A236 ASSOCIATION OF STOOL METABOLOMIC PROFILE AND MICROBIOME COMPOSITION RISK SCORE WITH FUTURE ONSET OF CROHN’S DISEASE

Background

Microbial composition-based risk score (MRS) was recently developed and validated to predict future risk of developing Crohn’s disease (CD) among healthy first-degree relatives (FDR) of CD patients. We hypothesized that stool metabolomic profiles, some of which are linked to the gut microbiome, are associated with future risk of CD.

Aims

To assess the association of stool metabolomic profile with onset of CD and to determine the correlation between stool metabolites and the MRS

Methods

Healthy FDR of CD patients were recruited as part of the nested case-control cohort of the CCC-GEM Project. Healthy FDRs who later developed CD (n=56) were matched approximately 1:1 by age, sex, follow-up duration, and geographical location with control FDRs remaining healthy (n=66). Stool metabolomics were assessed using the Metabolon’s DiscoveryHD4™ platform, and the stool microbiome characterised by 16s rDNA amplicon sequencing. We fitted a multivariable conditional logistic regression model on the disease status as a function of individual stool metabolites. We additionally performed Spearman correlation between each stool metabolite and the MRS.

Results

Among 1,029 stool metabolites that were analyzed, 79 were associated with future risk of CD (p<0.05); however, none remained significant after multiple testing correction (FDR correction). Considering the exploratory nature of this study with limited sample size, we focused on the top seven metabolites associated with CD onset (p<0.01). Of these, two stool metabolites (dimethylglycine, methylmyristate) were associated with increased risk of CD onset while five (cytosine, guanine, cytidine, hydroxyglutarate, nervonate) were associated with decreased risk of developing CD. The two metabolites positively associated with CD onset were positively correlated with the MRS, while the five metabolites negatively associated with CD onset, were negatively correlated with the MRS. Meanwhile, 24 stool metabolites had significant correlation with MRS (FDR-corrected p<0.2). Among those, a total of four stool metabolites (cytosine, guanine, methymyristate, cytidine) overlapped with the top seven stool metabolites associated with CD onset.

Conclusions

Stool metabolite profiles may predict future risk of CD. A subset of these metabolites have significant correlation with the MRS with consistent direction of effect. This may suggest that stool metabolites mediate the putative effect of the gut microbiome on CD risk. Further validation in the full GEM cohort is warranted.

Funding Agencies

CCC, CIHRThe Leona M. and Harry B. Helmsley Charitable Trust; Kenneth Croitoru is the recipient of the Canada Research Chair in Inflammatory Bowel Diseases; Sun-Ho Lee is a recipient of the Imagine/ CIHR/CAG Fellowship Award; Sun-Ho Lee, Juan Antonio Raygoza Garay, and Williams Turpin are recipients of fellowship awards from the Department of Medicine, Mount Sinai Hospital, Toronto, Canada.

Student selection to a rural veterinary school. 2: predictors of student performance and attrition

OBJECTIVE

To evaluate the extent to which current selection processes at Charles Sturt University, New South Wales, Australia, predict performance within and attrition from the veterinary degree program.

DESIGN

Retrospective evaluation of application details and student performance data.

METHODS

Database records of 424 students entering the veterinary program were retrieved from university records, including all students graduating (n = 356) or leaving the program without completing (n = 68) between 2005 and 2016. Demographic data were related to results of selection processes and achievement within the degree using univariable and multivariable general linear and logistic regression analyses.

RESULTS

The grade point average achieved over the 6 years of the degree was influenced by academic achievement prior to entry, gender (females performed ≈ 2% better than males) and interview scores. Preceptor evaluation of final-year clinical performance was associated with interview scores, gender (males performed ≈ 4% better than females) and residential address at the time of application. Attrition for personal reasons was more common for female students and students who had completed a prior degree, and students who experienced academic or personal attrition had lower written application scores. Factors that have been previously linked to poor academic outcomes, including rural or low socioeconomic background, were not associated with adverse student outcomes.

CONCLUSION

Selection processes did not systematically disadvantage students admitted to the degree program. Gender differences in personal attrition and academic and clinical performance warrant further evaluation. Factors in addition to academic aptitude predicted student success.

Student selection to a rural veterinary school. 1: applicant demographics and predictors of success within the application process

OBJECTIVE

To determine demographic details of applicants to the veterinary degree program at and relate this information to student selection processes.

DESIGN

Retrospective evaluation of applicant data.

METHODS

Database records of 4042 applicants to the veterinary program (2006-2016) were retrieved from university records. Summary statistics were used to determine basic demographic data, which were related to pre-entry academic achievement and results of selection processes using univariable and multivariable analyses.

RESULTS

The number of applications, interviews and acceptance of offers fluctuated but did not vary substantively for the duration of the study. Gender, rurality (as assessed by residential and school postcodes), socioeconomic background, academic background and pre-entry academic achievement all significantly influenced written application and interview scores in the multivariate models. Rural background, written application score, number of applications, pre-entry academic history and achievement significantly affected the chances of receiving an interview. Chances of receiving an offer and subsequent program entry were significantly influenced by academic background, interview score and pre-entry academic achievement. Male applicants were more likely to receive an offer, but gender had no effect on program entry. Rural residential and school background was associated with significantly reduced ATAR in comparison with city-based applicants.

CONCLUSION

Selection processes effectively identified applicants with demographic backgrounds and life experiences consistent with the School's commitment to the veterinary needs of rural and regional Australia. Findings support the provision of an academic loading for the ATAR results of rural students. Effects of these selection outcomes on student performance should be evaluated.

Faecal calprotectin, lactoferrin, M2-pyruvate kinase and S100A12 in severe ulcerative colitis: a prospective multicentre comparison of predicting outcomes and monitoring response

OBJECTIVE

To compare four faecal markers for their ability to predict steroid refractoriness in severe paediatric ulcerative colitis (UC). Construct validity and responsiveness to change were also assessed.

METHODS

This was a prospective multicentre cohort study. Stool samples from 101 children (13.3 + or - 3.6 years; Pediatric UC Activity Index (PUCAI) at admission 72 + or - 12 points) were obtained at the third day of intravenous steroid therapy. Repeated samples at discharge were obtained from 24 children. Predictive validity was assessed using diagnostic utility statistics to predict steroid failure (ie, the need for salvage treatment). Concurrent validity was assessed using correlational analysis with the following constructs: PUCAI, Lindgren and Seo scores, physician's global assessment, albumin, erythrocyte sedimentation rate and C-reactive protein (CRP). Responsiveness was assessed using test utility and correlational strategies.

RESULTS

Median values (IQR) were very high at baseline for all four markers (calprotectin 4215 microg/g (2297-8808); lactoferrin 212 microg/g (114-328); M2-pyruvate kinase (M2-PK) 363 U/g (119-3104); and S100A12 469 microg/g (193-1112)). M2-PK was numerically superior to the other three markers and CRP in predicting response to corticosteroid treatment (area under the receiver operating characteristic (ROC) curve 0.75 (95% CI 0.64 to 0.85; p<0.001) vs <0.65 for the others). However, it did not add to the predictive ability of the PUCAI (area under the ROC 0.81 (95% CI 0.73 to 0.89)). M2-PK also had the highest construct validity but with a modest mean correlation with all constructs (r=0.3; p<0.05). None of the markers was responsive to change (Spearman's rho correlation with change in the PUCAI <0.1; p>0.05, area under the ROC curve <0.65; p>0.05).

CONCLUSIONS

The four markers were greatly elevated in severe paediatric UC. Only M2-PK had good construct and predictive validity, and none was responsive to change. The PUCAI, a simple clinical index, performed better than the faecal markers in predicting outcome following a course of intravenous corticosteroids in severe UC.

Effect of different methods of selection on the background, attitudes and career plans of first year veterinary students

OBJECTIVES

To compare the family, educational and animal-related backgrounds and career aspirations of students who were selected on the basis of academic criteria with those selected using additional criteria.

METHODS

Questionnaires were completed during class time in the first few weeks of enrolment by incoming veterinary students at the University of Sydney, who had been selected on the basis of academic background, and at Charles Sturt University, selected using more broadly-based criteria. The data were transferred to an Excel spreadsheet, and frequency distributions and chi2 statistics estimated using the SAS System for Windows 8.

RESULTS

Students selected principally on academic criteria alone had higher average UAI scores, were more likely to have completed high school in a capital city, and to have parents with higher education levels than those selected using additional criteria. Both groups indicated that their choice of veterinary science was based largely on their affinity for animals and keenness to work in a veterinary practice. However, those at CSU placed much greater importance than those at Sydney on a desire to live and work in a rural area, and a desire to help farmers. The broad-based selection methods were the main reasons for students applying to CSU whereas the reputation of the university was the main attraction for Sydney students. Two-thirds of CSU students, but one-third of Sydney students, planned to enter rural mixed practice when they graduated, and most planned to stay for at least 10 years. Conversely, no CSU students, but 42% of those at Sydney, planned to enter small animal practice initially. The percentage planning to work full-time in the first, fifth and tenth year after graduation was not significantly different between the two groups.

CONCLUSIONS

Criteria which included actual experience with farm animals have resulted in the selection of more students who plan to enter and remain in rural mixed practice. Further studies over the longer term will be necessary to assess the extent to which these plans are realized.

Does cisapride influence cardiac rhythm? Results of a United States multicenter, double-blind, placebo-controlled pediatric study

BACKGROUND

Major concerns about serious cardiac side effects underlie the recent decision by the FDA and Janssen Pharmaceutica (Titusville, NJ) to make cisapride available only through a limited access program. Concerns have grown despite the fact that most instances of prolonged QTc and other ventricular arrhythmias occurred while the drug was used concomitantly with contraindicated drugs. This study sought to analyze electrocardiograms (ECGs) from a multicenter pediatric study and to identify abnormalities in QTc interval associated with cisapride use.

METHODS

Children between 6 months and 4 years of age were enrolled if they manifested symptoms of gastroesophageal reflux not responding to medical therapy for at least 6 weeks. In 49 subjects, ECGs obtained before and after randomization to receive 0.2 mg/kg dose three times daily or placebo were reviewed independently and blindly by two pediatric cardiologists. Placebo and active drug groups were compared for QTc and for change in QTc from baseline values after 3 to 8 weeks of treatment.

RESULTS

Mean QTc among patients taking the drug was 408+/-18 ms. None was higher than 450 ms. Change between baseline and subsequent QTc at 3 to 8 weeks of treatment was 2+/-20 ms.

CONCLUSIONS

In our study group of children without underlying cardiac disease or electrolyte imbalance, cisapride was found to have no significant effect on cardiac electrical function compared with placebo. These results are consistent with the drug's record of exceedingly infrequent cardiac events. Because the availability of this prokinetic is threatened, its safety and the safety and efficacy of alternative treatment options (including surgery) should be studied further.

Sacrosidase therapy for congenital sucrase-isomaltase deficiency

BACKGROUND

The purpose of this study was to determine if sacrosidase, a liquid produced from Saccharomyces cerevisiae containing 6000 IU of sucrase activity per mg protein, prevented symptoms of diarrhea, abdominal cramps, gas, and bloating in patients with congenital sucrase-isomaltase deficiency (CSID) consuming a normal sucrose and carbohydrate-containing diet.

METHODS

Twenty-eight children (aged 5 months to 11 years) underwent a randomized, double-blind trial consisting of two phases: 1) three sucrose breath H2 tests with three single-dose treatments (placebo, sacrosidase, and sacrosidase plus milk), and 2) a dose-response phase consisting of four multidose treatments, each for 10 days of full-strength sacrosidase, 1:10 dilution, 1:100 dilution, and 1:1000 dilution. Patients who weighed less than or equal to 15 kg received a dose of sacrosidase and those who weighed more than 15 kg received 2 ml. For the dose-response phase each patient consumed a normal diet. The number of stools and severity of symptoms were recorded daily for each concentration of sacrosidase administered and compared to a baseline period during which the patient took no sacrosidase and consumed a sucrose/starch-free diet. Data were analyzed using an ANOVA model and the nonparameter Wilcoxon signed-rank test.

RESULTS

Breath H2 excretion decreased significantly when patients received sacrosidase or sacrosidase plus milk compared to placebo during sucrose breath tests. During the dose-response phase significant treatment differences were observed between the two higher concentrations and the two lower concentrations of sacrosidase for both total stools (p < 0.001) and total symptom score (p = 0.003). Higher concentrations of sacrosidase were associated with fewer stools and a greater number of formed or hard stools compared to lower concentrations and compared to the baseline period. Higher concentrations were also associated with fewer symptoms of gas, abdominal cramps, or bloating, but no differences in vomiting. The only significant adverse event was wheezing in one child with a history of asthma.

CONCLUSIONS

Sacrosidase is a safe, effective, well-accepted treatment to prevent gastrointestinal symptoms in patients with CSID consuming a normal diet.

Cellular microbiology: cycling into the millennium

Cellular microbiology is a newly developing science born from the realization that many different aspects of eukaryotic cell biology are targeted by microbial virulence mechanisms. One example of this is the emerging evidence that several bacteria can interfere, directly or indirectly, with the eukaryotic cell cycle. This article discusses the cell-cycle effects of bacterially generated molecules, their role in virulence and their possible therapeutic potential.

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.

Detection of group C rotavirus in infants with extrahepatic biliary atresia

The purpose of this retrospective study was to examine liver tissue from patients with cholestatic disease for the presence of group C rotavirus RNA. The reverse transcriptase-polymerase chain reaction (PCR) for genes 5 and 6 was used, and the PCR products were subjected to liquid hybridization with a 32P-labeled probe. A second amplification with nested primers was also used. Samples from 32 subjects (20 with biliary atresia or choledochal cyst and 12 controls) were tested. Ten of 20 biliary atresia patients were positive for group C rotavirus RNA; no controls were positive (P < .003). Three of the positive patients were positive for both genes 5 and 6. Six of the 10 had > 1 sample that was positive. These data suggest a possible relationship between group C rotavirus and extrahepatic biliary atresia in the 10 patients in whom virus RNA was detected.

Organ transplantation at the Hartford Transplant Center

Over 1,243 organ transplants have been performed at the Hartford Transplant Center over the past two decades. Survival in kidney, heart, liver, and pancreas patients is at or above the national average. Hartford was one of the first centers to use triple immunosuppression, which significantly improved survival in kidney transplantation. For recipients of kidneys from living related donors and cadaveric kidneys, two-year actuarial graft survival has been 98% and 83%, respectively, over the last five years. For heart and liver transplants, two-year survival has been 79% and 67%, respectively. Despite high success rates at most transplant centers, donor organs remain scarce. This problem needs to be addressed through increased cooperative efforts in the health-care community and the general public.

Scoliosis surgery: a risk factor for cholelithiasis?

Scoliosis surgery has been associated with pancreatitis and acalculous cholecystitis, and also has been implicated as a risk factor for cholelithiasis. A prospective study of 36 children and adolescents undergoing scoliosis surgery was performed using ultrasound to determine the incidence of cholelithiasis following spine surgery. The patients underwent abdominal ultrasound exams preoperatively, immediately postoperatively, and then at intervals following surgery with 2-5-year follow-up. Four of 36 patients (11.1%) (one male, three female) developed gallstones, although all had been free of gallstones after surgery. The gallstones appeared between 2 + 5 and 5 years after surgery. Those with gallstones were not different from those without with respect to 14 factors. It is concluded that scoliosis surgery is not a risk factor for gallstones, because of the delay in onset of cholelithiasis after surgery. Furthermore, the prevalence of gallstones in this study sample is not greater than that reported in historical control studies of European young adults.

Atypical rectosigmoid histology in children with newly diagnosed ulcerative colitis

BACKGROUND

In the untreated patient with inflammatory colitis, rectal sparing or patchy rectal inflammation is generally considered a sign of Crohn's disease (CD), rather than ulcerative colitis (UC).

METHODS

The initial endoscopic rectosigmoid mucosal biopsies obtained at disease onset from 12 untreated children with UC who ultimately required surgery were blindly reviewed (randomly mixed with another 62 specimens obtained from children with CD or treated UC). Biopsies were classified as typical UC if there was diffuse, active inflammation and severe crypt destruction or distortion. Those with patchy, active inflammation and only mild crypt changes were classified as CD. Because all 12 subjects had ultimately been proven to have UC by examination of a subtotal colectomy specimen, for the purposes of this report biopsies read as either normal or CD were both considered evidence of atypical UC with rectal sparing.

RESULTS

Five of 12 subjects (seven biopsies) had atypical histology. Mild, patchy inflammation was seen in six rectal or sigmoid biopsies, whereas one rectal biopsy was normal. The remaining seven subjects (10 biopsies) had diffuse inflammation. Two of five subjects with atypical biopsies had an endoscopically normal rectosigmoid, one had patchy inflammation, and the remaining two had diffuse endoscopic changes. All seven subjects with typical UC histology had diffuse endoscopic changes. Subjects with atypical findings could not be differentiated by age, duration, or types of symptoms at presentation, years of disease at colectomy, or indications for colectomy.

CONCLUSIONS

Patchy or absent inflammation of the rectum and sigmoid can be present in untreated children with UC at disease onset. Because such children may be mistakenly diagnosed as having CD, these data must be considered when treatments or clinical research protocols are designed to include children with colitis.

Evaluation of liquid yeast-derived sucrase enzyme replacement in patients with sucrase-isomaltase deficiency

BACKGROUND

No enzyme replacement therapy exists for patients with congenital sucrase-isomaltase deficiency (CSID). A by-product of the manufacture of baker's yeast is a liquid preparation containing high sucrase activity. The aim of the present study was to investigate the activity and stability of this preparation and its effect on breath hydrogen excretion and gastrointestinal symptoms after sucrose ingestion in 14 patients with CSID.

METHODS

The homogeneity of yeast sucrase was studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its activity was measured. Stability at various temperatures and pH ranges and in the presence of gastric aspirate, pepsin, and bovine serum albumin was assessed. Fourteen patients with CSID underwent double-blind placebo-controlled breath tests with yeast sucrase. They then completed an 8-week dose response study that used different enzyme concentrations while consuming a sucrose-containing diet.

RESULTS

Liquid yeast sucrase is highly glycosylated, contains no lactase activity, and is stable at 4 degrees C and over a wide range of pH. Pepsin digestion of the enzyme in vitro can be blunted by bovine serum albumin and by increasing the pH. Yeast sucrase reduces breath hydrogen excretion in patients with CSID who are given a sucrose load (P < 0.001) and allows most patients to consume a sucrose-containing diet.

CONCLUSIONS

Liquid yeast sucrase offers effective enzyme replacement therapy for patients with CSID.

Psychopathology and relationship measures in children with inflammatory bowel disease and their parents

Children with inflammatory bowel disease and their parents were assessed for DMS-III diagnoses, maternal attachment, marital relationship, life stresses, illness severity and cognitive/affective profile. Eleven of 15 children and 21 of 27 parents had psychiatric diagnoses. Three children were suicidal. Thirteen of 15 mothers had insecure attachment. Marital difficulties and medical severity correlated with life stress. The higher prevalence of psychiatric disorders than epidemiologically and of insecure attachment suggest at-risk relationships.

Discrimination between forms of vitamin E by humans with and without genetic abnormalities of lipoprotein metabolism

To study the mechanisms of discrimination between various forms of vitamin E, four normal subjects, one patient with lipoprotein lipase deficiency, and three patients with abnormal apolipoprotein B-100 production were given an oral dose containing three tocopherols labeled with differing amounts of deuterium (2R,4'R,8'R-alpha-(5,7-(C2H3)2)tocopheryl acetate (d6-RRR-alpha-tocopheryl acetate), 2S,4'R,8'R-alpha-5-(C2H3)tocopheryl acetate (d3-SRR-alpha-tocopheryl acetate), and 2R,4'R,8'R-gamma-(3,4-2H)tocopherol (d2-RRR-gamma-tocopherol). The tocopherol contents of plasma, red cells, and lipoproteins were measured up to 76 h after the dose. In normal subjects all three tocopherols were absorbed and secreted in chylomicrons with equal efficiencies. Both d2-gamma- and d3-SRR-alpha-tocopherols peaked at similar concentrations in the other lipoprotein fractions, then decreased similarly, but 2-4 times more rapidly than did d6-RRR-alpha-tocopherol. A lipoprotein lipase-deficient patient and a patient with prolonged production of chylomicrons with absent apolipoprotein B-100 also demonstrated the lack of discrimination between tocopherols during absorption. Despite abnormal apolipoprotein B-100 production in two patients, the "VLDL" was preferentially enriched in d6-RRR-alpha-tocopherol. Our results show that there is no discrimination between the three tocopherols during absorption and secretion in chylomicrons, but subsequently there is a preferential enrichment of very low density lipoprotein (VLDL) with RRR-alpha-tocopherol. Catabolism of this VLDL results in the maintenance of plasma RRR-alpha-tocopherol concentrations.

Early cirrhosis in survivors with Jeune thoracic dystrophy

Two siblings with Jeune thoracic dystrophy had persistent evidence of hepatic dysfunction; one had cirrhosis. Liver disease, a significant problem in patients who survive this condition, may be progressive in some.

Cytoplasmic vacuolization of enterocytes: an unusual histopathologic finding in juvenile nutritional megaloblastic anemia

We report a case of juvenile nutritional megaloblastic anemia with emphasis on the histologic findings in the upper gastrointestinal system, including the previously unreported feature of periodic acid-Schiff (PAS)-negative, Alcian blue-negative cytoplasmic vacuoles (CV) in duodenal enterocytes. These CV were reminiscent of those described in abetalipoproteinemia; however, the patient's lipid profile was normal. All histopathologic changes in the upper gastrointestinal tract (with the exception of mild reflux esophagitis) reverted to normal following parenteral administration of vitamin B12. This case supports the notion that CV in enterocytes are a component (albeit a rare one) of the histopathology in cobalamin deficiency.

Cerebral vascular accident during the recovery phase of hemolytic uremic syndrome

The hemolytic uremic syndrome (HUS) of children is characterized by microangiopathic hemolytic anemia and acute renal failure. Although a wide spectrum of neurologic symptoms are commonly observed in patients with HUS, the pathogenesis of the central nervous system (CNS) impairment of HUS is often unclear. Microthrombi of cerebral vessels similar to those demonstrated in the kidneys have been reported. The neurologic manifestations generally occur during the early and active phase of the disease. We report a 4 year old boy with HUS who suddenly developed a dense hemiplegia subsequent to hematological and a marked nephrological recovery. The child's cranial axial tomography scan demonstrated a large area of infarction in the region of the right basal ganglia. Follow up examination eight weeks after insult revealed a distinct neurologic recovery with mild loss of fine motor function of the left hand and weakness of the left leg.