Refractory inflammatory bowel disease in children

Candidiasis associated with very early onset inflammatory bowel disease: First IL10RB deficient case from the National Iranian Registry and review of the literature

Defects in interleukin-10 (IL10) and interleukin-10 receptors (IL10R) are closely related to very early onset (infantile) inflammatory bowel disease (VEO-IBD). In the present study, we report a novel homozygous null mutation within interleukin-10 receptor B (IL10RB) gene in a child presenting with severe VEO-IBD. In accordance with previous reports, our patient manifested with chronic diarrhea, failure to thrive, intermittent fever and multiple anal ulcers associated with Candidiasis. Homozygous null mutation within IL10RB gene (c.92C > T, p.S31P) affecting the extracellular domain of protein was discovered in this patient. In conclusion, the diagnosis of IL-10R gene mutations should always be considered as a possible cause of refractory diarrhea and failure to thrive. Mutation analysis could help detect the genetic defects associated with these clinical manifestations and to determine the most appropriate treatment option for patients affected by this disease.

Clinical features of interleukin 10 receptor gene mutations in children with very early-onset inflammatory bowel disease

OBJECTIVES

In the present study, we studied a cohort of patients with very early onset inflammatory bowel disease (IBD) to determine the frequency of mutations in the interleukin 10 (IL10) receptor genes as a cause of early-onset IBD.

METHODS

Sanger sequencing was performed to determine the presence of IL10 and/or IL10 receptor mutations in 17 patients with a diagnosis of very early onset IBD (disease onset <2 years of age in 15 patients, between 3 and 4 years in the other 2). Mutation screening was performed including all of the coding regions of the IL10, IL10RA, and IL10RB genes. We then compared the follow-up findings of the patients with IL10 receptor mutations in terms of demographic, clinical, laboratory, and treatment response properties with those of patients diagnosed as having very early onset IBD with no mutation.

RESULTS

We identified 3 patients bearing mutations in the IL10 or IL10 receptor genes, including 1 mutation in IL10RB that has been described recently (c.G477A, p.Trp159*) and 2 novel mutations affecting the IL10RA gene (c.T192G, p.Tyr64 and c.T133G, p.Trp45Gly). Collectively, these mutations thus provided genetic etiology for 17.6% of the cohort under investigation. The presence of a family history of IBD and the clinical course of Crohn disease differed between patients with mutations in the IL-10 pathway and those without such mutations. Although perianal fistulas were found in all of the patients with IL10 receptor mutations, they were found in only 14.3% of those without such mutations. The lower values of weight-for-age and height-for-age z scores, necessity for more intensive therapy, achievement of longer periods until remission, and frequent relapses in the patients bearing mutations in the IL10 receptor genes all underlined the severity of the disease and its relatively poor response to treatment.

CONCLUSIONS

In spite of the small number of patients with mutations affecting the IL-10 signaling pathway in our study, in all of the patients with IL10 receptor mutations, the disease onset occurs at an early age, the prognosis is poor, and the response to treatment is insufficient.

Pediatric ulcerative colitis: current treatment approaches including role of infliximab

Ulcerative colitis is a chronic inflammatory bowel disease that can lead to derangements in the growth, nutritional status, and psychosocial development of affected children. There are several medical options for the induction and maintenance of disease remission, but the benefits of these medications need to be carefully weighed against the risks, especially in the pediatric population. As the etiology of the disease has become increasingly understood, newer therapeutic alternatives have arisen in the form of biologic therapies, which are monoclonal antibodies targeted to a specific protein or receptor. This review will discuss the classical treatments for children with ulcerative colitis, including 5-aminosalicylates, corticosteroids, thiopurine immunomodulators, and calcineurin inhibitors, with a particular focus on the newer class of anti-tumor necrosis factor-α agents.

Increase of regulatory T cells in ileal mucosa of untreated pediatric Crohn's disease patients

BACKGROUND

Inflammatory bowel disease (IBD) of pediatric and adult onset differs in several aspects although little knowledge exists about pathogenic disparity. Regulatory T cells (Tregs) characterized as CD4+CD25+Foxp3+ are modulators of gut homeostasis, but their role in human IBD remains unclear.

OBJECTIVE

To evaluate the mucosal distribution of Foxp3+ and CD25+ cells in untreated pediatric IBD patients at the time of diagnosis.

MATERIAL AND METHODS

Untreated pediatric (n = 14) and adult (n = 12) Crohn's disease (CD) patients were prospectively included together with age-matched symptomatic controls. Colonic and ileal mucosal biopsies collected at diagnosis were studied by immunohistochemistry for enumeration of T cells and for mucosal expression of Foxp3 and CD25. Multicolor immunofluorescence staining was performed in situ to phenotype Foxp3+ cells as Tregs and characterize the CD25+ cells.

RESULTS

The density of mucosal T cells displayed only small variations, while that of Foxp3+ cells and CD25+ cells was increased in CD patients. Multicolor immunofluorescence showed that most CD25+ cells were macrophages. Interestingly, in the ileum of pediatric CD patients the density of Foxp3+ cells was significantly higher than in adult CD patients. Co-expression of Foxp3 and CD25, as well as Foxp3 and CTLA-4, indicated that the Foxp3+ cells were Tregs.

CONCLUSION

Mucosal numbers of Foxp3(+) Tregs and activated (CD25+) macrophages are elevated in both pediatric and adult ileal CD. The greater increase of ileal Foxp3+ Tregs in pediatric CD than in adult CD might contribute to the relatively less frequent phenotype of isolated ileal enteritis in CD children.

Steroid response in moderate to severe pediatric ulcerative colitis: a single center's experience

BACKGROUND

we aimed to analyze clinical and inflammatory markers of steroid non-response in patients with moderate/severe ulcerative colitis (UC) at the time of diagnosis.

METHODS

this study included patients who were graded as having moderate/severe UC and received corticosteroids as first-line therapy. Demographic, clinical and laboratory findings and pediatric ulcerative colitis activity scores (PUCAS) were recorded. Response to corticosteroids was assessed 30 days after the induction and long-term therapy.

RESULTS

twenty-eight children were diagnosed as having moderate/severe UC. Their mean age ± SD was 1 2.2 ± 4 years, and 17% were under 5 years of age. PUCAS at their initial admission was 56.9 ± 11.8. UC was observed at the left colon in 9 patients (32.1%), and pancolitis in 19 (67.9%). At the end of the 30th day, UC was completely remitted in 15 patients (53.5%), partially remitted in 2 (7.1%), and no response in 11 (39.2%). Short-term follow-up showed partial remission in 2 patients, and overall remission with steroid in 17 (60.7%). Non-responders were given second-line treatment; steroid dependency was documented in 2 patients (7.1%) and another 2 (7.1%) patients underwent colectomy. Predictors for steroid non-response were analyzed and only PUCAS at the initial admission was found to be associated with non-response to steroids (51.4 ± 11.4 vs. 65.4 ± 6.8, P<0.05).

CONCLUSIONS

approximately half of the pediatric patients had complete response to steroid therapy in a long period. PUCAS could be used as a potential marker of "failed response" to steroid, but should be supported with a number of prospective randomized controlled studies.