Pediatric inflammatory bowel disease

Assessment of disease activity in pediatric ulcerative colitis

To date, we encounter more and more pediatric patients with ulcerative colitis (UC). For yet unclear reasons, UC in pediatric patients seems to be a more aggressive and extensive disease than in their adult counterparts. In the majority of pediatric patients, the disease presents as pancolitis. The severity of the disease is reflected in the high use of corticosteroids and immunosuppressants and a high rate of surgery for medically refractory patients. The means by which to assess disease activity or to accurately predict its course are far from optimal. This review summarizes the current knowledge on the means for assessing UC activity in children. Research for developing new tools by which to monitor and forecast disease activity, are needed in all areas including invasive endoscopy, clinical evaluation, and treatment follow-up.

Is indeterminate colitis determinable?

About 10% of patients with colitis due to inflammatory bowel disease have indeterminate colitis. Despite newer diagnostic tools, the frequency has not diminished over the past 33 years. The current preferred term among academicians is colonic inflammatory bowel disease unclassified(IBDU), although indeterminate colitis is the term endorsed for inclusion in the ICD-10 coding system. Indeterminate colitis is more frequent among children. Theanti-Saccharomyces cerevisiae (ASCA) and perinuclear anti-cytoplasmic antibody (pANCA) are useful in distinguishing IBDU from ulcerative colitis and Crohn’s disease. However, current serologic and genetic studies, as well as endoscopic and imaging studies lack sufficient positive predictive values to make a definite diagnosis of Crohn’s colitis or ulcerative colitis. Patients with IBDU who undergo proctocolectomy with ileal pouch-anal anastomosis have more complications than patients with ulcerative colitis. Although some patients with indeterminate colitis eventually develop characteristic ulcerative colitis or Crohn’s disease, a subgroup are durably indeterminate.

Diagnostic yield of upper endoscopy in paediatric patients with Crohn's disease and ulcerative colitis. Subanalysis of the HUPIR registry

BACKGROUND, AIMS

According to Porto Criteria upper gastrointestinal (UGI) endoscopy is recommended in patients with suspected inflammatory bowel disease (IBD). Nevertheless, previous studies revealed frequent involvement of UGI tract even in patients with ulcerative colitis (UC). The aim of the present study was to determine the diagnostic role of esophagogastroduodenoscopy (EGD) and assess the prevalence and different aspects of UGI involvement in children registered in the Hungarian Pediatric IBD Registry (HUPIR) from 1st of January 2007 to 31th of December 2009.

METHODS

Twenty seven institutes provided prospective follow-up data about newly diagnosed IBD patients to HUPIR. The registry was based on detailed questionnaire (76 parameters) involving anamnestic data, laboratory findings, activity indexes, diagnostic procedures, endoscopic examinations (EGD and ileocolonoscopy), and histological data. Localization and phenotype of disease were based on the Montreal classification criteria.

RESULTS

During the 3-year period 420 children were diagnosed with IBD, 265 (63%) of them had Crohn's disease (CD), 130 (31%) UC, and 25 (6%) IBD-unclassified (IBD-U). The mean age at diagnosis was 13.2 years (range: 1.2-18 years). EGD was performed in 237 patients (56%), in most cases in patients suffering from CD. Macroscopic lesions on EGD were noted in 64% of patients with CD and 40% of children with UC. Characteristic lesions for CD (ulcer, erosion, aphthous lesion, and granuloma) were noted in 31% of CD patients, however, EGD helped to establish the final diagnosis in 9% of CD patients (diagnostic yield, 9%).

CONCLUSIONS

There was a high frequency of UGI involvement in children with CD and UC. One third of CD patients showed significant lesions at upper endoscopy and one patient out of ten had real diagnostic help from EGD.

Clinical significance of colonic intraepithelial lymphocytosis in a pediatric population

The significance of colonic intraepithelial lymphocytosis has been well described in adults, and is associated with lymphocytic colitis, untreated celiac disease, and medications, among others. Little is known about the meaning of colonic intraepithelial lymphocytosis in the pediatric population; this study examines this finding in a cohort of children. Twenty patients in whom colonic intraepithelial lymphocytosis was a prominent feature were identified from 1999 to 2005. Colonic intraepithelial lymphocytosis was defined as 20 or more intraepithelial lymphocytes per 100 colonocytes present in at least one colonic mucosal biopsy. Each biopsy was examined for numbers of intraepithelial lymphocytes per 100 surface and crypt colonocytes; various architectural, inflammatory, and metaplastic changes were also noted. When available, concurrent duodenal and/or ileal biopsies were examined. Studied clinical parameters included indications for biopsy, clinical follow-up, final diagnosis, comorbidities, autoimmune serologies, and medications. A total of 121 colonic mucosal biopsies were examined in 20 patients who ranged from 1 to 17 years (mean 10.2 years; 40% male). Common indications for endoscopy included diarrhea and abdominal pain. A mean of 29 (+/-22) intraepithelial lymphocytes per 100 enterocytes were seen. Seven patients had colonic intraepithelial lymphocytosis as the only histologic finding. The remaining 13 patients had additional architectural, inflammatory, and metaplastic changes. The mean follow-up period was 14 months (range 1-48 months). Inflammatory bowel disease was diagnosed in 4 of 20 patients and was seen chiefly in biopsies in which colonic intraepithelial lymphocytosis was associated with architectural or inflammatory changes. Common disease associations include celiac disease, lymphocytic colitis, and autoimmune enteropathy. Pediatric colonic intraepithelial lymphocytosis, in the absence of other histologic findings, is associated with various diseases, including celiac disease, lymphocytic colitis, and autoimmune enteropathy. Colonic intraepithelial lymphocytosis in the presence of other inflammatory changes indicates the possibility of idiopathic inflammatory bowel disease. These findings are similar to those seen in adults, with the exception of autoimmune enteropathy.

Probiotic Lactobacillus reuteri suppress proinflammatory cytokines via c-Jun

BACKGROUND

Differential immunoregulatory capabilities of probiotic Lactobacillus were explored in the context of pediatric Crohn's disease. Experimental strategies addressed molecular mechanisms of tumor necrosis factor (TNF) suppression in activated macrophages by transcriptional regulation.

METHODS

Secreted factors produced by probiotic Lactobacillus reuteri strains were harvested and tested with human monocytes and macrophages. Quantitative immunoassays and real-time reverse-transcriptase polymerase chain reaction (RT-PCR) were used to examine relative quantities of human cytokines and TNF mRNA, respectively, and reporter assays assessed transcriptional regulation of TNF by probiotics. DNA-protein macroarrays interrogated probiotic-mediated effects on transcription factor activation. Finally, enzyme-linked immunosorbent assays (ELISAs) and immunoblots examined the involvement of the specific transcription factor AP-1 and its components.

RESULTS

Probiotic L. reuteri strain ATCC PTA 6475 demonstrated the ability to potently suppress human TNF production by lipopolysaccharide-activated monocytes and primary monocyte-derived macrophages from children with Crohn's disease. Quantities of the chemokine MCP-1/CCL2 were also reduced by probiotic L. reuteri strain ATCC PTA 6475 in macrophages of children in remission. Quantitative real-time RT-PCR and luciferase reporter assays showed that transcriptional regulation of human TNF was a primary mechanism of probiotic-mediated immunomodulation. Probiotic L. reuteri suppressed TNF transcription by inhibiting activation of MAP kinase-regulated c-Jun and the transcription factor, AP-1.

CONCLUSIONS

Human TNF and MCP-1 suppression by probiotic L. reuteri was strain-dependent, and the activation of c-Jun and AP-1 represent primary targets for probiotic-mediated suppression of TNF transcription. This report emphasizes the clonal nature of immunoprobiosis and delineation of a specific immunomodulatory mechanism for probiotic strain selection in future inflammatory bowel disease-oriented clinical trials.

Indeterminate colitis: a review of the concept--what's in a name?

The precise diagnosis of colitis cannot always be established with the available diagnostic tools. The subgroup of patients with an uncertain diagnosis has been classified as "indeterminate colitis" (IC). The definition of "indeterminate," however, has changed over the years. Originally, IC was proposed by pathologists for colectomy specimens, usually from patients operated on for severe colitis, showing overlapping features of ulcerative colitis (UC) and Crohn's disease (CD). Later, the same terminology was used for patients showing no clear clinical, endoscopic, histologic, and other features allowing a diagnosis of either UC or CD. Therefore, it is difficult to compare different studies. An International Organization of Inflammatory Bowel Diseases (IOIBD) working party confirmed 1) the ambiguous nature of the term, and 2) proposes an updated classification for the category of patients with an unclear diagnosis. According to this, the term IBD unclassified (IBDU) is confirmed, as suggested by the Montreal Working Party 2005 for patients with clinically chronic colitis, that clearly have IBD but when definitive features of CD or UC are absent. In resected specimens the term "colitis of uncertain type or etiology" (CUTE) is preferred. It is accepted that most of the time this may have a prefix, such as severe, chronic. The classification of IBD varies when based only on biopsies rather than on a colectomy specimen. The vast majority of these have severe colitis. For those that cannot bear to abandon the highly ambiguous term IC, if it is used at all, this is where it can be used parenthetically.

Response to corticosteroids in severe ulcerative colitis: a systematic review of the literature and a meta-regression

BACKGROUND & AIMS

Colectomy is a potentially life-saving procedure for patients with severe attacks of UC who fail medical therapy. We aimed to systematically review studies that reported the short-term colectomy rate in severe UC or reported variables that could predict treatment failure.

METHODS

We conducted a systematic literature search for cohort studies and controlled trials published between 1974-2006.

RESULTS

Thirty-two studies met the inclusion criteria; 16 reported short-term outcome and predictors of therapy failure, 13 only outcome, and 3 only predictors. In the pooled analysis, 581 of 1991 patients required colectomy (weighted mean 27; 95% confidence interval [CI], 26%-28%), and 22 died (1%; 95% CI, 0.7%-1.5%). In a heterogeneity-controlled meta-regression, colectomy rate did not change during the last 30 years (R(2) = 0.07, P = .8). Cyclosporine was used in only 100 patients, with a 51% (95% CI, 41%-60%) short-term success rate. A second meta-regression failed to demonstrate a dose-colectomy response of methylprednisolone therapy beyond 60 mg daily (R(2) < 0.01, P = .98). More than 20 variables were identified in 19 studies to predict medical therapy failure, but only a few were consistently reproduced: disease extent, stool frequency, temperature, heart rate, C-reactive protein, albumin, and radiologic assessment.

CONCLUSIONS

The short-term colectomy rate in severe UC has remained stable during the last 30 years, despite the introduction of cyclosporine, which was not used frequently. We could not find any support for administering methylprednisolone at a higher dose than 60 mg/day. Variables that predict outcome of corticosteroid therapy could aid in the development of guidelines for introduction of rescue therapies in severe UC.

Pediatric inflammatory bowel disease

Inflammatory bowel disease is an important cause of gastrointestinal pathology in children and adolescents. The incidence of pediatric inflammatory bowel disease is increasing; therefore, it is important for the clinician to be aware of the presentation of this disease in the pediatric population. Laboratory tests, radiology studies, and endoscopic procedures are helpful in diagnosing inflammatory bowel disease and differentiating between Crohn’s disease and ulcerative colitis. Once diagnosed, the goal of medical management is to induce remission of disease while minimizing the side effects of the medication. Specific attention needs to be paid to achieving normal growth in this susceptible population. Surgical management is usually indicated for failure of medical management, complication, or malignancy. Algorithms for diagnostic evaluation and treatment of pediatric inflammatory bowel disease are presented. The specific psychosocial issues facing these patients are also discussed in this review as are the future goals of research in the complex problem of pediatric inflammatory bowel disease.