Intestinal permeability in children/adolescents with functional dyspepsia.

BACKGROUND: An altered intestinal mucosal barrier has been demonstrated in subsets of patients with IBS and FAP and may be an additional biological factor contributing to symptom generation in children with FD. The objective of this study was to determine if intestinal permeability is increased in children/adolescents with functional dyspepsia (FD) and whether intestinal permeability is correlated with mucosal inflammation and/or symptoms of anxiety or depression in this population. METHODS: A sugar absorption test was performed in 19 patients with FD and 19 controls. Anxiety and depression were assessed in both groups utilizing a standard questionnaire. In FD patients, duodenal mean and peak mast cell and eosinophil densities were determined. RESULTS: Intestinal permeability as measured by the sugar absorption test did not differ between children with FD and controls. In children with FD, there was no correlation between permeability and mast cell density, eosinophil density, anxiety scores, or depression scores, respectively. CONCLUSIONS: Pediatric FD does not appear to be associated with increased small bowel intestinal permeability, however, there are some limitations to the current study. TRIAL REGISTRATION: ClinicalTrials.gov; NCT00363597.

National academy of clinical biochemistry laboratory medicine practice guidelines: follow-up testing for metabolic disease identified by expanded newborn screening using tandem mass spectrometry; executive summary.

BACKGROUND: Almost all newborns in the US are screened at birth for multiple inborn errors of metabolism using tandem mass spectrometry. Screening tests are designed to be sufficiently sensitive so that cases are not missed. The NACB recognized a need for standard guidelines for laboratory confirmation of a positive newborn screen such that all babies would benefit from equal and optimal follow-up by confirmatory testing. METHODS: A committee was formed to review available data pertaining to confirmatory testing. The committee evaluated previously published guidelines, published methodological and clinical studies, clinical case reports, and expert opinion to support optimal confirmatory testing. Grading was based on guidelines adopted from criteria derived from the US Preventive Services Task Force and on the strength of recommendations and the quality of the evidence. Three primary methods of analyte measurement were evaluated for confirmatory testing including measurement of amino acids, organic acids, and carnitine esters. The committee graded the evidence for diagnostic utility of each test for the screened conditions. RESULTS: Ample data and experience were available to make strong recommendations for the practice of analyzing amino acids, organic acids, and acylcarnitines. Likewise, strong recommendations were made for the follow-up test menu for many disorders, particularly those with highest prevalence. Fewer data exist to determine the impact of newborn screening on patient outcomes in all but a few disorders. The guidelines also provide an assessment of developing technology that will fuel a refinement of current practice and ultimate expansion of the diseases detectable by tandem mass spectrometry. CONCLUSIONS: Guidelines are provided for optimal follow-up testing for positive newborn screens using tandem mass spectrometry. The committee regards these tests as reliable and currently optimal for follow-up testing. .

Analytic performance of immunoassays for drugs of abuse below established cutoff values.

BACKGROUND: The analytic performance and accuracy of drug detection below Substance Abuse and Mental Health Services Administration (SAMHSA) cutoffs is not well known. In some patient populations, clinically significant concentrations of abused drugs in urine may not be detected when current SAMHSA cutoffs are used. Our objectives were to define the precision profiles of three immunoassay systems for drugs of abuse and to evaluate the accuracy of testing at concentrations at which the CV was <20%. METHODS: Drug-free urine was supplemented with analytes to assess the precision in three commercial drugs-of-abuse immunoassay systems below the SAMHSA-dictated cutoffs for amphetamines, opiates, benzoylecgonine, phencyclidine, and cannabinoids. Consecutive urine samples with signals associated with a CV <20% by Emit immunoassay and below SAMHSA cutoffs were then subjected to confirmatory analysis. RESULTS: The CV of all immunoassay systems tested remained <20% to drug concentrations well below SAMHSA cutoffs. The accuracy of urine drug-screening results between the SAMHSA-specified cutoffs and the precision-based cutoffs was less than accuracy for specimens above the SAMHSA cutoffs, but the use of the precision-based cutoff produced a 15.6% increase in the number of screen-positive specimens and a 7.8% increase in the detection of specimens that yielded positive results on confirmatory testing. CONCLUSION: The precision of three commercial immunoassay systems for drugs-of-abuse screening is adequate to detect drugs below SAMHSA cutoffs. Knowledge of the positive predictive values of screening immunoassays at lower cutoff concentrations could enable efficient use of confirmatory testing resources and improved detection of illicit drug use.