Chronic inflammatory bowel disease in children: a complex problem in management

Defects in mucosal immunity leading to Crohn's disease

Crohn's disease (CD) is characterized by patchy transmural inflammation involving any part of the intestinal tract. Animal models have provided a great deal of insight into the pathogenesis of CD, but no animal model has recapitulated the full spectrum of manifestations witnessed in human disease. The defects in mucosal immunity in CD can be divided into those that involve the epithelial barrier, those that involve the innate immune response, and finally, defects in the adaptive immune response. Defects in the epithelial barrier in CD include an increase in intestinal permeability, increased adherence of bacteria, and decreased expression of defensins. Murine and human studies have demonstrated an increased expression of T-helper 1 (Th1) cytokines by lamina propria lymphocytes. This increased Th1 cytokine expression is driven by interleukin-12 (IL-12)/IL-23 and tumor necrosis factor-like 1A (TL1A) production by antigen-presenting cells, resulting in Tbet expression by CD4+ T cells. Another dimension of the inappropriate immune response in CD is T-cell and B-cell reactivity to luminal microbes. With the identification of the nucleotide-binding oligomerization domain 2 (NOD2) gene as a susceptibility gene, defects in the innate immune response are beginning to be explored. One may consider a model in which defective innate immune clearance of pathogens or commensal bacteria in CD leads to an inappropriate adaptive immune response to the commensal flora.

Diagnostic role of upper gastrointestinal endoscopy in pediatric inflammatory bowel disease

BACKGROUND

Discrimination between ulcerative colitis (UC) and Crohn disease (CD) may be difficult on ileo-colonoscopy alone because of a lack of definitive lesions. Retrospective studies show upper gastrointestinal endoscopy may be helpful in confirming diagnosis in such cases.

AIMS

To prospectively determine importance of upper gastrointestinal endoscopy in diagnosis of inflammatory bowel disease (IBD) and assess factors predictive of upper gastrointestinal involvement in IBD.

METHODS

All pediatric patients were enrolled prospectively and consecutively over a 2-year period and investigated with an ileo-colonoscopy and barium meal follow-through. Children with procto-sigmoiditis, later confirmed histologically to be typical of UC, were excluded from the study. The remainder underwent upper gastrointestinal endoscopy. The protocol and methodology were determined a priori.

RESULTS

65 children suspected of IBD underwent colonoscopy. Of the total, 11 had recto-sigmoiditis with typical macroscopic appearances of UC; once this was confirmed on histology these patients were excluded from the study. Of the 54 children (males, 31; median age, 11.1 years) remaining, 23 were initially diagnosed with CD on ileo-colonoscopy and 18 (33%) were diagnosed with UC. The diagnosis remained ambiguous in 13 (six colonic, four ileo-colonic, three normal colon) on clinical, radiologic and histologic grounds. Upper GI endoscopy helped to confirm CD in a further 11 (20.4%). Two patients were diagnosed with indeterminate colitis. Upper gastrointestinal inflammation was seen in 29 of 54 (22 CD; 7 UC ). Epigastric and abdominal pain, nausea and vomiting, weight loss and pan-ileocolitis were predictive of upper gastrointestinal involvement (P < 0.05). However, 9 children with upper gastrointestinal involvement were asymptomatic at presentation (31%). Overall upper gastrointestinal tract inflammation was most common in the stomach (67%), followed by the esophagus (54%) and duodenum (22%).

CONCLUSIONS

Upper gastrointestinal tract endoscopy should be part of the first-line investigation in all new cases suspected of IBD. Absence of specific upper gastrointestinal symptoms do not preclude presence of upper gastrointestinal inflammation.

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.

Infliximab: an updated review of its use in Crohn's disease and rheumatoid arthritis

Infliximab is a chimeric monoclonal antibody that binds to tumour necrosis factor-alpha (TNFalpha) and neutralises its effects. TNFalpha plays an important role in the development of both Crohn's disease and rheumatoid arthritis. In a large, double-blind, randomised study involving patients with active, refractory Crohn's disease, significantly more recipients of intravenous infliximab, compared with placebo, achieved a clinical response after 4 weeks' follow-up. Moreover, infliximab administration was associated with a rapid improvement in endoscopic and histological findings in clinical trials involving patients with active, refractory Crohn's disease. The results of the A Crohn's Disease Clinical Trial Evaluating Infliximab in a New Long-Term Treatment Regimen (ACCENT) I study showed that maintenance infliximab therapy prolonged response and remission in patients with moderate to severe Crohn's disease. In patients with enterocutaneous fistulae associated with Crohn's disease who were involved in a double-blind, randomised study, significantly more patients who received multiple infusions of infliximab, compared with placebo, experienced a > or=50% reduction from baseline in the number of draining fistulae at > or =2 consecutive study visits. In patients with active rheumatoid arthritis refractory to treatment with methotrexate who were enrolled in a large, double-blind, randomised study [the Anti-TNF Trial in Rheumatoid Arthritis with Concomitant Therapy (ATTRACT) study], American College of Rheumatology (ACR) 20, 50 and 70% response rates were seen in significantly more patients who received multiple infusions of infliximab plus methotrexate, compared with methotrexate plus placebo, after 30 and 54 weeks' treatment. Moreover, the ACR 20% response rate was maintained after 102 weeks' treatment. In addition, significantly less radiographic progression was seen in infliximab plus methotrexate, compared with methotrexate plus placebo, recipients after 54 weeks' treatment. Infliximab therapy was also associated with improvements in health-related quality of life in patients with Crohn's disease or rheumatoid arthritis. Infliximab was generally well tolerated in clinical trials with the most common adverse events including upper respiratory tract infection, headache, nausea, coughing, sinusitis and diarrhoea. Infliximab therapy may be associated with an increased risk of reactivation of tuberculosis in patients with latent disease. In conclusion, infliximab is an important treatment option in patients with active Crohn's disease who have not responded to conventional therapy and in patients with Crohn's disease who have fistulae. Moreover, infliximab plus methotrexate is effective in patients with active rheumatoid arthritis who have not responded adequately to traditional disease-modifying antirheumatic drugs, in terms of reducing symptoms and signs, improving physical function and delaying the progression of structural damage.

Crohn's disease: disastrous consequences of late diagnosis

Chronic and recurrent perianal abscess is an uncommon condition in children. Tuberculosis is thought to be the common etiology for such a presentation in India. We report a case of a child with colonic and perianal disease due to Crohn's disease and emphasize the disastrous complication due to delayed diagnosis.