Radical Nephroureterectomy Tetrafecta: A Proposal Reporting Surgical Strategy Quality at Surgery.

Background: Standardized methods for reporting surgical quality have been described for all the major urological procedures apart from radical nephroureterectomy (RNU). Objective: To propose a tetrafecta criterion for assessing the quality of RNU based on a consensus panel within the Young Association of Urology (YAU) Urothelial Group, and to test the impact of this tetrafecta in a multicenter, large contemporary cohort of patients treated with RNU for upper tract urothelial carcinoma (UTUC). Design setting and participants: This was a retrospective analysis of 1765 patients with UTUC treated between 2000 and 2021. Outcome measurements and statistical analysis: We interviewed the YAU Urothelial Group to propose and score a list of items to be included in the "RNU-fecta." A ranking was generated for the criteria with the highest sum score. These criteria were applied to a large multicenter cohort of patients. Kaplan-Meier curves were built to evaluate differences in overall survival (OS) rates between groups, and a multivariable logistic regression model was used to find the predictors of achieving the RNU tetrafecta. Results and limitations: The criteria with the highest score included three surgical items such as negative soft tissue surgical margins, bladder cuff excision, lymph node dissection according to guideline recommendations, and one oncological item defined by the absence of any recurrence in ≤12 mo. These items formed the RNU tetrafecta. Within a median follow-up of 30 mo, 52.6% of patients achieved the RNU tetrafecta. The 5-yr OS rates were significantly higher for patients achieving tetrafecta than for their counterparts (76% vs 51%). Younger age, lower body mass index, and robotic approach were found to be independent predictors of tetrafecta achievement. Conversely, a higher Eastern Cooperative Oncology Group score, higher clinical stage, and bladder cancer history were inversely associated with tetrafecta. Conclusions: Herein, we present a "tetrafecta" composite endpoint that may serve as a potential tool to assess the overall quality of the RNU procedure. Pending external validation, this tool could allow a comparison between surgical series and may be useful for assessing the learning curve of the procedure as well as for evaluating the impact of new technologies in the field. Patient summary: In this study, a tetrafecta criterion was developed for assessing the surgical quality of radical nephroureterectomy in patients with upper tract urothelial carcinoma. Patients who achieved tetrafecta had higher 5-yr overall survival rates than those who did not.

Clinical Approach to Mast Cell Activation Syndrome: A Practical Overview.

The diagnosis of mast cell activation syndrome (MCAS) is defined by 3 criteria: (1) typical clinical signs and symptoms of acute, recurrent (episodic), and systemic mast cell activation (MCA); (2) increase in tryptase level to >20% + 2 ng/mL within 1-4 hours after onset of the acute crisis; and (3) response of MCA symptoms to antimediator therapy. Classification of MCAS requires highly sensitive and specific methodological approaches for the assessment of clonal bone marrow mast cells at low frequencies. The Spanish Network on Mastocytosis score has been used successfully as a predictive model for selecting MCAS candidates for bone marrow studies based on a high probability of an underlying clonal mast cell disorder. In this article, we propose a diagnostic algorithm and focus on the practical evaluation and management of patients with suspected MCAS.

Clinical Approach to Mast Cell ActivationSyndrome: A Practical Overview

The diagnosis of mast cell activation syndrome (MCAS) is defined by 3 criteria: (1) typical clinical signs and symptoms of acute, recurrent (episodic), and systemic mast cell activation (MCA); (2) increase in tryptase level to >20% + 2 ng/mL within 1-4 hours after onset of the acute crisis; and (3) response of MCA symptoms to antimediator therapy. Classification of MCAS requires highly sensitive and specific methodological approaches for the assessment of clonal bone marrow mast cells at low frequencies. The Spanish Network on Mastocytosis score has been used successfully as a predictive model for selecting MCAS candidates for bone marrow studies based on a high probability of an underlying clonal mast cell disorder. In this article, we propose a diagnostic algorithm and focus on the practical evaluation and management of patients with suspected MCAS (AU)

El diagnóstico de síndrome de activación mastocitaria (SAM) se basa en 3 criterios: 1) signos y síntomas específicos de activación mastocitaria aguda, recurrente y sistémica, 2) aumento de los valores de triptasa en un 20% + 2 ng/ml sobre el valor basal de cada individuo en el periodo comprendido entre 1-4 horas desde el inicio del cuadro agudo, y 3) resolución de los síntomas con tratamiento antimediador. Para realizar el diagnóstico de SAM, es preciso emplear métodos diagnósticos altamente sensibles y específicos capaces de detectar bajas cantidades de mastocitos en la médula ósea. El modelo predictivo de la Red Española de Mastocitosis (REMA score) resulta útil para identificar a los pacientes con mayor probabilidad de padecer una patología mastocitaria clonal y que, por tanto, requieren que se nealice un estudio de médula ósea en el proceso diagnóstico. En este artículo, proponemos un algoritmo diagnóstico para SAM y abordamos el manejo de estos pacientes desde un punto de vista práctico en la consulta alergológica (AU)

UX007 for the treatment of long chain-fatty acid oxidation disorders: Safety and efficacy in children and adults following 24weeks of treatment.

BACKGROUND: Long-chain fatty acid oxidation disorders (LC-FAOD) lead to accumulation of high concentrations of potentially toxic fatty acid intermediates. Newborn screening and early intervention have reduced mortality, but most patients continue to experience frequent hospitalizations and significant morbidity despite treatment. The deficient energy state can cause serious liver, muscle, and heart disease, and may be associated with an increased risk of sudden death. Triheptanoin is a medium odd-chain fatty acid. Anaplerotic metabolites of triheptanoin have the potential to replace deficient tricarboxylic acid (TCA) cycle intermediates, resulting in net glucose production as a novel energy source for the treatment of LC-FAOD. STUDY DESIGN: A single-arm, open-label, multicenter Phase 2 safety and efficacy study evaluated patients with severe LC-FAOD evidenced by ongoing related musculoskeletal, cardiac, and/or hepatic events despite treatment. After a four-week run-in on current regimen, investigational triheptanoin (UX007) was titrated to a target dose of 25-35% of total daily caloric intake. Patients were evaluated on several age/condition-eligible endpoints, including submaximal exercise tests to assess muscle function/endurance (12-minute walk test; 12MWT) and exercise tolerance (cycle ergometry), and health related quality of life (HR-QoL). Results through 24weeks of treatment are presented; total study duration is 78weeks. RESULTS: Twenty-nine patients (0.8 to 58years) were enrolled; most qualified based on severe musculoskeletal disease. Twenty-five patients (86%) completed the 24-week treatment period. At Week 18, eligible patients (n=8) demonstrated a 28% increase (LS mean=+181.9 meters; p=0.087) from baseline (673.4meters) in 12MWT distance. At Week 24, eligible patients (n=7) showed a 60% increase in watts generated (LS mean=+409.3W; p=0.149) over baseline (744.6W) for the exercise tolerance test. Improvements in exercise tests were supported by significant improvements from baseline in the adult (n=5) self-reported SF-12v2 physical component summary score (LS mean=+8.9; p<0.001). No difference from baseline was seen in pediatric parent-reported (n=5) scores (SF-10) at Week 24. Eighteen patients (62%) had treatment-related adverse events, predominantly gastrointestinal (55%), mild-to-moderate in severity, similar to that seen with prior treatment with medium chain triglyceride (MCT) oil. One patient experienced a treatment-related serious adverse event of gastroenteritis. One patient discontinued from study due to diarrhea of moderate severity; the majority of patients (25/29; 86%) elected to continue treatment in the extension period. CONCLUSIONS: In patients with severe LC-FAOD, UX007 interim study results demonstrated improved exercise endurance and tolerance, and were associated with positive changes in self-reported HR-QoL.

Predictive factors of overall and major postoperative complications after partial nephrectomy: Results from a multicenter prospective study (The RECORd 1 project).

INTRODUCTION AND OBJECTIVES: To analyze postoperative complications and to assess for significant predictive factors during partial nephrectomy (PN) using a large multicenter dataset. METHODS: Patients who underwent PN for clinical T1 renal tumors at 19 urological Italian centers (Registry of Conservative Renal Surgery [RECORd] project) were evaluated between 2009 and 2012. Anthropometric data, comorbidities and perioperative outcomes were analyzed. Complications were divided as intra- and postoperative, medical and surgical, as appropriate. The severity of postoperative complications was graded according to the modified Clavien classification system. Patients who experienced intraoperative complications were excluded from the analyses for the potential confounding effect in the evaluation of predicting factors for postoperative complications. RESULTS: Overall, 979 patients were analyzed: open, laparoscopic and robot-assisted (available since 2011) surgical approaches were used in 522 (56.4%), 286 (30.9%) and 117 (12.6%) cases, respectively. Surgical postoperative complications were reported in 121 (13.1%) cases (32 (3.5%) were Clavien 3), medical were reported in 52 (5.6%) cases (3 (0.3%) were Clavien 3). No Clavien 4 complications were reported. At multivariable analysis, ECOG score ≥1 (OR 1.98; p = 0.002), lower preoperative hemoglobin (OR 0.71; p < 0.0001) and open surgical approach (2.91; p = 0.02) were significant predictive factors of overall surgical postoperative complications, ECOG score ≥1 (OR 1.93; p = 0.04) and surgical approach (p = 0.05) were significant predictive factors of Clavien 3 either surgical or medical postoperative complications. CONCLUSIONS: Comorbidities and surgical approach should be considered in preoperative evaluation of patients undergoing PN, as they resulted to play a significant role in the occurrence of postoperative complications.

Heterogeneity in allergy to mollusks: a clinical-immunological study in a population from the North of Spain

Background: Allergy to mollusks has been the focus of fewer studies than allergy to crustaceans. Furthermore, allergy to mollusks is less well characterized. Objectives: To describe the clinical characteristics of mollusk-allergic patients, to identify the responsible allergens, and to assess crossreactivity. Methods: We performed a prospective multicenter study including 45 patients with mollusk allergy, which was diagnosed based on a suggestive clinical history and a positive skin test result with the agent involved. Fractions were identified using SDS-PAGE and immunoblotting. The proteins responsible were subsequently identified using mass spectrometry. ELISA inhibition studies were performed with mollusks, dust mites, and crustaceans. Results: We found that 25 patients (55%) were allergic to cephalopods, 14 (31%) to bivalves, and 11 (24%) to gastropods. Limpet was the third most frequent cause of allergy (15% of cases). In 31 patients (69%), the manifestation was systemic; 10 (22%) exhibited oral allergy syndrome, and 7 (15%) experienced contact urticaria. Most major allergens were found between 27 kDa and 47 kDa. ELISA inhibition assays revealed a high degree of inhibition of cephalopods and bivalves from all the groups of mollusks, mites, and crustaceans. Mass spectrometry identified tropomyosin, actin, and myosin as the major allergens. Conclusions: Cephalopods, especially squid, are the mollusks that most frequently trigger allergic symptoms. The very frequent occurrence of allergy to limpets is striking, given their low consumption in our area. It is worth highlighting the heterogeneity observed, exemplified by the gastropods. Tropomyosin appears to be responsible for the high cross-reactivity found between mollusks, mites, and crustaceans. Three new mollusk allergens were also identified, namely, actin, enolase, and a putative C1q domain-containing protein (AU)

Introducción: La alergia a moluscos ha sido menos estudiada y está peor caracterizada que la alergia a crustáceos. Objetivo: Describir las características clínicas de pacientes alérgicos a moluscos, identificar los alérgenos responsables y estudiar la reactividad cruzada entre ellos. Métodos: Estudio multicéntrico, prospectivo. Se incluyen 45 pacientes con alergia a moluscos, definida como una clínica sugestiva y prueba cutánea positiva con el molusco sospechoso. Se identificaron las bandas alergénicas mediante SDS-PAGE e inmunodetección. Las proteínas responsables se identificaron utilizando espectrometría de masas. Se realizaron ensayos de inhibición de ELISA entre moluscos, ácaros y crustáceos. Resultados: Veinticinco (55%) de los pacientes eran alérgicos a cefalópodos, 14 (31%) a bivalvos y 11 (24%) a gasterópodos. La lapa resultó ser la tercera causa de alergia (15% de los casos). Los síntomas fueron sistémicos en 31 pacientes (69%), diez (22%) tuvieron síndrome de alergia oral y siete (15%) urticaria de contacto. La mayoría de las bandas alergénicas estaban entre 27 y 47 kDa. Los ensayos de inhibición de ELISA mostraron un alto grado de inhibición de cefalópodos y bivalvos por parte de moluscos, ácaros y crustáceos. Mediante espectometría de masas se identificaron tropomiosina, actina y miosina como los alérgenos mayoritarios. Conclusiones: Los moluscos que con más frecuencia provocan reacciones alérgicas son los cefalópodos, especialmente el calamar. Llama la atención la elevada frecuencia de alergia a la lapa, a pesar de su bajo consumo. También hay que resaltar la heterogeneidad observada, por ejemplo en los gasterópodos. La tropomiosina parece ser responsable de la elevada reactividad cruzada encontrada entre moluscos, ácaros y crustáceos. Se han identificado tres nuevos alérgenos en los moluscos: actina, enolasa y putative C1q domain-containing protein (AU)

Creatine transporter deficiency: Novel mutations and functional studies.

X-linked cerebral creatine deficiency (MIM 300036) is caused by deficiency of the creatine transporter encoded by the SLC6A8 gene. Here we report three patients with this condition from Israel. These unrelated patients were evaluated for global developmental delays and language apraxia. Borderline microcephaly was noted in one of them. Diagnosis was prompted by brain magnetic resonance imaging and spectroscopy which revealed normal white matter distribution, but absence of the creatine peak in all three patients. Biochemical testing indicated normal plasma levels of creatine and guanidinoacetate, but an increased urine creatine/creatinine ratio. The diagnosis was confirmed by demonstrating absent ([14])C-creatine transport in fibroblasts. Molecular studies indicated that the first patient is hemizygous for a single nucleotide change substituting a single amino acid (c.619 C > T, p.R207W). Expression studies in HeLa cells confirmed the causative role of the R207W substitution. The second patient had a three base pair deletion in the SLC6A8 gene (c.1222_1224delTTC, p.F408del) as well as a single base change (c.1254 + 1G > A) at a splicing site in the intron-exon junction of exon 8, the latter occurring de novo. The third patient, had a three base pair deletion (c.1006_1008delAAC, p.N336del) previously reported in other patients with creatine transporter deficiency. These three patients are the first reported cases of creatine transporter deficiency in Israel.

Glutamine and hyperammonemic crises in patients with urea cycle disorders.

UNLABELLED: Blood ammonia and glutamine levels are used as biomarkers of control in patients with urea cycle disorders (UCDs). This study was undertaken to evaluate glutamine variability and utility as a predictor of hyperammonemic crises (HACs) in UCD patients. METHODS: The relationships between glutamine and ammonia levels and the incidence and timing of HACs were evaluated in over 100 adult and pediatric UCD patients who participated in clinical trials of glycerol phenylbutyrate. RESULTS: The median (range) intra-subject 24-hour coefficient of variation for glutamine was 15% (8-29%) as compared with 56% (28%-154%) for ammonia, and the correlation coefficient between glutamine and concurrent ammonia levels varied from 0.17 to 0.29. Patients with baseline (fasting) glutamine values >900 µmol/L had higher baseline ammonia levels (mean [SD]: 39.6 [26.2]µmol/L) than patients with baseline glutamine ≤ 900 µmol/L (26.6 [18.0]µmol/L). Glutamine values >900 µmol/L during the study were associated with an approximately 2-fold higher HAC risk (odds ratio [OR]=1.98; p=0.173). However, glutamine lost predictive significance (OR=1.47; p=0.439) when concomitant ammonia was taken into account, whereas the predictive value of baseline ammonia ≥ 1.0 upper limit of normal (ULN) was highly statistically significant (OR=4.96; p=0.013). There was no significant effect of glutamine >900 µmol/L on time to first HAC crisis (hazard ratio [HR]=1.14; p=0.813), but there was a significant effect of baseline ammonia ≥ 1.0 ULN (HR=4.62; p=0.0011). CONCLUSIONS: The findings in this UCD population suggest that glutamine is a weaker predictor of HACs than ammonia and that the utility of the predictive value of glutamine will need to take into account concurrent ammonia levels.

Effects of alpha1-blockers on urodynamic parameters of bladder outlet obstruction in patients with lower urinary tract symptoms suggestive of benign prostatic enlargement: a review.

α1-adrenergic receptors blockers (ABs) are recommended as first-line medical therapy in men with Lower Urinary Tract Symptoms suggestive of Benign Prostatic Enlargement (LUTS/BPE). Available ABs include: terazosin, doxazosin, tamsulosin, naftopidil, alfuzosin and silodosin. These agents have different profiles of selectivity for α1-adrenergic receptors subtypes. All these agents are efficacious in improving both storage and voiding LUTS. In recent years the efficacy of ABs in improving urodynamic parameters of bladder outlet obstruction (BOO) has been questioned. We reviewed literature evidences about the effects of available ABs on invasive urodynamic parameters of BOO in men with LUTS/BPE. The impact of ABs therapy on urodynamic parameters indicative of BOO has been evaluated for all currently approved drugs. Available data demonstrate improvements in terms of both free uroflowmetry and pressure-flow parameters. While the impact of ABs on maximum urinary flow is clinically modest, the improvement of detrusor pressure at maximum urinary flow is more robust. Only few studies exist that directly compare the urodynamic effects of a small number of ABs. According to these studies there are no differences among ABs in terms of urodynamic efficacy. Indirect comparison of ABs suggests greater effectiveness of silodosin in terms of detrusor pressure at maximum urinary flow reduction. Studies that stratified populations based upon the degree of obstruction at baseline demonstrated greater urodynamic changes in patients with baseline BOO with respect to the unobstructed patients. Globally, the quality of studies available is low and there is considerable heterogeneity among studies.

A snapshot of nephron-sparing surgery in Italy: a prospective, multicenter report on clinical and perioperative outcomes (the RECORd 1 project).

INTRODUCTION: Nephron-sparing surgery (NSS) has become the standard of care for the surgical management of small and clinically localized renal cell carcinoma (RCC). The conservative management of those RCCs is increasing over time. Aim of this study was to report a snapshot of the clinical, perioperative and oncological results after NSS for RCC in Italy. MATERIAL AND METHODS: We evaluated all patients who underwent conservative surgical treatment for renal tumours between January 2009 and December 2012 at 19 urological Italian Centers (RECORd project). Perioperative, radiological and histopathological data were recorded. Surgical eras (2009 vs 2012 and year periods 2009-2010 vs 2011-2012) were compared. RESULTS: Globally, 983 patients were evaluated. More recently, patients undergoing NSS were found to be significantly younger (p = 0.05) than those surgically treated in the first study period, with a significantly higher rate of NSS with relative and imperative indication (p < 0.001). More recently, a higher percentage of procedures for cT1b or cT2 renal tumours was observed (p = 0.02). Utilization rate of open partial nephrectomy (OPN) constantly decreased during years, laparoscopic partial nephrectomy (LPN) remained almost constant while robot-assisted partial nephrectomy (RAPN) increased. The rate of clampless NSS constantly increased over time. The use of at least one haemostatic agent has been significantly more adopted in the most recent surgical era (p < 0.001). CONCLUSIONS: The utilization rate of NSS in Italy is increasing, even in elective and more complex cases. RAPN has been progressively adopted, as well as the intraoperative utilization of haemostatic agents and the rate of clampless procedures.

Simple enucleation versus standard partial nephrectomy for clinical T1 renal masses: perioperative outcomes based on a matched-pair comparison of 396 patients (RECORd project).

OBJECTIVES: To compare simple enucleation (SE) and standard partial nephrectomy (SPN) in terms of surgical results in a multicenter dataset (RECORd Project). MATERIALS AND METHODS: patients treated with nephron sparing surgery (NSS) for clinical T1 renal tumors between January 2009 and January 2011 were evaluated. Overall, 198 patients who underwent SE were retrospectively matched to 198 patients who underwent SPN. The SPN and SE groups were compared regarding intraoperative, early post-operative and pathologic outcome variables. Multivariable analysis was applied to analyze predictors of positive surgical margin (PSM) status. RESULTS: SE was associated with similar WIT (18 vs 17.8 min), lower intraoperative blood loss (177 vs 221 cc, p = 0.02) and shorter operative time (121 vs 147 min; p < 0.0001). Surgical approach (laparoscopic vs. open), tumor size and type of indication (elective/relative vs absolute) were associated with WIT >20 min. The incidence of PSM was significantly lower in patients treated with SE (1.4% vs 6.9%; p = 0.02). At multivariable analysis, PSM was related to the surgical technique, with a 4.7-fold increased risk of PSM for SPN compared to SE. The incidence of overall, medical and surgical complications was similar between SE and SPN. CONCLUSIONS: Type of NSS technique (SE vs SPN) adopted has a negligible impact on WIT and postoperative morbidity but SE seems protective against PSM occurrence.

Sequencing analysis of insulin receptor defects and detection of two novel mutations in INSR gene.

Mutations in the insulin receptor gene cause the inherited insulin resistant syndromes Leprechaunism and Rabson-Mendenhall syndrome. These recessive conditions are characterized by intrauterine and post-natal growth restrictions, dysmorphic features, altered glucose homeostasis, and early demise. The insulin receptor gene (INSR) maps to the short arm of chromosome 19 and is composed of 22 exons. Here we optimize the conditions for sequencing this gene and report novel mutations in patients with severe insulin resistance. METHODS: PCR amplification of the 22 coding exons of the INSR gene was performed using M13-tailed primers. Bidirectional DNA sequencing was performed with BigDye Terminator chemistry and M13 primers and the product was analyzed on the ABI 3100 genetic analyzer. Data analysis was performed using Mutation Surveyor software comparing the sequence to a reference INSR sequence (Genbank NC_000019). RESULTS: We sequenced four patients with Leprechaunism or Rabson-Mendenhall syndromes as well as seven samples from normal individuals and confirmed previously identified mutations in the affected patients. Three of the four mutations identified in this group caused premature insertion of a stop codon. In addition, the INSR gene was sequenced in 14 clinical samples from patients with suspected insulin resistance and one novel mutation was found in an infant with a suspected diagnosis of Leprechaunism. DISCUSSION: Leprechaunism and Rabson-Mendenhall syndrome are very rare and difficult to diagnose. Diagnosis is currently based mostly on clinical criteria. Clinical availability of DNA sequencing can provide an objective way of confirming or excluding the diagnosis.

Recommendations for the Use of In Vitro Methods to Detect Specific Immunoglobulin E: Are They Comparable?

Total and specific immunoglobulin (Ig) E can be detected in vitro using several commercially available methods. The largest share of the global market for these methods is held by the ImmunoCAP technique (Thermo Fisher, previously Phadia), Immulite (Siemens), and Hytec-288 (Hycor). Most comparative studies examine Immulite and ImmunoCAP, which differ methodologically but use similar units of measurement relative to the same standard of total IgE (WHO IgE Standard 75/502). Despite their similarity, these kits differ in their quantification of specific IgE, which varies depending on the allergen studied. Thus, specific IgE results obtained with ImmunoCAP and Immulite are not interchangeable. It is important to bear this in mind, especially when determining cutoff points as predictors of a response to oral challenge with specific food allergens. The method used in practice must be the same as the one in the publication guiding clinical decision making. We analyze differences between ImmunoCAP and ISAC microarray, 2 methods from the same manufacturer used to detect IgE to specific proteins (purified or recombinant). The results show that the IgE values obtained with ImmunoCAP are not equivalent to the corresponding values obtained with the ISAC microarray system (AU)

Existen disponibles en el mercado distintos métodos para la detección de la IgE total y específica. Los métodos con mayor cuota de mercado son método ImmunoCAP deThermofi sher (anteriormente Phadia), Immulite de Siemens y Hytec-288 de Hycor. La mayoría de los estudios comparativos se han realizado con Immulite e ImmunoCAP, que si bien difieren metodológicamente, emplean similares unidades de medida relativas al mismo estándar de IgE total (IgE Estándard OMS 75/502). Aunque estas técnicas estiman la cantidad de IgE total de forma similar, difieren en la cuantificación de la IgE específica. Se ha observado que estas diferencias varían en función del alérgeno al que se une la IgE específica. De esta forma, los resultados de la IgE específica para un alérgeno concreto obtenido por ImmunoCAP y por Immulite no son equiparables. Es importante tener en cuenta esta realidad, especialmente en el caso de puntos de corte determinados como predictores de la respuesta a una provocación oral con un alimento. El método empleado en la práctica debe ser idéntico al publicado como predictor. También analizamos las diferencias en la determinación de IgE frente a proteínas específicas (purificadas o recombinantes) por la misma casa comercial pero empleando distintas tecnologías, ImmunoCAP y micromatriz ISAC. Los datos demuestran que los resultados obtenidos por ImmunoCAP para la IgE específica no son equivalentes a los obtenidos mediante la micromatriz ISAC (AU)

Elevated phenylacetic acid levels do not correlate with adverse events in patients with urea cycle disorders or hepatic encephalopathy and can be predicted based on the plasma PAA to PAGN ratio.

BACKGROUND: Phenylacetic acid (PAA) is the active moiety in sodium phenylbutyrate (NaPBA) and glycerol phenylbutyrate (GPB, HPN-100). Both are approved for treatment of urea cycle disorders (UCDs) - rare genetic disorders characterized by hyperammonemia. PAA is conjugated with glutamine in the liver to form phenylacetyleglutamine (PAGN), which is excreted in urine. PAA plasma levels ≥ 500 µg/dL have been reported to be associated with reversible neurological adverse events (AEs) in cancer patients receiving PAA intravenously. Therefore, we have investigated the relationship between PAA levels and neurological AEs in patients treated with these PAA pro-drugs as well as approaches to identifying patients most likely to experience high PAA levels. METHODS: The relationship between nervous system AEs, PAA levels and the ratio of plasma PAA to PAGN were examined in 4683 blood samples taken serially from: [1] healthy adults [2], UCD patients of ≥ 2 months of age, and [3] patients with cirrhosis and hepatic encephalopathy (HE). The plasma ratio of PAA to PAGN was analyzed with respect to its utility in identifying patients at risk of high PAA values. RESULTS: Only 0.2% (11) of 4683 samples exceeded 500 µg/ml. There was no relationship between neurological AEs and PAA levels in UCD or HE patients, but transient AEs including headache and nausea that correlated with PAA levels were observed in healthy adults. Irrespective of population, a curvilinear relationship was observed between PAA levels and the plasma PAA:PAGN ratio, and a ratio>2.5 (both in µg/mL) in a random blood draw identified patients at risk for PAA levels>500 µg/ml. CONCLUSIONS: The presence of a relationship between PAA levels and reversible AEs in healthy adults but not in UCD or HE patients may reflect intrinsic differences among the populations and/or metabolic adaptation with continued dosing. The plasma PAA:PAGN ratio is a functional measure of the rate of PAA metabolism and represents a useful dosing biomarker.

Phenotype and genotype in 101 males with X-linked creatine transporter deficiency.

BACKGROUND: Creatine transporter deficiency is a monogenic cause of X-linked intellectual disability. Since its first description in 2001 several case reports have been published but an overview of phenotype, genotype and phenotype--genotype correlation has been lacking. METHODS: We performed a retrospective study of clinical, biochemical and molecular genetic data of 101 males with X-linked creatine transporter deficiency from 85 families with a pathogenic mutation in the creatine transporter gene (SLC6A8). RESULTS AND CONCLUSIONS: Most patients developed moderate to severe intellectual disability; mild intellectual disability was rare in adult patients. Speech language development was especially delayed but almost a third of the patients were able to speak in sentences. Besides behavioural problems and seizures, mild to moderate motor dysfunction, including extrapyramidal movement abnormalities, and gastrointestinal problems were frequent clinical features. Urinary creatine to creatinine ratio proved to be a reliable screening method besides MR spectroscopy, molecular genetic testing and creatine uptake studies, allowing definition of diagnostic guidelines. A third of patients had a de novo mutation in the SLC6A8 gene. Mothers with an affected son with a de novo mutation should be counselled about a recurrence risk in further pregnancies due to the possibility of low level somatic or germline mosaicism. Missense mutations with residual activity might be associated with a milder phenotype and large deletions extending beyond the 3' end of the SLC6A8 gene with a more severe phenotype. Evaluation of the biochemical phenotype revealed unexpected high creatine levels in cerebrospinal fluid suggesting that the brain is able to synthesise creatine and that the cerebral creatine deficiency is caused by a defect in the reuptake of creatine within the neurones.

Recommendations for the use of in vitro methods to detect specific immunoglobulin E: are they comparable?

Total and specific immunoglobulin (Ig) E can be detected in vitro using several commercially available methods. The largest share of the global market for these methods is held by the ImmunoCAP technique (Thermo Fisher, previously Phadia), Immulite (Siemens), and Hytec-288 (Hycor). Most comparative studies examine Immulite and ImmunoCAP, which differ methodologically but use similar units of measurement relative to the same standard of total IgE (WHO IgE Standard 75/502). Despite their similarity, these kits differ in their quantification of specific IgE, which varies depending on the allergen studied.Thus, specific IgE results obtained with ImmunoCAP and Immulite are not interchangeable. It is important to bear this in mind, especially when determining cutoff points as predictors of a response to oral challenge with specific food allergens. The method used in practice must be the same as the one in the publication guiding clinical decision making. We analyze differences between ImmunoCAP and ISAC microarray, 2 methods from the same manufacturer used to detect IgE to specific proteins (purified or recombinant).The results show that the IgE values obtained with ImmunoCAP are not equivalent to the corresponding values obtained with the ISAC microarray system.

Urinary phenylacetylglutamine as dosing biomarker for patients with urea cycle disorders.

UNLABELLED: We have analyzed pharmacokinetic data for glycerol phenylbutyrate (also GT4P or HPN-100) and sodium phenylbutyrate with respect to possible dosing biomarkers in patients with urea cycle disorders (UCD). STUDY DESIGN: These analyses are based on over 3000 urine and plasma data points from 54 adult and 11 pediatric UCD patients (ages 6-17) who participated in three clinical studies comparing ammonia control and pharmacokinetics during steady state treatment with glycerol phenylbutyrate or sodium phenylbutyrate. All patients received phenylbutyric acid equivalent doses of glycerol phenylbutyrate or sodium phenylbutyrate in a cross over fashion and underwent 24-hour blood samples and urine sampling for phenylbutyric acid, phenylacetic acid and phenylacetylglutamine. RESULTS: Patients received phenylbutyric acid equivalent doses of glycerol phenylbutyrate ranging from 1.5 to 31.8 g/day and of sodium phenylbutyrate ranging from 1.3 to 31.7 g/day. Plasma metabolite levels varied widely, with average fluctuation indices ranging from 1979% to 5690% for phenylbutyric acid, 843% to 3931% for phenylacetic acid, and 881% to 1434% for phenylacetylglutamine. Mean percent recovery of phenylbutyric acid as urinary phenylacetylglutamine was 66.4 and 69.0 for pediatric patients and 68.7 and 71.4 for adult patients on glycerol phenylbutyrate and sodium phenylbutyrate, respectively. The correlation with dose was strongest for urinary phenylacetylglutamine excretion, either as morning spot urine (r = 0.730, p < 0.001) or as total 24-hour excretion (r = 0.791 p<0.001), followed by plasma phenylacetylglutamine AUC(24-hour), plasma phenylacetic acid AUC(24-hour) and phenylbutyric acid AUC(24-hour). Plasma phenylacetic acid levels in adult and pediatric patients did not show a consistent relationship with either urinary phenylacetylglutamine or ammonia control. CONCLUSION: The findings are collectively consistent with substantial yet variable pre-systemic (1st pass) conversion of phenylbutyric acid to phenylacetic acid and/or phenylacetylglutamine. The variability of blood metabolite levels during the day, their weaker correlation with dose, the need for multiple blood samples to capture trough and peak, and the inconsistency between phenylacetic acid and urinary phenylacetylglutamine as a marker of waste nitrogen scavenging limit the utility of plasma levels for therapeutic monitoring. By contrast, 24-hour urinary phenylacetylglutamine and morning spot urine phenylacetylglutamine correlate strongly with dose and appear to be clinically useful non-invasive biomarkers for compliance and therapeutic monitoring.

Concomitant CXCR4 and CXCR7 expression predicts poor prognosis in renal cancer.

CXCR4 is a chemokine receptor implicated in the metastatic process. The CXCR4 ligand, CXCL12, was shown to bind also the CXCR7 receptor, a recently deorphanized chemokine receptor whose signalling pathway and function are still controversial. This study was conducted to determine patients clinic-pathological factors and outcome according to the expressions of CXCR4 and CXCR7 in renal cell carcinoma (RCC). CXCR4 and CXCR7 expression was evaluated in 223 RCC patients through immunohistochemistry; moreover CXCR4 and CXCR7 was detected in 49 others consecutive RCC patients trough RT- PCR. CXCR4 expression was low in 42/223 RCC (18.8%), intermediate in 71/223 (31.9%) and high in 110/223 (49.3%). CXCR7 expression was low in 44/223 RCC patients (19.8%), intermediate in 65/223 (29.1%) and high in 114/223 (51.1%). High CXCR4 and high CXCR7 expression predicted shorter disease free survival. In multivariate analysis, high CXCR4 expression (p= 0.0061), high CXCR7 (p= 0.0194) expression and the concomitant high expression of CXCR4 and CXCR7 (p= 0.0235) are independent prognosis factors. Through RT-PCR, CXCR4 was overexpressed in 36/49 and CXCR7 in 33/49 samples correlating with symptoms at diagnosis and lymph nodes status. So we can hypothesize that CXCR4 and CXCR7, singularly evaluated and in combination, are valuable prognostic factors in RCC patients.