Ulcerative colitis in children

Inherited determinants of Crohn's disease and ulcerative colitis phenotypes: a genetic association study

BACKGROUND

Crohn's disease and ulcerative colitis are the two major forms of inflammatory bowel disease; treatment strategies have historically been determined by this binary categorisation. Genetic studies have identified 163 susceptibility loci for inflammatory bowel disease, mostly shared between Crohn's disease and ulcerative colitis. We undertook the largest genotype association study, to date, in widely used clinical subphenotypes of inflammatory bowel disease with the goal of further understanding the biological relations between diseases.

METHODS

This study included patients from 49 centres in 16 countries in Europe, North America, and Australasia. We applied the Montreal classification system of inflammatory bowel disease subphenotypes to 34,819 patients (19,713 with Crohn's disease, 14,683 with ulcerative colitis) genotyped on the Immunochip array. We tested for genotype-phenotype associations across 156,154 genetic variants. We generated genetic risk scores by combining information from all known inflammatory bowel disease associations to summarise the total load of genetic risk for a particular phenotype. We used these risk scores to test the hypothesis that colonic Crohn's disease, ileal Crohn's disease, and ulcerative colitis are all genetically distinct from each other, and to attempt to identify patients with a mismatch between clinical diagnosis and genetic risk profile.

FINDINGS

After quality control, the primary analysis included 29,838 patients (16,902 with Crohn's disease, 12,597 with ulcerative colitis). Three loci (NOD2, MHC, and MST1 3p21) were associated with subphenotypes of inflammatory bowel disease, mainly disease location (essentially fixed over time; median follow-up of 10·5 years). Little or no genetic association with disease behaviour (which changed dramatically over time) remained after conditioning on disease location and age at onset. The genetic risk score representing all known risk alleles for inflammatory bowel disease showed strong association with disease subphenotype (p=1·65 × 10(-78)), even after exclusion of NOD2, MHC, and 3p21 (p=9·23 × 10(-18)). Predictive models based on the genetic risk score strongly distinguished colonic from ileal Crohn's disease. Our genetic risk score could also identify a small number of patients with discrepant genetic risk profiles who were significantly more likely to have a revised diagnosis after follow-up (p=6·8 × 10(-4)).

INTERPRETATION

Our data support a continuum of disorders within inflammatory bowel disease, much better explained by three groups (ileal Crohn's disease, colonic Crohn's disease, and ulcerative colitis) than by Crohn's disease and ulcerative colitis as currently defined. Disease location is an intrinsic aspect of a patient's disease, in part genetically determined, and the major driver to changes in disease behaviour over time.

FUNDING

International Inflammatory Bowel Disease Genetics Consortium members funding sources (see Acknowledgments for full list).

Careful patient selection may improve response rates to infliximab in inflammatory bowel disease

BACKGROUND AND AIM

The use of infliximab in the treatment of Crohn's disease (CD) is acceptable and appears to be effective in ulcerative colitis (UC). Careful patient selection, resulting in infliximab only for truly refractory inflammatory bowel disease (IBD), may improve its efficacy. The present study aimed to determine if careful patient selection improved infliximab efficacy in IBD.

METHODS

CD or UC/IBD unclassified patients (Montreal classification) were considered for infliximab treatment only after failure of disease control with conventional therapies and confirmation of active disease. Patients with purely luminal IBD received a single infliximab dose. Patients with fistulizing disease (with or without luminal disease) received infliximab at 0, 2 and 6 weeks. Changes to Harvey Bradshaw (HBI) for inflammatory CD and Colitis Activity Index (CAI) for UC/IBDU were used to determine the response and remission rates. In fistulizing CD, a remission was sustained cessation of drainage and resolution of the fistula. Response was correlated to inflammatory marker levels.

RESULTS

Seventy IBD patients were treated. In CD, 85.2% (46/54) had active luminal and 40.7% (22/54) had fistulizing disease. In luminal CD, at 8 weeks a single infliximab dose induced remission in 75% (24/32) of patients compared to 92.9% (13/14) after infliximab at 0, 2 and 6 weeks. Fistulizing disease responded in 77.2% (17/22) and remitted in 50% (11/22) of patients at 8 weeks. In UC/IBDU, 75% (12/16) responded and 43.8% (7/16) of patients were in remission at 8 weeks.

CONCLUSION

Careful patient selection may improve infliximab's efficacy and clinical remission appears greater after induction with three infliximab doses in CD. Clinical efficacy is suggested for UC/IBDU.

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.

A prospective comparative study of ASCA and pANCA in Chinese and Caucasian IBD patients

BACKGROUND

Inflammatory bowel disease manifests throughout all ethnic groups. Antisaccharomyces cerevisiae (ASCA) and antineutrophil cytoplasmic antibodies (pANCA) can aid in the differentiation between Crohn's disease (CD) and ulcerative colitis (UC), but their sensitivity may vary between races.

OBJECTIVES

This study compared the sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of pANCA and ASCA between Chinese and Caucasian IBD populations and identified disease subtype associations.

RESULTS

Three hundred patients were prospectively recruited from Caucasian and Chinese populations (CD, n = 50, UC, n = 50, controls, n = 50 each). pANCA detection was greater in Caucasian than Chinese UC patients (p= 0.046). ASCA IgG detection was similar, but IgA was lower in Chinese CD patients (p < 0.001). Differentiation between UC and CD (+ve pANCA/-ve ASCA) demonstrated a PPV of 92% in isolated colonic disease. Logistic regression in CD identified positive pANCA had a lower association with ileal (OR = 6.8, p= 0.0067) and complicated disease (OR = 5.5, p= 0.015). Caucasian CD patients with positive ASCA IgA/IgG had a greater association with ileal (OR = 6.7, p= 0.022) or complicated disease (OR = 9.4, p= 0.0073) and in Chinese CD patients positive ASCA IgA/IgG was associated with isolated ileal disease (OR = 16.8, p= 0.032). Linear regression demonstrated that higher ASCA titers predicted complicated CD and isolated ileal disease.

CONCLUSIONS

This study identified that pANCA is more sensitive in Caucasian than Chinese UC and that ASCA IgA has a low yield in Chinese CD. pANCA and ASCA are useful for differentiating between UC and CD in both populations, and ASCA IgG and IgA titers have potential use in determining the risk of developing complicated CD.

Colite ulcerativa inespecífica em crianças e adolescentes: análise de casuística

OBJETIVOS: descrever uma série de casos de colite ulcerativa inespecífica, com ênfase nas manifestações iniciais, propedêutica e intervalo entre os primeiros sintomas e o diagnóstico. MÉTODOS: análise retrospectiva de casos de colite ulcerativa inespecífica, cujos sintomas iniciaram antes de 20 anos de idade. Os pacientes foram selecionados nos Serviços de Gastroenterologia Pediátrica do Hospital das Clínicas da Universidade Federal de Minas Gerais e do Instituto Materno Infantil de Pernambuco. RESULTADOS: foram encontrados 29 pacientes com diagnóstico de colite ulcerativa inespecífica, sendo 15 (51,7%) pacientes do sexo masculino. A idade ao início dos sintomas variou entre 0,3 a 15,8 anos. Os sintomas mais freqüentes ao diagnóstico foram diarréia (89,7%) e dor abdominal (82,8%). A manifestação extra-intestinal mais comum foi artralgia/artrite (41,4%). A relação peso para a idade estava abaixo do percentil 3 em 13,8% dos pacientes. O intervalo de tempo entre o início dos sintomas e o diagnóstico variou entre 0,1 e 10,9 anos. CONCLUSÕES: o intervalo entre os sintomas iniciais e o diagnóstico ainda continua elevado na nossa Região devido ao somatório de vários fatores.

Comparison of serological markers of inflammatory bowel disease with clinical diagnosis in children

BACKGROUND

Our purpose was to study the concordance of serological tests for inflammatory bowel disease with clinical diagnosis established by traditional testing in children.

METHODS

All children seen in our division who had IBD Diagnostic System (ie, pANCA, ASCA IgA, and ASCA IgG) performed over a 21-month period (June 1998 to February 2000) were identified. Their medical records were reviewed for basic demographics, test results (endoscopy, histology, and radiology), IBD Diagnostic System results, and patient symptoms/medications. Results of the IBD Diagnostic System were compared with several patient characteristics including age, sex, absence/presence of symptoms, medication use, disease activity and duration.

RESULTS

One hundred seven patients were divided into 6 groups based on clinical diagnosis and IBD Diagnostic System results. The sensitivity, specificity and +/- predictive values of the IBD Diagnostic System for ulcerative colitis were 69.2, 95.1, 90.0, and 87.1%, respectively, and for Crohn's disease were 54.1, 96.8, 90.9, and 80.8%, respectively. Overall, the results of the IBD Diagnostic System were concordant with the clinical diagnosis in 76 of the 107 (71%) patients.

CONCLUSIONS

In our experience, the specificity of IBD Diagnostic System is better than the sensitivity; the sensitivity is better for ulcerative colitis than Crohn's disease (69.2% vs 54.1%). The low sensitivity, especially for Crohn's disease, precludes the possibility that the IBD Diagnostic System can replace traditional studies when evaluating for inflammatory bowel disease. Though we do not exclude inflammatory bowel disease solely by IBD Diagnostic System results, it is reassuring to note that all patients without clinical evidence of inflammatory bowel disease also had negative IBD Diagnostic System results.

Ulcerative colitis in children: medical management

Ulcerative colitis is a chronic relapsing inflammatory disorder of the colonic mucosa of unknown etiology. The inflammatory process involves the mucosa and submucosa in a continuous segment of bowel with rectal involvement in almost all cases. Since its etiology is unknown, therapy is directed at modulating the inflammatory response in order to control symptoms and to prevent relapses. 5-aminosalicylates and corticosteroids have been the most widely used therapeutic agents for treatment of ulcerative colitis. Recently, experience has been gained with the use of other immunomodulators, such as mercaptopurine, azathioprine, methotrexate, cyclosporine, and tacrolimus, in pediatric patients. Colectomy is indicated in patients with severe colitis who do not respond to intensive medical therapy. The care of children with ulcerative colitis not only involves control of symptoms from gastrointestinal and extraintestinal manifestations, but also optimizing growth and development. The complications of chronic inflammation and long-term medical therapy must be weighed against the risks and benefits of surgery for children and adolescents with this condition.

Etiopathogenesis of inflammatory bowel disease: the importance of the pediatric perspective

Inflammatory bowel disease (IBD) is now recognized as a common chronic disease affecting children and adolescents. This article will review recent advances made in the fields of genetics, epidemiology, gut ecology, and immunology regarding the etiopathogenesis of IBD, with particular emphasis on the contributions made by pediatric studies. Areas where further study of the pediatric age group would be beneficial will be highlighted.

Epidemiology and the natural course of inflammatory bowel disease

Ulcerative colitis and Crohn's disease are inflammatory disorders of the gastrointestinal tract that are distributed unevenly within populations and throughout the world. Although the exact causes of inflammatory bowel disease (IBD) remain unknown, study of the epidemiology of IBD has provided insight into pathogenesis. This article examines the geographic, ethnic, and other trends of IBD; risk factors (including genetic and environmental); and the natural history of IBD.

Serologic testing for inflammatory bowel disease

OBJECTIVES

To determine the accuracy of anti-neutrophil cytoplasmic antibodies (ANCAs) and anti-Saccharomyces cerevisiae antibodies (ASCA) in distinguishing patients with inflammatory bowel disease from patients with other disorders, seen in a pediatric gastroenterology clinic setting, and in distinguishing ulcerative colitis (UC) from Crohn's disease (CD).

STUDY DESIGN

Serum samples from 120 children with new or established diagnoses of UC (n = 25) or CD (n = 20) and control children (n = 74) were analyzed in blinded fashion for the presence of IgG ANCAs and IgA and IgG ASCA.

RESULTS

The highest sensitivity for detecting inflammatory bowel disease, 71%, was achieved by using ANCAs and ASCA together. The best test for UC was ANCAs, which had a sensitivity of 80%. However, the ANCA pattern characteristic of UC, perinuclear ANCAs eliminated by DNAse, had a sensitivity of 60%. High-titer ANCAs were specific for UC, whereas ASCA were specific for CD.

CONCLUSIONS

Testing for ANCAs and ASCA together did not achieve sensitivity necessary for population screening. However, ANCAs and ASCA may be helpful in evaluating children suspected of having inflammatory bowel disease and in distinguishing UC from CD.

Sulfasalazine in the treatment of juvenile chronic arthritis: a randomized, double-blind, placebo-controlled, multicenter study. Dutch Juvenile Chronic Arthritis Study Group

OBJECTIVE

To assess the efficacy, tolerability, and safety of sulfasalazine (SSZ) in the treatment of juvenile chronic arthritis (JCA).

METHODS

We conducted a 24-week randomized, placebo-controlled, double-blind, multicenter study of patients with active JCA of both oligoarticular and polyarticular onset. Patients were treated with a dosage of 50 mg/kg/day of SSZ (maximum 2,000 mg/day) or placebo. The efficacy variables were joint scores, physician's, parents', and patient's overall assessments, and laboratory parameters of inflammation.

RESULTS

Of the 69 patients enrolled, 52 (75%) completed the trial. Six patients (18%) withdrew from the placebo group, and 11 (31%) withdrew from the SSZ group (P = 0.18). In the intention-to-treat analysis of end point efficacy, between-group differences were significant for the overall articular severity score (P = 0.02), all global assessments (P = 0.01), and the laboratory parameters (P < 0.001). Adverse events occurred more frequently in the SSZ group and were the main reason for withdrawal (P < 0.001), but in all instances, these events were transient or reversible upon cessation of treatment.

CONCLUSION

The results of this first placebo-controlled study show that SSZ is effective and safe in the treatment of children with oligoarticular- and polyarticular-onset JCA, although it was not well tolerated in one-third of the patients.