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| 2. |
- Alfirevic, Ana, et al.
(författare)
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In silico analysis of HLA associations with drug-induced liver injury : use of a HLA-genotyped DNA archive from healthy volunteers
- 2012
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Ingår i: Genome Medicine. - : BioMed Central. - 1756-994X. ; 4:6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Drug-induced liver injury (DILI) is one of the most common adverse reactions leading to product withdrawal post-marketing. Recently, genome-wide association studies have identified a number of human leukocyte antigen (HLA) alleles associated with DILI; however, the cellular and chemical mechanisms are not fully understood.METHODS: To study these mechanisms, we established an HLA-typed cell archive from 400 healthy volunteers. In addition, we utilized HLA genotype data from more than four million individuals from publicly accessible repositories such as the Allele Frequency Net Database, Major Histocompatibility Complex Database and Immune Epitope Database to study the HLA alleles associated with DILI. We utilized novel in silico strategies to examine HLA haplotype relationships among the alleles associated with DILI by using bioinformatics tools such as NetMHCpan, PyPop, GraphViz, PHYLIP and TreeView.RESULTS: We demonstrated that many of the alleles that have been associated with liver injury induced by structurally diverse drugs (flucloxacillin, co-amoxiclav, ximelagatran, lapatinib, lumiracoxib) reside on common HLA haplotypes, which were present in populations of diverse ethnicity.CONCLUSIONS: Our bioinformatic analysis indicates that there may be a connection between the different HLA alleles associated with DILI caused by therapeutically and structurally different drugs, possibly through peptide binding of one of the HLA alleles that defines the causal haplotype. Further functional work, together with next-generation sequencing techniques, will be needed to define the causal alleles associated with DILI.
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| 3. |
- Bell, Catherine C., et al.
(författare)
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T-cells from HLA-B*57 : 01+ human subjects are activated with abacavir through two independent pathways and induce cell death by multiple mechanisms
- 2013
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Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 26:5, s. 759-766
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Tidskriftsartikel (refereegranskat)abstract
- Susceptibility to abacavir hypersensitivity has been attributed to possession of the specific human leukocyte antigen allele HLA-B*57:01. HLA-B*57:01-restricted activation of CD8+ T-cells provides a link between the genetic association and the iatrogenic disease. The objectives of this study were to characterize the functionality of drug-responsive CD8+ T-cell clones generated from HLA-B*57:01+ drug-naive subjects and to explore the relationship between abacavir accumulation in antigen presenting cells and the T-cell response. Seventy-four CD8+ clones expressing different Vβ receptors were shown to proliferate and kill target cells via different mechanisms when exposed to abacavir. Certain clones were activated with abacavir in the absence of antigen presenting cells. Analysis of the remaining clones revealed two pathways of drug-dependent T-cell activation. Overnight incubation of antigen presenting cells with abacavir, followed by repeated washing to remove soluble drug, activated approximately 50% of the clones, and the response was blocked by glutaraldehyde fixation. In contrast, a 1 h antigen presenting cell pulse did not activate any of the clones. Accumulation of abacavir in antigen presenting cells was rapid (less than 1 h), and the intracellular concentrations were maintained for 16 h. However, intracellular abacavir was not detectable by mass spectrometry after pulsing. These data suggest that T-cells can be activated by abacavir through a direct interaction with surface and intracellular major histocompatibility complex (MHC) molecules. With the former, abacavir seemingly participates in the MHC T-cell receptor binding interaction. In contrast, the latter pathway likely involves MHC binding peptides displayed as a consequence of abacavir exposure, but not abacavir itself.
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| 4. |
- Cirulli, Elizabeth T., et al.
(författare)
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A Missense Variant in PTPN22 is a Risk Factor for Drug-induced Liver Injury
- 2019
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Ingår i: Gastroenterology. - : W B SAUNDERS CO-ELSEVIER INC. - 0016-5085 .- 1528-0012. ; 156:6, s. 1707-1716
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: We performed genetic analyses of a multiethnic cohort of patients with idiosyncratic drug-induced liver injury (DILI) to identify variants associated with susceptibility.METHODS: We performed a genome-wide association study of 2048 individuals with DILI (cases) and 12,429 individuals without (controls). Our analysis included subjects of European (1806 cases and 10,397 controls), African American (133 cases and 1,314 controls), and Hispanic (109 cases and 718 controls) ancestry. We analyzed DNA from 113 Icelandic cases and 239,304 controls to validate our findings.RESULTS: We associated idiosyncratic DILI with rs2476601, a nonsynonymous polymorphism that encodes a substitution of tryptophan with arginine in the protein tyrosine phosphatase, nonreceptor type 22 gene (PTPN22) (odds ratio [OR] 1.44; 95% confidence interval [CI] 1.28-1.62; P = 1.2 x 10(-9) and replicated the finding in the validation set (OR 1.48; 95% CI 1.09-1.99; P =.01). The minor allele frequency showed the same effect size (OR > 1) among ethnic groups. The strongest association was with amoxicillin and clavulanate-associated DILI in persons of European ancestry (OR 1.62; 95% CI 1.32-1.98; P = 4.0 x 10(-6); allele frequency = 13.3%), but the polymorphism was associated with DILI of other causes (OR 1.37; 95% CI 1.21-1.56; P = 1.5 x 10(-6); allele frequency = 11.5%). Among amoxicillin-and clavulanate-associated cases of European ancestry, rs2476601 doubled the risk for DILI among those with the HLA risk alleles A* 02: 01 and DRB1* 15: 01.CONCLUSIONS: In a genome-wide association study, we identified rs2476601 in PTPN22 as a non-HLA variant that associates with risk of liver injury caused by multiple drugs and validated our finding in a separate cohort. This variant has been associated with increased risk of autoimmune diseases, providing support for the concept that alterations in immune regulation contribute to idiosyncratic DILI.
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| 5. |
- Kumar, Nitin, et al.
(författare)
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Adaptation of host transmission cycle during Clostridium difficile speciation
- 2019
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Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 51:9, s. 1315-1320
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial speciation is a fundamental evolutionary process characterized by diverging genotypic and phenotypic properties. However, the selective forces that affect genetic adaptations and how they relate to the biological changes that underpin the formation of a new bacterial species remain poorly understood. Here, we show that the spore-forming, healthcare-associated enteropathogen Clostridium difficile is actively undergoing speciation. Through large-scale genomic analysis of 906 strains, we demonstrate that the ongoing speciation process is linked to positive selection on core genes in the newly forming species that are involved in sporulation and the metabolism of simple dietary sugars. Functional validation shows that the new C. difficile produces spores that are more resistant and have increased sporulation and host colonization capacity when glucose or fructose is available for metabolism. Thus, we report the formation of an emerging C. difficile species, selected for metabolizing simple dietary sugars and producing high levels of resistant spores, that is adapted for healthcare-mediated transmission.
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| 6. |
- Limdi, Nita A., et al.
(författare)
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Warfarin pharmacogenetics : a single VKORC1 polymorphism is predictive of dose across three racial groups
- 2010
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 115:18, s. 3827-3834
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Tidskriftsartikel (refereegranskat)abstract
- Warfarin dosing algorithms incorporating CYP2C9 and VKORC1-1639G>A improve dose prediction compared to algorithms based solely on clinical and demographic factors. However these algorithms better capture dose variability among Whites compared to Asians or Blacks. Herein we evaluate whether other VKORC1 polymorphisms and haplotypes explain additional variation in warfarin dose beyond that explained by VKORC1-1639G>A among Asians (n=1103), Blacks (n=670) and Whites (n=3113). Participants were recruited from 11 countries as part of the International Warfarin Pharmacogenetics Consortium effort. Evaluation of the effects of individual VKORC1 SNPs and haplotypes on warfarin dose employed both univariate and multivariable linear regression. VKORC1-1639G>A and 1173C>T individually explained the greatest variance in dose in all three racial groups. Incorporation of additional VKORC1 SNPs or haplotypes did not further improve dose prediction. VKORC1 explained greater variability in dose among Whites as compared to Blacks and Asians. Differences in the percent variance in dose explained by VKORC1 across race was largely accounted for by the frequency of the -1639 A (or 1173 T) allele. Thus, clinicians should recognize that although at a population level, the contribution of VKORC1 towards dose requirements is higher in Whites compared to non-whites; genotype predicts similar dose requirements across racial groups.
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| 7. |
- Marvig, Camilla L., et al.
(författare)
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Quality of life in patients with venous thromboembolism and atrial fibrillation treated with coumarin anticoagulants
- 2015
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Ingår i: Thrombosis Research. - : Elsevier BV. - 0049-3848 .- 1879-2472. ; 136:1, s. 69-75
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Little is known about the overall quality of life (QOL) in patients newly diagnosed with venous thromboembolism (VTE) and atrial fibrillation (AF). We studied QOL in patients with VTE and AF immediately after the start of anticoagulant therapy, and after three months of treatment. Furthermore we identified whether QOL was affected by age, gender and nationality. Materials and Methods: The European pharmacogenetics of anticoagulant therapy (EU-PACT) study was a multicentre, randomized controlled trial of patients aged > 18 years diagnosed with VTE or AF. QOL was assessed using EuroQol 5 dimensions (EQ-5D) questionnaires. Results: The EQ-5D questionnaires were completed by 187 patients with VTE and 660 patients with AF. The QOL in patients diagnosed with VTE or AF was significantly impaired, however, during a 3 months treatment period, patients experienced an improvement (p < 0.05). The QOL in patients diagnosed with VTE improved with increasing age, with similar effects seen in men and women. Men and women diagnosed with AF differed in QOL (respectively 0.84 and 0.74, p < 0.05), and QOL decreased with age. Comparison between countries showed significant differences in the EQ-Index score at follow-up of patients with VTE, and in both EQ-Index score and EQ-VAS of patients with AF. Conclusions: The QOL in patients with VTE and AF is strongly reduced directly after the start of anticoagulant treatment, but improves within 3 months. Moreover, QOL is influenced by demographic and disease-specific variables. These findings provide useful information for future cost-effectiveness studies.
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| 8. |
- Nicoletti, Paola, et al.
(författare)
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Association of Liver Injury From Specific Drugs, or Groups of Drugs, With Polymorphisms in HLA and Other Genes in a Genome-Wide Association Study
- 2017
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Ingår i: Gastroenterology. - : W B SAUNDERS CO-ELSEVIER INC. - 0016-5085 .- 1528-0012. ; 152:5, s. 1078-1089
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: We performed a genome-wide association study (GWAS) to identify genetic risk factors for druginduced liver injury (DILI) from licensed drugs without previously reported genetic risk factors. METHODS: We performed a GWAS of 862 persons with DILI and 10,588 population-matched controls. The first set of cases was recruited before May 2009 in Europe (n = 137) and the United States (n = 274). The second set of cases were identified from May 2009 through May 2013 from international collaborative studies performed in Europe, the United States, and South America. For the GWAS, we included only cases with patients of European ancestry associated with a particular drug (but not flucloxacillin or amoxicillin-clavulanate). We used DNA samples from all subjects to analyze HLA genes and single nucleotide polymorphisms. After the discovery analysis was concluded, we validated our findings using data from 283 European patients with diagnosis of DILI associated with various drugs. RESULTS: We associated DILI with rs114577328 (a proxy for A* 33: 01 a HLA class I allele; odds ratio [OR], 2.7; 95% confidence interval [CI], 1.9 - 3.8; P = 2.4 x 10(-8)) and with rs72631567 on chromosome 2 (OR, 2.0; 95% CI, 1.6 - 2.5; P = 9.7 x 10(-9)). The association with A* 33: 01 was mediated by large effects for terbinafine-, fenofibrate-, and ticlopidine-related DILI. The variant on chromosome 2 was associated with DILI from a variety of drugs. Further phenotypic analysis indicated that the association between DILI and A* 33: 01 was significant genome wide for cholestatic and mixed DILI, but not for hepatocellular DILI; the polymorphism on chromosome 2 was associated with cholestatic and mixed DILI as well as hepatocellular DILI. We identified an association between rs28521457 (within the lipopolysaccharide-responsive vesicle trafficking, beach and anchor containing gene) and only hepatocellular DILI (OR, 2.1; 95% CI, 1.6 - 2.7; P = 4.8 x 10(-9)). We did not associate any specific drug classes with genetic polymorphisms, except for statin-associated DILI, which was associated with rs116561224 on chromosome 18 (OR, 5.4; 95% CI, 3.0 - 9.5; P = 7.1 x 10(-9)). We validated the association between A* 33: 01 terbinafine-and sertraline-induced DILI. We could not validate the association between DILI and rs72631567, rs28521457, or rs116561224. CONCLUSIONS: In a GWAS of persons of European descent with DILI, we associated HLA-A* 33: 01 with DILI due to terbinafine and possibly fenofibrate and ticlopidine. We identified polymorphisms that appear to be associated with DILI from statins, as well as 2 non-drug-specific risk factors.
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| 9. |
- Nicoletti, Paola, et al.
(författare)
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Drug-Induced Liver Injury due to Flucloxacillin : Relevance of Multiple Human Leukocyte Antigen Alleles
- 2019
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Ingår i: Clinical Pharmacology and Therapeutics. - : John Wiley & Sons. - 0009-9236 .- 1532-6535. ; 106:1, s. 245-253
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Tidskriftsartikel (refereegranskat)abstract
- Some patients prescribed flucloxacillin (similar to 0.01%) develop drug-induced liver injury (DILI). HLA-B*57:01 is an established genetic risk factor for flucloxacillin DILI. To consolidate this finding, identify additional genetic factors, and assess relevance of risk factors for flucloxacillin DILI in relation to DILI due to other penicillins, we performed a genomewide association study involving 197 flucloxacillin DILI cases and 6,835 controls. We imputed single-nucleotide polymorphism and human leukocyte antigen (HLA) genotypes. HLA-B*57:01 was the major risk factor (allelic odds ratio (OR) = 36.62; P = 2.67 x 10(-97)). HLA-B*57:03 also showed an association (OR = 79.21; P = 1.2 x 10(-6)). Within the HLA-B protein sequence, imputation showed valine(97), common to HLA-B*57:01 and HLA-B*57:03, had the largest effect (OR = 38.1; P = 9.7 x 10(-97)). We found no HLA-B*57 association with DILI due to other isoxazolyl penicillins (n = 6) or amoxicillin (n = 15) and no significant non-HLA signals for any penicillin-related DILI.
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| 10. |
- Nicoletti, Paola, et al.
(författare)
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Genetic Risk Factors in Drug-Induced Liver Injury Due to Isoniazid-Containing Antituberculosis Drug Regimens
- 2021
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Ingår i: Clinical Pharmacology and Therapeutics. - : John Wiley & Sons. - 0009-9236 .- 1532-6535. ; 109:4, s. 1125-1135
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Tidskriftsartikel (refereegranskat)abstract
- Drug-induced liver injury (DILI) is a complication of treatment with antituberculosis (TB) drugs, especially in isoniazid (INH)-containing regimens. To investigate genetic risk factors, we performed a genomewide association study (GWAS) involving anti-TB DILI cases (55 Indian and 70 European) and controls (1,199 Indian and 10,397 European). Most cases were treated with a standard anti-TB drug regimen; all received INH. We imputed single nucleotide polymorphism and HLA genotypes and performed trans-ethnic meta-analysis on GWAS and candidate gene genotypes. GWAS found one significant association (rs117491755) in Europeans only. For HLA, HLA-B*52:01 was significant (meta-analysis odds ratio (OR) 2.67, 95% confidence interval (CI) 1.63-4.37, P = 9.4 × 10-5 ). For N-acetyltransferase 2 (NAT2), NAT2*5 frequency was lower in cases (OR 0.69, 95% CI 0.57-0.83, P = 0.01). NAT2*6 and NAT2*7 were more common, with homozygotes for NAT2*6 and/or NAT2*7 enriched among cases (OR 1.89, 95% CI 0.84-4.22, P = 0.004). We conclude HLA genotype makes a small contribution to TB drug-related DILI and that the NAT2 contribution is complex, but consistent with previous reports when differences in the metabolic effect of NAT2*5 compared with those of NAT2*6 and NAT2*7 are considered.
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