1.
2.
Gottlieb, Assaf, et al.
(författare)
Cohort-specific imputation of gene expression improves prediction of warfarin dose for African Americans
2017
Ingår i: Genome Medicine. - : Springer Science and Business Media LLC. - 1756-994X. ; 9:1
Tidskriftsartikel (refereegranskat) abstract
Background: Genome-wide association studies are useful for discovering genotype-phenotype associations but are limited because they require large cohorts to identify a signal, which can be population-specific. Mapping genetic variation to genes improves power and allows the effects of both protein-coding variation as well as variation in expression to be combined into "gene level" effects. Methods: Previous work has shown that warfarin dose can be predicted using information from genetic variation that affects protein-coding regions. Here, we introduce a method that improves dose prediction by integrating tissue-specific gene expression. In particular, we use drug pathways and expression quantitative trait loci knowledge to impute gene expression-on the assumption that differential expression of key pathway genes may impact dose requirement. We focus on 116 genes from the pharmacokinetic and pharmacodynamic pathways of warfarin within training and validation sets comprising both European and African-descent individuals. Results: We build gene-tissue signatures associated with warfarin dose in a cohort-specific manner and identify a signature of 11 gene-tissue pairs that significantly augments the International Warfarin Pharmacogenetics Consortium dosage-prediction algorithm in both populations. Conclusions: Our results demonstrate that imputed expression can improve dose prediction and bridge population-specific compositions. MATLAB code is available at https://github.com/assafgo/warfarin-cohort.
3.
Jacobson, Annica, et al.
(författare)
Can mutations in ELA2, neutrophil elastase expression or differential cell toxicity explain sulphasalazine-induced agranulocytosis?
2004
Ingår i: BMC Blood Disorders. - : Springer Science and Business Media LLC. - 1471-2326. ; 4:1, s. 5-
Tidskriftsartikel (refereegranskat) abstract
BACKGROUND: Drug-induced agranulocytosis, a severe side effect marked by a deficit or absolute lack of granulocytic white blood cells, is a rare side-effect of the anti-inflammatory drug sulphasalazine. Mutations in the human neutrophil elastase gene (ELA2), causing increased intracellular concentration of this serine protease, inhibits neutrophil differentiation in severe congenital neutropenia (SCN). Since the clinical symptoms of agranulocytosis and SCN are similar, we hypothesized that it may origin from a common genetic variation in ELA2 or that sulphasalazine may affect human neutrophil elastase activity and protein expression. METHODS: We screened for genetic differences in ELA2 in DNA from 36 patients who had suffered from sulphasalazine-induced agranulocytosis, and compared them with 72 patients treated with sulphasalazine without blood reactions. We also performed in vitro studies of the blood cell lines HL60 and U937 after sulphasalazine exposure with respect to cell survival index, neutrophil elastase protein expression and activity. RESULTS: None of the mutations in ELA2, which previously have been reported to be associated with SCN, was found in this material. Protein expression of human neutrophil elastase in lymphoma U937 cells was not affected by treatment with concentrations equivalent to therapeutic doses. Cell survival of lymphoma U937 and promyelocytic leukemia HL-60 cells was not affected in this concentration range, but exhibited a decreased proliferative capacity with higher sulphasalazine concentrations. Interestingly the promyelocytic cells were more sensitive to sulphasalazine than the lymphoma cell line. CONCLUSION: Neutrophil elastase expression and ELA2 mutations do, however, not seem to be involved in the etilogy of sulphasalazine-induced agranulocytosis. Why sulphasalazine is more toxic to promyelocytes than to lymphocytes remains to be explained.
4.
Josefsson, Ann, et al.
(författare)
CYP2D6 genotypes and depressive symptoms during late pregnancy and postpartum
2004
Ingår i: Nordic Journal of Psychiatry. - : Informa UK Limited. - 0803-9488 .- 1502-4725. ; 58:1, s. 61-4
Tidskriftsartikel (refereegranskat) abstract
The aim of this exploratory was to investigate the theory of a relation between cytochrome P450 2D6 (CYP2D6) genotype and depressive symptoms in late pregnancy and/or postpartum. We studied 145 women with depressive symptoms. CYP2D6 genotype was analysed in leukocyte DNA by polymerase chain reaction (PCR). There were no significant differences in CYP2D6 genotypes between the groups of women being depressed during and/or after pregnancy. The frequencies of CYP2D6 genotypes did not differ from other European studies. This study cannot confirm that depressive symptoms in late pregnancy and postpartum are connected with CYP2D6 genotype. It is, however, noteworthy that the frequency of ultrarapid metabolizers was higher than in a general Caucasian population. This warrants further exploration in a greater study sample, but should also be investigated in a general population with major depression.
5.
Kowalec, Kaarina, et al.
(författare)
Characteristics associated with drug-induced liver injury from interferon beta in multiple sclerosis patients
2014
Ingår i: Expert Opinion on Drug Safety. - : Informa Healthcare. - 1474-0338 .- 1744-764X. ; 13:10, s. 1305-1317
Forskningsöversikt (refereegranskat) abstract
Objective: To identify and characterize drug-induced liver injury (DILI) associated with IFN-beta in multiple sclerosis (MS) using recommended criteria. Methods: This retrospective, mixed methods design included a cohort of IFN-beta exposed MS patients from British Columbia (BC), Canada and a series of DILI cases from other Canadian provinces and two adverse drug reaction (ADR) networks (USA and Sweden). Associations between sex, age and IFN-beta product, and DILI were explored in BC cohort using Cox proportional hazard analyses. Characteristics, including the time to DILI, were compared between sites. Results: In BC, 18/942 (1.9%) of IFN-beta exposed MS patients met criteria for DILI, with a trend toward an increased risk for women and those exposed to IFN-beta-1a SC (44 mcg 3 x weekly) (adjusted Hazard Ratios: 3.15; 95% CI: 0.72 - 13.72, p = 0.13 and 6.26; 95% CI: 0.78 - 50.39, p = 0.08, respectively). Twenty-four additional cases were identified from other sites; the median time to DILI was comparable between BC and other Canadian cases (105 and 90 days, respectively), but longer for the ADR network cases (590 days, p = 0.006). Conclusions: Approximately 1 in 50 IFN-beta exposed patients developed DILI in BC, Canada. Identification of DILI cases from diverse sources highlighted that this reaction occurs even after years of exposure.
6.
Pirmohamed, Munir, et al.
(författare)
Oral anticoagulation : a critique of recent advances and controversies
2015
Ingår i: TIPS - Trends in Pharmacological Sciences. - : Elsevier BV. - 0165-6147 .- 1873-3735. ; 36:3, s. 153-163
Forskningsöversikt (refereegranskat) abstract
There have recently been significant advances in the field of oral anticoagulation, but these have also led to many controversies. Warfarin is still the commonest drug used for clotting disorders but its use is complicated owing to wide inter-individual variability in dose requirement and its narrow therapeutic index. Warfarin dose requirement can be influenced by both genetic and environmental factors. Two recent randomized controlled trials (RCTs) came to different conclusion regarding the utility of genotype-guided dosing; we critically explore the reasons for the differences. The new generation of oral anticoagulants have been demonstrated to be as efficacious as warfarin, but further work is needed to evaluate their safety in real clinical settings.
7.
Ås, Joel, et al.
(författare)
Whole genome case-control study of central nervous system toxicity due to antimicrobial drugs
2024
Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 19:2
Tidskriftsartikel (refereegranskat) abstract
A genetic predisposition to central nervous system (CNS) toxicity induced by antimicrobial drugs (antibiotics, antivirals, antifungals, and antiparasitic drugs) has been suspected. Whole genome sequencing of 66 cases and 833 controls was performed to investigate whether antimicrobial drug-induced CNS toxicity was associated with genetic variation. The primary objective was to test whether antimicrobial-induced CNS toxicity was associated with seventeen efflux transporters at the blood-brain barrier. In this study, variants or structural elements in efflux transporters were not significantly associated with CNS toxicity. Secondary objectives were to test whether antimicrobial-induced CNS toxicity was associated with genes over the whole genome, with HLA, or with structural genetic variation. Uncommon variants in and close to three genes were significantly associated with CNS toxicity according to a sequence kernel association test combined with an optimal unified test (SKAT-O). These genes were LCP1 (q = 0.013), RETSAT (q = 0.013) and SFMBT2 (q = 0.035). Two variants were driving the LCP1 association: rs6561297 (p = 1.15x10-6, OR: 4.60 [95% CI: 2.51-8.46]) and the regulatory variant rs10492451 (p = 1.15x10-6, OR: 4.60 [95% CI: 2.51-8.46]). No common genetic variant, HLA-type or structural variation was associated with CNS toxicity. In conclusion, CNS toxicity due to antimicrobial drugs was associated with uncommon variants in LCP1, RETSAT and SFMBT2.
8.
Alfirevic, A., et al.
(författare)
Phenotype Standardization for Statin-Induced Myotoxicity
2014
Ingår i: Clinical Pharmacology and Therapeutics. - : Springer Science and Business Media LLC. - 0009-9236 .- 1532-6535. ; 96:4, s. 470-476
Forskningsöversikt (refereegranskat) abstract
Statins are widely used lipid-lowering drugs that are effective in reducing cardiovascular disease risk. Although they are generally well tolerated, they can cause muscle toxicity, which can lead to severe rhabdomyolysis. Research in this area has been hampered to some extent by the lack of standardized nomenclature and phenotypic definitions. We have used numerical and descriptive classifications and developed an algorithm to define statin-related myotoxicity phenotypes, including myalgia, myopathy, rhabdomyolysis, and necrotizing autoimmune myopathy.
9.
Aomori, Tohru, et al.
(författare)
Rapid Single-Nucleotide Polymorphism Detection of Cytochrome P450 (CYP2C9) and Vitamin K Epoxide Reductase (VKORC1) Genes for the Warfarin Dose Adjustment by the SMart-Amplification Process Version 2
2009
Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 55:4, s. 804-812
Tidskriftsartikel (refereegranskat) abstract
BACKGROUND: Polymorphisms of the CYP2C9 (cytochrome P450, family 2, subfamily C, polypeptide 9) gene (CYP2C9*2, CYP2C9*3) and the VKORC1 (vitamin K epoxide reductase complex, subunit 1) gene (-1639G>A) greatly impact the maintenance dose for the drug warfarin. Prescreening patients for their genotypes before prescribing the drug facilitates a faster individualized determination of the proper maintenance dose, minimizing the risk for adverse reaction and reoccurrence of thromboembolic episodes. With current methodologies, therapy can be delayed by several hours to 1 day if genotyping is to determine the loading dose. A simpler and more rapid genotyping method is required. METHODS: We developed a single-nucleotide polymorphism (SNP)-detection assay based on the SMart Amplification Process version 2 (SMAP 2) to analyze CYP2C9*2, CYP2C9*3, and VKORC1 -1639G>A polymorphisms. Blood from consenting participants was used directly in a closed-tube real-time assay without DNA purification to obtain results within 1 h of blood collection. RESULTS: We analyzed 125 blood samples by both SMAP 2 and PCR-RFLP methods. The results showed perfect concordance. CONCLUSIONS: The results validate the accuracy of the SMAP 2 for determination of SNPs critical to personalized warfarin therapy. SMAP 2 offers speed, simplicity of sample preparation, the convenience of isothermal amplification, and assay-design flexibility, which are significant advantages over conventional genotyping technologies. In this example and other clinical scenarios in which genetic testing is required for immediate and better-informed therapeutic decisions, SMAP 2-based diagnostics have key advantages.
10.
Attelind, Sofia, et al.
(författare)
Identification of risk factors for adverse drug reactions in a pharmacovigilance database
2023
Ingår i: Pharmacoepidemiology and Drug Safety. - : John Wiley & Sons. - 1053-8569 .- 1099-1557. ; 32:12, s. 1431-1438
Tidskriftsartikel (refereegranskat) abstract
Introduction In addition to identifying new safety signals, pharmacovigilance databases could be used to identify potential risk factors for adverse drug reactions (ADRs).Objective To evaluate whether data mining in a pharmacovigilance database can be used to identify known and possible novel risk factors for ADRs, for use in pharmacovigilance practice.Method Exploratory data mining was performed within the Swedish national database of spontaneously reported ADRs. Bleeding associated with direct oral anticoagulants (DOACs)-rivaroxaban, apixaban, edoxaban, and dabigatran-was used as a test model. We compared demographics, drug treatment, and clinical features between cases with bleeding (N = 965) and controls who had experienced other serious ADRs to DOACs (N = 511). Statistical analysis was performed by unadjusted and age adjusted logistic regression models, and the random forest based machine-learning method Boruta.Results In the logistic regression, 13 factors were significantly more common among cases of bleeding compared with controls. Eleven were labelled or previously proposed risk factors. Cardiac arrhythmia (e.g., atrial fibrillation), hypertension, mental impairment disorders (e.g., dementia), renal and urinary tract procedures, gastrointestinal ulceration and perforation, and interacting drugs remained significant after adjustment for age. In the Boruta analysis, high age, arrhythmia, hypertension, cardiac failure, thromboembolism, and pharmacodynamically interacting drugs had a larger than random association with the outcome. High age, cardiac arrhythmia, hypertension, cardiac failure, and pharmacodynamically interacting drugs had odds ratios for bleeding above one, while thromboembolism had an odds ratio below one.Conclusions We demonstrated that data mining within a pharmacovigilance database identifies known risk factors for DOAC bleeding, and potential risk factors such as dementia and atrial fibrillation. We propose that the method could be used in pharmacovigilance for identification of potential ADR risk factors that merit further evaluation.
