Retrospective pharmacogenetic study in a cohort of pediatric tuberous sclerosis complex patients using everolimus.

Aim: Tuberous sclerosis complex (TSC) is a rare disease that produces multisystemic disorders. Everolimus (EVR) is the only immunosuppressive drug approved to control the symptoms and progression of the disease. The aim was to evaluate the genotype-phenotype association to improve the pediatric TSC pharmacotherapeutic outcome. Patients & methods: Ten pediatric TSC patients were recruited. Concomitant treatment and main metabolic enzymes and transporter coding gene variants of EVR were analyzed. Results: Significant associations were found between CYP3A4*22 allele and concomitant treatment with valproic acid (CYP3A4-inhibitor) with a poor metabolizer phenotype and the presence of pneumonia. Conclusion: This is the first pharmacogenetic study of EVR in pediatric TSC patients. The authors propose to consider concomitant treatment and pharmacogenetics due to their multifactorial status.

Pharmacokinetic interactions between clozapine and valproic acid in patients with treatment-resistant schizophrenia: Does UGT polymorphism affect these drug interactions?

The combination of valproic acid (VPA) and clozapine (CLZ) is regularly prescribed for augmentation therapy in treatment resistant schizophrenia. The VPA has been shown to reduce norclozapine (NCLZ) plasma levels, but the mechanism of this interaction remains unknown. The aim of this study is to examine the differences between patients treated with CLZ and patients treated with CLZ plus VPA. For it, various factors have been evaluated. The study was based on plasma samples from CLZ and CLZ plus VPA treated patients (n = 61) subjected to routine therapeutic drug monitoring considering clinical data, smoking status, daily dose of CLZ and VPA, concomitant medications, albumin, and renal and hepatic function. Genotyping of polymorphisms of CYP1A2, CYP3A4/5, CYP2C19, ABCB1, UGT2B10 and CYP2C19 were performed by real time PCR. CYP2D6 were genotyped using competitive allele-specific PCR and by a long PCR based method. Plasma CLZ and NCLZ concentrations were measured by Liquid Chromatography-Tandem masses (LC-MS/MS) and plasma VPA by Ultraviolet-Visible (UV-vis) spectrophotometric immunoassay. The patients presented adequate CLZ levels in relation to the dose. However, NCLZ levels were excessively low and the CLZ/NCLZ ratio very high. Patients with UGT2B10 GT (rs61750900) genotype showed lower NCLZ plasma levels and C/D NCLZ, and higher CLZ/NCLZ ratio versus patients with UGT2B10 GG genotype. VPA, smoking, the presence of UGT2B10 GT genotype and having low albumin levels indicate that the CLZ/NCLZ ratio is affected, mostly coinciding with decreased NCLZ levels and possibly with an increased risk of neutropenia.

Exploring the usefulness of plasma level determination and pharmacogenetics for patients treated with clozapine.

Aims: The aims of the present study were to assess the variance of plasma clozapine (CLZ) levels and to identify the influence of sociodemographic and pharmacogenetic factors on it and to introduce these tools in a clinical setting. Patients & methods: CLZ concentration was measured and genetic variants of CLZ pharmacokinetic and pharmacodynamic factors were assessed in 23 patients with psychotic disorders. Results: A significant association between mean concentration/dose ratio (C/D) and smoking status, age and weight were found. There was a significant difference in mean plasma CLZ levels and gender. The rs762551 AA genotype in smokers had a significantly lower C/D. Conclusion: In addition to classical factors, monitoring of plasma concentrations together with pharmacogenetics led to greater individualization of treatment.

Patients receiving clozapine (CLZ) usually show a variability in plasma concentrations. This study assesses the variance of plasma CLZ levels and explores the influence of gender, smoking, age, weight and genetics. Plasma CLZ levels were measured in 23 patients with psychotic disorders. Additionally, genetic analysis of genes involved in CLZ metabolism were carried out. An association between plasma concentration of CLZ adjusted for daily dose and smoking status, weight and age were found. Plasma CLZ and gender were also associated. A mutation of a genetic variant related to CLZ metabolism showed in smokers lower CLZ concentration adjusted for daily dose, explaining poor treatment response. Individual dose modification in these patients improved the clinical situation.

Implementation of pharmacogenetics in a clozapine treatment resistant patient: a case report.

We report the case of a young Caucasian male with disorganized chronic schizophrenia, an active smoker and nonresponder to 400 mg of clozapine/day. Therapeutic clozapine monitoring was analyzed revealing a low clozapine:norclozapine ratio. An additional pharmacogenetic test was carried out showing that the patient carried *1F variant (CYP1A2 gene), which has been associated with nonresponse to clozapine in smoker patients. A genetic variation in the SLC6A4 gene was also found, which could be related to the poor response to clozapine. The remainder of the genes analyzed (CYP2D6, ABCB1 and HTR2A) were not directly associated with the patient's phenotype. The dose of clozapine was increased to 600 mg/day, reaching the therapeutic range. This case shows how pharmacogenetics can help in understanding the value of plasma levels to provide clinical improvement.

Pharmacogenetic studies: a tool to improve antidepressant therapy.

The World Health Organization (WHO) predicts that major depressive disorder (MDD) will be the second leading cause of death and disability by 2020. Nowadays, approximately 60-70% of patients with this disorder have shown the lack of effectiveness and tolerability of the therapy with antidepressants. The US Food and Drug Administration (FDA) and the European Medicine Agency (EMA) are including pharmacogenetic information in the labeling of several antidepressants. The presence of this information represents the relevance of genetic polymorphisms in drug response. These pharmacogenetic studies have been based on the knowledge of genes involved in pharmacokinetic (CYP2D6, CYP2C19 and ABCB1) and pharmacodynamic (SLC6A4, HTR2A, BDNF, GNB3 and FKBP5) processes of antidepressant medications. The knowledge of the genotype of patients with MDD is an important tool for personalized therapy that can improve their clinical response to treatment. In this review, we highlight the most relevant genes involved in the metabolism of antidepressants (ADs) or the genes related to the presence of adverse reactions.

Can pharmacogenetics help patients under chronic treatment with coumarin anticoagulants?

Vitamin K antagonists are highly effective antithrombotic drugs. However, appropriate dosing is difficult to establish owing to its narrow therapeutic window as well as widespread inter- and intra-individual variability in dosage. Compared with dosing solely based on clinical information, pharmacogenetics can help improve the therapy with coumarins by decreasing the time to reach a stable dose and reducing the risk of bleeding. Most of the studies about genotyping of patients using vitamin K antagonists have focused on predicting the stable dose. Two genes have been shown to have the most influence on dosing: VKORC1 and CYP2C9. Furthermore, genotyping of more genes, such as CYP4F2 and APOE, is also being included in some dosing algorithms. The role of genotype beyond the initial dose-titration phase is less clear. Thus, a proven genetically determined risk of unstable dose or bleeding could help with the selection of patients who require more frequent monitoring of dose. On the other hand, patients who have a genetically determined stable dose could self-monitor their international normalized ratio (INR), making the therapy less expensive and more convenient.

Comparative ecotoxicology study of two neoteric solvents: Imidazolium ionic liquid vs. glycerol derivative.

In this study we have compared the acute ecotoxicity of two solvents, with very different structure and origin, but sharing many physical-chemical properties, so they can be used for similar purposes; a well-known ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) and a solvent partially derived from biomass, 3-bis(2,2,2-trifluoroethoxy)propan-2-ol (BTFIP). We have used three biomodels (Vibrio fischeri, Daphnia magna and Danio rerio) and performed the comparison applying the Environmental, Health and Safety (EHS) hazard assessment. According to the results, ecotoxicity of [BMIM][PF6] and BTFIP is quite similar in the simplest model Vibrio fischeri, while in Daphnia magna [BMIM][PF6] is clearly more toxic. However, in Danio rerio, toxicity of these chemicals is again quite similar and both can be classified as "nontoxic". The higher index value of [BMIM][PF6] in water mediate effect in the EHS assessment indicates that this ionic liquid is more dangerous than BTFIP, although accumulation and degradation properties have not been taken into account. Further studies will be necessary to ascertain these conclusions.

Identification of Legionella spp. in Environmental Water Samples by ScanVIT-Legionella™ Method in Spain.

Rapid and more sensitive methods for the detection and quantification of viable Legionella cells have been developed. In this paper, a comparative analysis of environmental water samples using the ScanVIT-Legionella™ method and the traditional "gold standard" method of culturing is realised indicating the usefulness of the ScanVIT method. The ScanVIT-Legionella™ method was performed on environmental water samples from different locations of Huesca region (Spain). Legionella micro-colonies should appear green colour and Legionella pneumophila micro-colonies appear red. Twenty-one environmental water samples analysed by standard culture plus five control samples (Two sterile water samples with Legionella as positive controls and three sterile water samples as negative controls). All of them were used to apply ScanVIT-Legionella™ method. From of 21 environmental samples eleven were positive, six negative with both methods and four samples were negative for culture method and positive for ScanVIT-Legionella™ method. The positive control samples were positive and the negative were negative for both methods. A comparative analysis of the results obtained with two methods showed a strong positive determination coefficient (R(2) = 0.99753). The results demonstrate the usefulness of the ScanVIT-Legionella™ method as a rapid diagnostic tool in order to provide a diagnosis as quick as possible. ScanVIT-Legionella™ method offers a series of advantages such as quickly diagnosis, higher sensitivity and the possibility to identify Legionella spp. and L. pneumophila simultaneously.