Validation of the Rome III criteria and alarm symptoms for recurrent abdominal pain in children.

OBJECTIVES: Rome criteria were formulated to define functional gastrointestinal disorders (Rome III criteria, 2006) excluding organic diagnoses when alarm symptoms were absent. The aims of the study were to validate the Rome III criteria as to their capacity to differentiate between organic and functional abdominal pain and to assess the role of alarm symptoms in this differentiation. METHODS: During 2 years all of the patients (ages 4-16 years) presenting with recurrent abdominal pain (Apley criteria) and referred to secondary care were included. Clinical diagnoses were based on protocolized evaluation and intervention with 6-month follow-up. Alarm symptoms were registered. Rome III criteria for functional pain syndromes were assigned independently. Descriptive statistical analyses were performed. RESULTS: In 200 patients (87 boys, mean age 8.8 years), organic (17%), functional (40%), combined organic and functional (9%), spontaneous recovery (27%), and other (8%) clinical diagnoses were established. Alarm symptoms were found in 57.5% (organic causes 56%, functional causes 61%). The evaluation for Rome symptom clusters revealed symptoms of irritable bowel syndrome in 27%, functional dyspepsia in 15%, functional abdominal pain in 28%, functional abdominal pain syndrome in 14.5%, and no pain syndrome in 15.5%. Rome diagnoses, based on symptoms and absence of alarm symptoms, predicted functional clinical diagnosis with sensitivity 0.35 (95% confidence interval 0.27-0.43), specificity 0.60 (0.46-0.73), positive predictive value 0.71 (0.61-0.82), and negative predictive value of 0.24 (0.17-0.32). CONCLUSIONS: The Rome III criteria for abdominal pain are not specific enough to rule out organic causes. Alarm symptoms do not differentiate between organic and functional abdominal pain.

Occult constipation: faecal retention as a cause of recurrent abdominal pain in children.

UNLABELLED: Recurrent abdominal pain (RAP) in children is generally believed to be functional. In practice, many children with RAP become pain-free with laxative therapy. The aims of the study were to establish the role of (occult) constipation in RAP and to investigate whether patients diagnosed with (occult) constipation could be identified by history and physical examination. During 2 years, all patients (age 4-16 years, secondary referral) fulfilling Apley criteria of RAP were included. After exclusion of gastrointestinal infections and food intolerance, laxatives were advised when pain persisted. (Occult) constipation was defined as 'abdominal pain disappearing with laxative treatment and not reappearing within a 6 month follow up period'; 'occult constipation' was diagnosed in patients who did not fulfil the Rome criteria of constipation. Two hundred children (87 M; median age 8.8 years) were evaluated. (Occult) constipation was found in 92 patients (46 %). Of these, 18 had considerable relief of pain when treated for a somatic cause but experienced complete relief only after laxative measures; they were considered to have two diagnoses. Using multivariate analysis, a simple model was developed with cystitis in past history, early satiety and flatulence as predictors for (occult) constipation. The risk of (occult) constipation ranged from 18/58 if no predictor was present to 4/4 if all three were present. CONCLUSION: Laxatives played a pivotal role in the recovery of patients with RAP. We developed a simple model to identify patients at risk of having (occult) constipation.

Protozoa as a cause of recurrent abdominal pain in children.

OBJECTIVES: The aim of this study was to investigate whether protozoa can be identified as a cause of recurrent abdominal pain (RAP), and whether protozoan infections can be recognized by a specific clinical presentation. METHODS: For 2 years, all patients (ages 4-16 years) fulfilling the Apley criteria of RAP referred to secondary care were prospectively evaluated for protozoa (Giardia lamblia, Dientamoeba fragilis, Blastocystis hominis) and treated if positive. Re-examination followed at least 10 days after treatment. Disappearance of pain with eradication and a pain-free follow-up of at least 6 months were considered to be indicative of a causal relation with RAP. The predictive value of the characteristics of the pain for protozoan infections was calculated. RESULTS: Of 220 included patients (92 boys, mean age 8.8 years), 215 brought a stool sample; 73 (34%) carried parasites, 10 of whom had 2 parasites, 2 had 3 parasites. Sixty-five patients were treated. Twenty-five (11%) were pain-free after eradication (21 had D fragilis, 8 B hominis, 4 G lamblia), of whom 11 had another infection (2) or constipation (9) as second diagnosis for the pain. Five had recurrence of infection with D fragilis and were again pain-free with eradication. Patients with protozoa as cause of their pain did not show differences with respect to their presentation when compared with patients with an asymptomatic infection and patients without protozoa. CONCLUSIONS: Protozoa were found as the cause of pain in 6% to 11% of children with RAP. These patients did not show a characteristic presentation when compared with patients with other causes of abdominal pain.

MYO5B mutations in patients with microvillus inclusion disease presenting with transient renal Fanconi syndrome.

BACKGROUND AND OBJECTIVE: : Microvillus inclusion disease (MVID) is a rare congenital enteropathy associated with brush border atrophy and reduced expression of enzymes at the enterocytes' apical surface. MVID is associated with mutations in the MYO5B gene, which is expressed in all epithelial tissues. Whether organs other than the intestine are affected in MVID is unclear. We report 2 patients with MVID that developed renal Fanconi syndrome while receiving total parenteral nutrition. Renal Fanconi syndrome has been correlated to apical plasma membrane defects in kidney proximal tubular epithelial cells. The aim of the present study was to determine whether MYO5B mutations in these patients correlate with similar apical plasma membrane defects in renal tubular epithelial cells as observed in the intestine. METHODS: : Biopsies from kidney, duodenum, ileum, jejunum, and colon of 2 patients with MVID carrying MYO5B mutations and of age-matched controls were fixed in paraffin and analyzed with immunohistochemistry and transmission electron microscopy. RESULTS: : Structural defects of the brush border and apical recycling endosome organization are observed in enterocytes of all of the segments of the small intestine and colon. MYO5B mutations in patients with MVID with renal Fanconi syndrome do not correlate with aberrant apical plasma membrane morphology or altered apical recycling endosome organization in renal tubular epithelial cells. CONCLUSIONS: : MYO5B mutations have divergent effects on the apical membrane system in kidney and intestinal epithelial cells. Epithelial defects presented in MVID are therefore likely triggered by intestine-specific factors, the identification of which may provide new targets and open avenues for the development of alternative therapeutic strategies to combat this devastating disease.

Four novel mutations in the lactase gene (LCT) underlying congenital lactase deficiency (CLD).

BACKGROUND: Congenital lactase deficiency (CLD) is a severe gastrointestinal disorder of newborns. The diagnosis is challenging and based on clinical symptoms and low lactase activity in intestinal biopsy specimens. The disease is enriched in Finland but is also present in other parts of the world. Mutations encoding the lactase (LCT) gene have recently been shown to underlie CLD. The purpose of this study was to identify new mutations underlying CLD in patients with different ethnic origins, and to increase awareness of this disease so that the patients could be sought out and treated correctly. METHODS: Disaccharidase activities in intestinal biopsy specimens were assayed and the coding region of LCT was sequenced from five patients from Europe with clinical features compatible with CLD. In the analysis and prediction of mutations the following programs: ClustalW, Blosum62, PolyPhen, SIFT and Panther PSEC were used. RESULTS: Four novel mutations in the LCT gene were identified. A single nucleotide substitution leading to an amino acid change S688P in exon 7 and E1612X in exon 12 were present in a patient of Italian origin. Five base deletion V565fsX567 leading to a stop codon in exon 6 was found in one and a substitution R1587H in exon 12 from another Finnish patient. Both Finnish patients were heterozygous for the Finnish founder mutation Y1390X. The previously reported mutation G1363S was found in a homozygous state in two siblings of Turkish origin. CONCLUSION: This is the first report of CLD mutations in patients living outside Finland. It seems that disease is more common than previously thought. All mutations in the LCT gene lead to a similar phenotype despite the location and/or type of mutation.

Infliximab dependency in pediatric Crohn's disease: long-term follow-up of an unselected cohort.

BACKGROUND: Infliximab is effective for induction and maintenance of remission in Crohn's disease. It is unknown how long patients should be kept on infliximab therapy. The primary aim of this study was to assess duration of effective maintenance therapy and infliximab dependency in pediatric CD patients initially responding to infliximab therapy. METHODS: All pediatric patients treated with infliximab by pediatric gastroenterologists in the Netherlands because of severe luminal or fistulizing CD with initial response to infliximab therapy were reviewed. Duration of therapy, clinical response and adverse events were recorded. RESULTS: Sixty-six CD patients (37 boys) in 10 hospitals were initially responding to infliximab therapy. Mean age at the start of infliximab therapy was 14.5 years (range, 8.1-18.5 years). Mean follow-up since infliximab was started was 41.3 months (range 12-165). In total, 991 infusions were administered. Analysis demonstrates that 15.2% of patients had prolonged response, while 56.1% were infliximab dependent and 28.8% lost response. In total, 10 patients (15.2%) developed an infection during infliximab therapy and 8 (12.1%) had an immediate allergic reaction. CONCLUSIONS: Good clinical response to maintenance infliximab therapy was seen in 70% of patients. Infliximab maintenance therapy seems very effective and safe in pediatric CD. However, more than half of the patients in this cohort is dependent on repeated infliximab infusions. The number of infliximab infusions received when patients lost response to infliximab was diverse. There was no statistical difference regarding response to infliximab therapy when started early as compared to later in the course of Crohn's disease.