Research and clinical challenges in paediatric inflammatory bowel disease.

Inflammatory bowel disease in childhood has become the subject of intense scientific debate during the last two decades, when there has been a significant rise in its incidence. There is a commonly agreed view that the disorder in children has peculiarities both in terms of underlying mechanisms and clinical management. This review highlights the emerging pathophysiologic concepts and clinical issues in paediatric inflammatory bowel disease and their effects on the management of children with this disorder are discussed. Particular emphasis is given to the link between the improvement of the research in the pathogenetic mechanisms and the development of novel therapeutic strategies able to promote a change in the natural course of the disorder.

Allergic esophagitis in children: a clinicopathological entity.

Infiltration of esophageal epithelium by eosinophils is seen in reflux esophagitis and allergic gastroenteritis. This study was performed to identify differences between patients with acid reflux esophagitis and those with non-acid reflux, possibly allergic, esophagitis. Intraepithelial eosinophils were demonstrated in posttherapy esophageal biopsy specimens in 28 children treated for gastroesophageal reflux disease (GERD). These patients were divided into three groups based on their response to treatment and the results of esophageal pH probe monitoring. Eleven patients (Group A) had incomplete clinical response and normal pH probe monitoring results. Ten patients (Group B) had incomplete response but did not have pH probe monitoring. These two groups formed the index population. Seven patients (Group C) had clinical improvement with GERD therapy and abnormal pH probe monitoring characteristic of GERD; they constituted the control population. Clinical, laboratory, and pathologic features were evaluated to detect differences between index and control populations. Dysphagia, food impaction, failure to thrive, peripheral eosinophilia, and abnormal allergen skin test results were detected only in Group A and B patients. Biopsy specimens of the distal 9 cm of the esophagus, after GERD therapy, contained larger numbers of eosinophils in Groups A and B than in Group C as shown on high-power fields (HPF) (A: 31/HPF +/- 19.5; B: 28/HPF +/-23.7; versus C: 5/HPF +/-6.7; p = 0.009). Eosinophil aggregates were identified only in Groups A and B (p = 0.07). Eosinophils located preferentially in the superficial layers of the squamous epithelium were noted only in Groups A and B (p = 0.02). Group A and B patients demonstrated clinical improvement when given antiallergic therapy. The authors identified a group of pediatric patients characterized by an allergic history, lack of adequate response to GERD therapy, normal esophageal pH probe monitoring results, and large numbers of eosinophils in esophageal biopsy specimens obtained after GERD treatment. On the basis of these features, the authors propose that these patients represent examples of allergic esophagitis.

Thalidomide in gastrointestinal disorders.

Thalidomide was originally marketed as a sedative, but was removed from the market in 1961 after it was associated with an epidemic of severe birth defects. Subsequently, it has been shown to have therapeutic efficacy in a number of the gastrointestinal tract conditions characterised by immune dysregulation. The exact mechanism of the immunosuppressive effects of thalidomide is unknown; proposed mechanisms include inhibition of tumour necrosis factor alpha release and inhibition of angiogenesis. In chronic graft versus host disease, use of high dose thalidomide (1200 mg/day) may bring about a response in 20% of patients with refractory disease. Thalidomide 200 mg/day helps eradicate ulcers in 50% of patients with HIV-associated oral aphthous ulceration. In Behçet's disease, thalidomide 100 to 300 mg/day can decrease the number of mucocutaneous ulcers, although full remission occurs in less than 20% of patients. In Crohn's disease, thalidomide 50 to 300 mg/day may decrease the severity of mucosal disease and prompt closure of fistulae. Patients to be placed on thalidomide therapy must practice either abstinence or strict birth control; women must undergo regular pregnancy testing and utilise 2 forms of contraception. Other adverse effects include sedation (present in nearly all patients), symptomatic neuropathy (present in approximately 20%), and skin rashes. Given the potential toxicity, thalidomide use should generally be limited to clinical protocols with institutional review board oversight.

Minocycline-related autoimmune hepatitis: case series and literature review.

BACKGROUND: Minocycline is an antibiotic commonly used in the treatment of adolescent acne. OBJECTIVES: To describe the clinical, laboratory, and histological features in 3 cases of minocycline-related autoimmune hepatitis and to review the literature of similar cases in the adolescent population. DESIGN: Case series. SETTING: Patients were cared for in the Division of Gastroenterology, Children's Hospital, Boston, Mass. RESULTS: Three adolescents (age, 15-16 years), while being treated with therapeutic doses of minocycline for periods of 12 to 20 months, met the 1993 International Autoimmune Hepatitis Group criteria for autoimmune hepatitis. All had a positive antinuclear antibody titer. Other features included hypergammaglobulinemia and a positive anti-smooth muscle antibody titer. Two patients underwent liver biopsy that revealed severe chronic lymphoplasmacytic inflammation, necrosis, and fibrosis. All other causes of liver disease were excluded. One patient had resolution of symptoms with withdrawal of the drug, while 2 required immunosuppression therapy. A review of the literature yielded only 18 similar cases, none in the pediatric literature, the majority of which contained incomplete pertinent data. CONCLUSIONS: Minocycline is related to the development of autoimmune hepatitis in some adolescents. Pediatricians who use this drug for treatment of acne should be aware of this serious potential relation and stop the drug immediately when suspicion is raised.

Cyclic vomiting syndrome in adults.

Cyclic vomiting syndrome (CVS) was initially described in children but can occur in all age groups. Cyclic vomiting syndrome is increasingly recognized in adults. However, the lack of awareness of CVS in adults has led to small numbers of diagnosed patients and a paucity of published data on the causes, diagnosis and management of CVS in adults. This article is a state-of-knowledge overview on CVS in adults and is intended to provide a framework for management and further investigations into CVS in adults.

Imaging of neuroblastoma: an overview.

This review article briefly describes the pathology, clinical features, prognosis, and treatment of neuroblastoma. The emphasis is on applications of newer diagnostic modalities (sonography, nuclear scintigraphy, computed tomography) for imaging and staging. The potential role of magnetic resonance imaging and spectroscopy is discussed.

Intraduodenal hematoma complicating intestinal biopsy: case reports and review of the literature.

We report two cases of postbiopsy duodenal hematoma and review 14 additional cases. Duodenal hematoma predominantly occurs in children and presents with abdominal pain, vomiting, and pancreatitis. Upper gastrointestinal series, abdominal ultrasound, and CT scan are useful in visualizing the hematoma. No comparative studies of the usefulness of these techniques are available, but a CT is indicated if perforation is suspected. The treatment is conservative if no perforation is detected, and resolution of symptoms generally occurs within 2 wk.

Abdominal migraine in children with neurofibromatosis type 1: a case series and review of gastrointestinal involvement in NF1.

BACKGROUND: Symptomatic involvement of the gastrointestinal tract in children with neurofibromatosis type 1 (NF1) is rare. Most reported complications in adults are caused by the presence of neurofibromas in the stomach, small bowel, or mesentery. In contrast, abdominal pain in children with NF1 may be the result of nonanatomic causes, such as migraine. There are no previous reports of an association between abdominal migraine and NF1. METHODS: Children with abdominal migraine were identified from a group of children with NF1, all of whom had been followed up for a minimum of 3 years. Medical records of cases were reviewed independently by two authors. MEDLINE was searched via PubMed for all reports of children with NF1 and any associated gastrointestinal involvement. RESULTS: Six children with NF1 and intermittent, episodic, severe abdominal pain are reported. Investigations for obstructive or inflammatory causes of abdominal pain were negative. All patients had previously been diagnosed with migraine headaches by a neurologist. In five of the six patients, propranolol (10-15 mg three times daily) resulted in relief of their abdominal pain within days of starting therapy. Our review identified 24 children in the medical literature with gastrointestinal complications of NF1, mostly secondary to visceral neurofibromas. In almost all of these cases, clinical examination and simple radiologic investigations led to the definitive diagnosis. There were no reports of abdominal migraine complicating NF1. CONCLUSIONS: Abdominal pain secondary to migraine is an unrecognized cause of abdominal pain in children with NF1 and may be more common than anatomic causes of abdominal pain in children with NF1. In children with NF1 and severe recurrent abdominal pain in whom an evaluation for anatomic lesions is negative, a trial of migraine therapy may be indicated.

Elevated serum hepatocyte growth factor in children and young adults with inflammatory bowel disease.

BACKGROUND: Elevated serum levels of several potent angiogenesis factors, including vascular endothelial growth factor and basic fibroblast growth factor have been described in children with active inflammatory bowel disease. Angiogenesis-promoting cytokines may promote inflammation by increasing vascular permeability but also mediate tissue repair by activating fibroblasts. Hepatocyte growth factor (HGF) is another angiogenesis-promoting cytokine that is increased in colon cancer tissues. We therefore evaluated serum HGF levels in individuals with Crohn disease and ulcerative colitis. METHODS: Serum samples were obtained from 60 patients with Crohn disease, 31 with ulcerative colitis, and 38 controls with functional abdominal pain and other gastrointestinal illnesses. Disease activity for Crohn disease patients was determined using the pediatric Crohn disease activity index, and for ulcerative colitis patients using the Kozarek score. The HGF levels were measured by enzyme-linked immunosorbent assay. RESULTS: Serum HGF levels were significantly ( P < 0.001) higher for Crohn disease patients (1439 +/- 84 pg/mL) and ulcerative colitis patients (1384 +/- 107 pg/mL) than for control patients (807 +/- 50 pg/mL). Serum HGF levels also rose with increasing disease activity in individuals with both Crohn disease and ulcerative colitis. CONCLUSION: Serum HGF is elevated in children and young adults who have Crohn disease or ulcerative colitis. Levels of serum HGF correlate directly with disease activity. The raised serum HGF suggests that HGF may mediate angiogenesis and vascular permeability in the mucosa of children with inflammatory bowel disease. Alternatively, the raised serum HGF may be an epiphenomenon of inflammation.

Elevation of serum interleukin-6 but not serum-soluble interleukin-2 receptor in children with Crohn's disease.

Previous studies have demonstrated elevated serum levels of interleukin-6 (IL-6) and the soluble interleukin-2 receptor (IL-2R, CD25) in individuals with inflammatory bowel disease (IBD). The aim of our study was to compare serum IL-6 and IL-2R levels to see if one marker better distinguished IBD from other intestinal disorders or better reflected disease activity. Blood samples were obtained from 41 pediatric patients with Crohn's disease, 22 with ulcerative colitis, 19 with other gastrointestinal inflammatory disorders, and 13 with functional abdominal pain. Disease activity and disease location were determined for patients with Crohn's disease and ulcerative colitis. Serum levels of IL-6 and IL-2R were determined by using an enzyme-linked immunosorbent assay. Mean serum levels of IL-6 were significantly elevated (p < 0.05) in patients with Crohn's disease when compared with individuals with ulcerative colitis, other gastrointestinal inflammatory disorders, or functional abdominal pain. By comparison, there was no significant difference in mean serum levels of IL-2R in individuals with Crohn's disease compared with these other groups. Patients with moderate/severe Crohn's disease had elevated mean serum levels of IL-6 and IL-2R when compared with those with mild and inactive disease (p < 0.05); however, neither marker distinguished between inactive and mild disease. IL-6 correlated better with the erythrocyte sedimentation rate (ESR; r = 0.57, p < 0.001) than did IL-2R (r = 0.28, p < 0.01). Our results suggest that elevated IL-6 levels a.e more likely to be seen in patients with Crohn's disease. Although IL-6 may be a better marker for Crohn's disease and active disease than IL-2R, it does not appear to offer any advantage over the ESR.

Interleukin-2 fusion protein (DAB389IL-2) selectively targets activated human peripheral blood and lamina propria lymphocytes.

Activated mucosal T lymphocytes correlate with the intestinal inflammation of inflammatory bowel disease. Activated T cells elaborate interferon-gamma (IFN-gamma) and express high-affinity interleukin-2 (IL-2) receptors. The IL-2/diphtheria toxin fusion protein (DAB389IL-2) has been shown to specifically kill high affinity IL-2 receptor-bearing cells. We tested whether DAB389IL-2 could specifically target activated lamina propria lymphocytes. Lymphocytes were activated in vitro with phytohemagglutinin and IL-2 for 24-48 hr. Toxin efficacy was determined by the [14C]leucine incorporation, IFN-gamma ELISA, and flow cytometry. DAB389IL-2 (10(-11) M) inhibited protein synthesis by 80% in activated lamina propria lymphocytes. This inhibition was blocked by coculture of either excess IL-2 or a nonfunctional IL-2 diphtheria toxin mutant protein. DAB389IL-2 (10(-12) M) also significantly reduced the numbers of activated helper T cells and IFN-gamma levels in 24-hr cultures. DAB389IL-2 specifically targets activated IL-2 receptor-positive lamina propria lymphocytes and is a potential new therapeutic agent for patients with active inflammatory bowel disease.

Serum leptin in children and young adults with inflammatory bowel disease.

BACKGROUND: Pediatric inflammatory bowel disease is often associated with growth failure and inadequate energy intake. Although several circulating cytokines are known to be elevated in inflammatory bowel disease, the mechanism for the related anorexia has not been described. Leptin is a newly recognized circulating protein that is an important regulator of appetite and energy metabolism; leptin levels are elevated in several animal models of inflammation. This study was conducted to determine whether serum leptin levels are elevated in young patients with inflammatory bowel disease. METHODS: One hundred twelve children and young adults with Crohn's disease or ulcerative colitis were studied prospectively. Forty-two patients with other gastrointestinal illnesses were used as control subjects. Height, weight, erythrocyte sedimentation rate, serum albumin concentration, and clinical information were collected prospectively, and leptin was measured by radioimmunoassay of stored serum. RESULTS: No significant differences in leptin levels were found among disease groups or control subjects. Body mass index and gender were the only independent predictors of serum leptin in all groups examined. Disease activity varied inversely with serum leptin in patients with Crohn's disease, but these differences were explained entirely by variations in body mass index. CONCLUSIONS: The determinants of serum leptin were the same in young patients with inflammatory bowel disease as in normal populations, indicating that alterations in leptin levels are unlikely to mediate the anorexia and growth failure associated with this disease.

Elevated serum vascular endothelial growth factor in children and young adults with Crohn's disease.

Vascular endothelial growth factor (VEGF) is a cytokine released by fibroblasts, epithelial cells, and leukocytes that potentiates vascular permeability and growth of new capillaries. Because of these multiple effects, VEGF has been postulated to play a role in the pathogenesis of autoimmune disease, as well as in wound healing. We hypothesized that VEGF was potentially important in mediating the vascular permeability and angiogenesis seen in Crohn's disease, and therefore that VEGF would be increased in the serum of children with Crohn's disease. Serum was obtained from 73 children and young adults with Crohn's disease, 47 with ulcerative colitis, and 29 controls. VEGF levels were measured by enzyme-linked immunosorbent assay. Mean VEGF levels were significantly higher in patients with Crohn's disease (436.4 +/- 37.2 pg/ml) than in ulcerative colitis (306 +/- 41.1 pg/ml) or control (167.8 +/- 29.6 pg/ml) patients. Serum VEGF also correlated significantly with disease activity, being elevated in patients with moderate/severe Crohn's disease and ulcerative colitis. We conclude that serum VEGF is released by inflamed tissues in children with Crohn's disease. This multifunctional cytokine could promote inflammation by increasing vascular permeability or promote wound healing by mediating capillary growth.

Treatment of pediatric autoimmune enteropathy with tacrolimus (FK506).

Autoimmune enteropathy is characterized by chronic secretory diarrhea, villous atrophy, associated autoantibodies, and a partial response to immunosuppression. Currently available therapy (including steroids and cyclosporine) has resulted in remission only in a subset of patients. We evaluated the effects of tacrolimus (FK506) in patients with autoimmune enteropathy refractory to steroids and cyclosporine. Three patients with diagnosed autoimmune enteropathy who continued to have intractable diarrhea despite treatment with steroids and/or cyclosporine were treated with oral tacrolimus. Despite documented histological villous atrophy and poor absorption of oral cyclosporine, therapeutic tacrolimus levels were easily achieved in all 3 patients. All patients showed clinical improvement as documented by decreased stool output and ability to be weaned off parenteral nutrition; response time ranged from 1 to 4 months after tacrolimus was begun. Histological improvement was noted in all patients, and the small bowel biopsy specimens of 2 of the 3 patients showed a return to normal. All patients have been followed up for at least 6 months and are in clinical remission; 1 has received a bone marrow transplant for underlying immunodeficiency. Tacrolimus is a useful drug in the treatment of autoimmune enteropathy, even in patients who have not responded to steroids or cyclosporine. No long-term follow-up of patients with autoimmune enteropathy treated with tacrolimus is currently available.

Serum basic fibroblast growth factor in pediatric Crohn's disease. Implications for wound healing.

Basic fibroblast growth factor is a heparin-binding protein known to stimulate angiogenesis and promote wound healing in tissues. Since Crohn's disease is characterized in part by submucosal vascular proliferation, we sought to determine whether serum basic fibroblast growth factor is elevated in children with Crohn's disease and whether serum levels reflect disease activity. Sera were obtained from 64 children with Crohn's disease, 44 children with ulcerative colitis, 20 children with functional abdominal pain, and 29 from children with documented inflammatory disease evaluated in our gastroenterology program. Disease activity indices and clinical data were gathered prospectively for the inflammatory bowel disease patients. Serum basic fibroblast growth factor levels were measured by enzyme-linked immunosorbent assay. Although the mean basic fibroblast growth factor level did not significantly differ between children with Crohn's disease and other conditions, there was a strong (r = 0.53, P < 0.001) correlation between basic fibroblast growth factor level and disease activity. The relationship of basic fibroblast growth factor with disease activity persisted even after adjusting for other covariates (including age, sex, hematocrit, albumin, and sedimentation rate) in a multivariate linear regression model. There was also a statistically significant, although less strong correlation (r = 0.33, P = 0.03) between basic fibroblast growth factor level and disease activity in ulcerative colitis. While basic fibroblast growth factor is not a specific marker for Crohn's disease, serum levels reflect disease activity. Therefore, basic fibroblast growth factor release may be important in mediating the angiogenesis and wound healing seen in Crohn's disease.

Vitamins A and E serum levels in children and young adults with inflammatory bowel disease: effect of disease activity.

BACKGROUND: Hypovitaminosis and fat-soluble vitamin deficiency have been reported in adults with inflammatory bowel disease (IBD). A prospective study was undertaken to determine the prevalence of low serum levels of vitamins A and E in children and young adults with IBD. METHODS: Clinical information and serum for vitamin levels was gathered prospectively from 61 patients with Crohn's disease, 36 patients with ulcerative colitis, and 23 control subjects. Disease activity and disease location were determined for IBD patients. Serum retinol and alpha-tocopherol levels were determined by high-performance liquid chromatography. RESULTS: The prevalence of hypovitaminosis A (defined as serum vitamin A < 20 micrograms/dl) or hypovitaminosis E (defined as serum vitamin E < 5 mg/l) was 16% in the pediatric IBD population studied. Low vitamin A levels were more common than low vitamin E levels. Serum retinol levels correlated significantly with alpha-tocopherol levels. Hypovitaminosis was significantly more prevalent in the Crohn's disease patients who had active disease, an erythrocyte sedimentation rate of more than 25 mm/hour, or a serum albumin level less than 3 mg/dl. CONCLUSIONS: Children and young adults with active IBD frequently have low serum levels of vitamin A or vitamin E. The severity of disease activity is a better predictor of risk for hypovitaminosis than is nutritional status. Further work is necessary to determine whether the hypovitaminosis seen in children with IBD reflects true deficiency.

Inflammatory bowel disease associated with immune thrombocytopenic purpura in children.

OBJECTIVE: Previous reports suggest an association between inflammatory bowel disease (IBD) and immune thrombocytopenic purpura (ITP) in adults. To date, only five children with both diseases have been described. The aim of the study was to describe the characteristics of children with IBD and ITP. METHODS: Cases were obtained from the pediatric gastroenterology community by means of the pediatric gastroenterology internet bulletin board in June 1999. Eight cases were submitted from seven medical centers. Medical records were reviewed by two pediatric gastroenterologists and a pediatric hematologist. RESULTS: The age range of the patients was 2.1 to 16.5 years, with a mean age of 9.6 +/- 5.2 years. Four children had ulcerative colitis, three had Crohn disease, and one had indeterminate colitis. All had colonic involvement of IBD. Of eight patients, three had IBD first, three had ITP first, and two had both simultaneously. At ITP diagnosis, platelet count was less than 10,000/mL in five children, 17,000/mL in one child, and 50,000 to 60,000/mL in two children. Of the three children diagnosed with ITP first, two initially had rectal bleeding at the time of ITP diagnosis. Bone marrow evaluations, performed in six of eight children, were consistent with ITP. Six of the eight children had chronic ITP, including three children who were 5 years of age or younger. Therapy for ITP included steroids (n = 6), intravenous immunoglobulin (n = 6), Rh o (D) intravenous immunoglobulin (n = 2), and splenectomy (n = 1). CONCLUSIONS: The authors describe the largest pediatric case series of children with IBD and ITP. More than 50% of the children had the chronic form of ITP. Most patients responded to conventional therapy for ITP and IBD.

Clinical outcome of ulcerative proctitis in children.

BACKGROUND: Although the course of ulcerative proctitis in adults has been well described, little data are available concerning its clinical behavior in children and adolescents. This study sought to characterize the presentation, response to therapy, and long-term course of ulcerative proctitis in the pediatric population. METHODS: A retrospective chart review was conducted at five pediatric gastroenterology centers. RESULTS: A total of 38 subjects (mean age 11.6 years) were identified with ulcerative proctitis (mean follow-up 4.3 years). Symptoms were mild at diagnosis in 74% and moderate or severe in 26%. Thirty-two percent had a complaint of constipation at presentation. Cessation of symptoms was noted in 68% within 3 months of therapy, an additional 24% within 6 months, and 8% were still symptomatic despite 6 months of therapy. During any subsequent yearly follow-up interval, -55% of patients were asymptomatic, 40% had a chronic intermittent course, and < 5% were continuously symptomatic despite therapy. Eight subjects were treated with oral corticosteroids, one with 6-mercaptopurine, and one with cyclosporine. Extension of inflammation proximal to the rectosigmoid occurred in 11 of 38 subjects (29%), 0.5-11.3 years postdiagnosis. Seven of the 13 subjects (54%) followed for > or = 5 years had proximal extension of disease, and two had undergone colectomy. CONCLUSIONS: Despite a mild presentation in most subjects, ulcerative proctitis seems to have a high risk of proximal extension of disease. The overall response to therapy seems to be similar to that reported for ulcerative colitis in children. Follow-up endoscopic evaluation of patients with ulcerative proctitis seems warranted, especially in the setting of recurrent or recalcitrant symptoms.

Chronic recurrent multifocal osteomyelitis associated with chronic inflammatory bowel disease in children.

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare disease of children characterized by aseptic inflammation of the long bones and clavicles. No infectious etiology has been identified, and CRMO has been associated with a number of autoimmune diseases (including Wegener's granulomatosis and psoriasis). The relationship between CRMO and inflammatory bowel disease is poorly described. Through an internet bulletin board subscribed to by 500 pediatric gastroenterologists, we identified six inflammatory bowel disease patients (two with ulcerative colitis, four with Crohn's colitis) with confirmed CRMO. In all cases, onset of the bony lesions preceded the onset of bowel symptoms by as much as five years. Immunosuppressive therapy for the bowel disease generally resulted in improvement of the bone inflammation. Chronic recurrent multifocal osteomyelitis should be considered in any inflammatory bowel disease patient with unexplained bone pain or areas of uptake on bone scan. CRMO may be a rare extraintestinal manifestation of inflammatory bowel disease; alternatively, certain individuals may be genetically predisposed to the development of both diseases.