Search Results (103)

Objectives: To investigate the clinical value of cerebrospinal fluid (CSF) testing for biogenic amine, pterins, amino acids, and folates in paediatric onset epilepsies. Methods: Retrospective clinical and biochemical phenotyping of patients with epilepsy who underwent diagnostic CSF measurement of monoamine neurotransmitters, pterins, folates, and amino acids between 2009 and 2022. Results: The studied cohort included 123 patients with epilepsy (mean age at the procedure: 4.54 ± 3.65 years). The diagnostic yield for primary neurotransmitter disorders was 1.68% and zero for inherited amino acid and folate metabolism disorders. Patients with higher seizure frequency showed higher levels of CSF homovanillic acid (HVA) and HVA/5-hydroxyindolacetic acid (5HIAA) ratio. Lower levels of 3-O-methyldopa (3-OMD) were found in patients with co-occurring neurodevelopmental disorders, and lower levels of biopterin, 3-methoxy-4-hydroxyphenylglycol (3-MHPG) and 5-methyltetrahydrofolate (5-MTHF) in those with movement disorders. Significantly lower CSF glutamine levels were found in patients receiving antiseizure medications as polytherapy. Patients with a history of status epilepticus had significantly lower levels of CSF aspartic acid, glycine, leucine, ornithine, and valine, and higher levels of CSF serine. Conclusions: CSF analysis disclosed differences in the concentrations of various metabolites that might be related to the severity of the epilepsy, the presence of comorbid conditions, and medications. Full article

Serotonin (5-hydroxytryptamine) is a key neurotransmitter involved in gastrointestinal and central nervous system functions. Given that approximately 90% of serotonin is synthesized in the gut, dietary interventions targeting the gut microbiota have emerged as promising strategies to modulate serotonin homeostasis. Kefir, a fermented milk beverage rich in probiotics and bioactive compounds, has been suggested to influence gut–brain axis signaling, yet its effects in the pediatric period remain insufficiently characterized. This study aimed to investigate the impact of kefir supplementation on serotonin biosynthesis, receptor expression, and metabolic pathways in a pediatric rat model, focusing on molecular markers across brain, jejunum, and serum tissues. Sixteen male Wistar rats (four weeks old) were divided into kefir and control groups. The kefir group received daily oral gavage of kefir (1 mL/100 g) for eight weeks, while controls received saline. Gene and protein expression levels of serotonergic markers (5-HT, TPH1, TPH2, SLC6A4, VMAT2, 5-HTR2B, 5-HTR3A, and 5-HTR4) were analyzed using quantitative PCR, ELISA, and Western blotting. Serotonin turnover was assessed via 5-HIAA levels. Kefir supplementation significantly increased 5-HT and TPH1 expression in both brain and jejunum tissues. In the brain, kefir elevated TPH2 and upregulated 5-HTR3A and 5-HTR2B, while reducing 5-HIAA levels, suggesting decreased serotonin degradation. In the jejunum, 5-HTR4 expression was markedly increased. Serum analyses revealed reduced TPH1/TPH2 expression but elevated 5-HTR4 levels, indicating systemic modulation of serotonergic signaling. Kefir exerts multifaceted effects on the serotonergic system in pediatric rats by enhancing serotonin biosynthesis, modulating receptor expression, and reducing serotonin turnover. These findings highlight kefir as a potential psychobiotic capable of influencing the gut–brain axis during early life, with implications for pediatric neurodevelopment and mental health. Further research, including clinical trials, is warranted to confirm its translational potential. Full article

The involvement of the serotoninergic system in the pathogenesis of calcific aortic stenosis introduced a novel dimension to our understanding of this complex cardiovascular condition. This study aimed to assess serotonin (5-HT) and its main metabolite, 5-Hydroxyindoleacetic acid (5-HIAA) in patients with severe aortic valve stenosis (AS). The study employed a case–control design, including 76 patients who underwent transthoracic echocardiography, computed tomography (CT), and peripheral blood sampling. Serum concentrations of 5-HT and 5-HIAA were quantified using enzyme-linked immunosorbent assay (ELISA). The severe aortic valve stenosis group exhibited significantly elevated levels of 5-HT and 5-HIAA compared to the control group (5-HT 1066.5 ng/mL (IQR = 961.9–1112 ng/mL) vs. 977.4 ng/mL (IQR = 394.3–1097.9 ng/mL); p = 0.034 and 5-HIAA 57 ± 12.7 ng/mL vs. 47.5 ± 15.3 ng/mL; p = 0.004, respectively). Receiver operating characteristic (ROC) analysis revealed that 5-HT predicted severe AS with a sensitivity of 73.7% and specificity of 50% at a cut-off level > 973.5 ng/mL, whereas 5-HIAA exhibited a sensitivity of 86.8% and specificity of 47.4% when a cut-off level > 45.49 ng/mL was used. This study showed a significant elevation in the 5-HT and 5-HIAA among patients with severe AS, further supporting the potential involvement of the peripheral serotonergic system in the pathophysiology of this condition. Full article

Background: Suicide attempts often co-occur with bipolar disorder (BD), major depressive disorder (MDD), and schizophrenia (SCH). Although impairments of the serotonin (5-HT) system have been associated with suicide attempts, it remains unclear whether these alterations reflect suicidal behavior or are confounded by underlying psychiatric diagnosis. This study used a genotype-informed dynamic model of the 5-HT presynapse to disentangle the effects of suicide attempts and psychiatric diagnosis. Methods: We applied a personalized dynamic model of the 5-HT presynapse to 392 psychiatric patients (with BD, MDD, or SCH), categorized by suicide attempt status, and 140 unaffected individuals. The model incorporated five variants across TPH2, SLC6A4, and MAOA genes simulating individual-specific concentration changes of five 5-HT-related molecular species. Model outputs were summarized by six statistical measures (mean, median, maximum, standard deviation, skewness, and kurtosis) and compared across groups. Results: No significant differences were found across groups defined by suicide attempt status and unaffected individuals. However, diagnosis significantly influenced 5-hydroxyindoleacetic acid (5-HIAA) mean, median, maximum, and standard deviation (all p < 0.05). BD patients had lower 5-HIAA levels than SCH patients (mean: p = 0.013; median: p = 0.013; maximum: p = 0.014; standard deviation: p = 0.014). MDD patients also showed lower 5-HIAA levels than SCH patients for the same measures, with differences approaching significance. No significant difference was observed between BD and MDD patients. A diagnosis-by-suicide attempt status interaction was observed for 5-HIAA skewness (p = 0.013). Conclusions: Model-derived 5-HT profiles were shaped primarily by diagnosis, while temporal dynamics of 5-HIAA, rather than its absolute levels, was associated with suicide attempt status. Thus, personalized dynamic modeling incorporating genetic variants may aid in detecting subtle molecular signatures across diagnoses and suicidal behavior. Full article

Background: A subset of patients with chronic dyspepsia exhibits palpable upper abdominal hardness and systemic symptoms like headache, chest discomfort, neck/shoulder stiffness, fatigue, and depression. In traditional Korean medicine (TKM), this symptom complex is referred to as Damjeok syndrome (痰积症候群, DJS). Although DJS is frequently observed in TKM practice, it lacks a clear case definition and biological mechanism, limiting its integration in gastroenterology research and evidence-based practice. Clarifying its clinical and biological features is essential to understand its pathophysiology and clinical significance. Methods: This case–control study aimed to characterize DJS by comparing 16 female patients diagnosed with DJS and 15 age-matched healthy females as controls. A female-only cohort was selected to reflect the higher prevalence of chronic dyspepsia in women and reduce biological variability. Clinical characteristics and potential DJS-specific biomarkers were evaluated through complete blood count (CBC), serum biochemical tests, heart rate variability (HRV) for autonomic function, and plasma 5-hydroxyindoleacetic acid (5-HIAA), a serotonin metabolite linked to gastrointestinal motility and autonomic regulation. Results: The DJS group had a mean disease duration of 58.0 ± 46.2 months, with epigastric fullness and underlying abdominal hardness as primary complaints. Postprandial distress syndrome (PDS) was the most common (43.8%) dyspepsia subtype, often combined with epigastric pain syndrome (EPS). Extra-gastrointestinal symptoms such as headache/fatigue (87.5%) and anxiety/depression (81.3%) were highly prevalent. Neutrophil counts were significantly lower in the DJS group (p = 0.01), while other hematological or biochemical markers showed no differences (p > 0.1). HRV analysis revealed decreased parasympathetic activity (RMSSD and HF, p < 0.1), and plasma 5-HIAA levels were significantly elevated compared to healthy controls (p = 0.01). Conclusions: DJS aligns with functional gastrointestinal disorders (FGIDs), sharing psychosomatic symptoms and reduced parasympathetic activity, suggesting gut–brain axis dysregulation. However, distinct features like palpable upper abdominal hardness and elevated plasma 5-HIAA levels indicate that DJS may represent a unique subtype within the category of FGIDs. These findings highlight the need for larger, well-designed studies to further elucidate the pathophysiology of DJS. Full article

Background: The gut microbiome is a key modulator of the gut–brain axis and may contribute to the pathophysiology of both gastrointestinal and systemic disorders. This study aimed to evaluate gut microbiota composition and tryptophan/phenylalanine metabolism in women with unclassified irritable bowel syndrome (IBS-U), with or without coexisting chronic fatigue syndrome (CFS). Methods: Eighty women were enrolled and divided into two groups: IBS-U without CFS (Group I, n = 40) and IBS-U with coexisting CFS (Group II, n = 40). Microbial composition and diversity were assessed using the GA-map™ Dysbiosis Test, including the dysbiosis index (DI) and Shannon Diversity Index (SDI). Hydrogen and methane levels were measured in breath samples. Urinary concentrations of selected microbial and neuroactive metabolites—homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), kynurenine (KYN), kynurenic acid (KYNA), xanthurenic acid (XA), quinolinic acid (QA), hydroxyphenylacetic acid (HPA), and 3-indoxyl sulfate (3-IS)—were quantified using LC-MS/MS. Fatigue severity was assessed using the Chalder Fatigue Questionnaire (CFQ-11) and the fatigue severity scale (FSS). Results: Compared to Group I, patients with IBS-CFS showed significantly greater microbial diversity, higher breath methane levels, and elevated urinary concentrations of QA, XA, 3-IS, and HVA, alongside lower concentrations of 5-HIAA and KYN. Fatigue severity was positively correlated with urinary XA and QA levels. Conclusions: Women with IBS and coexisting CFS exhibit distinct gut microbiota and tryptophan metabolite profiles compared to those without fatigue. The observed metabolite–symptom associations, particularly involving neuroactive kynurenine derivatives, warrant further investigation. These preliminary findings should be interpreted as hypothesis-generating and require validation through high-resolution microbiome analyses, functional pathway profiling, and longitudinal or interventional studies to clarify causality and clinical significance. Full article

Cancer during pregnancy is a rare but complex clinical scenario that affects approximately 0.1% of pregnant individuals and is associated with increased maternal morbidity. With the trend of delayed childbearing, the incidence of pregnancy-associated cancers is expected to rise. Neuroendocrine neoplasms (NENs), although rare in pregnancy, present unique diagnostic and therapeutic challenges due to their hormonal activity, histological diversity, and limited data on management in the gestational context. Objectives: This manuscript reviews the current evidence on the diagnosis, staging, and management of NENs during pregnancy, focusing on maternal–fetal safety, therapeutic limitations, and multidisciplinary care strategies. Methods: A comprehensive narrative review was conducted using relevant case reports, retrospective studies, clinical guidelines, and expert consensus documents addressing cancer in pregnancy and NEN-specific management. Results: Pregnancy complicates the evaluation and treatment of NENs due to overlapping symptoms, contraindications to standard imaging and systemic therapies, and unreliable biomarkers such as chromogranin A and 5-HIAA. Most systemic therapies for NENs, including somatostatin analogs, tyrosine kinase inhibitors, and peptide receptor radionuclide therapy, are contraindicated or lack safety data in pregnancy. Surgical interventions and supportive care require careful planning. Decisions regarding pregnancy continuation or termination must be individualized and supported by a multidisciplinary team. Conclusions: The management of NENs during pregnancy demands a highly individualized approach, coordinated among oncology, maternal–fetal medicine, and supportive care teams. Given the paucity of robust data, future research is essential to establish evidence-based guidelines and improve outcomes for both mother and fetus. Full article

Background: Acute appendicitis (AA) is a common surgical emergency worldwide. Over the past few decades, diagnostic imaging has become a cornerstone in the identification of acute appendicitis, significantly contributing to the reduction in unnecessary laparotomies and associated healthcare costs. This study aimed to investigate the influence of serum and spot urine 5-hydroxyindoleacetic acid (5-HIAA) levels, as well as other established clinical and biochemical parameters on the diagnosis of acute appendicitis. Methods: This prospective study was conducted between January and November 2023, evaluating 97 patients diagnosed with acute appendicitis. Serum and spot urine 5-HIAA levels, level of white blood cell (WBC), neutrophils, lymphocytes, platelets, C-reactive protein (CRP), and Alvarado score were analyzed. Patients were further allocated to subgroups based on their Alvarado scores, the onset time of the symptoms, and pathological findings to statistically assess the relationship between the parameters. Results: The mean age of the patients was 34.6 ± 14.8 years. Of the patients, 57 (58.8%) were male, and 40 (41.2%) were female. Spot urine 5-HIAA levels exhibited statistically significant variation among different symptom onset time groups, with elevated levels observed in patients presenting within the first 12 h of symptom onset (p < 0.001). Neutrophil counts were significantly different among Alvarado score groups (p < 0.001), whereas CRP levels significantly increased with the onset time of the symptoms (p < 0.001). Conclusions: Increased spot urine 5-HIAA is supportive of the diagnosis of AA in patients presenting within the first 12 h of symptom onset. Hematological parameters, especially CRP, may provide more reliable information regarding disease severity and progression. Full article

Suicide attempts are prevalent among patients with bipolar disorder (BD). Impaired serotonin (5-HT) system in the pathogenesis of suicide attempt is partially heritable. To quantify the combined effects of multiple genetic variants, we developed a dynamic model of the 5-HT presynapse with functionally integrated individual genetic variants. The model includes five genetic variants in 5-HT system genes (TPH2, SLC6A4, MAOA) and quantitatively assesses their influence on 5-HT synthesis, reuptake, and degradation. The model was validated on 140 unaffected individuals and tested on 101 BD patients. Predicted mean concentrations of 5-HT, 5-HT precursor, and degradation product were compared between BD patients with and without a history of attempted suicide, and unaffected individuals. The model consists of eight differential equations that describe the temporal concentration change of model outputs. Calculated concentrations in unaffected control individuals aligned with published experimentally measured values, validating our model. BD patients with a history of suicide attempt showed lower calculated concentrations of 5-HT degradation product 5-hydroxy-3-indolacetic acid (5-HIAA) compared to unaffected individuals (p = 0.044). Additionally, higher calculated concentrations of free cellular 5-HT (p = 0.048) and stored 5-HT (p = 0.047), with the effect size d = 0.35, were observed when comparing suicide attempters to non-attempters.. Our approach illuminated a complex interplay of genetic variants in 5-HT system genes that contributes to the risk of suicide attempt, with quantitative and personalized outputs unattainable through genetic association studies. Full article

Autism spectrum disorder (ASD) has been associated with disruptions in tryptophan (TRP) metabolism, affecting the production of key neuroactive metabolites. Investigating these metabolic pathways could yield valuable biomarkers for ASD severity and progression. We included 44 children with ASD and 44 healthy children, members of the same family. The average age in the ASD group was 10.7 years, while the average age in the control group was 9.4 years. Urinary tryptophan metabolites were quantified via liquid chromatography—mass spectrometry operating multiple reaction monitoring (MRM). Urinary creatinine was analyzed on an Advia 2400 analyzer using the Jaffe reaction. Statistical comparisons were made between ASD subgroups based on CARS scores. Our findings indicate that children with ASD have higher TRP concentrations (19.94 vs. 16.91; p = 0.04) than their siblings. Kynurenine (KYN) was found at higher levels in children with ASD compared to children in the control group (82.34 vs. 71.20; p = 0.86), although this difference was not statistically significant. The ASD group showed trends of higher KYN/TRP ratios and altered TRP/ indole-3-acetic acid (IAA) and TRP/5-hydroxyindoleacetic acid (5-HIAA) ratios, correlating with symptom severity. Although the numbers of the two groups were different, our findings suggest that mild and severe illnesses involve separate mechanisms. However, further comprehensive studies are needed to validate these ratios as diagnostic tools for ASD. Full article

Introduction: Neuroendocrine tumors are a diverse group of tumors predominantly found in the gastrointestinal tract or respiratory system. Methods: This retrospective study aimed to measure the serum concentrations of LRP6 (low-density lipoprotein receptor-related protein 6), SFRP3 (secreted frizzled-related protein 3), and DVL1 (segment polarity protein dishevelled homolog) using the ELISA method in patients with NETs (N = 80) and a control group (N = 62). We evaluated the results against various demographic, clinicopathological, and biochemical characteristics. Results: Our analyses revealed that the concentration of SFRP3 in patients with neuroendocrine tumors was significantly elevated (p < 0.001) compared to the control group. Additionally, DVL1 concentrations were significantly higher (p < 0.01) in patients with BP-NETs compared to GEP-NETs. Furthermore, DVL1 analysis showed a moderate negative correlation with chromogranin A (p < 0.001) and weak negative correlations with serotonin (p < 0.05) and 5-HIAA (p < 0.05). Significant negative correlations were also observed between DVL1 and age in the control group (p < 0.01), and between LRP6 and Ki-67 in the study group. Conclusions: These results suggest that changes in the SFRP3 and DVL1 pathways play a key role in NET development. Elevated levels of these proteins highlight their importance in tumor biology, with SFRP3 and DVL1 potentially being crucial in NET molecular mechanisms. Further research is needed to explore their roles and potential in diagnosis and treatment. Full article

Objects: Taurine exhibits protective effects in the context of cardiovascular pathophysiology. A range of evidence suggests that hypertension activates inflammatory responses and oxidative stress in the paraventricular nucleus (PVN), elevating the arterial tone and sympathetic activity, while it induces gut–brain axis dysfunction in the context of hypertension. However, the mechanism underlying taurine’s anti-hypertensive effects via the gut–brain axis remains unclear. Method: Male spontaneously hypertensive rats (SHRs) were administered 3% taurine in their drinking water for eight weeks, with their arterial pressure measured weekly. Molecular techniques were employed to investigate taurine’s effects on the hypertensive gut and PVN. Additionally, 16S rRNA gene sequencing was used to analyze the gut microbiota composition, and untargeted metabolomics was applied to assess the fecal metabolites following taurine supplementation. Results: Taurine supplementation not only reduced the blood pressure, sympathetic activity, and inflammatory and oxidative stress in the PVN but also improved the cardiac pathology and microbiota composition while alleviating gut inflammation in hypertensive rats. The untargeted metabolite analysis indicated that the primary effect of the taurine intervention in SHRs was exerted on tryptophan metabolism. The levels of serum metabolites such as kynurenine, L-tryptophan, serotonin (5-HT), and 5-hydroxyindole-3-acetic acid (5-HIAA) were altered in hypertensive rats following taurine treatment. Conclusions: Taurine supplementation restored the microbiota balance, strengthened the mucosal barrier, reduced intestinal inflammation, and stimulated tryptophan metabolism. The metabolites derived from the gut microbiota likely crossed the brain barrier and reached the paraventricular nucleus, thereby reducing the inflammatory responses and oxidative stress in the PVN via gut–brain communication, leading to decreased sympathetic nerve activity and blood pressure in the studied hypertensive rats. Full article

Background: Small intestinal neuroendocrine tumors (SI-NETs) are characterized by carcinoid syndrome and carcinoid heart disease (CHD). The aim of the present study was to identify early risk markers for carcinoid heart disease and survival in a prospective median-term follow-up setting. Methods: We measured 5-HIAA and cumulative 5-HIAA exposure (Cum-5-HIAA) based on repeated measurements, proBNP, vascular function, hepatic tumor load, and transthoracic echocardiography (TTE) at baseline and during the median 5-year follow-up. Of 65 patients with SI-NETs, 54 patients underwent a prospective follow-up. In addition, survival was evaluated during the median follow-up of 6 years. Results: At baseline, three patients had CHD. During the median follow-up of 5 years, two patients (4%) developed CHD. Cum-5-HIAA and proBNP correlated with CHD (Westberg score, Spearman’s ρ = 0.32 and 0.31, respectively). Cum-5-HIAA had a superior diagnostic capability, predicting CHD in receiver operator characteristic analysis with an AUC of 0.98 (95% CI: 0.94–1.00) and outperformed proBNP, chromogranin A (CgA), and individual serum 5-HIAA measurements (AUC = 0.75, 0.85, and 0.91, respectively). Minor changes in valve regurgitation were frequently detected but did not correlate with vascular function. Regurgitation increased or decreased in 29% of tricuspid and 30% of pulmonic valves. CHD, hepatic tumor load, serum 5-HIAA, and elevated aortic pulse wave velocity (PWV) were associated with increased mortality in SI-NET patients. Conclusions: Cum-5-HIAA is a promising biomarker for CHD risk and outperformed other biomarkers. CHD and hepatic tumor load are the strongest predictors of mortality. PWV is a novel predictor of survival. The incidence of CHD was low among the SI-NET patients, probably reflecting successful treatment regimens. Full article

The management of neuroendocrine neoplasms (NENs) involves the measurement of serum chromogranin A (s-CGA), serum neuro-specific enolase (s-NSE), and urinary 5-hydroxindolacetic acid (5-HIAA). Urinary para-hydroxyphenylacetic acid (u-pHPAA), a metabolite of tyrosine, has been proposed as a potential biomarker for these diseases. This study aims to evaluate the effectiveness of u-pHPAA and tyrosine as biomarkers. We measured the levels of s-CgA, s-NSE, u-5-HIAA, u-pHPAA, and tyrosine in blood or 24 h urine samples collected at baseline (T₀) and after 1 year of follow-up (T₁) from a limited cohort of patients enrolled at Istituto Nazionale Tumori-IRCCS-Fondazione “G. Pascale”. Biomarker values were normalized using the ratios between T₁ and T₀ values (T₁/T₀ parameters). The T₁/T₀ ratios for s-CgA and u-pHPAA were significantly associated with the outcome of death (p = 0.044 and p = 0.022, respectively). An ROC curve analysis demonstrated outstanding performances for these biomarkers (AUC = 0.958 and AUC = 1.00, respectively) and the Kaplan–Meier survival analysis showed significant Log-rank test results (p = 0.001 and p < 0.001, respectively). Additionally, T₀ serum tyrosine correlated with the outcome of death (p = 0.044), with the ROC curve showing good performance (AUC = 0.958) and the Kaplan–Meier analysis yielding significant Log-rank test results (p = 0.007). Our study confirms the role of s-CgA in the management of NEN patients and highlights the potential roles of u-pHPAA and serum tyrosine as biomarkers. Further research is needed to validate our findings in larger populations. Full article

Background: IL-33, a pleiotropic cytokine, has been associated with a plethora of immune-related processes, both inflammatory and anti-inflammatory. T regulatory (Treg) cells, the main leukocyte population involved in immune tolerance, can be induced by the administration of IL-33, the local microbiota, and its metabolites. Here, we demonstrate that IL-33 drastically induces the production of intestinal metabolites involved on tryptophan (Trp) metabolism. Methods: naïve mice were treated with IL-33 for 4 days and leukocyte populations were analyzed by flow cytometry, and feces were processed for microbiota and intestinal metabolites studies. Using a murine skin transplantation model, the effect of Kynurenic acid (KA) on allograft survival was tested. Results: Under homeostatic conditions, animals treated with IL-33 showed an increment in Treg cell frequencies. Intestinal bacterial abundance analysis indicates that IL-33 provokes dysbiosis, demonstrated by a reduction in Enterobacteria and an increment in Lactobacillus genera. Furthermore, metabolomics analysis showed a dramatic IL-33 effect on the abundance of intestinal metabolites related to amino acid synthesis pathways, highlighting molecules linked to Trp metabolism, such as kynurenic acid (KA), 5-Hydroxyindoleacetic acid (5-HIAA), and 6-Hydroxynicotinic acid (6-HNA), which was supported by an enhanced expression of Ido and Kat mRNA in MLN cells, which are two enzymes involved on KA synthesis. Interestingly, animals receiving KA in drinking water and subjected to skin transplantation showed allograft acceptance, which is associated with an increment in Treg cell frequencies. Conclusions: Our study reveals a new property for IL-33 as a modulator of the intestinal microbiota and metabolites, especially those involved with Trp metabolism. In addition, we demonstrate that KA favors Tregs in vivo, positively affecting skin transplantation survival. Full article