Loss of function polymorphisms in SLCO1B1 (c.521T>C, rs4149056) and ABCG2 (c.421C>A, rs2231142) genes are associated with adverse events of rosuvastatin: a case-control study.

PURPOSE: The study aims to evaluate relationship between polymorphisms associated with a reduced function of two transporter proteins resulting in increased exposure to rosuvastatin - organic anion transporter 1B1 (OATP1B1) (SLCO1B1 c.521T>C) and ATP binding cassette subfamily G member 2 (ABCG2) (ABCG2 c.421C>A) and occurrence of rosuvastatin related myotoxicity/hepatotoxicity. METHODS: In a case-control study, cases (rosuvastatin treated patients developing myotoxicity or hepatotoxicity) and controls (concurrent rosuvastatin treated patients free of adverse events) were prospectively recruited over a 2 year period in a single tertiary center specialized in treatment of metabolic disorders. Subjects were evaluated for clinical, comorbidity, and comedication characteristics and for genotype predicted metabolizing phenotypes regarding cytochrome P450 enzymes CYP2C9 and CYP2C19. Standard regression analysis and analysis in matched sets of cases and controls (optimal full matching) were undertaken by fitting frequentist and Bayesian models (covariates/matching variables: age, sex, diabetes, liver/renal disease, hypertension, CYP2C9 and C19 phenotype, use of CYP or transporter inhibitors, non evaluated transporter genotype). RESULTS: A total of 88 cases (81 with myotoxicity, 6 with hepatotoxicity, 1 with both) and 129 controls were recruited. Odds of variant SLCO1B1 c.521T>C allele were 2.2-2.5 times higher in cases than in controls (OR = 2.45, 95% CI 1.34-4.48; Bayesian OR = 2.59, 95% CrI 1.42-4.90 in regression analysis; OR = 2.20, 1.10-4.42; Bayesian OR = 2.26, 1.28-4.41 in matched analysis). Odds of variant ABCG2 c.421C>A allele were 2.1-2.3 times higher in cases than in controls (OR = 2.24, 1.04-4.83; Bayesian OR = 2.35, 1.09-4.31 in regression analysis; OR = 2.10, 0.83-5.31; Bayesian OR = 2.17, 1.07-4.35 in matched analysis). CONCLUSION: Loss of function polymorphisms in SLCO1B1 c.521T>C and ABCG2 c.421C>A genes are associated with the presence of rosuvastatin related myotoxicity and/or hepatotoxicity.

ABCG2 and SLCO1B1 gene polymorphisms in the Croatian population.

BACKGROUND: Organic anion-transporting polypeptide 1B1 (OATP1B1) and the ATP-binding cassette subfamily G member 2, ABCG2, are important transporters involved in the transport of endogenous substrates and xenobiotics, including drugs. Genetic polymorphisms of these transporters have effect on transporter activity. There is significant interethnic variability in the frequency of allele variants. AIM: To determined allele and genotype frequencies of ABCG2 and SLCO1B1 genes in Croatian populations of European descent. SUBJECTS AND METHODS: A total of 905 subjects (482 women) were included. Genotyping for ABCG2 c.421C > A (rs2231142) and for SLCO1B1 c.521T > C (rs4149056), was performed by real-time polymerase chain reaction (PCR) using TaqMan® DME Genotyping Assays. RESULTS: For ABCG2 c.421C > A, the frequency of CC, CA and AA genotypes was 81.4%, 17.8% and 0.8% respectively. The frequency of variant ABCG2 421 A allele was 9.7%. For SLCO1B1 c.521T > C, the frequency of TT, TC and CC genotypes was 61.7%, 34.8% and 3.5% respectively. The frequency of variant SLCO1B1 521 C allele was 20.9%. CONCLUSION: The frequency of the ABCG2 and SLCO1B1 allelic variants and genotypes in the Croatian population is in accordance with other European populations. Pharmacogenetic analysis can serve to individualise drug therapy and minimise the risk of developing adverse drug reactions.

Association of HSPA1B genotypes with psychopathology and neurocognition in patients with the first episode of psychosis: a longitudinal 18-month follow-up study.

Our aim was to analyze the association of HSPA1B genotypes and treatment response measured by the changes of psychopathology and neurocognitive symptoms in patients with first-episode psychosis (FEP) after 18 months of treatment. A sample of 159 patients with FEP admitted at two Croatian psychiatric hospitals in the period between year 2014 and year 2017 was assessed at baseline and after 18 months of follow-up with Positive and Negative Syndrome Scale (PANSS), Calgary Depression Scale for Schizophrenia (CDSS) and a battery of neurocognitive tests. Associations of scale and test results with HSPA1B polymorphic locus rs1061581 were analyzed using the general linear model. The carriers of the AA genotype showed the highest improvement in CDSS and RAVLT A test after the 18-month follow-up. Concordantly, we found significantly higher improvement assessed with the CDSS, RAVLT A, RAVLT A 30' and positive PANSS scales in the not-GG (AA/AG) group compared with the GG group. Our study suggests that HSPA1B rs1061581variants may moderate treatment response in FEP measured with changes of psychopathology and neurocognitive test results.

Impact of Continuous P2Y12 Inhibition Tailoring in Acute Coronary Syndrome and Genetically Impaired Clopidogrel Absorption.

Clopidogrel is still widely used in acute coronary syndrome despite the development of more potent P2Y12 inhibitors. Previously, we conducted a trial that evaluated serial clopidogrel dose adjustment based on platelet function testing in acute coronary syndrome patients with initial high on-treatment platelet reactivity (HTPR). In this substudy, we performed post hoc analysis of the effect of ABCB1 genetic variants C3435T and G2677T/A on platelet inhibition and outcomes. There were no differences in the proportion of HTPR patients among C3435T carriers and noncarriers in both interventional and control group. G2677T carriers expressed significantly higher proportion of HTPR pattern throughout 12-month follow-up in the control group with no difference in the interventional group. There was no difference in ischemic outcomes between C3435T and G2677T carriers and noncarriers in both groups of patients. The results indicate that ABCB1 genotyping is not useful to guide clopidogrel therapy tailoring to improve high-risk patient management.

Integration of complementary biomarkers in patients with first episode psychosis: research protocol of a prospective follow up study.

In this project, we recruited a sample of 150 patients with first episode of psychosis with schizophrenia features (FEP) and 100 healthy controls. We assessed the differences between these two groups, as well as the changes between the acute phase of illness and subsequent remission among patients over 18-month longitudinal follow-up. The assessments were divided into four work packages (WP): WP1- psychopathological status, neurocognitive functioning and emotional recognition; WP2- stress response measured by saliva cortisol during a stress paradigm; cerebral blood perfusion in the resting state (with single photon emission computed tomography (SPECT) and during activation paradigm (with Transcranial Ultrasonography Doppler (TCD); WP3-post mortem analysis in histologically prepared human cortical tissue of post mortem samples of subjects with schizophrenia in the region that synaptic alteration was suggested by WP1 and WP2; WP4- pharmacogenetic analysis (single gene polymorphisms and genome wide association study (GWAS). We expect that the analysis of these data will identify a set of markers that differentiate healthy controls from patients with FEP, and serve as an additional diagnostic tool in the first episode of psychosis, and prediction tool which can be then used to help tailoring individualized treatment options. In this paper, we describe the project protocol including aims and methods and provide a brief description of planned post mortem studies and pharmacogenetic analysis.

Is there any association of apolipoprotein E gene polymorphisms with metabolic syndrome in a young population of Croatian origin?

BACKGROUND: Apolipoprotein E has an important role in lipid metabolism and adipocyte activity and apo E gene (APOE) might serve as a potential determinant of metabolic syndrome (MetS). AIM: The aim of the presented study was to investigate the association between APOE polymorphism and MetS in young adult subjects of Croatian origin. METHODS: This study measured biochemical and anthropometric parameters of 149 young (aged 20-33) subjects. The APOE was genotyped by real-time PCR. RESULTS: No APOE genotype significantly increased the risk for development of MetS. Significant association was found between APOE polymorphism and elevated blood pressure (EBP) (p = .019). The carriers of the ɛ4 allele had decreased risk for EBP (OR = 0.28, 95% CI) compared to ɛ3 allele carriers (ɛ3 allele vs others, χ2 = 7.08; p = .005). APOE alleles were significantly associated with the concentration of TC and LDL-C (χ2 = 12.11, p = .002 and χ2 = 15.76, p < .001, respectively). With diet as a modification covariate there was a significant correlation of APOE alleles with the concentrations of adiponectin and leptin (χ2 = 7.076; p = .029 and χ2 = 7.46; p = .024, respectively). CONCLUSION: Although APOE variants were not confirmed as the risk factor for development of MetS, the APOE alleles were associated with some of the metabolic parameters in young Croatian subjects. The relation of APOE alleles with a concentration of adiponectin and leptin depends on the diet intake.

Is CYP2C Haplotype Relevant for Efficacy and Bleeding Risk in Clopidogrel-Treated Patients?

A recently discovered haplotype-CYP2C:TG-determines the ultrarapid metabolism of several CYP2C19 substrates. The platelet inhibitor clopidogrel requires CYP2C19-mediated activation: the risk of ischemic events is increased in patients with a poor (PM) or intermediate (IM) CYP2C19 metabolizer phenotype (vs. normal, NM; rapid, RM; or ultrarapid, UM). We investigated whether the CYP2C:TG haplotype affected efficacy/bleeding risk in clopidogrel-treated patients. Adults (n = 283) treated with clopidogrel over 3-6 months were classified by CYP2C19 phenotype based on the CYP2C19*2*17 genotype, and based on the CYP2C19/CYP2C cluster genotype, and regarding carriage of the CYP2:TG haplotype, and were balanced on a number of covariates across the levels of phenotypes/haplotype carriage. Overall, 45 (15.9%) patients experienced ischemic events, and 49 (17.3%) experienced bleedings. By either classification, the incidence of ischemic events was similarly numerically higher in PM/IM patients (21.6%, 21.8%, respectively) than in mutually similar NM, RM, and UM patients (13.2-14.8%), whereas the incidence of bleeding events was numerically lower (13.1% vs. 16.6-20.5%). The incidence of ischemic events was similar in CYP2C:TG carries and non-carries (14.1% vs. 16.1%), whereas the incidence of bleedings appeared mildly lower in the former (14.9% vs. 20.1%). We observed no signal to suggest a major effect of the CYP2C19/CYP2C cluster genotype or CYP2C:TG haplotype on the clinical efficacy/safety of clopidogrel.

Common P-glycoprotein (ABCB1) polymorphisms do not seem to be associated with the risk of rivaroxaban-related bleeding events: Preliminary data.

Introduction: Considering conflicting previous reports, we aimed to evaluate whether the common ABCB1 polymorphisms (rs1128503, rs2032582, rs1045642, rs4148738) affected the risk of bleeding in rivaroxaban-treated patients. Materials and methods: We report preliminary data from a larger nested case-control study. Consecutive adults started on rivaroxaban for any indication requiring > 6 months of treatment were followed-up to one year. Patients who experienced major or non-major clinically relevant bleeding during the initial 6 months were considered cases, whereas subjects free of bleeding over > 6 months were controls. The polymorphisms of interest (rs1128503, rs2032582, rs1045642, rs4148738) were in a strong linkage disequilibrium, hence patients were classified regarding the "load" of variant alleles: 0-2, 3-5 or 6-8. The three subsets were balanced regarding a range of demographic, comorbidity, comedication and genetic characteristics. A logistic model was fitted to probability of bleeding. Results: There were 60 cases and 220 controls. Raw proportions of cases were similar across the subsets with increasing number of ABCB1 variant alleles (0-2, N = 85; 3-6, N = 133; 6-8, N = 62): 22.4%, 21.8%, and 19.4%, respectively. Fully adjusted probabilities of bleeding were also similar across the subsets: 22.9%, 27.5% and 17.7%, respectively. No trend was observed (linear, t = -0.63, df = 273, P = 0.529; quadratic, t = -1.10, df = 273, P = 0.272). Of the 15 identified haplotypes, the completely variant (c.1236T_c.2677T(A)_c.3435T_c.2482-2236A) (40.7%) and completely wild-type (C_G_C_G) (39.5%) haplotypes prevailed, and had a closely similar prevalence of cases: 21.1% vs. 23.1%, respectively. Conclusions: The evaluated common ABCB1 polymorphisms do not seem to affect the risk of early bleeding in patients started on rivaroxaban.

Effects of lipoprotein lipase and peroxisome proliferator-activated receptor-gamma gene variants on metabolic syndrome traits.

Peroxisome proliferator activated receptor-gamma (PPARG) and lipoprotein lipase (LPL) play important role in lipid homeostasis, insulin resistance and adipogenesis, and their gene variability could be considered as predictive genetic markers for metabolic syndrome (MetSy). The aim of the study was to estimate possible associations of PPARG (Pro12Ala) and LPL PvuII (+/-) polymorphisms with MetSy and its traits. Study included 527 subjects. According to the modified National Cholesterol Education Program Adult Treatment Panel III definitions, subjects were classified into the metabolic syndrome group and control group. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism methods. In the total sample, LPL variants were associated with waist circumference (chi2 = 7.263, d.f = 2, p = 0.026) and with BMI (chi2 = 6.549, d.f = 2, p = 0.038), where PvuII (+/+) genotype carriers had the highest risk for increased waist circumference (specific PvuII (+/+) vs. others analysis chi2 = 7.033, p = 0.008) and increased BMI (specific PvuII( +/+) vs. others analysis chi2 = 5.154, p = 0.023). LPL gene variants were also associated with HDL-C levels (chi2 = 6.901, d.f = 2, p = 0.032), where PvuII (-/-) genotype carriers had higher HDL-C values in comparison to others (specific Pvu (+/+) vs. others analysis chi2 = 6.504, p = 0.011). Furthermore, PvuII (-) allele carriers had significantly lower glucose (allele based analysis Add Value = -0.0878, chi2 = 5.878, d.f. = 1, p = 0.015). Significant interaction was detected between PPARG and LPL that affected HDL-C levels in male population (chi2 = 11.790, d.f = 1, p = 0.0006) in the manner that Ala/PvuII(+) contributed to the lowest HDL-C values (Specific Ala/ Pvu(+) vs. others analysis was chi2 = 11.750, p = 0.0006). According to obtained results LPL and PPARG gene variants could be susceptibility factors of obesity and lipid status, contributing to development of MetSy, particularly in males. Because of antiatherogenic function of HDL-C, the identification of genetic variants associated with HDL-C can provide useful information related to genotype-phenotype relationships. Since the interplay between PPARG and LPL gene and gender seems to be significant it could point to the personalized behavioural recommendations for prevention of metabolic and cardiovascular diseases.

The effects of simvastatin and fenofibrate on malondialdehyde and reduced glutathione concentrations in the plasma, liver, and brain of normolipidaemic and hyperlipidaemic rats.

The objective of study was to investigate the effects of different doses of simvastatin and fenofibrate on malondialdehyde (MDA) and reduced glutathione (GSH) in the plasma, liver, and brain tissue of male normolipidaemic and hyperlipidaemic rats. Normolipidaemic (Wistar) rats were receiving 10 or 50 mg/kg a day of simvastatin or 30 or 50 mg/kg a day of fenofibrate. Hyperlipidaemic (Zucker) rats were receiving 50 mg/kg/day of simvastatin or 30 mg/kg/day of fenofibrate. Control normolipidaemic and hyperlipidaemic rats were receiving saline. Simvastatin, fenofibrate, and saline were administered by gavage for three weeks. In normolipidaemic rats simvastatin and fenofibrate showed similar and dose-independent effects on plasma and brain MDA and GSH concentrations. Generally, plasma and brain MDA decreased, while brain GSH concentration increased. In hyperlipidaemic rats simvastatin did not affect plasma and brain MDA and GSH concentrations but significantly decreased liver GSH. Fenofibrate decreased plasma and liver MDA but increased brain MDA. In both rat strains fenofibrate significantly decreased liver GSH concentrations, most likely because fenofibrate metabolites bind to GSH. Our findings suggest that simvastatin acts as an antioxidant only in normolipidaemic rats, whereas fenofibrate acts as an antioxidant in both rat strains.

Risk Factors for Rivaroxaban-Related Bleeding Events-Possible Role of Pharmacogenetics: Case Series.

Non-vitamin K antagonist oral anticoagulants' interindividual trough concentration variability affects efficacy and safety, especially in bleeding events. Rivaroxaban is metabolised via CYP3A4/5-, CYP2J2-, and CYP-independent mechanisms and is a substrate of two transporter proteins: ABCB1 (MDR1, P-glycoprotein) and ABCG2 (BCRP; breast-cancer-resistance protein). The polymorphisms of these genes may possibly affect the pharmacokinetics of rivaroxaban and, consequently, its safety profile. Rivaroxaban variability may be associated with age, liver and kidney function, concomitant illness and therapy, and pharmacogenetic predisposition. This case series is the first, to our knowledge, that presents multiple risk factors for rivaroxaban-related bleeding (RRB) including age, renal function, concomitant diseases, concomitant treatment, and pharmacogenetic data. It presents patients with RRB, along with their complete clinical and pharmacogenetic data, as well as an evaluation of possible risk factors for RRB. Thirteen patients were carriers of ABCB1, ABCG2, CYP2J2, and/or CYP3A4/5 gene polymorphisms. Possible drug-drug interactions with increased bleeding risk were identified in nine patients. Six patients had eGFR <60 mL/min/1.73 m2. Our data suggest a possible role of multiple factors and their interactions in predicting RRB; however, they also indicate the need for further comprehensive multidisciplinary research to enable safer use of this product based on a personalised approach.

Association between lamotrigine concentrations and ABCB1 polymorphisms in patients with epilepsy.

BACKGROUND: Epilepsy is treated with a variety of anticonvulsants that are often used concomitantly. Therefore, therapeutic drug monitoring is often necessary. Along with clinical and environmental factors, genetic predisposition has been recognized to be relevant for interindividual variability in drug response. Polymorphic transporter proteins such as P-glycoprotein significantly influence pharmacokinetics and bioavailability of many structurally unrelated drugs. The aim of the study was to evaluate the impact of polymorphisms in the P-glycoprotein-encoding gene ABCB1 (C1236T, G2677T/A, C3435T) on antiepileptic drug disposition. METHODS: We recruited 222 patients with epilepsy who were prescribed lamotrigine in monotherapy or polytherapy. Lamotrigine plasma concentrations were analyzed and compared with ABCB1 gene variants. The ABCB1 genotyping was performed by real-time polymerase chain reaction methods. The therapeutic drug monitoring was performed by high-performance liquid chromatography-diode array detector (DAD) and immunoassay. RESULTS: A significant correlation was confirmed between lamotrigine concentration and additional drugs (P < 0.001). In the whole group, statistical analysis showed correlations between lamotrigine concentrations and ABCB1 C1236T variants: 10.1 and 6.5 µmol/L for CC versus CT + TT, respectively (P = 0.021), and for dose corrected lamotrigine 0.068 and 0.053 µmol·L·mg, for CC versus CT + TT, respectively (P = 0.017). Analysis of a specific haplotype showed that 1236C-2677G-3435C carriers had higher lamotrigine concentrations than 1236T-2677G-3435T carriers (P < 0.001), followed by 1236T-2677T-3435C carriers (P < 0.001). CONCLUSIONS: ABCB1 C1236T, G2677T/A, C3435T polymorphisms have an influence on lamotrigine serum concentrations.

UGT2B7 c.-161C>T polymorphism frequency in Croatian population.

Uridine diphosphate glucuronosyltransferase-2B7 (UGT2B7), enzyme responsible for the elimination of a number of xenobiotics through glucuronidation, is expressed in the gut, kidneys, intestines, and brain. However, data on the frequency of UGT2B7 polymorphisms in the Croatian population are limited. The aim of this study was to assess the frequency of the UGT2B7 c.-161C>T (rs7668258) polymorphism in the Croatian population and to compare it with reported frequencies in other populations. This polymorphism is in complete linkage disequilibrium with the UGT2B7 c.802C>T (UGT2B7*2, rs7439366) variant, which is important in clinical medicine. The study reports data of 501 participants from University Hospital Centre Zagreb. All data were collected and analysed retrospectively. Genotyping was performed by real-time polymerase chain reaction (PCR) using the TaqMan® Drug Metabolism Genotyping Assay for UGT2B7 c.-161C>T (rs7668258). We found that 120 (23.95 %) participants were carriers of the UGT2B7 c.-161CC genotype and 255 (50.9 %) were heterozygous carriers (UGT2B7 c.-161CT), while 126 (25.15 %) were homozygous carriers of the variant allele (UGT2B7 c.-161TT). The frequency of the variant UGT2B7 c.-161C>T allele in this study was T=0.506. The frequency of the UGT2B7 c.-161C>T allelic variants and genotypes in the Croatian population is similar to other European populations.

ABCB1, ABCG2 and CYP2D6 polymorphism effects on disposition and response to long-acting risperidone.

The relevance of the multidrug resistance (ABCB1) and breast cancer resistance (ABCG2) protein transporter polymorphisms for treatment with long-acting intramuscular (LAI) risperidone is largely unknown. We explored the relationship between these polymorphisms and cytochrome P450 (CYP) 2D6 genotype-predicted phenotype in their effects on drug disposition and clinical outcomes in adults with schizophrenia. In a 24-week observational study, patients initiated on LAI-risperidone (n=101) were genotyped [enzymes (CYP2D6 dupl,*3,*4,*5,*6,*41; CYP3A4*22, CYP3A5*3), transporters (ABCG2 421C>A; ABCB1 1236C>T, 2677G>T/A, 3435C>T)] and evaluated for steady-state (weeks 6-8) serum levels of dose-corrected risperidone, 9-OH-risperidone, risperidone+9-OH-risperidone (active moiety), and for response to treatment (PANSS, reduction vs. baseline ≥30% at week 12 and ≥45% at week 24). CYP2D6 normal/ultrarapid metabolizers (NM/UM) (vs. other) had lower risperidone (29%) and active moiety levels (24%) (9-OH-risperidone not affected). The effect on the three analytes was mild (0 to 23% reduction) in ABCG2 wild-type homozygotes and pronounced (44-55% reduction) in ABCG2 variant allele carriers. ABCG2 variant had no effect on disposition in CYP2D6 "other" phenotypes, while the effect was pronounced in CYP2D6 NM/UM subjects (31-37% reduction). ABCB1 polymorphisms had no effect on exposure to risperidone. CYP2D6 NM/UM phenotype tended to lower odds of PANSS response, ABCG2 variant was associated with 4-fold higher odds and ABCB1 (1236C>T, 2677G>T/A, 3435C>T) overall mainly wild-type genotype was associated with around 4--fold lower odds of response. In patients treated with LAI-risperidone, CYP2D6 phenotype effect on systemic exposure is conditional on the ABCG2 421C>A polymorphism. ABCG2 and ABCB1 polymorphisms affect clinical response independently of systemic risperidone disposition.

Drug-drug-gene interactions as mediators of adverse drug reactions to diclofenac and statins: a case report and literature review.

Concomitant treatment with drugs that inhibit drug metabolising enzymes and/or transporters, such as commonly prescribed statins and nonsteroidal anti-inflammatory drugs (NSAIDs), has been associated with prolonged drug exposure and increased risk of adverse drug reactions (ADRs) due to drug-drug interactions. The risk is further increased in patients with chronic diseases/comorbidities who are more susceptible because of their genetic setup or external factors. In that light, we present a case of a 46-year-old woman who had been experiencing acute renal and hepatic injury and myalgia over two years of concomitant treatment with diclofenac, atorvastatin, simvastatin/fenofibrate, and several other drugs, including pantoprazole and furosemide. Our pharmacogenomic findings supported the suspicion that ADRs, most notably the multi-organ toxicity experienced by our patient, may be owed to drug-drug-gene interactions and increased bioavailability of the prescribed drugs due to slower detoxification capacity and decreased hepatic and renal elimination. We also discuss the importance of CYP polymorphisms in the biotransformation of endogenous substrates such as arachidonic acid and their modulating role in pathophysiological processes. Yet even though the risks of ADRs related to the above mentioned drugs are substantially evidenced in literature, pre-emptive pharmacogenetic analysis has not yet found its way into common clinical practice.

[Does Lp-PLA2 determination help predict atherosclerosis and cardiocerebrovascular disease?]. / Moze li odredivanje Lp-PLA2 pomoci u predvidanju ateroskleroze i kardiocerebrovaskularnih bolesti?

Thorough control of risk factors is pivotal for cardiocerebrovascular diseases. As classic risk assessment accounts for only 50% of risk variability and due to the role of inflammatory processes in endothelial dysfunction and atherosclerotic plaque rupture, it is necessary to identify new biomarkers for risk prediction. In addition to the inflammatory marker high sensibility C-reactive protein (hs-CRP), lipoprotein associated phospholipase A2 (Lp-PLA2) is gaining increasing significance, since it is directly involved in the pathogenesis of atherosclerotic plaque progression. Lp-PLA2 is highly specific for vascular inflammation, has low biological variability, and plays a causative role in atherosclerotic plaque inflammation. It belongs to the group of intracellular and secretory phospholipase enzymes that can hydrolyze sn-2 phospholipid ester bond of cellular membranes and lipoproteins. Lp-PLA2 enzyme is formed by macrophages and foam cells in atherosclerotic plaque, and is associated primarily with LDL particles in blood. Lp-PLA2 that is bound to LDL is the sole enzyme responsible for hydrolysis of oxidized phospholipids (oxPL) on LDL particles. Lp-PLA2 hydrolyzes oxPL at the surface of lipoproteins, but has weak activity against non-oxPL. Lp-PLA2 is also the enzyme that hydrolyzes oxPL on HDL particles, where it may have a role in the antioxidative function of HDL. The distribution of Lp-PLA2 between LDL and HDL particles depends on the extent of Lp-PLA2 glycosylation, which may affect the activity of Lp-PLA2 in plasma. Stable atherosclerotic plaques contain few inflammatory cells and a small amount of Lp-PLA2. In contrast, unstable plaques most often do not have significant impact on arterial lumen but may be detected by its thin connective tissue cap, low collagen and high lipid content. A distinguishing factor between stable and unstable atherosclerotic plaque may also be the presence of activated inflammatory cells and increased Lp-PLA2 concentration in unstable plaque. These new insights indicate that Lp-PLA2 may be a risk factor, which is important for the formation of atherosclerotic plaque but also for its rupture. The purpose of applying markers of inflammation is to improve stratification of patients at risk, so that treatment intensity may be adjusted to the risk level. Lp-PLA2 inhibition is associated with decreased cytokines. Lipid-affecting drugs stabilize atherosclerotic plaque by reducing the central lipid core, decreasing macrophage infiltration, and thickening of the connective tissue cap. These drugs reduce Lp-PLA2 concentration and the frequency of cardiocerebrovascular events as well. Besides acting as a specific marker of atherosclerotic plaque inflammation, Lp-PLA2 has a significant prognostic value because of its direct role in the formation of rupture-prone atherosclerotic plaque, unlike classic risk factors, for example lipid measurement or vascular imaging, which do not directly estimate acute ischemic potential in the arterial wall. Studies have demonstrated correlation between increased Lp-PLA2 concentrations and enhanced risk of cardiocerebrovascular events, even after multivariate adjustment to classic risk factors. In addition to its high specificity for vascular inflammation, Lp-PLA2 concentration is stable in terms of time, unlike, for instance, CRP levels. Lp-PLA2 has been confirmed as an independent risk predictor, which is complementary to hsCRP. It could be used in clinical practice for improved risk assessment in patients with transient cardiocerebrovascular risk, particularly in those with metabolic syndrome (obese patients with mixed dyslipidemia, hyperglycemia, insulin resistance, and arterial hypertension). Lp-PLA2 levels allow for further risk stratification of high-risk patients into a very high risk group where more aggressive therapy is recommended, as well as the achievement of LDL-cholesterol levels < 2.5 or, even better, < 2.0 mmol/L as a feasible therapeutic target. Similar to hsCRP, the levels of Lp-PLA2 are reduced by lipid-affecting drugs, while its low concentrations are associated with a very low risk of cardiocerebrovascular events both in low- and high-risk population. According to recent American guidelines for assessing the risk of cardiovascular disease, Lp-PLA2 determination is recommended as an additional marker to the classic risk assessment in patients with moderate and high risk.

Pharmacogenetics and the treatment of epilepsy: what do we know?

Seizure control with antiepileptic drugs (AEDs) as well as susceptibility to adverse drug reactions varies among individuals with epilepsy. This interindividual variability is partly determined by genetic factors. However, genetic testing to predict the efficacy and toxicity of AEDs is limited and genetic variability is, as yet, largely unexplainable. Accordingly, genetic testing can only be advised in a very limited number of cases in clinical routine. Currently, by applying different methodologies, many trials have been undertaken to evaluate cost benefits of preventive pharmacogenetic analysis for patients. There is significant progress in sequencing technologies, and focus is on next-generation sequencing-based methods, like exome and genome sequencing. In this review, an overview of the current scientific knowledge considering the pharmacogenetics of AEDs is given.

Association of CNR1 genotypes with changes in neurocognitive performance after eighteen-month treatment in patients with first-episode psychosis.

INTRODUCTION: We analyzed the association of cannabinoid receptor CNR1 genotypes with changes in neurocognitive performance in patients with first-episode psychosis (FEP) after 18 months of treatment. Our secondary aim was to analyze the association of CNR1 genotypes with changes of perceived levels of stress. METHODS: We enrolled a sample of 159 patients with FEP from two Croatian psychiatric hospitals between 2014 and 2017. Patients were assessed at baseline and after 18 months. We analyzed the associations of changes in neurocognitive test results and the perceived levels of stress with CNR1 polymorphic loci (rs7766029 and rs12720071) in 121 patients. RESULTS: In the analysis adjusted only for baseline neurocognitive test scores, carriers of rs7766029 CC genotype had significantly (with false discovery rate, FDR < 15%) higher improvement in verbal memory (Wechsler, Wechsler 30') and attention (Digit span F) compared with other participants. In such analysis, rs12720071 carriers of AG genotype had significantly (FDR < 15%) higher improvement in executive functions (Block design), but lower improvement in language functions than AA carriers. In the fully adjusted analysis for age, sex, cannabis use and negative symptoms, only the association of rs7766029 genotypes with the change in the Weschler 30' score was significant (FDR < 15%). In the analysis adjusted only for the baseline neurocognitive tests' scores, both rs7766029 and rs12720071 genotypes were significantly associated with the change in perceived levels of stress (FDR < 15%). In the fully adjusted analysis, only the association with rs7766029 genotype remained significant. CONCLUSIONS: The rs7766029 CNR1 variants may moderate changes in neurocognitive performance as well as in perceived levels of stress of patients with FEP over time.

Genetic polymorphisms of cytochrome P450 enzymes: CYP2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5 in the Croatian population.

BACKGROUND: Data on the frequency of pharmacogenetic polymorphisms in the Croatian population are limited. We determined and analyzed frequencies for the most important CYP2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5 genetic variants in the Croatian population. METHODS: 2637 subjects were included. Genotyping was performed by real-time polymerase chain reaction (PCR) using TaqMan® DME or TaqMan® SNP Genotyping Assays, and by PCR, and PCR-RFLP analysis. RESULTS: For CYP2C9, allele frequencies of *2 and *3 variant were 14.5% and 7.6%, respectively. Among them, 3.98% of subjects were predicted to be poor metabolizers. For CYP2C19, the most frequent variant alleles were *2 (14.8%), and *17 (23.7%), while 2.4% of subjects were predicted to be poor metabolizers, and 5.39% were homozygous carriers of *17 predicted to be ultrarapid metabolizers (UM). For CYP2D6, the frequencies of tested variant alleles were *3 (2.2%), *4 (17.4%), *5 (1%), *6 (1.1%), and *41 (10.8%). Out of these, 5.59% were predicted to be poor metabolizers, 3.19% were classified as UM while 1.0% were carriers of variant alleles duplications (undefined phenotype). For CYP3A4 allele frequencies of *1B and *22 variants were 1.4% and 2.7%, respectively. Allele frequency of CYP3A5*3 was 95.5%. Analyzing CYP3A cluster according to the combination of CYP3A4*22 and CYP3A5*3 revealed 5.34% of subjects to be poor metabolizers, while 8.66% were classified as extensive metabolizers. CONCLUSIONS: The frequency of the CYP allelic variants, genotypes, and predicted phenotypes in the Croatian population is in accordance with the other European populations, between the values of published data for Middle European and Mediterranean populations.