Gluten Immunogenic Peptides Are Not Correlated With Reported Adherence to Gluten-Free Diet in Children With Celiac Disease.

OBJECTIVE: There is no gold standard to assess adherence to gluten-free diet (GFD) among patients with celiac disease (CeD). Gluten immunogenic peptides (GIPs) in urine and stool were suggested as novel markers for evaluating adherence to GFD. Our aim was to assess the presence of GIP in pediatric patients with CeD, and to compare the results with alternative methods for evaluating GFD adherence. METHODS: Pediatric patients diagnosed with CeD, who were on GFD for at least 1 year, were enrolled and followed prospectively between November 2018 and January 2021. Study visits included clinical assessment, a dietitian interview, Biagi score, food questionnaires, anthropometric and laboratory measurements, and urine and stool samples obtained for laboratory GIP analysis. RESULTS: The study included 74 patients (63.5% females), with median (interquartile range, IQR) age of 9.9 (7.8-11.7) years, and median (IQR) duration on GFD of 2.5 (2-5.5) years. Good GFD adherence, assessed by Biagi score, was reported in 93.1% of cases. GIP was evaluated during 134 visits, with GIP detected in 27 of 134 (20.1%) of the visits (16.3% of stool samples and 5.3% of urine samples). Positive GIP results were significantly more common in males compared to females (30.6% vs 14.1%, respectively, P < 0.05). Detection of positive GIP was not associated with dietary assessment of GFD adherence, celiac serology results, or reported symptoms. CONCLUSIONS: Stool and urine GIP can be detected in children with CeD, even when dietary assessment indicate good adherence to GFD. The role of GIP testing in clinical practice should be further explored.

A Novel Fecal Elastase Assay for the Detection of Pancreatic Exocrine Insufficiency.

BACKGROUND: Fecal pancreatic elastase 1 (FPE1) is an established screening test for pancreatic exocrine insufficiency (PEI), a condition that is underdiagnosed and if not treated may cause significant morbidity. The aim of this study was to compare a new FPE1 machine based CLIA kit to an ELISA assay which is considered the de facto gold standard in our laboratory for FPE1 measurement. METHODS: Levels of FPE1 from the 227 stool samples were analyzed by the ScheBo ELISA kit and the CLIA Liaison XL system simultaneously with the same cutoff values for both assays. Performance of the Liaison XL system was assessed by calculating sensitivity, specificity, and accuracy. RESULTS: The comparison between the Liaison XL system performance and the ScheBo ELISA kit as reference revealed a sensitivity, specificity, and accuracy of 86.8%, 94.3%, and 92.1%, respectively, using a cutoff of 100 µg FPE1/g stool. When the cutoff is 200 µg FPE1/g stool the sensitivity, specificity, and accuracy were 86.6%, 97.1%, and 90.7%, respectively. Furthermore, linear correlation of FPE1 levels between the two assays were found to be significant by Pearson's correlation coefficient test (R = 0.85, p-values < 0.0001). CONCLUSIONS: The Liaison XL system showed good laboratory performance with our pre-determined cutoff values when compared to our previous assay. An important advantage of this system is its semi-automated mechanism that enables large scale analysis of FPE1. In addition to that, the Liaison XL system is ideal for both qualitative and quantitative analysis of FPE1 allowing for its application to the clinical setting.

Comparing a New Flow Immune-Chromatography Fast Assay with a Random Access Semi-Automatic Chemiluminescent Immunoassay to Measure Fecal Calprotectin.

OBJECTIVE: The biomarker fecal calprotectin is an efficacious tool for evaluating the level of disease activity in Crohn's and Ulcerative colitis, as well as for discriminating between inflammatory bowel disease and irritable bowel syndrome. The aim of this investigation was to appraise the analytical proficiency of a novel flow immune-chromatography assay through comparison with the established gold standard system in our laboratory. METHODS: A cohort comprising of 125 stool samples, submitted for the purpose of routine calprotectin levels analysis, underwent assessment using two distinct approaches: the Liaison XL system and the SmarTest assay, while adhering to identical cut-off criteria. The present study assessed the performance of the SmarTest assay by calculating its sensitivity, specificity, and accuracy measures. RESULTS: The sensitivity, specificity, and accuracy of the SmarTest assay were found to be 97.75%, 80.56%, and 92.80%, respectively, upon comparison with the gold standard. Moreover, the Pearson correlation coefficient analysis ascertained that the linear correlation pertaining to the calprotectin levels, as identified between both assays, was statistically significant (R=0.8158, P values <0.0001). CONCLUSIONS: Upon comparison with the Liaison XL system, it was found that the SmarTest assay demonstrated satisfactory results in both qualitative and quantitative aspects. This novel and expedient diagnostic assay is commended for evaluating fecal calprotectin in situations where access to laboratory services may be insufficient or nonexistent, rendering it an ideal option for point-of-care or at-home testing purposes.

PKA and PI3K activities during capacitation protect sperm from undergoing spontaneous acrosome reaction.

In order to fertilize the egg, the spermatozoon should undergo a process called acrosomal exocytosis or acrosome reaction (AR), a process which can take place only after a series of biochemical changes collectively called capacitation occur in the female reproductive tract. We present here for the first time the involvement of protein-kinase A (PKA) and phosphatidyl-inositol-3-kinase (PI3K) in protecting sperm from undergoing spontaneous AR (sAR) which decreases fertilization rate. Previously we showed that Calmodulin-kinase II (CaMKII) and phospholipase-D (PLD) prevent the occurrence of sAR in two distinct pathways by enhancing actin polymerization. Here we show that PKA mediates PLD activation, and inhibition of PKA resulting in an increase of sAR and a decrease of F-actin levels, two functions which can be recovered by adding phosphatidic acid (PA), the product of PLD activity. PKA is known to induce CaMKII activation. Inhibition of CaMKII, also enhanced sAR and reduced F-actin levels which can be recovered by adding PA. Inhibition of the PLD pathway resulted in an increase in sAR and a decrease in F-actin levels which can be artificially reversed by inhibition of protein - phosphatase 1 (PP1), and this effect is mediated by PI3K. All together, we showed that PKA via PLD and PI3K activation protects the sperm from undergoing sAR by enhancing actin polymerization.