies (ASCAs) have long been used to differentiate between Crohn's disease (CD) and ulcerative colitis (UC), more recently having been used as prognostic indicators.

OBJECTIVE

To determine the diagnostic accuracy of serological markers in the identification of pediatric CD and UC in Sao Paulo, Brazil, as well as to correlate those markers with characteristics demographic and clinical of these two diseases.

METHODS

Retrospective cross-sectional multi-center study involving pediatric patients with inflammatory bowel disease (IBD). We identified ASCAs serological markers and p-ANCA, correlating their presence with demographic and clinical data, not only in the patients with IBD but also in a group of age-matched gastrointestinal disease-free controls.

RESULTS

A total of 122 patients, 74 with IBD (46% males), treated at four pediatric gastroenterology referral centers, the mean age of 13±7 years, 49 (66%) with CD, and 25 (34%) with UC. The control Group comprised 48 patients (54% males). The proportion of patients testing positive for p-ANCA was significantly higher in the UC group (69.9%) compared to the CD group (30.4%), as well as being significantly higher in the CD group versus the control Group (P<0.001 for both). The proportion of patients testing positive for ASCA IgA (76.2%) and ASCA IgG (94.4%) markers was also significantly higher in the CD group than in the control Group (P<0.001), and such positivity correlated significantly with the use of immunomodulatory medications such as azathioprine and anti-tumor necrosis factor agents (azathioprine 38.9%, anti-TNF 55.6%; P=0.002). In the CD group, the proportion of patients testing positive for the ASCA IgA was significantly higher among those who underwent surgery than among those who did not (26.86±17.99; P=0.032).

CONCLUSION

In pediatric patients with IBD in Sao Paulo, Brazil, serological tests proving to be highly specific, although not very sensitive, for the diagnosis of IBD. However, the serological markers showed a positive correlation with the severity of the disease.

New Insights on CD8+ T Cells in Inflammatory Bowel Disease and Therapeutic Approaches

CD8⁺ T cells are involved in the pathogenesis of inflammatory bowel disease (IBD), a complex multifactorial chronic disease. Here, we present an overview of the current research with the controversial findings of CD8⁺ T cell subsets and discuss some possible perspectives on their therapeutic value in IBD. Studies on the role of CD8⁺ T cells in IBD have contradictory outcomes, which might be related to the heterogeneity of the cells. Recent data suggest that cytotoxic CD8⁺ T cells (Tc1) and interleukin (IL) 17-producing CD8⁺ (Tc17) cells contribute to the pathogenesis of IBD. Moreover, subsets of regulatory CD8⁺ T cells are abundant at sites of inflammation and can exhibit pro-inflammatory features. Some subsets of tissue resident memory CD8⁺ T cells (Trm) might be immunosuppressant, whereas others might be pro-inflammatory. Lastly, exhausted T cells might indicate a positive outcome for patients. The function and plasticity of different subsets of CD8⁺ T cells in health and IBD remain to be further investigated in a challenging field due to the limited availability of mucosal samples and adequate controls.

Can molecular stratification improve the treatment of inflammatory bowel disease?

Inflammatory bowel disease (IBD) is a debilitating chronic inflammatory disease of the gastrointestinal (GI) tract. It affects more than 3.5 million people in the western world and places a huge financial burden on healthcare systems. IBD is highly heterogeneous; disease severity and outcomes in IBD are highly variable, and patients may experience episodes of relapse and remission. However, treatment often follows a step-up model whereby the patients start with anti-inflammatory agents (corticosteroids or immunosuppressants) and step-up to monoclonal anti-tumour necrosis factor-α (TNFα) antibodies and then other biologics if the initial drugs cannot control disease. Unfortunately, many patients do not respond to the costly biologics, and thus often still require gut-resective surgery, which decreases quality of life. In order to decrease rates of surgery and ineffective treatments, it is important to identify markers that accurately predict disease progression and treatment responses, to inform decisions about the best choice of therapeutics. Here we examine molecular approaches to patient stratification that aim to increase the effectiveness of treatments and potentially reduce healthcare costs. In the future, it may become possible to stratify patients based on their suitability for specific molecular-targeted therapeutic agents, and eventually use molecular stratification for personalised medicine in IBD.

The significance of ANCA positivity in patients with inflammatory bowel disease

Traditionally anti-neutrophil cytoplasmic antibodies (ANCA) are used to subtype patients with inflammatory bowel disease (IBD) and to predict primary sclerosing cholangitis (PSC). The clinical utility of this testing in the Australian context is not known. Our retrospective, cross-sectional study looked at the results of ANCA testing performed during routine clinical review and aimed to retrospectively review (1) the distribution of different ANCA subtypes for IBD patients, (2) the temporal change of ANCA status, and (3) the predictive value of ANCA for PSC. Sixty-four IBD patients attending our hospital gastroenterology clinic between 2012 and 2016 had at least one ANCA test requested. Surprisingly, >80% of the IBD patients in our cohort who underwent ANCA testing had a positive ANCA result and a significant proportion had positive PR3 antibodies. However, no specific ANCA pattern predicted a specific IBD subtype or clinical course. Pairing ANCA and anti-Saccharomyces cerevisiae (ASCA) did not add value in subtyping IBD for these patients. Our study suggests that there is little value in ordering an ANCA for patients with IBD.

IBD血清学标志物的临床应用前景

炎症性肠病(inflammatory bowel disease, IBD)是一种病因不明的慢性非特异性肠道炎症性疾病, 包括溃疡性结肠炎(ulcerative colitis, UC)和克罗恩病(Crohn's disease, CD). 目前IBD的诊断及临床过程主要依据其临床表现、常规检验、影像学特征、内镜所见及组织病理综合判断, 但远未满足临床实践. 因此, 寻找一种简单、准确的诊断方法成为目前亟待解决的问题. 迄今, IBD相关血清学标志物的应用对IBD的诊断与鉴别诊断、疾病严重程度界定、疗效判断和预后评估均凸显出其临床优势. 本文就近年来IBD血清学标志物的研究及其临床应用前景作一述评.

Retrospective evaluation of the clinical utility of serological biomarkers in Chinese patients with inflammatory bowel disease: 2-year clinical experience

BACKGROUND

Antibodies to saccharomyces cerevisiae (ASCA), antibodies to perinuclear anti-neutrophil cytoplasmic (pANCA), pancreatic autoantibodies (PAB) and antibodies against intestinal goblet cells (GAB) are important in diagnosing Crohn's disease (CD) and ulcerative colitis (UC). However, little is known about their diagnostic value in real clinical practice in China. This retrospective study aimed to present our 2-year clinical experience with those biomarkers in diagnosis of CD and UC.

METHODS

A total of 140 patients with UC, 128 patients with CD, and 224 patients with intestinal associated diseases as disease controls were included. Serum ASCA were determined by ELISA. Serum pANCA, GAB, and PAB were tested by indirect immunofluorescent assay. Retrospective review of laboratory results and clinical information was performed.

RESULTS

ASCA and ASCA+/pANCA- showed poor abilities in differentiating CD from UC, CD from intestinal Behçet's disease (BD), or CD from intestinal tuberculosis (ITB). In contrast, PAB exhibited good capacities in differentiating CD from UC, CD from intestinal BD, and CD from ITB. IgG pANCA demonstrated a high sensitivity and specificity in differentiating UC from CD. pANCA+/ASCA- or pANCA+/PAB- displayed a high sensitivity and specificity in differentiating UC from CD. GAB showed poor potential in differentiating UC from CD. PAB were positively correlated with early disease onset, ileocolonic disease, and perianal disease in CD patients.

CONCLUSIONS

Our data suggest that pANCA and PAB are helpful in diagnosis of UC and CD, respectively, while ASCA and GAB were not. Our findings indicate a clear need for additional biomarkers for diagnosis of CD in China.

The use of selected neutrophil protein plasma concentrations in the diagnosis of Crohn's disease and ulcerative colitis - a preliminary report

BACKGROUND

Difficulties in diagnosis of inflammatory bowel disease (IBD) motivate the search for new diagnostic tools, including laboratory tests. The aim of this study was to evaluate concentrations of the neutrophil (NEU) proteins leukocyte elastase (HLE-α1AT), lactoferrin and calprotectin as potential biomarkers used in the diagnosis and assessment of clinical activity of Crohn's disease (CD) and ulcerative colitis (UC).

MATERIAL/METHODS

The study included 27 patients with CD, 33 patients with UC and 20 healthy controls. Plasma concentrations of calprotectin, lactoferrin and HLE-α1AT were measured using ELISA.

RESULTS

In patients with CD higher concentrations of HLE-α1AT (64.3±43.1 vs. 30.1±7.7 ng/l, P<0.001), calprotectin (151.6±97.8 vs. 69.9±22.1 ng/l, P<0.001) and lactoferrin (243.2±102.0 vs. 129.7±32.7 ng/l, P<0.001) than in the control group were found. In patients with UC higher plasma concentrations of HLE-α1AT (62.0±30.9 vs. 30.1±7.7 ng/l, P<0.001), calprotectin (149.6±72.3 vs. 69.9±22.1 ng/l, P<0.001) and lactoferrin (242.6±107.5 vs 129.7±32.7 ng/l, P<0.001) than in the control group were found. HLE-α1AT/NEU and lactoferrin/NEU ratios in patients with UC were significantly higher compared with patients with CD. Calprotectin (P=0.010) and lactoferrin (P=0.023) levels were higher in patients with the active compared with inactive phase of CD.

CONCLUSIONS

The diagnostic characteristics of plasma granulocyte protein concentrations indicate the usefulness of these tests in the diagnosis of IBD. Higher HLE-α1AT and lactoferrin/NEU ratios in patients with UC than with CD may suggest the usefulness of these ratios in differential diagnostics. Plasma calprotectin and lactoferrin levels may be useful in CD activity assessment.

Variable outcome in infantile-onset inflammatory bowel disease in an Asian cohort

AIM

Infantile-onset inflammatory bowel disease (IO-IBD) with the onset of disease before 12 mo of age, is a different disease entity from childhood IBD. We aimed to describe the clinical features, outcome and role of mutation in interleukin-10 (IL-10) and interleukin-10 receptors (IL-10R) in Asian children with IO-IBD.

METHODS

All cases of IO-IBD, defined as onset of disease before 12 mo of age, seen at University Malaya Medical Center, Malaysia were reviewed. We performed mutational analysis for IL10 and IL10R genes in patients with presenting clinical features of Crohn’s disease (CD).

RESULTS

Six [13%; CD = 3, ulcerative colitis (UC) = 2, IBD-unclassified (IBD-U) = 1] of the 48 children (CD = 25; UC = 23) with IBD have IO-IBD. At final review [median (range) duration of follow-up: 6.5 (3.0-20) years], three patients were in remission without immunosuppression [one each for post-colostomy (IBD-U), after standard immunosuppression (CD), and after total colectomy (UC)]. Three patients were on immunosuppression: one (UC) was in remission while two (both CD) had persistent disease. As compared with later-onset disease, IO-IBD were more likely to present with bloody diarrhea (100% vs 55%, P = 0.039) but were similar in terms of an associated autoimmune liver disease (0% vs 19%, P = 0.31), requiring biologics therapy (50% vs 36%, P = 0.40), surgery (50% vs 29%, P = 0.27), or achieving remission (50% vs 64%, P = 0.40). No mutations in either IL10 or IL10R in the three patients with CD and the only patient with IBD-U were identified.

CONCLUSION

The clinical features of IO-IBD in this Asian cohort of children who were negative for IL-10 or IL-10R mutations were variable. As compared to childhood IBD with onset of disease after 12 mo of age, IO-IBD achieved remission at a similar rate.

Hidden musculoskeletal involvement in inflammatory bowel disease: a multicenter ultrasound study

Background

Inflammatory bowel diseases are associated with a variety of extra-intestinal manifestations. The most frequent of these is joint involvement, which affects 16–33 % of IBD patients. Our aim was to evaluate the ultrasound prevalence of sub-clinical joint and entheseal involvement in patients with IBD without musculoskeletal symptoms, and to correlate the US findings with clinical and laboratory variables.

Methods

We recorded the clinical and laboratory data of 76 patients with IBD, 20 patients with spondyloarthritis (SpA) and 45 healthy controls at three rheumatology centers. All of the IBD patients and healthy controls were clinically examined by a rheumatologist in order to confirm the absence of musculoskeletal symptoms, and all of the subjects underwent grey-scale (GS) and power Doppler (PD) US examinations of the second and third metacarpophalangeal joints, knees and lower limbs in order to detect joint or entheseal abnormalities.

Results

A total of 1410 entheseal sites and 1410 joints were evaluated by US. Of the 76 patients with IBD, 64 (84.1 %) had at least one GS entheseal abnormality, and 11 (13.9 %) had more than one PD-positive entheseal site; 32 (42.1 %) showed sub-clinical joint involvement.

There was a significant difference between the IBD patients and healthy controls in terms of global entheseal, PD-positive entheseal, and joint involvement (p < 0.0001), but no difference between the IBD and SpA patients. Anti-neutrophil cytoplasmic antibodies predicted entheseal involvement in patients with IBD (OR 6.031; p = 0.015).

Conclusions

The prevalence of sub-clinical joint and entheseal involvement was higher in IBD patients than healthy controls, but there was no difference between the IBD and SpA patients.

Gastrointestinal comorbidities in patients with psoriasis in the Czech Republic: The results of 189 patients with psoriasis and 378 controls

AIMS

The aim of the study was to investigate gastrointestinal comorbidities, identify risk factors and detect the early stages of autoimmune gastrointestinal diseases, such as Crohn's disease, ulcerative colitis and coeliac disease in patients with psoriasis.

METHODS

This was a hospital-based case-control study. Patients with chronic plaque psoriasis were included as cases. The control group consisted of patients with other skin diseases and who complied with the same selection criteria as cases. Two controls were selected per one case. We analysed the following antibodies (ASCA, AEP, p-ANCA, AGC, EMA, ARA, tTG, AGA) and non-specific signs of gastrointestinal diseases.

RESULTS

There were significant differences between cases and controls in several parameters. Leucocyte count, CRP, total protein, transglutaminase IgA antibodies and p-ANCA were statistically significant between groups (P < 0.05). In the binary logistic model, leucocyte count and p-ANCA (for all parameters included in the logistic model P ≤ 0.001) were associated with psoriasis.

CONCLUSION

Patients with psoriasis should be regularly screened for coeliac and inflammatory bowel disease. Early diagnosis of gastrointestinal diseases and risk factors may prevent complications and greatly improve the patient's quality of life.

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.

Proteomics and metabolomics in inflammatory bowel disease

Genome-wide studies in inflammatory bowel disease (IBD) have allowed us to understand Crohn's disease and ulcerative colitis as forms of related autoinflammatory disorders that arise from a multitude of pathogenic origins. Proteomics and metabolomics are the offspring of genomics that possess unprecedented possibilities to characterize unknown pathogenic pathways. It has been about a decade since proteomics was first applied to IBD, and 5 years for metabolomics. These techniques have yielded novel and potentially important findings, but turning these results into beneficial patient outcomes remains challenging. This review recounts the history and context of clinical IBD developments before and after proteomics and metabolomics IBD in this field, discusses the challenges in consolidating high complexity data with physiological understanding, and provides an outlook on the emerging principles that will help interface the bioanalytical laboratory with IBD prognosis.

The role of autoantibodies in inflammatory bowel disease

The search for the underlying trigger of an inappropriate inflammatory reaction characteristic of inflammatory bowel diseases (IBD) has led to the discovery of several antibodies. The panel of serologic markers for IBD is rapidly expanding. Serologic markers hold the promise of helping researchers and clinicians to better understand IBD heterogeneity and natural history. The real importance of the antibodies produced against various microbial and autoantigens is still uncertain. Whether these antibodies play a primary role in the pathogenesis of IBD, or their presence is only a consequence of the inflamed mucosa is a fundamental question that remains to be clarified. The impact of the routine evaluation of these serologic markers in the everyday clinical IBD diagnostic algorithm is questionable due to their limited sensitivity. Despite their great potential, the routine use of serologic markers for diagnosis and follow-up is currently not justified. However, their correlation with disease phenotype and behavior is more established. A combination of serum markers has been shown to be of more value compared to using single markers alone. The ongoing challenge is how to best utilize these serologic markers to provide clinically relevant information in a cost-effective manner. Further prospective clinical trials are needed to determine their exact role in pathogenesis and practical clinical importance. We review the current standpoint of the clinical impact of various established and newly suggested markers in Crohn's disease and ulcerative colitis.