Urinary Peptides Research Articles

Application of urinary peptide-biomarkers in trauma patients as a predictive tool for prognostic assessment, treatment and intervention timing

Treatment of severely injured patients represents a major challenge, in part due to the unpredictable risk of major adverse events, including death. Preemptive personalized treatment aimed at preventing these events is a crucial objective of patient management; however, the currently available scoring systems provide only moderate guidance. Biomarkers from proteomics/peptidomics studies hold promise for improving the current situation, ultimately enabling precision medicine based on individual molecular profiles. To test the hypothesis that peptide biomarkers could predict patient outcomes in severely injured patients, we initiated a pilot study involving consecutive urine sampling (on days 0, 2, 5, 10, and 14) and subsequent peptidome analysis using capillary electrophoresis coupled to mass spectrometry (CE-MS) of 14 severely injured patients and two additional intensive care unit patients. The urine peptidomes of these patients were compared to those of age- and sex-matched controls. Moreover, previously established urinary peptide-based classifiers, CKD273, AKI204, and Cov50, were applied to the obtained peptidome data, and the association of the classifier’s scores with a combined endpoint (death and/or kidney failure and/or respiratory insufficiency) was investigated. CE-MS peptidome analysis identified 191 significantly altered peptides in severely injured patients. A consistent increase in the abundance of peptides from A1AT, AHSG, and HBA1 was observed, while peptides derived from PIGR and UROM were consistently decreased. Most of the significant peptides (adjusted p < 0.05) were from COL1A1, and most were reduced in abundance. Two of the previously defined and validated peptidomic classifiers, CKD273 and AKI204, showed significant associations with the combined endpoint, which was not observed for the routine scores generally applied in the clinics. This prospective pilot study confirmed the hypothesis that urinary peptides provide information on patient outcomes and may guide personalized interventions in severely injured patients based on individual molecular changes. The results obtained allow the planning of a well-powered prospective trial investigating the value of urinary peptides in this context in more detail.

What is the Role of Measuring Urinary Gluten Immunogenic Peptides in Clinical Practice in Patients with Coeliac Disease?

In coeliac disease, the clinical role of the urinary gluten immunogenic peptide is unclear. It has been suggested it can be a non-invasive marker of villous atrophy. Therefore, we present the largest cross-sectional clinical data in patients with coeliac disease to establish the diagnostic accuracy of the urinary gluten immunogenic peptide in identifying villous atrophy. Patients providing urinary gluten immunogenic peptide were identified between September 2018 and August 2023 at the National Health Service (NHS) England National Centre for Non-Responsive and Refractory CD. In our retrospective study, the results of the urinary gluten immunogenic peptide test collected within 7 days, self-reported adherence to a gluten free diet reported within 3 months, serology collected within 7 days (immunoglobulin A - tissue transglutaminase and endomysial antibody) and histology at the time of endoscopy were compared in individuals with coeliac disease who were either asymptomatic and undergoing remission biopsies (group 1), non-responsive coeliac disease (group 2) and refractory coeliac disease on immunosuppressive therapy (group 3). Associations between dichotomous variables were calculated using chi-squared test. In group 1 the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting villous atrophy were 42.9%, 83.3.%, 64.3% and 67.6% respectively. In group 2 the sensitivity, specificity, PPV and NPV for detecting villous atrophy were 36.2%, 79.0%, 39.5% and 76.6% respectively. In group 3 the sensitivity, specificity, PPV and NPV for detecting villous atrophy were 56.3%, 70.6%, 73.0% and 53.3%. More patients on immunosuppression had a positive urinary gluten immunogenic peptide than those not on immunosuppression (43.3% vs 24.1%, p<0.001). The urinary gluten immunogenic peptide does not have a role in identifying villous atrophy. Therefore, to assess for villous atrophy an upper gastrointestinal endoscopy is still required.

Suboptimal adherence to a gluten-free diet in adults with both type 1 diabetes and celiac disease using urinary gluten immunogenic peptide measurement

Objectives Concurrent type 1 diabetes (T1D) and celiac disease (CeD) pose challenges in insulin dosage adjustments and gluten-free dietary adherence. Urine testing for gluten immunogenic peptides (GIP) is a new method to detect gluten exposure within the last 3–12 h. Our aims were to compare gluten-free dietary adherence between T1D + CeD and CeD individuals and evaluate urinary GIP testing in an outpatient setting. Materials and methods This observational cross-sectional study included three adult groups: (1) T1D and CeD, (2) CeD only, and (3) T1D only. T1D participants were recruited from outpatient clinics, the CeD group via social media. One urine sample (12 pm–7 pm) was analyzed using a qualitative immunographic GIP test. CeD participants completed ‘Celiac Dietary Adherence Test’ (CDAT) and ‘Celiac Symptom Index’ (CSI) questionnaires. IgA anti-transglutaminase 2 (IgA-TG2) and IgG anti-deamidated gliadin (IgG-DGP) serology were also analyzed. Results 197 participants, mean (SD) age 43 (15) years, were included. Female percentages were: CeD: 90%, T1D + CeD: 64%, and T1D: 47%. Positive urinary GIP was found in 15% (14/96) of T1D + CeD and 0% (0/50) of CeD (p = 0.002). As expected, most T1D only participants had positive urinary GIP (86%, 44/51). CDAT and CSI scores did not differ between T1D + CeD and CeD groups. Positive IgA-TG2 and/or IgG-DGP levels were found in 12% of T1D + CeD and 6% of CeD participants (p = 0.38). Conclusions A single GIP urine test revealed higher gluten exposure in T1D + CeD versus CeD only, questioning dietary adherence in this population. Urinary GIP tests can be useful for clinical follow-up.

Evaluation of predictive performance of fetal urinary inflammatory markers of postnatal kidney function in fetuses with posterior urethral valves

Abstract Background There are proposed roles for inflammation in the development of congenital obstructive uropathy in the setting of posterior urethral valves (PUV). However, the value of inflammatory proteins as predictive markers of postnatal kidney function, key in the management of fetuses with PUV, has not been explored. We screened fetal urine of fetuses with PUV with a panel of inflammatory proteins to determine their predictive value of postnatal kidney function. Methods Twenty-five different chemokines and cytokines were measured using a multiplex immunoassay in fetal urine of 79 PUV patients from retrospective cohorts, separated in discovery (n = 52) and validation (n = 27). The candidate markers were also quantified in amniotic fluid samples obtained from 16 PUV and 25 other congenital anomalies of the kidney and the urinary tract pregnancies. The performance of validated candidate inflammatory proteins was compared to the previously published 12PUV fetal urine peptide signature. Results Fetal urine chemokines CCL2 (MCP-1), CXCL9 (MIG), and CCL4 (MIP-1β) were identified as predictive of postnatal kidney failure in fetuses with PUV from the discovery cohort. Their predictive potential was confirmed in the validation cohort (AUCs of 0.87, 0.81, and 0.86, respectively). The performance of these individual chemokines was lower than the previously published 12PUV fetal urine peptide signature. However, the combination of the three chemokines performed similarly to 12PUV. In contrast, these three chemokines were not predictive of outcome in amniotic fluid. Conclusions We identified chemokines in fetal urine of PUV pregnancies that, after external validation, could serve as predictive biomarkers of postnatal outcome and contribute to improve prenatal PUV management. Graphical Abstract

Urinary Proteomics and Systems Biology Link Eight Proteins to the Higher Risk of Hypertension and Related Complications in Blacks Versus Whites.

Blacks are more prone to salt-sensitive hypertension than Whites. This cross-sectional analysis of a multi-ethnic cohort aimed to search for proteins potentially involved in the susceptibility to salt sensitivity, hypertension, and hypertension-related complications. The study included individuals enrolled in African Prospective Study on the Early Detection and Identification of Cardiovascular Disease and Hypertension (African-PREDICT), Flemish Study of the Environment, Genes and Health Outcomes (FLEMENGHO), Prospective Cohort Study in Patients with Type 2 Diabetes Mellitus for Validation of Biomarkers (PROVALID)-Austria, and Urinary Proteomics Combined with Home Blood Pressure Telemonitoring for Health Care Reform Trial (UPRIGHT-HTM). Sequenced urinary peptides detectable in 70% of participants allowed the identification of parental proteins and were compared between Blacks and Whites. Of 513 urinary peptides, 300 had significantly different levels among healthy Black (n=476) and White (n=483) South Africans sharing the same environment. Analyses contrasting 582 Blacks versus 1731 Whites, and Sub-Saharan Blacks versus European Whites replicated the findings. COL4A1, COL4A2, FGA, PROC, MGP, MYOCD, FYXD2, and UMOD were identified as the most likely candidates underlying the racially different susceptibility to salt sensitivity, hypertension, and related complications. Enriched pathways included hemostasis, platelet activity, collagens, biology of the extracellular matrix, and protein digestion and absorption. Our study suggests that MGP and MYOCD being involved in cardiovascular function, FGA and PROC in coagulation, FYXD2 and UMOD in salt homeostasis, and COL4A1 and COL4A2 as major components of the glomerular basement membrane are among the many proteins potentially incriminated in the higher susceptibility of Blacks compared to Whites to salt sensitivity, hypertension, and its complication. Nevertheless, these eight proteins and their associated pathways deserve further exploration in molecular and human studies as potential targets for intervention to reduce the excess risk of hypertension and cardiovascular complications in Blacks versus Whites.

(Prote)omics for Superior Management of Kidney and Cardiovascular Disease-A Thought-Provoking Impulse From Nephrology.

Chronic kidney disease (CKD) and cardiovascular disease (CVD) are complex conditions often managed by nephrologists. This viewpoint paper advocates for a multi-omics approach, integrating clinical symptom patterns, non-invasive biomarkers, imaging and invasive diagnostics to enhance diagnosis and treatment. Early detection of molecular changes, particularly in collagen turnover, is crucial for preventing disease progression. For instance, urinary proteomics can detect early molecular changes in diabetic kidney disease (DKD), heart failure (HF) and coronary artery disease (CAD), enabling proactive interventions and reducing the need for invasive procedures like renal biopsies. For example, urinary proteomic patterns can differentiate between glomerular and extraglomerular pathologies, aiding in the diagnosis of specific kidney diseases. Additionally, urinary peptides can predict CKD progression and HF development, offering a non-invasive alternative to traditional biomarkers like eGFR and NT-proBNP. The integration of multi-omics data with artificial intelligence (AI) holds promise for personalised treatment strategies, optimizing patient outcomes. This approach can also reduce healthcare costs by minimizing unnecessary invasive procedures and hospitalizations. In conclusion, the adoption of multi-omics and non-invasive biomarkers in nephrology and cardiology can revolutionize disease management, enabling early detection, personalised treatment and improved patient outcomes.

Urinary proteomic signature of mineralocorticoid receptor antagonism by spironolactone: evidence from the HOMAGE trial

Abstract Background Heart failure (HF) is characterised by collagen deposition. Urinary proteomic profiling (UPP) detects many sequenced peptides, for &amp;gt;70% derived from collagens. Purpose UPP and serum fibrosis markers were analysed together in patients at risk of HF with as objective to generate insights into the antifibrotic action of spironolactone. Methods In the open-label HOMAGE trial, patients were randomised to usual therapy combined or not with spironolactone 25-50 mg/d and followed for 9 months (n=290; 23.8% women; median age: 73 years). UPP was done by capillary electrophoresis coupled with mass spectrometry; 1498 urinary peptides with detectable signal in ≥30% of patients were analysed. Serum markers of COL1A1 synthesis (PICP and PICP/CITP) were measured. After rank normalisation of the biomarker distributions, between-group differences in their changes were assessed by multivariable-adjusted models. Correlations between the changes in urinary peptides and in serum PICP and PICP/CITP were compared between groups using Fisher Z transform. Results Among all the urinary peptides, only the changes in collagen fragments remained significantly different (p&amp;lt;0.05) between randomisation groups after accounting for baseline levels, covariables and multiple testing. Compared to the control group, spironolactone reduced 16 of 27 collagen-derived urinary peptides. From baseline to 9 months, serum PICP and the PICP/CITP ratio decreased from 79.0 to 75.4 µg/L and from 21.3 to 18.3, respectively (p≤0.0129), reflecting decreased COL1A1 synthesis. Spironolactone did not affect the correlations between changes in urinary COL1A1 fragments and the serum fibrosis markers. Conclusions Spironolactone downregulated urinary collagen-derived peptides, probably by shrinking the body-wide pool of collagens. Spironolactone did not affect the interaction between urinary and serum fibrosis markers, suggesting that collagen scaffolding is maintained, thereby explaining why some urinary collagen fragments increased. Combining urinary and serum fibrosis biomarkers opens new avenues for discovery of antifibrotic drugs and refines insight in the action of antifibrotic drugs.Figure 1Figure 2

OSTEO18, a novel urinary proteomic signature, associated with osteoporosis in heart transplant recipients

Abstract Background Immunosuppressive treatment in heart transplant (HTx) recipient causes osteoporosis. The urinary proteomic profile (UPP) includes peptide fragments derived from the bone extracellular matrix. Purpose Study aims were to develop and validate a multidimensional UPP biomarker for osteoporosis in HTx patients from single sequenced urinary peptides identifying the parent proteins. Methods A single-center HTx cohort was analyzed. Urine samples were measured by capillary electrophoresis coupled with mass spectrometry. Cases with osteoporosis and matching controls were randomly selected from all available 389 patients. In derivation case-control dataset, 1576 sequenced peptides detectable in ≥30% of patients. Applying statistical analysis on these, an 18-peptide multidimensional osteoporosis UPP biomarker (OSTEO18) was generated by support vector modeling. The 2 replication datasets included 118 and 94 patients. For further validation, the whole cohort was analyzed. Statistical methods included logistic regression and receiver operating characteristic curve (ROC) analysis. Results In derivation dataset, the AUC, sensitivity and specificity of OSTEO18 were 0.83 (95% CI: 0.76-0.90), 74.3% and 87.1%, respectively. In replication datasets, results were confirmatory. In the whole cohort (154 osteoporotic patients [39.6%]), the ORs for osteoporosis increased (p &amp;lt; 0.0001) across OSTEO18 quartiles from 0.39 (95% CI: 0.25-0.61) to 3.14 (2.08-4.75). With full adjustment for known osteoporosis risk factors, OSTEO18 improved AUC from 0.708 to 0.786 (p = 0.0003) for OSTEO18 categorized (optimized threshold: 0.095) and to 0.784 (p = 0.0004) for OSTEO18 as continuously distributed classifier. Conclusion OSTEO18 is a clinically meaningful novel biomarker indicative of osteoporosis in HTx recipients and is being certified as in-vitro diagnostic.

Hydroxyprolyl-Glycine in 24 H Urine Shows Higher Correlation with Meat Consumption than Prolyl-Hydroxyproline, a Major Collagen Peptide in Urine and Blood.

Background. Urinary collagen peptides, the breakdown products of endogenous collagen, have been used as biomarkers for various diseases. These non-invasive biomarkers are easily measured via mass spectrometry, aiding in diagnostics and therapy effectiveness. Objectives. The objective of this study was to investigate the effects of consuming collagen-containing meat on collagen peptide composition in human blood and urine. Methods. Ten collagen peptides in 24 h urine were quantified. Results. Prolyl-hydroxyproline (Pro-Hyp) was the most abundant peptide. Except for hydroxyprolyl-glycine (Hyp-Gly), levels of other minor collagen peptides showed high correlation coefficients with Pro-Hyp (r = 0.42 vs. r > 0.8). Notably, 24 h urinary Hyp-Gly showed a correlation coefficient of r = 0.72 with meat consumption, significantly higher than the coefficient for Pro-Hyp (r = 0.37). Additionally, the levels of Pro-Hyp and Hyp-Gly in the blood of seven young women participants increased similarly after consuming fish meat, while before ingestion, only negligible amounts of Hyp-Gly were present. To examine which peptides are generated by the degradation of endogenous collagen, mouse skin was cultured. The amount of Pro-Hyp released from the skin was approximately 1000-fold higher than that of Hyp-Gly. Following consumption of collagen-containing meat, both Pro-Hyp and Hyp-Gly are released in blood and excreted into urine, although Pro-Hyp is primarily generated from endogenous collagen even under physiological conditions. Conclusions. Therefore, in 24 h urine samples, the non-negligible fraction of Pro-Hyp is contributed by endogenous collagen, making 24 h urine Hyp-Gly level a potential biomarker for evaluating meat consumption on the day.

Urinary and fecal gluten immunogenic peptides’ detection to monitor gluten challenge in patients with suspected celiac disease

Urinary and fecal gluten immunogenic peptides’ detection to monitor gluten challenge in patients with suspected celiac disease

Urinary proteomic signature of mineralocorticoid receptor antagonism by spironolactone: evidence from the HOMAGE trial

ObjectiveHeart failure (HF) is characterised by collagen deposition. Urinary proteomic profiling (UPP) followed by peptide sequencing identifies parental proteins, for over 70% derived from collagens. This study aimed to refine...

Mortality Risk and Urinary Proteome Changes in Acute COVID-19 Survivors in the Multinational CRIT-COV-U Study.

Survival prospects following SARS-CoV-2 infection may extend beyond the acute phase, influenced by various factors including age, health conditions, and infection severity; however, this topic has not been studied in detail. Therefore, within this study, the mortality risk post-acute COVID-19 in the CRIT-COV-U cohort was investigated. Survival data from 651 patients that survived an acute phase of COVID-19 were retrieved and the association between urinary peptides and future death was assessed. Data spanning until December 2023 were collected from six countries, comparing mortality trends with age- and sex-matched COVID-19-negative controls. A death prediction classifier was developed and validated using pre-existing urinary peptidomic datasets. Notably, 13.98% of post-COVID-19 patients succumbed during the follow-up, with mortality rates significantly higher than COVID-19-negative controls, particularly evident in younger individuals (<65 years). These data for the first time demonstrate that SARS-CoV-2 infection highly significantly increases the risk of mortality not only during the acute phase of the disease but also beyond for a period of about one year. In our study, we were further able to identify 201 urinary peptides linked to mortality. These peptides are fragments of albumin, alpha-2-HS-glycoprotein, apolipoprotein A-I, beta-2-microglobulin, CD99 antigen, various collagens, fibrinogen alpha, polymeric immunoglobulin receptor, sodium/potassium-transporting ATPase, and uromodulin and were integrated these into a predictive classifier (DP201). Higher DP201 scores, alongside age and BMI, significantly predicted death. The peptide-based classifier demonstrated significant predictive value for mortality in post-acute COVID-19 patients, highlighting the utility of urinary peptides in prognosticating post-acute COVID-19 mortality, offering insights for targeted interventions. By utilizing these defined biomarkers in the clinic, risk stratification, monitoring, and personalized interventions can be significantly improved. Our data also suggest that mortality should be considered as one possible symptom or a consequence of post-acute sequelae of SARS-CoV-2 infection, a fact that is currently overlooked.

O67 URINARY PROTEOMIC PROFILING REVEALS MOLECULAR CUES UNDERLYING HIGHER HYPERTENSION SUSCEPTIBILITY IN BLACKS THAN WHITES

Background and Objective: Compared with Whites, Blacks are more prone to hypertension and salt-sensitivity. The objective was to investigate whether sequenced urinary peptide fragments derived from proteins with a key role in cardiovascular or renal structure or function have different levels in sub-Saharan Blacks compared with Whites. Methods: This individual-participant meta-analysis included individuals enrolled in African-PREDICT (476 Blacks and 483 Whites), FLEMENGHO (720 Whites), PROVALID-Austria (467 Whites) and UPRIGHT-HTM (106 Nigerian Blacks and 61 Polish and Slovenian Whites). Urinary peptides were quantified by capillary electrophoresis combined with mass spectrometry. Results: Among 2313 participants (49.7% women), median age was 40.9 years. Of 513 urinary peptides with 70% prevalence, 300 had Bonferroni-corrected significantly different levels among Black and White South Africans sharing the same environment. Analyses contrasting 582 Blacks vs 1731 Whites, sub-Saharan Blacks (582) vs European Whites (1248) replicated the findings. Combining these results with information from public databases, we identified COL4A1, COL4A2, CD99, FAT1, FGA, FXYD2, MGP, MYOCD, PCDH7, PROC, and UMOD as most likely candidates underlying the different susceptibility to hypertension and salt sensitivity between Blacks and Whites. The most relevant enriched pathways were related to hemostasis, platelet activity, collagens and biology of the extracellular matrix, and protein digestion and absorption. Disease Ontology terms comprised small-vessel disease and coronary and macrovascular atherosclerotic disease. Conclusions: MGP and MYOCD being involved in cardiovascular function, FGA in clot formation, FYXD2 and UMOD in salt homeostasis, and COL4A1 and COL4A2 as major component of the glomerular basement membrane are proteins deserving further exploration in molecular and human studies as potential targets for intervention to reduce the excess hypertension risk and associated complications in Blacks.

Urinary opioid peptides in children with autism spectrum disorders. A Pilot Study

BACKGROUND: Circulating β-casomorphins (BCM) and gluten exorphins (GE), which are exogenous opioid peptides originating from bovine milk protein casein and cereal protein gluten, respectively, have been proposed as potential trigger factor to symptoms observed in children with autism. OBJECTIVE: Given the debate surrounding the detectability of these opioid peptides in body fluids, particularly using highly sensitive and specific mass spectrometry (HPLC-MS) techniques, we aimed to investigate their presence in urine samples of autistic subjects. METHODS: We employed an HPLC-MS method for peptide detection. RESULTS: The presence of several BCMs and GEs in the urine of both autistic children (ASD) and healthy controls (HC) was documented. The detection of dietary opioid peptides even at very low concentrations underscores the sensitivity of this novel HPLC-MS method. BCM-8 was more often detected in the ASD group compared to the HC group. A higher prevalence of gastrointestinal (GI) symptoms were also observed in the ASD group. CONCLUSIONS: This pilot study supports the presence of BCMs and GEs in urine samples in subjects with autism as well as healthy controls which was the main goal of this pilot study. Prolonged exposure to bovine BCMs and GEs may play a role in the manifestation of core and GI symptoms in subgroups of autism. Further research is warranted to investigate this phenomenon thoroughly.

Multiple urinary peptides are associated with hypertension: a link to molecular pathophysiology.

Hypertension is a common condition worldwide; however, its underlying mechanisms remain largely unknown. This study aimed to identify urinary peptides associated with hypertension to further explore the relevant molecular pathophysiology. Peptidome data from 2876 individuals without end-organ damage were retrieved from the Human Urinary Proteome Database, belonging to general population (discovery) or type 2 diabetic (validation) cohorts. Participants were divided based on systolic blood pressure (SBP) and diastolic BP (DBP) into hypertensive (SBP ≥140 mmHg and/or DBP ≥90 mmHg) and normotensive (SBP <120 mmHg and DBP <80 mmHg, without antihypertensive treatment) groups. Differences in peptide abundance between the two groups were confirmed using an external cohort ( n = 420) of participants without end-organ damage, matched for age, BMI, eGFR, sex, and the presence of diabetes. Furthermore, the association of the peptides with BP as a continuous variable was investigated. The findings were compared with peptide biomarkers of chronic diseases and bioinformatic analyses were conducted to highlight the underlying molecular mechanisms. Between hypertensive and normotensive individuals, 96 (mostly COL1A1 and COL3A1) peptides were found to be significantly different in both the discovery (adjusted) and validation (nominal significance) cohorts, with consistent regulation. Of these, 83 were consistently regulated in the matched cohort. A weak, yet significant, association between their abundance and standardized BP was also observed. Hypertension is associated with an altered urinary peptide profile with evident differential regulation of collagen-derived peptides. Peptides related to vascular calcification and sodium regulation were also affected. Whether these modifications reflect the pathophysiology of hypertension and/or early subclinical organ damage requires further investigation.

Development and Validation of a Tool for Assessing Adherence to Gluten-Free Diet in Patients With Celiac Disease.

Life-long adherence to gluten-free diet (GFD) and its assessment is essential for patients with celiac disease (CeD). We have developed and validated a tool for assessing adherence to GFD which can be used by both physicians and dietitians. Phase 1: Development, content validation, and assessment of reliability of tool. Phase 2: Validation of tool against standard dietary evaluation (SDE) (gold standard), immunoglobulin A - anti-tissue transglutaminase antibodies (IgA anti-tTG Ab), and gluten immunogenic peptides in urine. Overall, 380 biopsy-confirmed patients with CeD (derivation cohort: n = 100 [phase 1], n = 210 [phase 2] and independent validation cohort, n = 70) were recruited. Of an initial 90-point questionnaire, 84 items (Celiac Disease: Compliance Assessment Test [CD-CAT.v1]) were retained after content validation and pilot testing. In phase 1, upon administering CD-CAT.v1 on 100 patients, a comprehensive 35-item tool (CD-CAT.v2; α = 0.86) was obtained after removing items with low test-retest reliability and item-rest correlation values. In phase 2, upon administering CD-CAT.v2 on 210 patients, 22 items were removed having low correlation values (R < 0.4) with SDE. Finally, a 13-item tool (CD-CAT.v3; α = 0.84) was obtained with high criterion validity with SDE ( r = 0.806, P < 0.001), moderate convergent validity with celiac disease adherence test ( r = 0.602, P = 0.007), and moderate to weak correlation with urine gluten immunogenic peptides ( r = 0.46, P = 0.001) and IgA anti-tTG Ab ( r = 0.39, P = 0.008), respectively. The final 13-item tool also strongly correlated with SDE ( r = 0.78, P < 0.001) in an independent validation cohort of 70 patients with CeD. Principal component analysis identified 3 relevant subscales with a cumulative variance of 62%. The sensitivity and specificity of CD-CAT.v3 were 80% and 91%, respectively, with an area under curve of 0.905 with SDE. The obtained cutoff score of <19 from the receiver operating characteristic curve was further categorized as 13 = excellent, 14-18 = very good, 19-28 = average, and >28 = poor adherence to GFD. CD-CAT is a new and rapid tool for monitoring dietary adherence to GFD with high sensitivity and specificity, which can be administered by both physicians and dietitians.

Investigating and Annotating the Human Peptidome Profile from Urine under Normal Physiological Conditions.

Examining the composition of the typical urinary peptidome and identifying the enzymes responsible for its formation holds significant importance, as it mirrors the normal physiological state of the human body. Any deviation from this normal profile could serve as an indicator of pathological processes occurring in vivo. Consequently, this study focuses on characterizing the normal urinary peptidome and investigating the various catalytic enzymes that are involved in generating these native peptides in urine. Our findings reveal that 1503 endogenous peptides, corresponding to 436 precursor proteins, were consistently identified robustly in at least 10 samples out of a total of 19 samples. Notably, the liver and kidneys exhibited the highest number of tissue-enriched or enhanced genes in the analyzed urinary peptidome. Furthermore, among the catalytic types, CTSD (cathepsin D) and MMP2 (matrix metalloproteinase-2) emerged as the most prominent peptidases in the aspartic and metallopeptidases categories, respectively. A comparison of our dataset with two of the most comprehensive urine peptidome datasets to date indicates a consistent relative abundance of core endogenous peptides for different proteins across all three datasets. These findings can serve as a foundational reference for the discovery of biomarkers in various human diseases.

Long-Term Changes of Urinary Exosomal Peptide Levels After Thyroidectomy in Patients with Thyroid Cancer: A Prospective Observational Study.

The recurrence rate of thyroid cancer can be as high as 30%. The purpose of this study was to examine changes of urine exosomal peptide levels after thyroidectomy in patients with thyroid cancer to determine if levels can predict the risk of recurrence. Patients >20 years old as newly diagnosed with papillary thyroid cancer who had received a thyroidectomy were recruited. Urine samples were collected at 12 months after enrollment to the study, and 1 year later. Urine exosomes containing different peptides were identified and compared. A total of 70 patients were enrolled in the study, and were classified by the interval between surgery and enrollment: 42 patients with < 5 years between surgery and enrollment, 14 patients between 5-10 years, and 14 patients longer than 10 years. No recurrence was observed in any patient during the 2 years after enrollment. No significant differences were found in the levels of serum proteins or urine exosomal peptides between groups, or between intervals. Known risk factors for high-risk thyroid cancer had only a mild correlation with serum protein levels and urine exosomal peptides. Our study revealed the long-term basal fluctuation ranges of serum proteins and urine exosomal peptides in patients with thyroid cancer who underwent thyroidectomy. For high-risk patients after thyroidectomy, concentrations of serum proteins or urine exosomal peptides within the ranges may indicate there is a lower risk of thyroid cancer recurrence during long-term follow-up. ClinicalTrials.gov: NCT03488134.

Urinary peptide profiling for prediction of kidney disease progression in community populations: A prospective study with 6-year follow-up

Urinary peptide profiling for prediction of kidney disease progression in community populations: A prospective study with 6-year follow-up

Gluten Free Casein Free Diet for Children with Autism Spectrum Disorder – A Review

Autism Spectrum Disorder is a group of neurodevelopmental conditions characterized by social and repetitive behaviour. As per WHO it is estimated that worldwide 1 in 160 children has ASD. Based on epidemiological studies conducted over the past 50 years, the prevalence of ASD appears to be increasing globally. Delayed speech, frequent repetition of set words and phrases, no social interactions, sensory changes etc. are the main symptoms of ASD. There is no known cure for ASD, but many different approaches are used to treat the symptoms of the disorders, for example, visual aids are used to improve communication, social stories interventions are used to teach appropriate social behaviour, and medication is used to ameliorate specific symptoms like aggression. Dietary intervention as a tool for maintaining and improving physical health and wellbeing for ASD is a widely researched and discussed topic. Studies have depicted that there is a link between diet, gut epithelial changes and altered immune response in the spectrum disorders exhibited by children with Autism. A gluten-free casein-free diet is also known as the GFCF diet. It is one of several alternative treatments for children with autism. When following this strict elimination diet, all foods containing and casein are removed from the child's daily food intake. Foods that contained proteins such as gluten and casein causes hypersensitivity to children with ASD. The children cannot digest these proteins properly. This result to increase the level of urinary small peptides. These peptides bind to opioid receptors and become biologically active, which results excess of opioid and leads to an increase of the behavioural difficulties seen in the children. Dietary interventions with the exclusion of gluten, casein or both is thought to have a positive effect on behavioural symptoms because of the elevated levels of peptides seen in the urinary analyses. Since the chemical structure of gluten and casein are very similar to each other, it is very likely that having a sensitivity to one of them means having a sensitivity to both, even though one could be worse than the other. This paper provide an overview of the gluten free casein free diet and its positive and negative results of Gluten free Casein free diet on the basis of reviewing case studies.