Urine 5-Hydroxyindoleacetic Acid Negatively Correlates with Migraine Occurrence and Characteristics in the Interictal Phase of Episodic Migraine.

Although migraine belongs to the main causes of disability worldwide, the mechanisms of its pathogenesis are poorly known. As migraine diagnosis is based on the subjective assessment of symptoms, there is a need to establish objective auxiliary markers to support clinical diagnosis. Tryptophan (TRP) metabolism has been associated with the pathogenesis of neurological and psychiatric disorders. In the present work, we investigated an association between migraine and the urine concentration of TRP and its metabolites 5-hydroxyindoleacetic acid (5-HIAA), kynurenine (KYN), kynurenic acid (KYNA) and quinolinic acid (QA) in 21 low-frequency episodic migraine patients and 32 controls. We chose the interictal phase as the episodic migraine patients were recruited from the outpatient clinic and had monthly migraine days as low as 1-2 in many cases. Migraine patients displayed lower urinary levels of 5-HIAA (p < 0.01) and KYNA (p < 0.05), but KYN and QA were enhanced, as compared with the controls (p < 0.05 and 0.001, respectively). Consequently, the patients were characterized by different values of the 5-HIAA/TRP, KYN/TRP, KYNA/KYN, and KYNA/QA ratios (p < 0.001 for all). Furthermore, urinary concentration of 5-HIAA was negatively correlated with Migraine Disability Assessment score and monthly migraine and monthly headache days. There was a negative correlation between Patient Health Questionnaire 9 scores assessing depression. In conclusion, the urinary 5-HIAA level may be further explored to assess its suitability as an easy-to-determine marker of migraine.

Quantification of 5-Hydroxyindoleacetic Acid in Urine by Ultra-performance Liquid Chromatography Tandem Mass Spectrometry.

Serotonin (5-hydroxytryptamine) is a neurotransmitter produced in excess by carcinoid tumors, which develop from enterochromaffin cells. 5-Hydroxyindoleacetic acid (5-HIAA) is the primary urinary metabolite of serotonin, making measurement of 5-HIAA useful in the diagnosis and management of carcinoid tumors. Here we describe a simple, inexpensive, and fast method for the detection and quantification of 5-HIAA in urine. Samples are prepared by simple 1:1 dilution. The instrumental analysis is performed by chromatographic separation on a reverse-phase analytical column followed by detection using a triple quadrupole mass spectrometer with electrospray ionization in positive ion mode. Data are acquired by multiple reaction monitoring (MRM).

Characterization of the spontaneous degenerative mitral valve disease in FVB mice.

BACKGROUND: The development of new non-surgical treatments dedicated to mitral valve degeneration is limited by the absence of relevant spontaneous and rapidly progressing animal experimental models. ANIMALS: We characterized the spontaneous mitral valve degeneration in two inbred FVB mouse strains compared to C57BL/6J and investigated a contribution of the serotonergic system. METHODS: Males and females FVB/NJ and FVB/NRj were compared to the putative C57BL/6J control at 12, 16, 20 and 24 weeks of age. Body weight, systolic blood pressure, heart rate, urinary 5-hydroxyindoleacetic acid (5-HIAA), whole blood and plasma serotonin, tail bleeding time, blood cell count, plasma TGF-ß1 and plasma natriuretic peptide concentrations were measured. Myocardium and mitral valves were characterized by histology. mRNA mitral expression of 5-HT2A and 5-HT2B receptors was measured in the anterior leaflet. Cardiac anatomy and function were assessed by echocardiography. RESULTS: Compared to C57BL/6J, FVB mice strains did not significantly differ regarding body weight increase, arterial blood pressure and heart rate. A progressive augmentation of plasma pro-ANP was observed in FVB mice. Nevertheless, no cardiac hypertrophy or left-ventricular fibrosis were observed. Accordingly, plasma TGF-ß1 was not different among the three strains. Conversely, FVB mice demonstrated a high prevalence of fibromyxoid highly cellularized and enriched in glycosaminoglycans lesions, inducing major mitral leaflets thickening without increase in length. The increased thickness was correlated with urinary 5-HIAA and blood platelet count. Whole blood serotonin concentration was similar in the two strains but, in FVB, a reduction of plasma serotonin was observed together with an increase of the bleeding time. Finally, echocardiography identified left atrial and left ventricular remodeling associated with thickening of both mitral leaflets and mitral insufficient in 30% of FVB mice but no systolic protrusion of mitral leaflets towards the atrium. CONCLUSION: The FVB mouse strain is highly prone to spontaneous mitral myxomatous degeneration. A contribution of the peripheral serotonergic system is suggested.

Peptide Receptor Radionuclide Therapy With 177Lu-DOTATATE for Symptomatic Control of Refractory Carcinoid Syndrome.

CONTEXT: Peptide receptor radionuclide therapy (PRRT) with [Lutetium-177-DOTA0-Tyr3]octreotate (177Lu-DOTATATE) results in an increase of progression-free survival and quality of life in patients with progressive, well-differentiated neuroendocrine neoplasms (NENs). OBJECTIVE: To study the effect of 177Lu-DOTATATE in patients with carcinoid syndrome and radiologically stable or newly diagnosed disease treated solely for the purpose of symptom reduction. DESIGN: Retrospective cohort study. SETTING: Tertiary care hospital. PATIENTS: Twenty-two patients with a metastatic midgut NEN, elevated urinary 5-hydroxyindolacetic acid excretion, and flushing and/or diarrhea despite treatment with a somatostatin analog, without documented disease progression. INTERVENTION: PRRT with 177Lu-DOTATATE (intended cumulative dose: 29.6 GBq) with a primary aim to reduce symptoms. RESULTS: After PRRT, mean bowel movement frequency (BMF) decreased from 6.1 ± 3.4 to 4.6 ± 3.6 per day (P = 0.009). Flushes decreased from 4.3 ± 2.9 to 2.4 ± 2.7 flushes per day (P = 0.002). A decrease of BMF of more than 30% occurred in 47% of patients with baseline BMF of 4 or more (n = 17). In patients with ≥2 episodes of flushing a day (n = 15), 67% of patients had more than 50% decrease of daily flushing. A decrease in urinary 5-hydroxyindolacetic acid excretion of more than 30% was seen in 56% of patients. The European Organization for Research and Treatment of Cancer-Core Module diarrhea subscale score showed a trend toward improvement by an average of 16.7 ± 33.3 points (P = 0.11). CONCLUSION: PRRT with 177Lu-DOTATATE effectively reduced diarrhea and flushing in patients with carcinoid syndrome and can be considered for symptomatic treatment of carcinoid syndrome insufficiently controlled with somatostatin analogs.

Diagnostic Utility of Serum and Urinary Metabolite Analysis in Patients with Interstitial Cystitis/Painful Bladder Syndrome.

OBJECTIVE: To identify the potential biomarkers of interstitial cystitis/painful bladder syndrome (IC), a chronic syndrome of bladder-centric pain with unknown etiology that has an adverse impact on quality of life, we analyzed the urine and serum metabolomes of a cohort of IC patients and non-disease controls (NC). METHODS: Home collection of serum and urine samples was obtained from 19 IC and 20 NC females in the Veterans Affairs (VA) Health Care System. IC was diagnosed independently by thorough review of medical records using established criteria. Biostatistics and bioinformatics analyses, including univariate analysis, unsupervised clustering, random forest analysis, and metabolite set enrichment analysis (MSEA), were then utilized to identify potential IC biomarkers. RESULTS: Metabolomics profiling revealed distinct expression patterns between NC and IC. Random forest analysis of urine samples suggested discriminators specific to IC; these include phenylalanine, purine, 5-oxoproline, and 5-hydroxyindoleacetic acid. When these urinary metabolomics-based analytes were combined into a single model, the AUC was 0.92, suggesting strong potential clinical value as a diagnostic signature. Serum-based metabolomics did not provide potential IC discriminators. CONCLUSION: Analysis of serum and urine revealed that women with IC have distinct metabolomes, highlighting key metabolic pathways that may provide insight into the pathophysiology of IC. The findings from this pilot study suggest that integrated analyses of urinary metabolites, purine, phenylalanine, 5-oxoproline, and 5-HIAA, can lead to promising IC biomarkers for pathophysiology of IC. Validation of these results using a larger dataset is currently underway.

SLC6A4 polymorphisms modulate the efficacy of a tryptophan-enriched diet on age-related depression and social cognition.

BACKGROUND & AIMS: In a placebo controlled study we sought to determine if a four-weeks tryptophan-enriched diet is able to improve age-related depression or social cognitive impairment, depending on polymorphisms located in the promoter region of Solute Carrier Family 6 Member 4 (SLC6A4), also known as serotonin transporter (SERT1) gene. METHODS: 91 young volunteers (age: 21 ± 2 yrs) and 127 above 50 years old (58 ± 6 yrs) healthy volunteers completed the study. Participants from the placebo and tryptophan group followed the same protocol. Before starting the study blood samples, to measure serotonin-transporter-linked polymorphic region (5-HTTLPR) and rs25531 polymorphisms, were collected. In addition, before and after completing the study urine samples (to measure 5-hydroxyindolacetic acid (5-HIAA) were taken, while psychological questionnaires (to assess depression and social cognition levels), and a one week dietary record (to calculate the tryptophan (TRP) intake) were assessed. RESULTS: The triallelic approach of SLC6A4 showed that in S'S´ subjects there was a positive correlation between TRP intake and 5-HIAA levels. Age of participants, SLC6A4 genotype, and experimental condition were important factors contributing to the outcome of depression and social cognition. CONCLUSIONS: 5-HTTLPR and rs25531 polymorphisms play a key role in the response to the TRP- based nutritional intervention, improving only age-related depressive symptoms and empathy in S'S´ subjects who have a higher risk to show signs of depression during their lifetime.

Plasmatic and Urinary 5-Hydroxyindolacetic Acid Measurements in Patients With Midgut Neuroendocrine Tumors: A GTE Study.

CONTEXT: Although 24-hour urinary 5-hydroxyindolacetic acid (24u5HIAA) is a key biomarker in midgut neuroendocrine tumors (NETs), it may be inaccurate and inconvenient. OBJECTIVE: We compared the diagnostic performances of 24u5HIAA, overnight urinary 5HIAA (Ou5HIAA), and plasmatic 5HIAA (p5HIAA) in midgut NETs. METHODS: This prospective, multicenter study included 80 patients with metastatic midgut NETs and 17 control patients with irritable bowel syndrome. 24u5HIAA, Ou5HIAA, and p5HIAA were measured in urine and plasma collected on 2 consecutive days following a specific recommended diet. Reproducibility of the biomarkers was evaluated by the Spearman test. Diagnostic performance was assessed by the area under the receiver operating characteristic curve (AUROC). Correlations with the main clinical features and declared observance to the specific diet were assessed using AUROC and logistic regression models. RESULTS: The reproducibility of 24u5HIAA, Ou5HIAA, and p5HIAA were excellent (ρ = 0.916; 0.897; 0.978, respectively, P < .001) with significant discrimination between patients and controls (AUROC = 0.795, P < .001; 0.757, P = .001; 0.717, P = .005, respectively). All 3 markers were correlated with the presence of carcinoid syndrome (AUROC = 0.702, P = .006; 0.701, P = .006; 0.697, P = .007, respectively), carcinoid heart disease (AUROC = 0.896; 0.887; 0.923, P < .001, respectively, P < .001), and liver metastatic involvement greater than 30% (AUROC = 0.827; 0.807; 0.849, P < .001, respectively, P < .001), independent from other traditional prognostic factors. Biomarker levels were similar between patients with optimal or suboptimal diet observance. CONCLUSION: Ou5HIAA and p5HIAA could be used as more convenient alternatives to 24u5HIAA in patients with metastatic midgut NETs. Prospective long-term studies with repeated dosages are needed.

Carcinoid Heart Disease: Prognostic Value of 5-Hydroxyindoleacetic Acid Levels and Impact on Survival: A Systematic Literature Review.

BACKGROUND: Carcinoid heart disease (CHD) can develop in patients with carcinoid syndrome (CS), itself caused by overproduction of hormones and other products from some neuroendocrine tumours. The most common hormone is serotonin, detected as high 5-hydroxyindoleacetic acid (5-HIAA). This systematic literature review summarises current literature on the impact of CHD on survival, and the relationship between 5-HIAA levels and CHD development, progression, and mortality. METHODS: MEDLINE, Embase, Cochrane databases, and grey literature were searched using terms for CHD, 5-HIAA, disease progression, and mortality/survival. Eligible articles were non-interventional and included patients with CS and predefined CHD and 5-HIAA outcomes. RESULTS: Publications reporting on 31 studies were included. The number and disease states of patients varied between studies. Estimates of CHD prevalence and incidence among patients with a diagnosis/symptoms indicative of CS were 3-65% and 3-42%, respectively. Most studies evaluating survival found significantly higher mortality rates among patients with versus without CHD. Patients with CHD reportedly had higher 5-HIAA levels; median urinary levels in patients with versus without CHD were 266-1,381 versus 67.5-575 µmol/24 h. Higher 5-HIAA levels were also found to correlate with disease progression (median progression/worsening-associated levels: 791-2,247 µmol/24 h) and increased odds of death (7% with every 100 nmol/L increase). CONCLUSIONS: Despite the heterogeneity of studies, the data indicate that CHD reduces survival, and higher 5-HIAA levels are associated with CHD development, disease progression, and increased risk of mortality; 5-HIAA levels should be carefully managed in these patients.

Pattern of postruminal administration of l-tryptophan affects blood serotonin in cattle.

Serotonin (5-HT) has many important functions in both central and peripheral nervous systems. Although it has been demonstrated that manipulation of serotonin metabolism is possible in many species, there is limited information about l-tryptophan (TRP), a serotonin precursor, in cattle, and these provide conflicting results. Furthermore, there is no study evaluating how different patterns of intra-abomasal infusion of TRP impact circulating 5-HT. The objective of this study was to evaluate if intra-abomasal infusion patterns of TRP can affect circulating 5-HT and other metabolites from TRP metabolism in the plasma and serum and circulating glucose and insulin in cattle. Eight ruminally cannulated Holstein steers were used in a replicated 4 × 4 Latin square design. Each received intra-abomasal water infusion (control) or intra-abomasal TRP infusion (50 mg/kg BW) in 3 different patterns: a pulse infusion once a day (pulse once), pulse infusion twice a day (pulse twice), or continuous infusion (continuous). For continuous treatment, the TRP dose was diluted in tap water and infused by a peristaltic pump (300 mL/h). To equalize conditions, the other treatments had a water infusion (300 mL/h). The steers were fed every 2 h, and blood was collected from a jugular vein catheter every 4 h for 24 h after the initial infusion. Urine produced during the 24 h period was collected. Serum and plasma TRP, 5-HT and kynurenine, plasma glucose, and serum insulin concentrations were analyzed. Urine was analyzed for concentrations of 5-hydroxyindoleacetic acid. Both serum TRP and kynurenine were increased (P < 0.05) by all TRP infusion treatments, but concentrations in pulse dose treatments were greater than those in continuous infusion. Serum 5-HT increased (P < 0.05) with both pulse TRP infusion treatments; however, the continuous TRP infusion did not increase the serum 5-HT. Plasma 5-HT, glucose, and insulin had a tendency to increase with TRP pulse infusions. The urinary 5-hydroxyindoleacetic acid excretion was highest for pulse dose treatments. An acute supply of TRP in 1 or 2 daily doses increases serum 5-HT and increases circulating glucose and insulin in cattle. The TRP and kynurenine concentrations are similar in plasma and serum. However, the serum 5-HT concentration is more responsive to TRP administration than plasma.

Application of multisegment injection on quantification of creatinine and standard addition analysis of urinary 5-hydroxyindoleacetic acid simultaneously with creatinine normalization.

In this paper, the development of a simple dilute-and-shoot method for quantifying urinary creatinine by CE-ESI-MS was described. The creatinine analysis time was about 7 min/sample by conventional single injection (SI) method and can be significantly reduced to less than 2 min/sample with multi-segment injection (MSI). In addition, the standard addition analysis of 5-hydroxyindole-3-acetic acid (5-HIAA) and creatinine normalization was performed within one run by the MSI technique, and the total analysis time was 14-min faster compared to the SI method for analyzing the same set of samples. The uses of isotopic and non-isotopic internal standards (ISs) were compared. Creatinine-(methyl-13 C) and 5-hydroxyindole-4,6,7-D3 -3-acetic-D2 acid (5-HIAA-D5 ) used as isotopic ISs can provide both accurate and precise results. In contrast, 1,5,5-trimethylhydantoin (1,5,5-TH) used as the non-isotopic IS for creatinine may cause a bias of over 13% in SI method and even worse when the MSI technique was used. Another compound, 2-methyl-3-indoleacetic acid (2-MIAA), was determined not suitable for MSI analysis of 5-HIAA due to endogenous interferences despite its acceptable performance in conventional methods of analysis.

Urine 5-hydroxyindoleacetic acid in Cavalier King Charles spaniels with preclinical myxomatous mitral valve disease.

Higher concentrations of circulating serotonin have been reported in Cavalier King Charles spaniels (CKCS) compared to other dog breeds. The CKCS is also a breed highly predisposed to myxomatous mitral valve disease (MMVD). The aim of this study was to determine urine concentrations of 5-hydroxyindoleacetic acid (5-HIAA), the major metabolite and excretion product of serotonin, in a population of CKCS with preclinical MMVD, and to evaluate whether urine 5-HIAA concentrations were associated with MMVD severity, dog characteristics, setting for urine sampling, platelet count, and serotonin concentration in serum and platelet-poor plasma (PPP). The study population consisted of 40 privately-owned CKCS (23 females; 17 males) with and without preclinical MMVD as follows: American College of Veterinary Internal Medicine (ACVIM) group A (n = 11), ACVIM group B1 (n = 21) and ACVIM group B2 (n = 8). Urine 5-HIAA concentrations were not significantly associated with preclinical MMVD disease, platelet count or circulating concentrations of serotonin (in serum and PPP; P > 0.05). Females had higher 5-HIAA concentrations than males in morning urine collected at home (females, 3.1 [2.9-3.7] µmol/mmol creatinine [median and quartiles]; males, 1.7 [1.2-2.2] µmol/mmol creatinine; P = 0.0002) and urine collected at the clinic (females, 3.5 [3.1-3.9] µmol/mmol creatinine; males, 1.6 [1.3-2.1] µmol/mmol creatinine; P < 0.0001). Five-HIAA concentrations in urine collected at home and at the clinic were significantly associated (P = 0.0004; r = 0.73), and higher concentrations were found in urine collected at the clinic (P = 0.013). Urine 5-HIAA concentration was influenced by sex and setting of urine sampling. Urine 5-HIAA concentration was not associated with MMVD severity or circulating concentrations of serotonin in CKCS with preclinical disease.

Specific Urinary Metabolites in Malignant Melanoma.

Background and objectives: Melanin, which has a confirmed role in melanoma cell behaviour, is formed in the process of melanogenesis and is synthesized from tryptophan, L-tyrosine and their metabolites. All these metabolites are easily detectable by chromatography in urine. Materials and Methods: Urine samples of 133 individuals (82 malignant melanoma patients and 51 healthy controls) were analysed by reversed-phase high-performance liquid chromatography (RP-HPLC). The diagnosis of malignant melanoma was confirmed histologically. Results: Chromatograms of melanoma patients showed increased levels of 5,6-dihydroxyindole-2-carboxylic acid, vanilmandelic acid, homovanilic acid, tryptophan, 5-hydroxyindole-3-acetic acid, and indoxyl sulphate compared to healthy controls. Concentration of indoxyl sulphate, homovanilic acid and tryptophan were significantly increased even in the low clinical stage 0 of the disease (indoxyl sulphate, homovanilic acid and tryptophan in patients with clinical stage 0 vs. controls expressed as medium/ interquartile range in µmol/mmol creatinine: 28.37/15.30 vs. 5.00/6.91; 47.97/33.08 vs. 7.33/21.25; and 16.38/15.98 vs. 3.46/6.22, respectively). Conclusions: HPLC detection of metabolites of L-tyrosine and tryptophan in the urine of melanoma patients may play a significant role in diagnostics as well as a therapeutic strategy of melanoma cancer.

[Determination of thresholds values for platelet serotonin and urinary 5-HIAA concentrations for the biological diagnosis of digestive neuroendocrine tumors]. / Quelles valeurs de référence pour la concentration de la sérotonine plaquettaire et du 5-HIAA urinaire pour le diagnostic des tumeurs neuroendocrines digestives ?

OBJECTIVES: Platelet serotonin and its urinary metabolite 5-HIAA (5-hydroxyindolacetic acid) are the main biomarkers measured for the detection of neuroendocrine tumors (NET). We observe in our laboratory many false positives or false negatives for the 2 assays using threshold values given by the manufacturer. We aim to determine our own local threshold values for a better detection of gastrointestinal NETs. METHODS: We studied patients with measurement of platelet serotonin and/or urinary 5-HIAA in University Hospital of Tours between January 2005 and June 2016. We established an « index ¼ cohort with 75% of patients to determine local threshold value for the 2 parameters. A "validation" cohort constituted with 25% of remaining patients allowed us to compare the performances of manufacturer's values with local threshold values. RESULTS: Two hundred ninety patients were included, with 19 suffering from NETs. Local threshold value for platelet serotonin was determined at 5.13 amol/platelet, the one for urinary 5-HIAA at 3.60 µmol/mmol urinary creatinine. Platelet serotonin specificity was better with local threshold value for identical sensibility (0.75). Urinary 5-HIAA sensibility was improved with local threshold value (1 vs 0.667) for identical specificity (0.902). CONCLUSION: Using our local threshold value for platelet serotonin and urinary 5-HIAA improved diagnostic performances of these biochemical markers to detect NETs.

Urinary organic acids as biomarkers in the assessment of pulmonary function in children with asthma.

Childhood asthma prevalence continues to rise despite advancements in prevention and medical management strategies. The purpose of this study was to investigate correlations between urinary organic acids and pulmonary diagnostic tests, asthma control in Greek asthmatic children. We hypothesized that urinary organic acids are positively associated with poor pulmonary function in children with asthma. Seventy-two children, 5 to 12 years old with asthma were recruited from a pediatric asthma clinic in Athens, Greece. Pulmonary function was assessed using spirometry and exhaled nitric oxide analysis. Asthma control was measured qualitatively using the Asthma Control Questionnaire. Targeted metabolomic analysis of 34 urinary organic acids in children was conducted by gas chromatography-mass spectrometry. A statistically significant difference between girls and boys was found for asthma control score (P = .02), lactic acid (P = .03), but not for any other organic acids (P > .05). Statistically significant correlations were found between lactic acid and Forced Expiratory Volume in 1 second (FEV1) (P = .02), Forced Vital Capacity (FVC) (P = .03); 4- hydroxyphenylacetic acid and FEV1 (P = .01), FVC (P = .01); 5-hydroxyindoleacetic acid and FEV1/FVC (P = .03), eNO (P = .05); glycolic acid with Peak Expiratory Flow (PEF) (P = .03); and malic acid with asthma control (P = .02). In conclusion, metabolomics was used to determine correlations between urinary organic acids and conventional pulmonary diagnostic tests in Greek asthmatic children. Metabolomics could be a promising approach for asthma research and in detection of novel biomarkers for asthma monitoring and therapeutic targets for childhood asthma. This study contributes towards a better understanding of the biochemical pathways involved in asthma.

Evaluation of 5-hydroxyindoloacetic acid excretion in urine in patients with small intestine neuroendocrine neoplasm and carcinoid syndrome treated with somatostatin analogues.

BACKGROUND: The assessment of hormonal function of neuroendocrine neoplasm (NEN) is an important stage in the diagnosis and monitoring of these diseases treatment. Objective of this study was to analyze the results of urinary excretion of 5-hydroxyindoloacetic acid (5-HIAA) in patients with carcinoid syndrome treated with somatostatin analogues, depending on the histologic maturity, degree of liver involvement and stage of the disease. METHODS: The final group comprised of 41 patients. All patients were subject to surgical removal of the primary site. Presence of hepatic metastases was determined in all patients. All patients were treated with somatostatin analogues. The 5-HIAA urine excretion was determined using the ELISA immunoenzymatic method. RESULTS: The mean excretion of 5-HIAA in patients with histological maturity grade G1 was 45.64 mg/24h, while in the group G2 the mean excretion was 108.41 mg/24h and was higher than in the group G1 (p=0.003). In the analysis of 5-HIAA value depending on the degree of liver involvement, the mean value of 5-HIAA excretion in patients with 10% liver involvement was 38.99 mg/24h, whereas in patients with 25% liver involvement this value was considerably higher and amounted 131.00 mg/24h (p< 0.001). In patients with disease progression the mean excretion was 117.37 mg/24h compared to the group of patients with stabilization of the disease, where the mean value was lower and amounted to 39.39 mg/24h (p<0.001). CONCLUSION: Assessment of 5-HIAA excretion in patients with carcinoid syndrome is of considerable significance in the diagnostics and monitoring of the treatment.

Effect of Lanreotide Depot/Autogel on Urinary 5-Hydroxyindoleacetic Acid and Plasma Chromogranin A Biomarkers in Nonfunctional Metastatic Enteropancreatic Neuroendocrine Tumors.

BACKGROUND: Urinary 5-hydroxyindoleacetic acid (5-HIAA) is an established biomarker in neuroendocrine tumors and carcinoid syndrome; however, its role in nonfunctional neuroendocrine tumors is not defined. We present post hoc data on urinary 5-HIAA and plasma chromogranin A (CgA) from the CLARINET study. METHODS: Patients with well- or moderately differentiated, nonfunctioning, locally advanced or metastatic enteropancreatic neuroendocrine tumors were randomized to deep subcutaneous lanreotide depot/autogel 120 mg or placebo once every 28 days for 96 weeks. Tumor response, evaluated centrally (RECIST 1.0), and progression-free survival (PFS) were assessed by treatment and biochemical response, defined as (a) baseline >upper limit of normal (ULN, 41.6 µmol per day 5-HIAA; 98.1 µg/L CgA) and (b) ≥50% decrease from baseline and to ≤ULN value on study. RESULTS: Forty-eight percent (82 of 171; lanreotide, n = 45; placebo, n = 37) and 66% (129 of 195; lanreotide, n = 65; placebo, n = 64) of randomized patients had 5-HIAA and CgA > ULN at baseline. Among patients with >ULN baseline values who did not progress after 96 weeks of treatment, significantly greater reductions in 5-HIAA and CgA were observed in lanreotide-treated versus placebo-treated patients throughout the study (all p < .05). PFS was significantly prolonged among 5-HIAA responders versus nonresponders (median not reached vs. 16.2 months, p < .0001; hazard ratio [HR] = 0.21, 95% confidence interval [CI], 0.09-0.48) and CgA responders versus nonresponders (median not reached vs. 16.2 months, p = .0070; HR = 0.30, 95% CI, 0.12-0.76), regardless of treatment arm. PFS was also significantly prolonged among lanreotide-treated 5-HIAA responders versus nonresponders (p = .0071) but was not significantly different among placebo-treated 5-HIAA responders versus nonresponders. There were no significant differences in PFS between lanreotide-treated CgA responders versus nonresponders or between placebo-treated CgA responders versus nonresponders. CONCLUSIONS: The 5-HIAA findings are noteworthy because they occurred in patients with nonfunctioning enteropancreatic neuroendocrine tumors. Monitoring 5-HIAA and CgA may be useful when treating patients with nonfunctional neuroendocrine tumors. IMPLICATIONS FOR PRACTICE: Current guidelines focus only on the monitoring of 5-hydroxyindoleacetic acid (5-HIAA) in the diagnosis and management of functional neuroendocrine tumors with carcinoid syndrome. The current post hoc analysis of patients with nonfunctional enteropancreatic neuroendocrine tumors in the CLARINET study demonstrated that measuring and following both 5-HIAA and chromogranin A as biomarkers of disease progression may be useful in the management of patients with nonfunctional neuroendocrine tumors.

Prognostic Utility of 24-Hour Urinary 5-HIAA Doubling Time in Patients With Neuroendocrine Tumors.

OBJECTIVE: New clinical prognostic tools are needed to select the population of patients with neuroendocrine tumors (NETs) that have a high risk of disease progression and disease-specific mortality (DSM). Biochemical biomarker doubling time (DT) is used clinically for prognosis prediction in several solid malignancies. The aim of the current study was to determine whether 24-hour urinary 5-hydroxyindoleacetic acid (5-HIAA) level DT has any prognostic utility in patients with NETs. METHODS: Patients with NETs were enrolled in a prospective study with comprehensive biochemical analysis. The current analysis included 90 subjects with increasing 5-HIAA levels in two consecutive measurements. DT was calculated using the Schwartz equation. The primary outcome measures were DSM and disease progression. RESULTS: 5-HIAA DT of <434 days was associated with a higher rate of DSM ( P = .02), with positive and negative predictive values for DSM of 75 and 77%, respectively. The difference in DSM was accounted for mainly by patients with small intestine or unknown primary NET ( P = .01). In addition, a shorter 5-HIAA DT in patients with small intestine or unknown primary NET was associated with a higher risk of disease progression both in univariate ( P = .001) and multivariable analyses (hazard ratio, 15.8; 95% confidence interval, 1.3 to 198.0; P = .03). CONCLUSION: 5-HIAA DT may be used as a risk stratification tool in patients with small intestine NET or NET of unknown primary after it is validated in an independent cohort and can assist in identifying patients with a high risk for disease progression and DSM. ABBREVIATIONS: CT = computed tomography; DSM = disease-specific mortality; DT = doubling time; 5-HIAA = 5-hydroxyindoleacetic acid; MRI = magnetic resonance imaging; NET = neuroendocrine tumor; NETUP = neuroendocrine tumor of unknown primary; PET = positron emission tomography; PFS = progression-free survival; PNET = pancreatic neuroendocrine tumor; ROC = receiver operating characteristic; SINET = small-intestine neuroendocrine tumor.

Clinical and biochemical assessment of depressive symptoms in patients with Alkaptonuria before and after two years of treatment with nitisinone.

OBJECTIVE: Concerns exist over hypertyrosinaemia that is observed following treatment with nitisinone. It has been suggested that tyrosine may compete with tryptophan for uptake into the central nervous system, and or inhibit tryptophan hydroxylase activity reducing serotonin production. At the National Alkaptonuria (AKU) Centre nitisinone is being used off-licence to treat AKU, and there is uncertainty over whether hypertyrosinaemia may alter mood. Herein results from clinical and biochemical assessments of depression in patients with AKU before and after treatment with nitisinone are presented. PATIENTS AND METHODS: 63 patients were included pre-nitisinone treatment, of these 39 and 32 patients were followed up 12 and 24 months after treatment. All patients had Becks Depression Inventory-II (BDI-II) assessments (scores can range from 0 to 63, the higher the score the more severe the category of depression), and where possible urinary monoamine neurotransmitter metabolites and serum aromatic amino acids were measured as biochemical markers of depression. RESULTS: Mean (±standard deviation) BDI-II scores pre-nitisinone, and after 12 and 24 months were 10.1(9.6); 9.8(10.0) and 10.5(9.9) (p ≥ 0.05, all visits). Paired scores (n = 32), showed a significant increase at 24 months compared to baseline 10.5(9.9) vs. 8.6 (7.8) (p = 0.03). Serum tyrosine increased at least 6-fold following nitisinone (p ≤ 0.0001, all visits), and urinary 3-methoxytyramine (3-MT) increased at 12 and 24 months (p ≤ 0.0001), and 5-hydroxyindole acetic acid (5-HIAA) decreased at 12 months (p = 0.03). CONCLUSIONS: BDI-II scores were significantly higher following 24 months of nitisinone therapy in patients that were followed up, however the majority of these patients remained in the minimal category of depression. Serum tyrosine and urinary 3-MT increased significantly following treatment with nitisinone. In contrast urinary 5-HIAA did not decrease consistently over the same period studied. Together these findings suggest nitisinone does not cause depression despite some observed effects on monoamine neurotransmitter metabolism.

Quantification of vanillylmandelic acid, homovanillic acid and 5-hydroxyindoleacetic acid in urine using a dilute-and-shoot and ultra-high pressure liquid chromatography tandem mass spectrometry method.

BACKGROUND: Urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA) are biomarkers for the diagnosis and follow-up of neuroblastoma, whereas urinary 5-hydroxyindoleacetic acid (5-HIAA) is used to assess a carcinoid tumor. These analytes are conventionally analyzed in a single run by chromatography (LC) coupled with electrochemical detection (LC-ECD) using commercial kits. A rapid dilute-and-shoot LC tandem mass spectrometry (LC-MS/MS) assay was validated in order to replace the LC-ECD method and therefore improve analytical specificity and throughput. METHODS: Sample preparation was carried out by dilution of the urine sample with a solution containing the deuterated internal standards. The separation was achieved on an ultra-high pressure LC system with MS detection using a triple quadrupole mass spectrometer. The method was validated according to the current EMA and FDA guidelines. RESULTS: The full chromatographic run was achieved in 8 min. The method validation showed excellent linearity (r2>0.999 for all three analytes), precision (CV <15%), negligible matrix effect (recoveries >90%), low carryover (<1%) and LLOQ of 0.25, 0.4 and 0.4 µM for VMA, HVA and 5-HIAA, respectively. Deming fits and Bland-Altman analyses showed no significant differences between the values obtained between the two assays. CONCLUSIONS: The LC-MS/MS method proposed in this study is fast and robust, and the simple sample preparation saves time and avoids the additional costs of dedicated kits used for the LC-ECD assays by switching to LC-MS/MS. Additionally, the near-perfect correlation observed herein between both assays allows the previously established reference ranges to be maintained.

Outcomes of Cytoreductive Surgery for Metastatic Low-Grade Neuroendocrine Tumors in the Setting of Extrahepatic Metastases.

BACKGROUND: Neuroendocrine tumors (NETs) have a uniquely indolent biology. Management focuses on tumor and hormonal burden reduction. Data on cytoreduction with extrahepatic disease remain limited. OBJECTIVE: We sought to define the outcomes of cytoreduction for metastatic NETs with extrahepatic metastases. METHODS: Patients undergoing cytoreductive surgery for grade 1 or 2 NETs with extrahepatic metastases (with or without intrahepatic disease) were identified from an institutional database (2003-2014). Primary outcomes included postoperative hormonal response (> 50% urinary 5HIAA decrease), progression-free survival (PFS) and overall survival (OS), while secondary outcomes were 30-day postoperative major morbidity (Clavien grade III-V), mortality, and length of stay. RESULTS: Fifty-five patients were identified (median age 59.3 years, 80% small bowel primaries, 56.4% grade 1); 87% of patients presented with combined intra- and extrahepatic metastases. Resection most commonly included the liver (87%), small bowel (22%), mesenteric (25%) and retroperitoneal (11%) lymph nodes, and peritoneum (7%). Thirty-day major morbidity (Clavien III-V) was 18%, with 3.6% mortality, and median length of stay was 7 days [interquartile range (IQR) 5-9]. Liver embolization was performed in 31% of patients after surgery, at a median of 23 months following surgery. Overall, postoperative hormonal response occurred in 70% of patients. At median follow-up of 37 months (IQR range 22-93), 42 (76%) patients were alive and 23 (41.8%) had progressed. Five-year OS was 77% and 5-year PFS was 51%. CONCLUSION: Patients undergoing cytoreduction of metastatic well-differentiated NET in the setting of extrahepatic metastatic disease experience good tumoral control with favorable PFS and OS. Cytoreductive surgery can be safely included in the therapeutic armamentarium for NET with extrahepatic metastases.