Thiopurine metabolite ratios for monitoring therapy in pediatric Crohn disease.

OBJECTIVES: Thiopurines (azathioprine, 6-mercaptopurine) are a mainstay of treatment in Crohn disease (CD). Monitoring intracellular metabolite (6-thioguanine nucleotides [6-TGN] and 6-methylmercaptopurine [6-MMP]) levels can help optimize therapeutic efficacy and minimize potential toxicity. Determination of 6-MMP/6-TGN ratios may provide additional useful information, such as the identification of individuals with excessive thiopurine methyltransferase activity and disadvantageous 6-MMP overproduction. These patients are at increased risk of therapeutic failure and hepatotoxicity. The aim of the study was to evaluate the correlation of 6-MMP/6-TGN ratios with therapeutic efficacy and risk of hepatotoxicity in CD. METHODS: The present study was a single-center cross-sectional study including pediatric patients with CD studied prospectively with clinical and laboratory assessments along with serial measurements of 6-MMP and 6-TGN. Clinical response was determined using established clinical indices. RESULTS: The study included 238 pediatric patients with CD with a total of 1648 evaluation points. The patients were in steroid-free remission at 59.1% of the evaluation points. 6-MMP/6-TGN ratios of 4 to 24 were protective against relapse (odds ratio [OR] 0.52, 95% confidence interval [CI] -0.39 to 0.69, P = 0.001). Hepatotoxicity was associated with high 6-MMP levels (>3919  pmol/8 × 10 red blood cell count: OR 7.65, 95% CI 3.7-15.9, P = 0.001) and high 6-MMP/6-TGN ratios (>24: OR 5.35, 95% CI -3.43 to 8.43, P = 0.001). CONCLUSIONS: We observed significant associations between 6-MMP/6-TGN ratios and clinical response, and risk of hepatotoxicity. Our results suggest that determination of thiopurine metabolite ratios is a valuable tool for identification of patients at increased risk of therapeutic failure and hepatotoxicity.

Association between genetic variants in the HNF4A gene and childhood-onset Crohn's disease.

Hepatocyte nuclear 4 alpha (HNF4α), involved in glucose and lipid metabolism, has been linked to intestinal inflammation and abnormal mucosal permeability. Moreover, in a genome-wide association study, the HNF4A locus has been associated with ulcerative colitis. The objective of our study was to evaluate the association between HNF4α genetic variants and Crohn's disease (CD) in two distinct Canadian pediatric cohorts. The sequencing of the HNF4A gene in 40 French Canadian patients led to the identification of 27 single nucleotide polymorphism (SNP)s with a minor allele frequency >5%. To assess the impact of these SNPs on disease susceptibility, we first conducted a case-control discovery study on 358 subjects with CD and 542 controls. We then carried out a replication study in a separate cohort of 416 cases and 1208 controls. In the discovery cohort, the genotyping of the identified SNPs revealed that six were significantly associated with CD. Among them, rs1884613 was replicated in the second CD cohort (odds ratio (OR): 1.33; P<0.012) and this association remained significant when both cohorts were combined and after correction for multiple testing (OR: 1.39; P<0.004). An 8-marker P2 promoter haplotype containing rs1884613 was also found associated with CD (P<2.09 × 10(-4) for combined cohorts). This is the first report showing that the HNF4A locus may be a common genetic determinant of childhood-onset CD. These findings highlight the importance of the intestinal epithelium and oxidative protection in the pathogenesis of CD.

Phenotypic Variation in Paediatric Inflammatory Bowel Disease by Age: A Multicentre Prospective Inception Cohort Study of the Canadian Children IBD Network.

BACKGROUND AND AIMS: Incidence of paediatric inflammatory bowel disease [IBD] in Canada is among the highest worldwide, and age of onset may be decreasing. In a multicentre nationwide inception cohort study, we examined variation in phenotype of IBD throughout the paediatric age spectrum. METHODS: Children aged ≥2 years [y] and <17y [A1 age at diagnosis], with new onset IBD, were systematically evaluated at sites of the Canadian Children IBD Network. Prospectively recorded phenotypic data were compared between age groups. RESULTS: Among 1092 children (70% Caucasian; 64% Crohn's disease [CD], 36% ulcerative colitis/inflammatory bowel disease unclassified [UC/IBD-U]; median age 13 y, interquartile range [IQR] 11-15 y), 210 [19%] were diagnosed before the age of age 10 y [Paris A1a] and 43 [4%] before age 6 y (very-early-onset [VEO-IBD]). CD was less common in younger children [42%, 56%, 66%, respectively, of VEO-IBD, A1a; A1b]. Colon-only IBD [UC/IBDU or CD-colon] was present in 81% of VEO-IBD and 65% of A1a; ileal disease increased progressively, reaching plateau at age 10 y. CD location was ileocolonic [L3] in 53% overall. Ileitis [L1] increased with age [6% of VEO-IBD; 13% of A1a; 21% of A1b], as did stricturing/penetrating CD [4% of A1a; 11% of A1b]. At all ages UC was extensive [E3/E4] in >85%, and disease activity moderate to severe according to Physician's Global Assessment [PGA] and weighted Paediatric Crohn's Disease Activity Index/Paediatric Ulcerative Colitis Activity Index [wPCDAI/PUCAI] in >70%. Heights were modestly reduced in CD [mean height z score -0.30 ± 1.23], but normal in UC/IBD-U. CONCLUSIONS: Paris classification of age at diagnosis is supported by age-related increases in ileal disease until age 10 years. Other phenotypic features, including severity, are similar across all ages. Linear growth is less impaired in CD than in historical cohorts, reflecting earlier diagnosis.

Role of small-bowel endoscopy in the management of patients with inflammatory bowel disease: an international OMED-ECCO consensus.

Crohn's disease and ulcerative colitis are lifelong diseases seen predominantly in the developed countries of the world. Whereas ulcerative colitis is a chronic inflammatory condition causing diffuse and continuous mucosal inflammation of the colon, Crohn's disease is a heterogeneous entity comprised of several different phenotypes, but can affect the entire gastrointestinal tract. A change in diagnosis from Crohn's disease to ulcerative colitis during the first year of illness occurs in about 10 % - 15 % of cases. Inflammatory bowel disease (IBD) restricted to the colon that cannot be characterized as either ulcerative colitis or Crohn's disease is termed IBD-unclassified (IBDU). The advent of capsule and both single- and double-balloon-assisted enteroscopy is revolutionizing small-bowel imaging and has major implications for diagnosis, classification, therapeutic decision making and outcomes in the management of IBD. The role of these investigations in the diagnosis and management of IBD, however, is unclear. This document sets out the current Consensus reached by a group of international experts in the fields of endoscopy and IBD at a meeting held in Brussels, 12-13th December 2008, organised jointly by the European Crohn's and Colitis Organisation (ECCO) and the Organisation Mondiale d'Endoscopie Digestive (OMED). The Consensus is grouped into seven sections: definitions and diagnosis; suspected Crohn's disease; established Crohn's disease; IBDU; ulcerative colitis (including ileal pouch-anal anastomosis [IPAA]); paediatric practice; and complications and unresolved questions. Consensus guideline statements are followed by comments on the evidence and opinion. Statements are intended to be read in context with qualifying comments and not read in isolation.

Successful videocapsule endoscopy in patients with an abdominal cardiac pacemaker.

Pacemaker location in the abdominal wall is considered a contraindication to videocapsule endoscopy (VCE). The aim of this study was to review our experience on the use of VCE in patients with a pacemaker located in the abdominal wall. VCE was carried out with monitoring of cardiac rhythm. This was a retrospective review of VCE case studies performed at two tertiary care university medical centers (pediatric and adult). The main outcome measures were adverse events and quality of VCE images. No adverse events were experienced in any of the five patients with implanted cardiac pacemakers, including the two with abdominal pacemaker. No interference with the VCE recording was observed during the studies, although the capsule was observed to be briefly inactivated by the pacemaker in one case. The present study, though small, suggests that VCE is safe in adult and pediatric patients who are fitted with cardiac pacemakers, even when implanted in the abdominal wall. The VCE exam can be carried out successfully under close supervision. Dysfunction of the capsule appears to be more likely than problems with cardiac pacing.

Review and clinical perspectives for the use of infliximab in ulcerative colitis.

Infliximab is a chimeric, monoclonal anti-tumour necrosis factor-alpha antibody. It has been previously demonstrated to be an effective treatment for patients with Crohn's disease who do not achieve the desired response with conventional treatments. Although the etiology of ulcerative colitis (UC) differs from that of Crohn's disease, randomized controlled trials have demonstrated that infliximab is also beneficial for the treatment of moderate to severe UC in patients who are either intolerant of or refractory to immunosuppressant agents or steroids, or those who are steroid-dependent. A review of the literature is followed by practical recommendations regarding infliximab that address the needs of clinicians and UC patients. Where there is a lack of evidence-based information, the expert panel provides its combined opinion derived from the members' clinical experiences.

Evidence of allelic heterogeneity for associations between the NOD2/CARD15 gene and ulcerative colitis among North Indians.

BACKGROUND: Three common disease susceptibility variants in the NOD2 gene are associated with inflammatory bowel disease in Caucasians, but not in Asians. Aim To screen for NOD2 variants and examine susceptibility for inflammatory bowel disease in North Indians. METHODS: A case-control study was carried out in Punjab, India. Confirmed cases of ulcerative colitis and Crohn's disease and healthy controls matched for age (+/-10 years) and ethnicity were studied. Besides genotyping the three disease susceptibility variants (SNP8, SNP12 and SNP13), all 12 exons were resequenced to determine other potential single nucleotide polymorphisms. RESULTS: Two hundred and ninety-eight ulcerative colitis, 25 Crohn's disease and 262 controls were investigated. Median age (range) at diagnosis was 39 (7-78) years for ulcerative colitis and 40 (32-58) years for Crohn's disease. All three disease susceptibility variants were either monomorphic or rare in the population. Sequencing (n = 30) revealed two single nucleotide polymorphisms: SNP5 (268 Pro/Ser) and rs2067085 (178 Ser/Ser). The frequency of SNP5 was higher among ulcerative colitis (17% vs. 12% in controls, P = 0.016) and Crohn's disease cases (20% vs. 12%, P = 0.28). SNP5 carriers had elevated risks for ulcerative colitis (OR = 1.72, 95% CI = 1.17-2.52, P = 0.005). CONCLUSIONS: The absence of known inflammatory bowel disease susceptibility variants and potential associations between SNP5 and ulcerative colitis in North Indians suggests the presence of allelic heterogeneity for ulcerative colitis susceptibility.

Endogenous lipase activity in Caco-2 cells.

Dietary triglycerides, the major precursors of long chain fatty acids (FA), require hydrolysis by pancreatic enzymes prior to their absorption by the small intestine. Although Caco-2 cells are frequently employed for the study of enterocyte lipid metabolism, the presence of an endogenous lipase activity has never been previously reported. The major goal of this investigation was to determine the presence of endogenous Caco-2 cell lipase activity, to examine its capacity to hydrolyze triglycerides, and to define its intracellular location. Caco-2 cells were found to have an endogenous lipase activity, capable of hydrolyzing [1-14C]triolein from the apical cell compartment. A time and concentration dependence of lipase activity was observed, with hydrolysis of triolein into free fatty acids and monoglyceride. The majority of the lipase activity was found in the cytosolic cell fraction and, to a lesser extent, in the apical brush border membrane and other organelles. Protamine sulfate markedly reduced the Caco-2 cell lipase activity, yet it remained relatively insensitive to high concentrations of NaCl, taurocholate, calcium, heparin and chloroquine. The addition of exogenous human gastric lipase to the medium of the apical compartment resulted in a significant increased rate of hydrolysis of triolein, followed by enhanced Caco-2 cell fatty acid uptake and basolateral lipid secretion. The major esterified intracellular lipids were triglycerides and phospholipids. We conclude that Caco-2 cells possess an endogenous lipase capable of hydrolyzing cytosolic triglycerides. Furthermore, activity present on the apical membrane and secreted into the apical medium, though quantitatively less important than the cytosolic lipase, may permit an additional route for energy uptake. The addition of gastric lipase to the Caco-2 cell cultures greatly enhanced FA uptake above that seen with the endogenous lipase alone.

Caco-2 cells and human fetal colon: a comparative analysis of their lipid transport.

Caco-2 cells and human colonic explants were compared for their ability to esterify lipid classes, synthesize apolipoproteins and assemble lipoproteins. Highly differentiated cells and colonic explants were incubated with [(14)C]oleic acid or [(35)S]methionine for 48 h. Caco-2 cells demonstrated a higher ability to incorporate [(14)C]oleic acid into cellular phospholipids (13-fold, P<0.005), triglycerides (28-fold, P<0.005) and cholesteryl ester (2-fold, P<0. 01). However, their medium/cell lipid ratio was 11 times lower, indicating a limited capacity to export newly synthesized lipids. De novo synthesis of apo B-48 and apo B-100 was markedly increased (7%0 and 240%, respectively), whereas the biogenesis of apo A-I was decreased (60%) in Caco-2 cells. The calculated apo B-48/apo B-100 ratio was substantially diminished (107%), suggesting less efficient mRNA editing in Caco-2 cells. When lipoprotein distribution was examined, it displayed a prevalence of VLDL and LDL, accompanied along with a lower proportion of chylomicron and HDL. In addition, differences in lipoprotein composition were evidenced between colonic explants and Caco-2 cells. Therefore, our findings stress the variance in the magnitude of lipid, apolipoprotein and lipoprotein synthesis and secretion between the two intestinal models. This may be due to various factors, including the origin of Caco-2 cell line, i.e., colon carcinoma.

Butyrate mediates Caco-2 cell apoptosis via up-regulation of pro-apoptotic BAK and inducing caspase-3 mediated cleavage of poly-(ADP-ribose) polymerase (PARP).

Butyrate exerts potent anti-tumor effects by inhibiting cancer cell growth and inducing apoptosis. However, the molecular mechanisms mediating these effects remain largely unknown. Using the Caco-2 cell line, a well established model of colon cancer cells, our data show that butyrate induced apoptosis (maximum 79%) is mediated via activation of the caspase-cascade. A key event was the proteolytic activation of caspase-3, triggering degradation of poly-(ADP-ribose) polymerase (PARP). Inactivation of caspase-3 with the tetrapeptide zDEVD-FMK completely inhibited the apoptotic response to butyrate. In parallel, butyrate potently up-regulated the expression of the pro-apoptotic protein bak, without changing Caco-2 cell bcl-2 expression. Butyrate-induced Caco-2 cell apoptosis was completely blocked by the addition of cycloheximide, indicating the necessity of protein synthesis. However, when this inhibitor was added at a time point where bak expression was already enhanced (12 - 16 h after butyrate stimulation), it failed to protect Caco-2 cells against apoptosis. Taken together, these data provide evidence that the molecular events involved in butyrate induced colon cancer cell apoptosis include the caspase-cascade and the mitochondrial bcl-pathway.

Both insulin resistance and diabetes in Psammomys obesus upregulate the hepatic machinery involved in intracellular VLDL assembly.

OBJECTIVE: In the current study, we examined the mechanisms that regulate hepatic apolipoprotein B (apoB)-containing lipoprotein secretion in Psammomys obesus, a good animal model for the investigation of insulin resistance and diabetes. METHODS AND RESULTS: When fed chow ad libitum, 22% maintained normoglycemia and normoinsulinemia (group A), 33% exhibited normoglycemia and appreciable hyperinsulinemia (group B), and 45% developed overt diabetes (group C). Body weight gain, plasma free fatty acid elevation, hypertriglyceridemia, and hypercholesterolemia characterized groups B and C. Triton WR-1339 injection, at fasting, resulted in higher plasma VLDL-triglyceride and VLDL-apoB accumulation in groups B and C, suggesting increased VLDL production by the liver. Pulse-chase labeling experiments in cultured hepatocytes with [35S]methionine revealed reduced intracellular degradation and enhanced secretion of newly synthesized apoB in groups B and C. Concomitant with the raised triglyceride and cholesterol contents in the livers of groups B and C, there was an increase in lipogenesis and in the activity of microsomal triglyceride transfer protein, monoacylglycerol acyltransferase, and diacylglycerol transferase. Pretreatment of hepatocytes with proteasomal inhibitors eliminated the differences in apoB secretion among groups A, B, and C. CONCLUSIONS: Our data indicate that both insulin resistance and diabetes triggered the intracellular machinery involved in VLDL assembly and secretion.

A conformational model for the human liver microsomal glucose-6-phosphatase system: evidence from rapid kinetics and defects in glycogen storage disease type 1.

Rapid kinetics of glucose-6-phosphate (G6P) uptake and hydrolysis as well as of orthophosphate uptake were investigated in microsomes prepared from normal and glycogen storage disease type 1a (GSD 1a) human livers using a fast sampling, rapid filtration apparatus and were compared to those of rat liver microsomes. As shown before with rat microsomes, the production of [U-14C]glucose from 0.2 mmol/L [U-14C]G6P by untreated normal human microsomes was characterized by a burst in activity during the first seconds of incubation, followed by a slower linear rate. The initial velocity of the burst was equal to the rate of glucose production in detergent-treated microsomes. In untreated and detergent-treated GSD 1a microsomes, no glucose-6-phosphatase activity was observed. When untreated normal human or rat microsomes were incubated in the presence of 0.2 mmol/L [U-14C]G6P, an accumulation of [U-14C]glucose was observed, whereas no radioactive compound (G6P and/or glucose) was taken up by GSD 1a microsomes. Orthophosphate uptake was, however, detectable in both GSD 1a and normal untreated vesicles. These results do not support a rate-limiting transport of G6P in untreated normal human microsomes and further show that in this case of GSD 1a, no distinct G6P transport activity is present.

Severe autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy in an adolescent girl with a novel AIRE mutation: response to immunosuppressive therapy.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disorder for which the gene (AIRE) has recently been identified on chromosome 21q22.3. We present the mutational analyses of a French-Canadian family with APECED, in which there are two affected siblings, as well as the response to cyclosporine A(CyA) therapy in the index patient, the eldest sibling. Haplotype analysis suggested compound heterozygozity at the AIRE locus. Direct sequencing of exon 8 revealed a previously described mutation, a 13-bp deletion (1085-1097) of maternal origin, found in the index patient, her affected sister, and her unaffected sister. A novel missense mutation characterized by a T-->G transversion at nucleotide position 398, resulting in a leu-->arg amino acid substitution (L93R), was found in exon 2. The mutation was present in the father, the brother, the index patient, and the affected sister. The presence of the mutation in the propositus was verified by cloning of PCR products from genomic DNA. The mutation destroys a PstI restriction enzyme site, as confirmed in the aforementioned patients. Screening of 50 French-Canadian controls with PstI digestion did not show destruction of the restriction-enzyme site. The index patient's phenotype was severe, manifested by classic features of the illness (adrenal insufficiency, hypoparathyroidism, candidiasis, and keratoconjunctivitis with alopecia universalis), as well as by severe exocrine pancreatic insufficiency, diabetes mellitus, hepatic inflammation, growth hormone (GH) deficiency due to lymphocytic hypophysitis, and primary ovarian failure. Oral CyA (5 mg/kg/day) was initiated at 13 yr of age. After 8 months of therapy, stimulated pancreatic lipase increased 24-fold with normalization of stool fat (from 31.5 g/day to 2.5 g/day, normal(N) < 5). There was complete resolution of her photophobia, and considerable hair regrowth was diffusely apparent. Minimal side effects were noted. Our experience supports the use of oral CyA for the treatment of severe APECED-associated exocrine pancreatic failure and keratoconjunctivitis.

Modulation of endoplasmic reticulum-bound cholesterol regulatory enzymes by iron/ascorbate-mediated lipid peroxidation.

Mammalian sterol regulatory enzymes are integral membrane proteins of the endoplasmic reticulum. They play a critical role in liver cholesterol homeostasis and the maintenance of overall cholesterol balance in different species. Because lipid peroxidation has been implicated in hepatic dysfunction and atherosclerosis, we hypothesized that its occurrence could alter the composition and properties of the bilayer lipid environment, and thereby affect the functions of these membrane proteins. Preincubation of rat liver microsomes with iron (Fe)/ascorbate (50 microM/200 microM), known to induce peroxidation, resulted in a significant inhibition of (i) the rate-limiting enzyme in cholesterol biosynthesis, HMG-CoA reductase (46%, p < .01), (ii) the crucial enzyme controlling the conversion of cholesterol in bile acids, cholesterol 7alpha-hydroxylase (48%, p < .001), and (iii) the central enzyme for cholesterol esterification: Acyl-CoA:cholesterol acyltransferase (ACAT, 80%, p < .0001). The disturbances of these key enzymes took place concomitantly with the high production of malondialdehyde (350%, p < .007) and the loss of polyunsaturated fatty acids (36.19 +/- 1.06% vs. 44.24 +/- 0.41 in controls, p < .0008). While alpha-tocopherol simultaneously neutralized lipid peroxidation, preserved microsomal fatty acid status, and restored ACAT activity, it was not effective in preventing Fe/ascorbate-induced inactivation of both HMG-CoA reductase (44%, p < .01) and cholesterol 7alpha-hydroxylase (71%, p < .0001). These results indicate that Fe/ascorbate alters the activity of the rate-determining steps in liver cholesterol metabolism, either directly or via lipid peroxidation, capable of modifying their membrane environment. The present data also suggest that the three regulatory enzymes respond differently when exposed to Fe/ascorbate or antioxidants, which may be due to dissimilar mechanisms.

Altered lipid profile, lipoprotein composition, and oxidant and antioxidant status in pediatric Crohn disease.

BACKGROUND: Growing evidence supports a role for peroxidation in the pathogenesis of Crohn disease (CD). The activation of inflammatory cells, the release of their mediators, and the excessive production of free radicals may affect circulating lipids. OBJECTIVE: We examined the lipid profile, lipoprotein composition, and oxidant-antioxidant status of children with CD. DESIGN: We studied 22 pediatric CD patients and 10 healthy control subjects. RESULTS: The proportion of saturated and monounsaturated fatty acids in plasma of CD patients was higher but that of polyunsaturated fatty acids was lower than in control subjects. This resulted in higher ratios in CD patients of palmitoleic acid to linoleic acid (P < 0. 05) and of eicosatrienoic acid to arachidonic acid (P < 0.04), 2 established indexes of essential fatty acid deficiency. Hypocholesterolemia was noted in CD patients as a result of lower LDL-cholesterol concentrations than in control subjects (P < 0.02). Plasma apolipoproteins B (P < 0.02) and A-I (P < 0.02) were also lower in CD patients, whereas plasma triacylglycerols were higher (P < 0.005). Lipoprotein composition was altered in CD patients, with relative triacylglycerol depletion and protein enrichment in VLDL. In contrast, intermediate-density lipoprotein of CD patients was characterized by an increased percentage of triacylglycerol and protein (P < 0.005) and a reduced proportion of phospholipids (P < 0. 01). Additional abnormalities were observed in the chemical distribution of HDL(2) and HDL(3) moieties. Lipid peroxidation was documented by higher plasma malondialdehyde concentrations in CD patients (P < 0.05), accompanied by lower retinol concentrations (P < 0.02). CONCLUSION: Disturbances in the lipid profile, in lipoprotein concentrations and composition, and in oxidant-antioxidant status occur in CD patients.

Beneficial effects of fish-oil supplements on lipids, lipoproteins, and lipoprotein lipase in patients with glycogen storage disease type I.

Glycogen storage disease type I (GSD-I) is frequently complicated by severe hyperlipoproteinemia and the increased potential risk of premature atherosclerosis. The effects of fish-oil supplementation [MaxEPA, 10 g.(1.73 m2)-1 for 3 mo] were investigated prospectively in seven hyperlipoproteinemic patients with GSD-I. Hypertriglyceridemia and hypercholesterolemia improved after 3 mo of fish-oil treatment, decreasing 49% (P < 0.005) and 23%, respectively. This was accompanied by a reduction in both low-density-lipoprotein (LDL) cholesterol (25%, P < 0.03) and apolipoprotein B (40%) and by increased high-density-lipoprotein increased (HDL) cholesterol (30%, P < 0.002) and apolipoprotein A-I (31%, P < 0.05). Low pretreatment ratios of HDL to total cholesterol and HDL to LDL, indicators of elevated atherosclerosis risk, increased significantly (P < 0.05). Plasma lipoprotein profile as well as lipoprotein composition [triglyceride (TG) enrichment and cholesteryl depletion] improved. Reduced TG concentrations were due to enhanced fat catabolism, as evidenced by the significantly increased hepatic and extrahepatic lipoprotein lipase activity (P < 0.05). Withdrawal of fish oil for 3 mo was associated with a return to pretreatment abnormalities in plasma lipids and lipoproteins. Fish-oil supplementation thus improves the hyperlipoproteinemia in GSD-I and may significantly reduce the risk of premature atherosclerotic cardiovascular disease.

Comparative analysis of serologic screening tests for the initial diagnosis of celiac disease.

OBJECTIVE: To prospectively evaluate and compare the sensitivity, specificity, and positive and negative predictive values of serum antigliadin (AGA) and antiendomysium antibodies (EMA) in predicting the initial diagnosis of celiac disease. DESIGN: Sera were tested prospectively for IgA and IgG AGA by enzymed-linked immunosorbent assay and IgA EMA by immunofluorescence techniques on monkey esophagus and human umbilical cord sections in 95 pediatric patients referred for duodenal biopsies. PATIENTS: Ninety-five pediatric patients were referred for duodenal biopsies, with a clinical suspicion of celiac disease; 24 of those patients had celiac disease by criteria of the European Society for Pediatric Gastroenterology and Nutrition. SETTING: A pediatric gastroenterology clinic of a tertiary care pediatric university hospital. RESULTS: EMA testing on human umbilical cords was the most specific but was also the least sensitive. All the patients with biopsy-proven celiac disease were identified by either one or both serologic tests (100% combined sensitivity). The combination of AGA and EMA on monkey esophagus resulted in a negative predictive value of 100% accuracy. CONCLUSIONS: A combination of AGA and EMA tests resulted in 100% sensitivity and 100% negative predictive value, useful in selecting patients for duodenal biopsy.

High incidence of upper gastrointestinal tract involvement in children with Crohn disease.

This retrospective study of Crohn disease in 230 children and adolescents with a mean age of 12.5 years at the time of diagnosis and an average follow-up of 6.6 years showed that 30% had lesions of the esophagus, stomach, and duodenum. Three patients had Crohn disease isolated to the upper gastrointestinal tract. The 169 patients with both small and large bowel disease were at greater risk (33%, P less than .05) of having upper gastrointestinal lesions than the 37 with isolated small bowel disease and the 21 with disease limited to the colon and/or rectum. An aggregate of symptoms and signs more likely present in those with upper gastrointestinal involvement included: dysphagia, pain when eating, nausea and/or vomiting, and aphthous lesions of the mouth. Furthermore, weight loss was more severe and hypoalbuminemia more frequent. Because upper gastrointestinal series x-ray studies failed to detect upper gastrointestinal lesions in 13 patients of 69 of those with upper gastrointestinal disease, endoscopy should be considered in all children and adolescents in whom a diagnosis of Crohn disease is entertained. Endoscopy and biopsy of the upper gastrointestinal tract should be done in any patient with symptoms suggestive of proximal involvement. Finally, in view of the fact that endoscopy established the diagnosis of Crohn disease in five patients previously thought to have chronic ulcerative colitis, the procedure should routinely be performed in all patients with chronic ulcerative colitis or indeterminate colitis before surgery is performed.

Primary sclerosing cholangitis in children: study of five cases and review of the literature.

Primary sclerosing cholangitis in five children is described and 78 cases in the pediatric age group are reviewed. In 24% of the cases, primary sclerosing cholangitis is not associated with an underlying disease and may appear to be prolonged cholestasis of infancy. When an associated condition is present, chronic inflammatory bowel disease, in particular ulcerative colitis, is most common (47%). Histiocytosis X and a variety of immune disorders account for 15% and 10% of cases, respectively. Primary sclerosing cholangitis should be considered in the differential diagnosis of chronic liver disease in the pediatric age group, even in young infants. Results of this survey demonstrate that neither clinical features nor liver function tests are reliable diagnostic predictors, that histologic changes are often nonspecific, and that cholangiography is essential to establish the correct diagnosis.

Circulating levels of transforming growth factor-beta1 and lymphokines among children with hemolytic uremic syndrome.

Verotoxin-producing Escherichia coli (VTEC) cause hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS). The aim of this study was to compare the circulating levels of transforming growth factor-beta 1 (TGF-beta1), T helper (T(H))1 (interferon [IFN]-gamma, interleukin [IL]-2), and T(H)2-associated lymphokines (IL-4, IL-13) in children with uncomplicated Escherichia coli O157:H7 HC and patients who developed HUS. Circulating levels of IL-2, IL-4, and IL-13 were undetectable, and those of IFN-gamma were low and comparable among groups. Concentrations of TGF-beta1 were higher in children with uncomplicated O157:H7 HC than among those who developed HUS (934 +/- 680 versus 514 +/- 497 pg/mL, respectively; P < 0.04). The circulating levels of TGF-beta1 were also higher among children who did not take antidiarrheal agents (P < 0.008) and those who have been immediately discharged from the emergency room (P < 0.03). Our results did not show an imbalanced T(H)1/T(H)2-associated lymphokine response during the development of HUS. Increased circulating levels of TGF-beta1 in children with milder O157:H7 or uncomplicated HC most likely reflect appropriate intestinal tissue repair mechanisms rather than a remote systemic endocrine effect on the kidneys.