Diagnostic performance of three serologic tests in childhood celiac disease.

BACKGROUND: IgA- and IgG-antibodies against deamidated gliadin peptides (DGP) specifically bind the disease-inducing antigen and might be superior to transglutaminase type 2 (TG2) IgA in monitoring patients on a gluten-free diet (GFD). The aim of this study was to compare the performance of DGP-IgG and DGP-IgA with TG2-IgA of four manufacturers in pediatric celiac patients at diagnosis and during follow-up under a GFD. PATIENTS AND METHODS: In total 411 sera of 91 IgA competent children with biopsy proven celiac disease were analyzed at diagnosis and during follow-up on a GFD. Ninety-eight children with normal duodenal histology served as controls. The tests (TheBindingSite, Euroimmun, Phadia, part of Thermo Fisher Scientific, INOVA) for detection of TG2-IgA, DGP-IgG and DGP-IgA were used according to the manufacturers' instructions. RESULTS: Sensitivity to diagnose CD was high for TG2-IgA (100 %) and DGP-IgG (90 - 100 %), but lower for DGP-IgA (67 - 86 %). Specificity was high for all tests (97 - 100 %). The frequency of TG2-IgA titers > 10â€Š× upper limit of normal at diagnosis ranged from 47 - 90 %. Under a GFD DGP-IgA became negative more rapidly than DGP-IgG and TG2-IgA. Non-adherence to GFD was best indicated by positive TG2-IgA. CONCLUSIONS: Combined testing for TG2-IgA and DGP-IgG does not increase the detection rate of CD in IgA competent children compared to TG2-IgA only. There are significant differences with respect to proportions of celiac children with titers > 10â€Š× ULN between the manufacturers. This calls for harmonization of tests. TG2-IgA showed the highest titer rise with non-adherence to the GFD, independent of the manufacturer.

Neuronal nitric oxide synthase (NOS1) and its adaptor, NOS1AP, as a genetic risk factors for psychiatric disorders.

Nitric oxide (NO) is a gaseous transmitter produced by nitric oxide synthases (NOSs). The neuronal isoform (NOS-I, encoded by NOS1) is the main source of NO in the central nervous system (CNS). Animal studies suggest that nitrinergic dysregulation may lead to behavioral abnormalities. Unfortunately, the large number of animal studies is not adequately reflected by publications concerning humans. These include post-mortem studies, determination of biomarkers, and genetic association studies. Here, we review the evidence for the role of NO in psychiatric disorders by focusing on the human NOS1 gene as well as biomarker studies. Owing to the complex regulation of NOS1 and the varying function of NOS-I in different brain regions, no simple, unidirectional association is expected. Rather, the 'where, when and how much' of NO formation is decisive. Present data, although still preliminary and partially conflicting, suggest that genetically driven reduced NO signaling in the prefrontal cortex is associated with schizophrenia and cognition. Both NOS1 and its interaction partner NOS1AP have a role therein. Also, reduced NOS1 expression in the striatum determined by a length polymorphism in a NOS1 promoter (NOS1 ex1f-VNTR) goes along with a variety of impulsive behaviors. An association of NOS1 with mood disorders, suggested by animal models, is less clear on the genetic level; however, NO metabolites in blood may serve as biomarkers for major depression and bipolar disorder. As the nitrinergic system comprises a relevant target for pharmacological interventions, further studies are warranted not only to elucidate the pathophysiology of mental disorders, but also to evaluate NO function as a biomarker.

Bile acid malabsorption assessed by 7 alpha-hydroxy-4-cholesten-3-one in pediatric inflammatory bowel disease: correlation to clinical and laboratory findings.

BACKGROUND AND AIMS: Measurement of 7 alpha-hydroxy-4-cholesten-3-one (C4) in serum is a semiquantitative test for bile acid malabsorption (BAM). We have previously established pediatric normal values for C4 with an upper limit of normal of 66.5 ng/mL, independent of age and sex. Here we performed the C4 test in 58 pediatric patients with Crohn's disease (CD) and ulcerative colitis (UC). METHODS: C4 was measured using high performance liquid chromatography (HPLC) in fasting serum samples of 44 patients with CD (range 7-19 years) and 14 with UC (4-18 years). Disease activity was assessed by the pediatric CD and UC activity indices (PCDAI and PUCAI, respectively) plus serum (CRP, ESR) and fecal inflammatory markers (calprotectin). RESULTS: C4 concentrations were increased in 10 CD (23%) (range: 70.8-269.3 ng/mL) but only one UC patient (72.9 ng/mL). CD patients with diarrhea (n=12) had higher C4-values compared to those without (76.9 vs. 30.4 ng/mL; p=0.0043). Ileal resection in CD patients (n=10) was associated with increased C4 concentrations (81.2 vs. 24.3 ng/mL, p=0.0004). No correlation was found between C4 values and inflammatory markers. Six of 7 CD patients with persistent diarrhea but quiescent disease (PCDAI ≤12.5) had C4 values indicating BAM. CONCLUSION: Elevated C4 concentrations indicating BAM are common in children with CD. They are associated with ileal resection and non-bloody diarrhea in the absence of active disease or elevated inflammatory markers. The C4-test identifies a subgroup of CD patients with persistent diarrhea in spite of clinical remission which may benefit from bile acid binding therapy.

The genetic contribution of the NO system at the glutamatergic post-synapse to schizophrenia: further evidence and meta-analysis.

NO is a pleiotropic signaling molecule and has an important role in cognition and emotion. In the brain, NO is produced by neuronal nitric oxide synthase (NOS-I, encoded by NOS1) coupled to the NMDA receptor via PDZ interactions; this protein-protein interaction is disrupted upon binding of NOS1 adapter protein (encoded by NOS1AP) to NOS-I. As both NOS1 and NOS1AP were associated with schizophrenia, we here investigated these genes in greater detail by genotyping new samples and conducting a meta-analysis of our own and published data. In doing so, we confirmed association of both genes with schizophrenia and found evidence for their interaction in increasing risk towards disease. Our strongest finding was the NOS1 promoter SNP rs41279104, yielding an odds ratio of 1.29 in the meta-analysis. As findings from heterologous cell systems have suggested that the risk allele decreases gene expression, we studied the effect of the variant on NOS1 expression in human post-mortem brain samples and found that the risk allele significantly decreases expression of NOS1 in the prefrontal cortex. Bioinformatic analyses suggest that this might be due the replacement of six transcription factor binding sites by two new binding sites as a consequence of proxy SNPs. Taken together, our data argue that genetic variance in NOS1 resulting in lower prefrontal brain expression of this gene contributes to schizophrenia liability, and that NOS1 interacts with NOS1AP in doing so. The NOS1-NOS1AP PDZ interface may thus well constitute a novel target for small molecules in at least some forms of schizophrenia.

Cholesteryl ester storage disease: an easily missed diagnosis in oligosymptomatic children.

Cholesteryl ester storage disease (CESD) is a rare, autosomal recessively inherited disorder resulting from deficient activity of lysosomal acid lipase (LAL). LAL is the key enzyme hydrolyzing cholesteryl esters and triglycerides stored in lysosomes after LDL receptor-mediated endocytosis. Mutations within the LIPA gene locus on chromosome 10q23.2-q23.3 may result either in the always fatal Wolman disease, where no LAL activity is found, or in the more benign disorder CESD with a reduced enzymatic activity, leading to massive accumulation of cholesteryl esters and triglycerides in many body tissues. CESD affects mostly the liver, the spectrum is ranging from isolated hepatomegaly to liver cirrhosis. Chronic diarrhea has been reported in some pediatric cases, while calcifications of the adrenal glands, the hallmark of Wolman disease, are rarely observed. Hypercholesterolemia and premature atherosclerosis are other typical disease manifestations. Hepatomegaly as a key finding has been reported in all 71 pediatric patients and in 134 of 135 adult cases in the literature. We present a 13-year-old boy with mildly elevated liver enzymes in the absence of hepatomegaly, finally diagnosed with CESD. Under pravastatine treatment, the patient has normal laboratory findings and is clinically unremarkable since 5 years of follow-up. To our knowledge, this is the first pediatric case of genetically and biopsy confirmed CESD without hepatomegaly, suggesting that this diagnosis can be easily missed. It further raises the question about the natural course and the therapy required for this oligosymptomatic form.

[Cholesterol ester storage disease: a rare disease or a rare diagnosis?]. / Cholesterinesterspeicherkrankheit: Eine seltene, weil zu selten diagnostizierte Krankheit?

We report the case of a 13-year-old boy with a longstanding history of unspecific hepatomegaly. The morphological investigations were diagnostic of a cholesterol ester storage disease (CESD), a rare autosomal recessive inherited disease with deficient activity of lysosomal acid lipase (LAL). The combination of hepatomegaly with accumulation of macrophages and ultrastructural evidence of lysosomal lipid storage are groundbreaking for the diagnosis. The probability of a underdiagnosis or false disease classification, for example as nonalcoholic steatohepatitis (NASH), is high, particularly with regard to genetic data which indicate a higher incidence of the disease.

Selective breeding for deficient sensorimotor gating is accompanied by increased perseveration in rats.

Prepulse inhibition (PPI) of the acoustic startle response is a measure of sensorimotor gating that is deficient in some neuropsychiatric disorders, such as schizophrenia and Tourette's syndrome. Experimentally induced PPI deficits in rats are regarded as endophenotype to study the biological mechanisms and therapeutic strategies of these disorders. We have recently shown that selectively breeding rats for high and low PPI levels, respectively, leads to groups with different PPI performance that remains stable from the second generation on. We here tested whether the low PPI is accompanied by other behavioral deficits. Different spatial and operant learning paradigms were used to assess rats' learning and memory abilities as well as their behavioral flexibility. In the delayed alternation T-maze task the two groups did not differ in task acquisition and working memory. Rats with low PPI showed enhanced perseveration during switching between an egocentric and allocentric radial maze task. Enhanced perseveration was also found in an operant behavioral task, where different demands, i.e. a different number of lever presses for a pellet-reward, were assigned to and switched between two levers of a Skinner box. Rats with low PPI stayed longer at the ineffective lever before switching, thus being less able to adjust their behavior to changing reward values. Additionally, PPI low rats had a higher breakpoint value during a progressive ratio-schedule of reinforcement. Rats selectively bred for low PPI showed some cognitive deficits that are apparent in a number of psychiatric disorders with deficient information processing. Specifically in both, spatial and operant behavioral paradigms, PPI low rats are deteriorated in their ability to modulate behavior based upon new changing information. They may thus provide a non-pharmacological model that can be used to evaluate new therapeutic strategies ranging from pharmacological treatment to functional neurosurgery.

3-Hydroxyglutaric acid fails to affect the viability of primary neuronal rat cells.

Glutaric aciduria type I (GA I) is an autosomal recessive inherited metabolic disorder caused by deficiency of glutaryl-CoA dehydrogenase (GCD) resulting in the accumulation of 3-hydroxyglutaric acid (3OHG), glutaric acid and glutaconic acid in body fluids. GA I is characterized by a specific age- and brain region-dependent neuropathology. Previous studies using organotypic slice cultures of rats and primary chick embryo telencephalon cell cultures indicated that death of neurons is a consequence of an excitotoxic mechanism induced by 3OHG. We used primary neuronal cells of neonatal rats as a model system to test cell viability after treatment with 3OHG. Western blot analysis was used to prove the expression of functional N-methyl-D-aspartate (NMDA) receptors revealing no alteration in the expression of NMDA-2a and -2b receptor subtypes in response to 3OHG. When neuronal cells cultured for 10 or 20 days were treated with 1 mM glutamate, the viability of cells was reduced by 40%. This effect could be prevented by coincubation with the NMDA receptor antagonist MK801. In contrast, incubation of cells with 3OHG for up to 24 h in concentrations of 4-8 mM did not cause increased cell death as compared with untreated control cultures. These results indicate that 3OHG is not excitotoxic in this model of neuronal rat cell cultures despite the presence of functional NMDA receptors. Therefore, alternative or additional pathomechanisms than excitotoxicity may be relevant for neurodegeneration in GA I.

Investigation of the cerebral energy status in patients with glutaric aciduria type I by 31P magnetic resonance spectroscopy.

In vivo phosphorus magnetic resonance spectroscopy (MRS) was used to investigate markers of the cerebral energy status in two patients with glutaric aciduria type I (GA-I). Besides an increased concentration of phosphomonoesters in one patient, no other significant alterations from controls were found. This might indicate increased resynthesis of dendritic processes secondary to preceding metabolic crises. In contrast to previous cell-culture studies, no cerebral depletion of phosphocreatine (PCr) was observed. In conclusion, a severe global and permanent depletion of cerebral energy supplies must be ruled out. The benefit of a permanent creatine substitution to stabilize mitochondrial energy metabolism seems thus questionable. However, as MRS was performed during stable clinical conditions, the possibility of a PCr decrease during acute metabolic crises cannot be assessed.

Characterization of CCK receptors in stomach smooth muscle: evidence for two subtypes.

Cholecystokinin (CCK) and related peptides such as gastrin are important regulators of gastric smooth muscle contraction. Several studies have shown that these effects of CCK and gastrin are mediated by CCK(B) receptors. However, recent studies suggest the expression of an additional CCK receptor subtype distinct from CCK(B) receptors in this tissue. This study was designed to distinguish between CCK(A) and CCK(B) receptors on guinea-pig stomach smooth muscle cells and to evaluate these cells for additional receptor subtypes. We cloned these receptors by hybridization screening of a guinea-pig smooth muscle cDNA library using 32P random primed labeled cDNA probes from the recently cloned rat CCK(A) and CCK(B) receptor coding regions. In addition to clones representing the CCK(B) subtype, clones of CCK(A) receptor subtype, but no additional CCK receptor subtypes, could be identified. All isolated clones displayed highly homologous nucleotide sequences in comparison to previously characterized CCK(A) and CCK(B) receptors from different species. The results of cDNA hybridization at different levels of stringency and Southern blot analysis using guinea-pig genomic DNA suggest that it is unlikely that additional CCK receptors despite CCK(A) and CCK(B) receptors exist in stomach smooth muscle.