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Eniayewu O, Akinloye A, Shenkoya B, Azuka U, Bolaji O, Adejuyigbe E, Owen A, Olagunju A. Prenatal efavirenz exposure is independently associated with maternal, but not fetal CYP2B6 genotype. Pharmacogenet Genomics 2024; 34:253-260. [PMID: 38934229 PMCID: PMC7616417 DOI: 10.1097/fpc.0000000000000542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
OBJECTIVES Understanding the influence of fetal and maternal genetics on prenatal drug exposure could potentially improve benefit-risk evaluation. In this study, we investigated the impact of two functional polymorphisms in CYP2B6 on prenatal exposure to efavirenz. METHODS Dried blood spot (DBS) samples were collected from HIV-positive pregnant women ( n = 112) and their newborns ( n = 107) at delivery. They were genotyped for single nucleotide polymorphisms in CYP2B6. Efavirenz was quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS Significant correlations were observed in efavirenz concentration between maternal and newborn ( r = 0.46, R2 = 0.21, P < 0.001), and maternal and cord ( r = 0.83, R2 = 0.68, P < 0.001) samples. Median (interquartile range) newborn plasma-to-maternal plasma and cord-to-maternal plasma ratios were 0.85 (0.03-3.49) and 0.78 (0.23-1.96), respectively. Newborn efavirenz concentration in DBS varied significantly based on composite maternal CYP2B6 genotype: fast ( CYP2B6 516GG and 983TT, n = 26), 747 ng/ml (602-1060); intermediate ( CYP2B6 516GT or 983TC n = 50), 1177 ng/ml (898-1765); and slow ( CYP2B6 516GT and 983TC or 516TT or 983CC, n = 14), 3094 ng/ml (2126-3812). Composite newborn CYP2B6 genotype was, however, not significantly associated with prenatal exposure. Efavirenz concentration in newborn stratified as fast ( n = 25), intermediate ( n = 36), and slow metabolizers ( n = 19) from prenatal exposure was 999.7 (774-1285), 1240 (709-1984), and 1792 ng/ml (1201-3188), respectively. CONCLUSION The clinical relevance of the observed influence of maternal genetics on prenatal efavirenz exposure requires further investigation.
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Affiliation(s)
- Oluwasegun Eniayewu
- Department of Pharmaceutical Chemistry, Obafemi Awolowo University, Ile-Ife
- Department of Pharmaceutical and Medicinal Chemistry, University of Ilorin, Ilorin
| | | | - Babajide Shenkoya
- Department of Pharmaceutical Chemistry, Obafemi Awolowo University, Ile-Ife
| | - Uche Azuka
- Department of Obstetrics and Gynaecology, Federal Medical Centre, Makurdi
| | - Oluseye Bolaji
- Department of Pharmaceutical Chemistry, Obafemi Awolowo University, Ile-Ife
| | - Ebunoluwa Adejuyigbe
- Department of Paediatrics and Child Health, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Andrew Owen
- Department of Pharmacology and Therapeutics, University of Liverpool, Liverpool, UK
| | - Adeniyi Olagunju
- Department of Pharmacology and Therapeutics, University of Liverpool, Liverpool, UK
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Yamoune S, Müller JP, Langmia IM, Scholl C, Stingl JC. Uncoupling of Cytochrome P450 2B6 and stimulation of reactive oxygen species production in pharmacogenomic alleles affected by interethnic variability. Biochim Biophys Acta Gen Subj 2024; 1868:130595. [PMID: 38467309 DOI: 10.1016/j.bbagen.2024.130595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/29/2024] [Accepted: 03/04/2024] [Indexed: 03/13/2024]
Abstract
Cytochrome P450 mediated substrate metabolism is generally characterized by the formation of reactive intermediates. In vitro and in vivo reaction uncoupling, results in the accumulation and dissociation of reactive intermediates, leading to increased ROS formation. The susceptibility towards uncoupling and altered metabolic activity is partly modulated by pharmacogenomic alleles resulting in amino acid substitutions. A large variability in the prevalence of these alleles has been demonstrated in CYP2B6, with some being predominantly unique to African populations. The aim of this study is to characterize the uncoupling potential of recombinant CYP2B6*1, CYP2B6*6 and CYP2B6*34 metabolism of specific substrates. Therefore, functional effects of these alterations on enzyme activity were determined by quantification of bupropion, efavirenz and ketamine biotransformation using HPLC-MS/MS. Determination of H2O2 levels was performed by the AmplexRed/horseradish peroxidase assay. Our studies of the amino acid substitutions Q172H, K262R and R487S revealed an exclusive use of the peroxide shunt for the metabolism of bupropion and ketamine by CYP2B6*K262R. Ketamine was also identified as a trigger for the peroxide shunt in CYP2B6*1 and all variants. Concurrently, ketamine acted as an uncoupler for all enzymes. We further showed that the expressed CYP2B6*34 allele results in the highest H2O2 formation. We therefore conclude that the reaction uncoupling and peroxide shunt are directly linked and can be substrate specifically induced with K262R carriers being most likely to use the peroxide shunt and R487S carrier being most prone to reaction uncoupling. This elucidates the functional diversity of pharmacogenomics in drug metabolism and safety.
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Affiliation(s)
- Sabrina Yamoune
- Institute of Clinical Pharmacology, University Hospital of RWTH Aachen, Germany; Research Division, Federal Institute for Drugs and Medical Devices (BfArM), Bonn, Germany.
| | - Julian Peter Müller
- Institute of Clinical Pharmacology, University Hospital of RWTH Aachen, Germany
| | | | - Catharina Scholl
- Research Division, Federal Institute for Drugs and Medical Devices (BfArM), Bonn, Germany
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Nthontho KC, Ndlovu AK, Sharma K, Kasvosve I, Hertz DL, Paganotti GM. Pharmacogenetics of Breast Cancer Treatments: A Sub-Saharan Africa Perspective. Pharmgenomics Pers Med 2022; 15:613-652. [PMID: 35761855 PMCID: PMC9233488 DOI: 10.2147/pgpm.s308531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/31/2022] [Indexed: 11/30/2022] Open
Abstract
Breast cancer is the most frequent cause of cancer death in low- and middle-income countries, in particular among sub-Saharan African women, where response to available anticancer treatment therapy is often limited by the recurrent breast tumours and metastasis, ultimately resulting in decreased overall survival rate. This can also be attributed to African genomes that contain more variation than those from other parts of the world. The purpose of this review is to summarize published evidence on pharmacogenetic and pharmacokinetic aspects related to specific available treatments and the known genetic variabilities associated with metabolism and/or transport of breast cancer drugs, and treatment outcomes when possible. The emphasis is on the African genetic variation and focuses on the genes with the highest strength of evidence, with a close look on CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4/5, CYP19A1, UGT1A4, UGT2B7, UGT2B15, SLC22A16, SLC38A7, FcγR, DPYD, ABCB1, and SULT1A1, which are the genes known to play major roles in the metabolism and/or elimination of the respective anti-breast cancer drugs given to the patients. The genetic variability of their metabolism could be associated with different metabolic phenotypes that may cause reduced patients' adherence because of toxicity or sub-therapeutic doses. Finally, this knowledge enhances possible personalized treatment approaches, with the possibility of improving survival outcomes in patients with breast cancer.
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Affiliation(s)
- Keneuoe Cecilia Nthontho
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
- Botswana-University of Pennsylvania Partnership, Gaborone, Botswana
| | - Andrew Khulekani Ndlovu
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
| | | | - Ishmael Kasvosve
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
| | - Daniel Louis Hertz
- Department of Clinical Pharmacy, University of Michigan College of Pharmacy, Ann Arbor, MI, USA
| | - Giacomo Maria Paganotti
- Botswana-University of Pennsylvania Partnership, Gaborone, Botswana
- Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, Gaborone, Botswana
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4
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Maseng MJ, Tawe L, Thami PK, Moyo S, Kasvosve I, Novitsky V, Essex M, Russo G, Gaseitsiwe S, Paganotti GM. The role of CYP2B6 516G>T polymorphism on efavirenz/nevirapine toxicity. Implications on treatment outcomes: Lessons from Botswana. Medicine (Baltimore) 2022; 101:e29066. [PMID: 35512066 PMCID: PMC9276322 DOI: 10.1097/md.0000000000029066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/25/2022] [Indexed: 01/04/2023] Open
Abstract
The two non-nucleoside reverse transcriptase inhibitors (NNRTIs), efavirenz (EFV) and nevirapine (NVP), are currently the core antiretroviral drugs for treatment of HIV in sub-Saharan Africa including Botswana. The drugs are metabolized by Cytochrome P450 2B6 (CYP2B6) liver enzyme. The CYP2B6 gene that encodes for metabolism of these drugs is known to be highly polymorphic. One of the polymorphism in the CYP2B6 gene, 516G>T, particularly the 516T allele, is known to confer poor metabolism of EFV and NVP. This may lead to high levels of plasma drug concentrations and development of treatment toxicities, like central nervous system toxicities, and cutaneous and hepatic toxicities, for EFV and NVP, respectively. The CYP2B6 516G allele on the other hand is associated with an extensive metabolism of the two NNRTIs drugs. We sought to establish association between possible developments of NNRTIs toxicities with CYP2B6 516G>T variation in Botswana.A total of 316 peripheral blood mononuclear cells samples were used in a retrospective view. All the samples were from participants on EFV/NVP-containing regimen with known toxicity output. TaqMan Real-Time PCR approach was applied for assessing CYP2B6 516 allele variation in cases with treatment toxicity and those without. Analysis was performed by chi-square statistics and logistic regression analysis.The rate of poor metabolizers among participants with toxicity and those without toxicity was 18.4% and 15.1%, respectively. The CYP2B6 516 genotype distribution comparisons between the participants with toxicity and those without were not statistically different (chi-square = .326; P = .568).CYP2B6 516 variation was not associated with NNRTI toxicity. No other factors were associated with toxicity when considering age, baseline body mass index, baseline CD4, baseline HIV viral load and adherence. The results were discussed in the context of all the studies done in Botswana to date.
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Affiliation(s)
- Monkgomotsi J. Maseng
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, UB Campus, Block 246, Gaborone, Botswana
- Botswana-Harvard AIDS Institute Partnership, Plot 1836 North Ring Road, Gaborone, Botswana
| | - Leabaneng Tawe
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, UB Campus, Block 246, Gaborone, Botswana
- Botswana-Harvard AIDS Institute Partnership, Plot 1836 North Ring Road, Gaborone, Botswana
- Botswana-University of Pennsylvania Partnership, UB Campus, Block 244G, Gaborone, Botswana
| | - Prisca K. Thami
- Botswana-Harvard AIDS Institute Partnership, Plot 1836 North Ring Road, Gaborone, Botswana
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Anzio Road Observatory, Cape Town, South Africa
| | - Sikhulile Moyo
- Botswana-Harvard AIDS Institute Partnership, Plot 1836 North Ring Road, Gaborone, Botswana
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, 677 Hungtinton Avenue, Boston, MA
| | - Ishmael Kasvosve
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, UB Campus, Block 246, Gaborone, Botswana
| | - Vladimir Novitsky
- Botswana-Harvard AIDS Institute Partnership, Plot 1836 North Ring Road, Gaborone, Botswana
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, 677 Hungtinton Avenue, Boston, MA
| | - Max Essex
- Botswana-Harvard AIDS Institute Partnership, Plot 1836 North Ring Road, Gaborone, Botswana
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, 677 Hungtinton Avenue, Boston, MA
| | - Gianluca Russo
- Department of Public Health and Infectious Disease, Faculty of Medicine, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome, Italy
| | - Simani Gaseitsiwe
- Botswana-Harvard AIDS Institute Partnership, Plot 1836 North Ring Road, Gaborone, Botswana
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, 677 Hungtinton Avenue, Boston, MA
| | - Giacomo M. Paganotti
- Botswana-University of Pennsylvania Partnership, UB Campus, Block 244G, Gaborone, Botswana
- Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, 3120-2740 Hamilton Walk, Philadelphia, PA
- Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, UB Campus, Block 246, Gaborone, Botswana
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Maseng MJ, Tawe L, Thami PK, Seatla KK, Moyo S, Martinelli A, Kasvosve I, Novitsky V, Essex M, Russo G, Gaseitsiwe S, Paganotti GM. Association of CYP2B6 Genetic Variation with Efavirenz and Nevirapine Drug Resistance in HIV-1 Patients from Botswana. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2021; 14:335-347. [PMID: 33758532 PMCID: PMC7981136 DOI: 10.2147/pgpm.s289471] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/22/2021] [Indexed: 12/11/2022]
Abstract
Purpose CYP2B6 liver enzyme metabolizes the two non-nucleoside reverse transcriptase inhibitors Efavirenz (EFV) and Nevirapine (NVP) used in the antiretroviral therapy (ART) regimens for HIV-infected individuals. Polymorphisms of the CYP2B6 gene influence drug levels in plasma and possibly virological outcomes. The aim of this study was to explore the potential impact of CYP2B6 genotype and haplotype variation on the risk of developing EFV/NVP drug resistance mutations (DRMs) in HIV-1 patients receiving EFV-/NVP-containing regimens in Botswana. Patients and Methods Participants were a sub-sample of a larger study (Tshepo study) conducted in Gaborone, Botswana, among HIV-infected individuals taking EFV/NVP containing ART. Study samples were retrieved and assigned to cases (with DRMs) and controls (without DRMs). Four single-nucleotide polymorphisms (SNPs) in the CYP2B6 gene (−82T>C; 516G>T; 785A>G; 983T>C) were genotyped, the haplotypes reconstructed, and the metabolic score assigned. The possible association between drug resistance and several independent factors (baseline characteristics and CYP2B6 genotypes) was assessed by Binary Logistic Regression (BLR) analysis. EFV/NVP resistance status and CYP2B6 haplotypes were also analyzed using Z-test, chi-square and Fisher’s exact test statistics. Results Two hundred and twenty-seven samples were analysed (40 with DRMs, 187 without DRMs). BLR analysis showed an association between EFV/NVP resistance and CYP2B6 516G allele (OR: 2.26; 95% CI: 1.27–4.01; P=0.005). Moreover, haplotype analysis revealed that the proportion of EFV/NVP-resistant infections was higher among CYP2B6 fast than extensive/slow metabolizers (30.8% vs 16.8%; P=0.035), with the 516G allele more represented in the haplotypes of fast than extensive/slow metabolizers (100.0% vs 53.8%; P<0.001). Conclusion We demonstrated that the CYP2B6 516G allele, and even more when combined in fast metabolic haplotypes, is associated with the presence of EFV/NVP resistance, strengthening the need to assess the CYP2B6 genetic profiles in HIV-infected patients in order to improve the virologic outcomes of NNRTI containing ART.
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Affiliation(s)
- Monkgomotsi J Maseng
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana.,Botswana-Harvard AIDS Institute Partnership, Gaborone, Botswana
| | - Leabaneng Tawe
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana.,Botswana-Harvard AIDS Institute Partnership, Gaborone, Botswana.,Botswana-University of Pennsylvania Partnership, Gaborone, Botswana
| | - Prisca K Thami
- Botswana-Harvard AIDS Institute Partnership, Gaborone, Botswana.,Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Kaelo K Seatla
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana.,Botswana-Harvard AIDS Institute Partnership, Gaborone, Botswana
| | - Sikhulile Moyo
- Botswana-Harvard AIDS Institute Partnership, Gaborone, Botswana.,Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, USA
| | | | - Ishmael Kasvosve
- School of Allied Health Professions, Faculty of Health Sciences, University of Botswana, Gaborone, Botswana
| | - Vladimir Novitsky
- Botswana-Harvard AIDS Institute Partnership, Gaborone, Botswana.,Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, USA
| | - Max Essex
- Botswana-Harvard AIDS Institute Partnership, Gaborone, Botswana.,Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, USA
| | - Gianluca Russo
- Department of Public Health and Infectious Disease, Faculty of Medicine, Sapienza University of Rome, Rome, Italy
| | - Simani Gaseitsiwe
- Botswana-Harvard AIDS Institute Partnership, Gaborone, Botswana.,Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, USA
| | - Giacomo M Paganotti
- Botswana-University of Pennsylvania Partnership, Gaborone, Botswana.,Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, Gaborone, Botswana
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Xu L, Peng W, Song X, Li Y, Han Y, Zhu T, Fu Q, Du X, Cao W, Li T. Pharmacodynamics of efavirenz 400 mg in treatment-naïve Chinese HIV-infected patients in a prospective cohort study. BMC Infect Dis 2021; 21:112. [PMID: 33485301 PMCID: PMC7824943 DOI: 10.1186/s12879-021-05802-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 01/14/2021] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The plasma concentration of patients treated with efavirenz (EFV) 600 mg was found to exceed the upper limit of the proposed therapeutic window in most Chinese HIV-infected individuals; thus, dosage reduction of EFV to 400 mg daily warranted consideration. This study aimed to assess the pharmacodynamics of EFV 400 mg for HIV-1-infected patients in China. METHOD Twenty cART-naïve individuals were enrolled in this study. EFV 400 mg combined with tenofovir (TDF) and lamivudine (3TC) as an initial antiretroviral regimen was administered for 48 weeks. EFV concentration and T cell subsets as well as HIV RNA load were evaluated at baseline and at 4, 12, 24, and 48 weeks. Moreover, neuropsychiatric adverse effects were also assessed by the Hamilton depression (HAMD) scale and Pittsburgh sleep quality index (PSQI). RESULTS Eighteen males and two females whose median age was 26 (interquartile range [IQR]: 23-32) years completed 48 weeks of follow-up. The median EFV concentrations were 1.88 (IQR: 1.54-2.42), 1.74 (IQR: 1.36-1.93), 1.93 (IQR: 1.66-2.22), and 1.85 (IQR: 1.54-2.14) mg/L at weeks 4, 12, 24, and 48, respectively. The viral load was 4.59 (IQR: 4.10-5.19) log10 copies/mL at baseline, and it decreased by 4.6 (IQR: 3.98-5.18) log10 copies/mL from baseline to week 48. Three of 20 (15%), 10 of 20 (50.0%), 17 of 20 (85%), and 18 of 19 (95%) participants had a plasma viral load less than 50 copies/mL at weeks 4, 12, 24, and 48, respectively. The median CD4 cell count was 330 (IQR: 237-410) cells/μL at baseline, and it increased to 473 (IQR: 344-574) cells/μL at 48 weeks. The HAMD score was 5 (IQR: 3-9.8) and 3 (IQR: 2.25-4) at baseline and 48 weeks, respectively. The PSQI score was 4 (IQR: 2-5.8) and 3 (IQR: 2-4) at baseline and 48 weeks, respectively. Dizziness was the most common event, occurring in 70% of patients within the first 2 weeks of treatment. CONCLUSION Patients prescribed with EFV 400 mg-containing agents demonstrated favourable virological and immunological responses. And the plasma EFV concentration was within the recommended therapeutic range, with fewer adverse reactions than with EFV 600 mg. EFV 400 mg was effective and safe in Chinese HIV-infected patients. TRIAL REGISTRATION NCT04596488 ; Registered 21 October, 2020; Retrospectively registered.
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Affiliation(s)
- Ling Xu
- Department of Infectious Diseases, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Wenxiu Peng
- Department of Pharmacy and Pharmacology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaojing Song
- Department of Infectious Diseases, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Yanling Li
- Department of Infectious Diseases, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Yang Han
- Department of Infectious Diseases, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Ting Zhu
- Department of Infectious Diseases, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Qiang Fu
- Department of Pharmacy and Pharmacology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaoli Du
- Department of Pharmacy and Pharmacology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Wei Cao
- Department of Infectious Diseases, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Taisheng Li
- Department of Infectious Diseases, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China. .,Clinical Immunology Center, Chinese Academy of Medical Sciences, Beijing, China. .,Tsinghua University Medical College, Beijing, China.
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Carvalho Henriques B, Yang EH, Lapetina D, Carr MS, Yavorskyy V, Hague J, Aitchison KJ. How Can Drug Metabolism and Transporter Genetics Inform Psychotropic Prescribing? Front Genet 2020; 11:491895. [PMID: 33363564 PMCID: PMC7753050 DOI: 10.3389/fgene.2020.491895] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 09/25/2020] [Indexed: 12/11/2022] Open
Abstract
Many genetic variants in drug metabolizing enzymes and transporters have been shown to be relevant for treating psychiatric disorders. Associations are strong enough to feature on drug labels and for prescribing guidelines based on such data. A range of commercial tests are available; however, there is variability in included genetic variants, methodology, and interpretation. We herein provide relevant background for understanding clinical associations with specific variants, other factors that are relevant to consider when interpreting such data (such as age, gender, drug-drug interactions), and summarize the data relevant to clinical utility of pharmacogenetic testing in psychiatry and the available prescribing guidelines. We also highlight areas for future research focus in this field.
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Affiliation(s)
| | - Esther H. Yang
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Diego Lapetina
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Michael S. Carr
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Vasyl Yavorskyy
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Joshua Hague
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Katherine J. Aitchison
- Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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8
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Decloedt EH, Sinxadi PZ, van Zyl GU, Wiesner L, Khoo S, Joska JA, Haas DW, Maartens G. Pharmacogenetics and pharmacokinetics of CNS penetration of efavirenz and its metabolites. J Antimicrob Chemother 2020; 74:699-709. [PMID: 30535366 DOI: 10.1093/jac/dky481] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 10/11/2018] [Accepted: 10/24/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND There are limited data on the pharmacogenetics and pharmacokinetics of the CNS penetration of efavirenz. OBJECTIVES We investigated genetic polymorphisms associated with CSF concentrations of efavirenz and its metabolites and explored the relationships with neurocognitive performance. METHODS We included 47 HIV-infected South African black adults with and without HIV-associated neurocognitive disorder on efavirenz/tenofovir/emtricitabine and collected paired plasma-CSF samples. We considered 2049 SNPs, including SNPs known to affect plasma efavirenz exposure, from potentially relevant genes (ABCC5, ABCG2, ABCB1, SLCO2B1, SCLO1A2, ABCC4, CYP2B6 and CYP2A6) and 880 met a linkage disequilibrium (LD)-pruning threshold. RESULTS We identified 9 slow, 21 intermediate and 17 extensive metabolizers. The CYP2B6 983 genotype in multivariate analyses predicted log10-transformed concentrations of plasma efavirenz (β = 0.38, P = 2.7 × 10-03), plasma 7-hydroxy-efavirenz (β = 0.59, P = 3.7 × 10-03), plasma 8-hydroxy-efavirenz:efavirenz ratio (β = -0.31, P = 1.8 × 10-04) and CSF efavirenz (β = 0.36, P = 0.01). Lower plasma 7-hydroxy-efavirenz concentrations were independently associated with CYP2A6 rs10853742 (β = -0.55, P = 3.5 × 10-05), ABCB1 rs115780656 (β = -0.65, P = 4.1 × 10-05) and CYP2A6 -48A→C (β = -0.59, P = 0.01). CYP2A6 -48A→C was independently associated with higher CSF 8-hydroxy-efavirenz:efavirenz ratio (β = 0.54, P = 0.048). CYP2B6 rs2279345 polymorphism was associated with lower plasma 7-hydroxy-efavirenz:efavirenz ratio in multivariate analyses (P < 0.05). No polymorphisms were associated with CSF:plasma ratios of efavirenz, plasma or CSF concentrations of 8-hydroxy-efavirenz or neurocognitive performance. CONCLUSIONS We identified novel genetic associations with plasma efavirenz, plasma 7-hydroxy-efavirenz, plasma 7-hydroxy-efavirenz:efavirenz ratio, plasma 8-hydroxy-efavirenz:efavirenz ratio, CSF efavirenz and CSF 8-hydroxy-efavirenz:efavirenz ratio.
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Affiliation(s)
- Eric H Decloedt
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.,Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Phumla Z Sinxadi
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Gert U van Zyl
- Division of Medical Virology, Faculty of Medicine and Health Sciences, Stellenbosch University and National Health Laboratory Service, Cape Town, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Saye Khoo
- Institute of Translational Medicine, University of Liverpool and Royal Liverpool University Hospital, Liverpool, UK
| | - John A Joska
- Division of Neuropsychiatry, Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - David W Haas
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA.,Department of Internal Medicine, Meharry Medical College, Nashville, TN, USA
| | - Gary Maartens
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
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Differential Impact of Nevirapine on Artemether-Lumefantrine Pharmacokinetics in Individuals Stratified by CYP2B6 c.516G>T Genotypes. Antimicrob Agents Chemother 2020; 64:AAC.00947-19. [PMID: 31871092 PMCID: PMC7038275 DOI: 10.1128/aac.00947-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 12/02/2019] [Indexed: 01/11/2023] Open
Abstract
There is an increased recognition of the need to identify and quantify the impact of genetic polymorphisms on drug-drug interactions. This study investigated the pharmacogenetics of the pharmacokinetic drug-drug interaction between nevirapine and artemether-lumefantrine in HIV-positive and HIV-negative adult Nigerian subjects. There is an increased recognition of the need to identify and quantify the impact of genetic polymorphisms on drug-drug interactions. This study investigated the pharmacogenetics of the pharmacokinetic drug-drug interaction between nevirapine and artemether-lumefantrine in HIV-positive and HIV-negative adult Nigerian subjects. Thirty each of HIV-infected patients on nevirapine-based antiretroviral therapy and HIV-negative volunteers without clinical malaria, but with predetermined CYP2B6 c.516GG and TT genotypes, were administered a complete treatment dose of 3 days of artemether-lumefantrine. Rich pharmacokinetic sampling prior to and following the last dose was conducted, and the plasma concentrations of artemether/dihydroartemisinin and lumefantrine/desbutyl-lumefantrine were quantified using tandem mass spectrometry. Pharmacokinetic parameters of artemether-lumefantrine and its metabolites in HIV-infected patients on nevirapine were compared to those in the absence of nevirapine in HIV-negative volunteers. Overall, nevirapine reduced exposure to artemether and desbutyl-lumefantrine by 39 and 34%, respectively. These reductions were significantly greater in GG versus TT subjects for artemether (ratio of geometric mean [90% confidence interval]: 0.42 [0.29 to 0.61] versus 0.81 [0.51 to 1.28]) and for desbutyl-lumefantrine (0.56 [0.43 to 0.74] versus 0.75 [0.56 to 1.00]). On the contrary, it increased exposure to dihydroartemisinin and lumefantrine by 47 and 30%, respectively. These increases were significantly higher in TT versus GG subjects for dihydroartemisinin (1.67 [1.20 to 2.34] versus 1.25 [0.88 to 1.78]) and for lumefantrine (1.51 [1.20 to 1.90] versus 1.08 [0.82 to 1.42]). This study underscores the importance of incorporating pharmacogenetics into all drug-drug interaction studies with potential for genetic polymorphisms to influence drug disposition.
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10
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Seden K, Kiiza D, Laker E, Arinaitwe WJ, Waitt C, Lamorde M, Khoo S. High prevalence and long duration of nervous system and psychiatric adverse drug reactions in Ugandan patients taking efavirenz 600 mg daily. J Antimicrob Chemother 2019; 73:3158-3161. [PMID: 30085168 PMCID: PMC6198741 DOI: 10.1093/jac/dky298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/26/2018] [Indexed: 12/01/2022] Open
Abstract
Background Efavirenz-related nervous system or psychiatric adverse drug reactions (ADRs) are conventionally reported to resolve soon after initiation, with incidence of dizziness at 8.5% in large clinical trials. Patients of black ethnicity are genetically at greater risk of elevated efavirenz exposure, which has been linked to nervous system toxicity. Patients and methods The current data derive from a prospective longitudinal observational study of adult HIV-positive outpatients taking current antiretrovirals, at three diverse clinics in central Uganda. As part of an interview about medicine use, patients were asked by trained pharmacy technicians to detail current side effects and to rate their severity on a simple visual analogue scale (1–10). Details of the reported ADRs were verified by case note review. Severity and causality of ADRs were rated by the study team using validated tools. Results A total of 300 patients taking efavirenz were analysed. Of these, 108 (36%, 95% CI 30.6%–41.7%) were affected by persisting nervous system/psychiatric ADRs (median duration 22 months). Dizziness affected 27.3% (95% CI 22.4%–32.8%) of patients taking efavirenz. Severity of the ADRs was rated by patients at ≥5/10 in 76 (58.5%) cases. In 95 (86%) cases, there was no record of the ADRs in the clinical notes. Conclusions Strategies are needed to identify and prioritize patients urgently with persisting efavirenz neurotoxicity for a switch to newer regimens as they become available.
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Affiliation(s)
- Kay Seden
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.,Infectious Diseases Institute, Makerere University, Kampala, Uganda
| | - Daniel Kiiza
- Infectious Diseases Institute, Makerere University, Kampala, Uganda
| | - Eva Laker
- Infectious Diseases Institute, Makerere University, Kampala, Uganda
| | - Walter J Arinaitwe
- Advanced Treatment Information Centre (ATIC), Infectious Diseases Institute, Makerere University, Kampala, Uganda
| | - Catriona Waitt
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.,Infectious Diseases Institute, Makerere University, Kampala, Uganda.,Royal Liverpool University Hospital, Liverpool, UK
| | - Mohammed Lamorde
- Infectious Diseases Institute, Makerere University, Kampala, Uganda
| | - Saye Khoo
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.,Royal Liverpool University Hospital, Liverpool, UK
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11
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Chang JL, Lee SA, Tsai AC, Musinguzi N, Muzoora C, Bwana B, Boum Y, Haberer JE, Hunt PW, Martin J, Bangsberg DR, Kroetz DL, Siedner MJ. CYP2B6 Genetic Polymorphisms, Depression, and Viral Suppression in Adults Living with HIV Initiating Efavirenz-Containing Antiretroviral Therapy Regimens in Uganda: Pooled Analysis of Two Prospective Studies. AIDS Res Hum Retroviruses 2018; 34:982-992. [PMID: 29973058 DOI: 10.1089/aid.2018.0062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Single-nucleotide polymorphisms (SNPs) in CYP2B6 have been shown to predict variation in plasma efavirenz concentrations, but associations between these SNPs and efavirenz-mediated depression and viral suppression are less well described. We evaluated three SNPs in CYP2B6 (rs3745274, rs28399499, and rs4803419) in Ugandan persons living with HIV. To define exposure, we used previously published pharmacokinetic modeling data to categorize participants as normal, intermediate, and poor efavirenz metabolizers. Our outcomes were probable depression in the first 2 years after antiretroviral therapy (ART) initiation (mean score of >1.75 on the Hopkins Symptom Depression Checklist) and viral suppression 6 months after ART initiation. We fit generalized estimating equation and modified Poisson regression models adjusted for demographic, clinical, and psychosocial characteristics with or without individuals with depression at the time of ART initiation. Among 242 participants, there were no differences in the pre-ART depression or viral load by efavirenz metabolism strata (p > .05). Participants were classified as normal (32%), intermediate (50%), and poor (18%) metabolizers. Seven percent (56/242) of follow-up visits met criteria for depression. Eighty-five percent (167/202) of participants who completed a 6-month visit achieved viral suppression. CYP2B6 metabolizer strata did not have a statistically significant association with either depression [adjusted risk ratio (aRR) comparing intermediate or poor vs. normal, 1.46; 95% confidence interval (CI), 0.72-2.95] or 6-month viral suppression (aRR, 1.01; 95% CI, 0.88-1.15). However, in analyses restricted to participants without pre-ART depression, poorer CYP2B6 metabolism was associated with increased odds of depression (adjusted odds ratio, 4.11; 95% CI, 1.04-16.20). Efavirenz-metabolizing allele patterns are strongly associated with risk of incident depression. Future work should elucidate further region-specific gene-environment interactions and whether alternate polymorphisms may be associated with efavirenz metabolism.
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Affiliation(s)
- Jonathan L. Chang
- Duke University School of Medicine, Durham, North Carolina
- Center for Global Health, Massachusetts General Hospital, Boston, Massachusetts
| | - Sulggi A. Lee
- Department of Medicine, University of California, San Francisco, California
| | - Alexander C. Tsai
- Center for Global Health, Massachusetts General Hospital, Boston, Massachusetts
- Chester M. Pierce, MD Division of Global Psychiatry, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
- Mbarara University of Science and Technology, Mbarara, Uganda
| | | | - Conrad Muzoora
- Mbarara University of Science and Technology, Mbarara, Uganda
| | - Bosco Bwana
- Mbarara University of Science and Technology, Mbarara, Uganda
| | - Yap Boum
- Epicentre Mbarara, Mbarara, Uganda
| | - Jessica E. Haberer
- Center for Global Health, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
- Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Peter W. Hunt
- Department of Medicine, University of California, San Francisco, California
| | - Jeff Martin
- Department of Medicine, University of California, San Francisco, California
| | - David R. Bangsberg
- Mbarara University of Science and Technology, Mbarara, Uganda
- School of Public Health, Oregon Health & Science University, Portland, Oregon
| | - Deanna L. Kroetz
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California
| | - Mark J. Siedner
- Center for Global Health, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
- Mbarara University of Science and Technology, Mbarara, Uganda
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts
- Africa Health Research Institute, Durban, South Africa
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12
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13
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Kimulwo MJ, Okendo J, Aman RA, Ogutu BR, Kokwaro GO, Ochieng DJ, Muigai AWT, Oloo FA, Ochieng W. Plasma nevirapine concentrations predict virological and adherence failure in Kenyan HIV-1 infected patients with extensive antiretroviral treatment exposure. PLoS One 2017; 12:e0172960. [PMID: 28235021 PMCID: PMC5325546 DOI: 10.1371/journal.pone.0172960] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 02/13/2017] [Indexed: 11/19/2022] Open
Abstract
Treatment failure is a key challenge in the management of HIV-1 infection. We conducted a mixed-model survey of plasma nevirapine (NVP) concentrations (cNVP) and viral load in order to examine associations with treatment and adherence outcomes among Kenyan patients on prolonged antiretroviral therapy (ART). Blood plasma was collected at 1, 4 and 24 hours post-ART dosing from 58 subjects receiving NVP-containing ART and used to determine cNVP and viral load (VL). Median duration of treatment was 42 (range, 12–156) months, and 25 (43.1%) of the patients had virologic failure (VF). cNVP was significantly lower for VF than non- VF at 1hr (mean, 2,111ng/ml vs. 3,432ng/ml, p = 0.003) and at 4hr (mean 1,625ng/ml vs. 3,999ng/ml, p = 0.001) but not at 24hr post-ART dosing. Up to 53.4%, 24.1% and 22.4% of the subjects had good, fair and poor adherence respectively. cNVP levels peaked and were > = 3μg.ml at 4 hours in a majority of patients with good adherence and those without VF. Using a threshold of 3μg/ml for optimal therapeutic nevirapine level, 74% (43/58), 65.5% (38/58) and 86% (50/58) of all patients had sub-therapeutic cNVP at 1, 4 and 24 hours respectively. cNVP at 4 hours was associated with adherence (p = 0.05) and virologic VF (p = 0.002) in a chi-square test. These mean cNVP levels differed significantly in non-parametric tests between adherence categories at 1hr (p = 0.005) and 4hrs (p = 0.01) and between ART regimen categories at 1hr (p = 0.004) and 4hrs (p<0.0001). Moreover, cNVP levels correlated inversely with VL (p< = 0.006) and positively with adherence behavior. In multivariate tests, increased early peak NVP (cNVP4) was independently predictive of lower VL (p = 0.002), while delayed high NVP peak (cNVP24) was consistent with increased VL (p = 0.033). These data strongly assert the need to integrate plasma concentrations of NVP and that of other ART drugs into routine ART management of HIV-1 patients.
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Affiliation(s)
- Maureen J. Kimulwo
- Center for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya
- ITROMID, Jomo Kenyatta University of Science and Technology, Nairobi, Kenya
| | - Javan Okendo
- Center for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya
| | - Rashid A. Aman
- Center for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya
- Institute of Healthcare Management, Strathmore University, Nairobi, Kenya
- African Centre for Clinical Trials, Nairobi, Kenya
| | - Bernhards R. Ogutu
- Center for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya
- Institute of Healthcare Management, Strathmore University, Nairobi, Kenya
- Kenya Medical Research Institute, Nairobi, Kenya
| | - Gilbert O. Kokwaro
- Institute of Healthcare Management, Strathmore University, Nairobi, Kenya
| | - Dorothy J. Ochieng
- School of Pharmacy, MCPHS University, Worcester, Massachusetts, United States of America
| | - Anne W. T. Muigai
- ITROMID, Jomo Kenyatta University of Science and Technology, Nairobi, Kenya
| | - Florence A. Oloo
- Center for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya
- Department of Chemical Science and Technology, Technical University of Kenya, Nairobi, Kenya
| | - Washingtone Ochieng
- Center for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya
- Institute of Healthcare Management, Strathmore University, Nairobi, Kenya
- Kenya Medical Research Institute, Nairobi, Kenya
- Immunology and Infectious Diseases Department, Harvard School of Public Health, Boston, Massachusetts, United States of America
- * E-mail:
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14
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Swart M, Evans J, Skelton M, Castel S, Wiesner L, Smith PJ, Dandara C. An Expanded Analysis of Pharmacogenetics Determinants of Efavirenz Response that Includes 3'-UTR Single Nucleotide Polymorphisms among Black South African HIV/AIDS Patients. Front Genet 2016; 6:356. [PMID: 26779253 PMCID: PMC4703773 DOI: 10.3389/fgene.2015.00356] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/10/2015] [Indexed: 01/11/2023] Open
Abstract
Introduction: Efavirenz (EFV) is a non-nucleoside reverse transcriptase inhibitor prescribed as part of first-line highly active antiretroviral therapy (HAART) in South Africa. Despite administration of fixed doses of EFV, inter-individual variability in plasma concentrations has been reported. Poor treatment outcomes such as development of adverse drug reactions or treatment failure have been linked to EFV plasma concentrations outside the therapeutic range (1–4 μg/mL) in some studies. The drug metabolizing enzyme (DME), CYP2B6, is primarily responsible for EFV metabolism with minor contributions by CYP1A2, CYP2A6, CYP3A4, CYP3A5, and UGT2B7. DME coding genes are also regulated by microRNAs through targeting the 3′-untranslated region. Expanded analysis of 30 single nucleotide polymorphisms (SNPs), including those in the 3′-UTR, was performed to identify pharmacogenetics determinants of EFV plasma concentrations in addition to CYP2B6 c.516G>T and c.983T>C SNPs. Methods: SNPs in CYP1A2, CYP2B6, UGT2B7, and NR1I2 (PXR) were selected for genotyping among 222 Bantu-speaking South African HIV-infected patients receiving EFV-containing HAART. This study is a continuation of earlier pharmacogenetics studies emphasizing the role of genetic variation in the 3′-UTR of genes which products are either pharmacokinetic or pharmacodynamic targets of EFV. Results: Despite evaluating thirty SNPs, CYP2B6 c.516G>T and c.983T>C SNPs remain the most prominent predictors of EFV plasma concentration. Conclusion: We have shown that CYP2B6 c.516G>T and c.983T>C SNPs are the most important predictors of EFV plasma concentration after taking into account all other SNPs, including genetic variation in the 3′-UTR, and variables affecting EFV metabolism.
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Affiliation(s)
- Marelize Swart
- Division of Human Genetics, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town Cape Town, South Africa
| | - Jonathan Evans
- Division of Human Genetics, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town Cape Town, South Africa
| | - Michelle Skelton
- Division of Human Genetics, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town Cape Town, South Africa
| | - Sandra Castel
- Division of Clinical Pharmacology, Faculty of Health Sciences, University of Cape Town Cape Town, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Faculty of Health Sciences, University of Cape Town Cape Town, South Africa
| | - Peter J Smith
- Division of Clinical Pharmacology, Faculty of Health Sciences, University of Cape Town Cape Town, South Africa
| | - Collet Dandara
- Division of Human Genetics, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town Cape Town, South Africa
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15
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Russo G, Paganotti GM, Soeria-Atmadja S, Haverkamp M, Ramogola-Masire D, Vullo V, Gustafsson LL. Pharmacogenetics of non-nucleoside reverse transcriptase inhibitors (NNRTIs) in resource-limited settings: Influence on antiretroviral therapy response and concomitant anti-tubercular, antimalarial and contraceptive treatments. INFECTION GENETICS AND EVOLUTION 2015; 37:192-207. [PMID: 26602158 DOI: 10.1016/j.meegid.2015.11.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 01/11/2023]
Abstract
The burden of human immunodeficiency virus (HIV) is mainly concentrated to resources-limited countries where the response to available antiretroviral therapy is often limited by the occurrence of toxicity or by the emergence of HIV drug resistance. Efavirenz and nevirapine are the antiretroviral drugs most prescribed in resources-limited countries as part of antiretroviral combination therapy. Their metabolism and conjugation are largely influenced by enzymatic genetic polymorphisms. The genetic variability of their metabolism could be associated to different metabolic phenotypes causing reduced patients' adherence because of toxicity or drug-drug interactions with concomitant therapies. The purpose of this review is to summarize published evidence on pharmacogenetic and pharmacokinetic aspects related to efavirenz and nevirapine, the influence of concomitant anti-tubercular, anti-malarial or contraceptive treatments, and the impact of human genetic variation and drug-drug interaction on the virologic and immunologic response to antiretroviral therapy in resources-limited countries.
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Affiliation(s)
- Gianluca Russo
- Department of Public Health and Infectious Diseases, University "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy
| | - Giacomo Maria Paganotti
- Botswana-University of Pennsylvania Partnership, P.O. Box AC 157 ACH, Gaborone, Botswana; Medical Education Partnership Laboratory, c/o Faculty of Medicine, University of Botswana, Pvt Bag 00713, Gaborone, Botswana.
| | - Sandra Soeria-Atmadja
- Division of Pediatrics, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Karolinska University Hospital, B57, SE-141 86, Stockholm, Sweden
| | - Miriam Haverkamp
- Botswana-University of Pennsylvania Partnership, P.O. Box AC 157 ACH, Gaborone, Botswana
| | - Doreen Ramogola-Masire
- Botswana-University of Pennsylvania Partnership, P.O. Box AC 157 ACH, Gaborone, Botswana
| | - Vincenzo Vullo
- Department of Public Health and Infectious Diseases, University "La Sapienza", P.le Aldo Moro 5, 00185 Rome, Italy
| | - Lars Lennart Gustafsson
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, SE-141 86, Stockholm, Sweden
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16
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Sinxadi PZ, Leger PD, McIlleron HM, Smith PJ, Dave JA, Levitt NS, Maartens G, Haas DW. Pharmacogenetics of plasma efavirenz exposure in HIV-infected adults and children in South Africa. Br J Clin Pharmacol 2015; 80:146-56. [PMID: 25611810 DOI: 10.1111/bcp.12590] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 12/09/2014] [Accepted: 01/06/2015] [Indexed: 12/22/2022] Open
Abstract
AIMS Genetic factors, notably CYP2B6 516G→T [rs3745274] and 983T→C [rs28399499], explain much of the interindividual variability in efavirenz pharmacokinetics, but data from Africa are limited. We characterized relationships between genetic polymorphisms and plasma efavirenz concentrations in HIV-infected Black South African adults and children. METHODS Steady-state mid-dosing interval efavirenz concentrations were measured. We genotyped 241 polymorphisms in genes potentially relevant to efavirenz metabolism and transport, including ABCB1, CYP2A6, CYP2B6, CYP3A4, CYP3A5, NR1I2 and NR1I3. RESULTS Among 113 participants (59 adults and 54 children), minor allele frequencies for CYP2B6 516G→T, 983T→C, and 15582C→T [rs4803419] were 0.36, 0.07, and 0.09, respectively. Based on composite CYP2B6 15582/516/983 genotype, there were 33 extensive metabolizer, 62 intermediate metabolizer and 18 slow metabolizer genotypes. Median (IQR) mid-dose efavirenz concentrations were 1.44 (1.21-1.93) µg ml(-1), 2.08 (1.68-2.94) µg ml(-1) and 7.26 (4.82-8.34) µg ml(-1) for extensive, intermediate and slow metabolizers, respectively. In univariate analyses, a model that included composite genotype best predicted efavirenz concentrations (β = 0.28, 95% CI 0.21, 0.35, P = 2.4 × 10(-11)). Among individual CYP2B6 polymorphisms, 516G→T best predicted efavirenz concentrations (β = 0.22, 95% CI 0.13, 0.30, P = 1.27 × 10(-6)). There was also associations with 983T→C (β = 0.27, 95% CI 0.10, 0.44, P = 0.002) and 15582C→T (β = 0.11, 95% CI 0.01, 0.22, P = 0.04). Associations were consistent in adults and children. No other polymorphisms were independently associated with efavirenz concentrations. CONCLUSIONS Composite CYP2B6 genotype based on CYP2B6 516G→T, 983T→C, and 15582C→T best described efavirenz exposure in HIV-infected Black South African adults and children.
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Affiliation(s)
- Phumla Z Sinxadi
- Division of Clinical of Pharmacology, Division of Exercise and Endocrine Metabolism, University of Cape Town, Cape Town, South Africa
| | - Paul D Leger
- Vanderbilt University Medical Center, Department of Medicine, Nashville, Tennessee, United States of America
| | - Helen M McIlleron
- Division of Clinical of Pharmacology, Division of Exercise and Endocrine Metabolism, University of Cape Town, Cape Town, South Africa
| | - Peter J Smith
- Division of Clinical of Pharmacology, Division of Exercise and Endocrine Metabolism, University of Cape Town, Cape Town, South Africa
| | - Joel A Dave
- Division of Exercise and Endocrine Metabolism, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Naomi S Levitt
- Division of Exercise and Endocrine Metabolism, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Gary Maartens
- Division of Clinical of Pharmacology, Division of Exercise and Endocrine Metabolism, University of Cape Town, Cape Town, South Africa
| | - David W Haas
- Vanderbilt University School of Medicine, Department of Medicine, Nashville, Tennessee, United States of America
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Čolić A, Alessandrini M, Pepper MS. Pharmacogenetics of CYP2B6, CYP2A6 and UGT2B7 in HIV treatment in African populations: focus on efavirenz and nevirapine. Drug Metab Rev 2014; 47:111-23. [PMID: 25391641 DOI: 10.3109/03602532.2014.982864] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The CYP450 and UGT enzymes are involved in phase I and phase II metabolism of the majority of clinically prescribed drugs, including the non-nucleoside reverse transcriptase inhibitors, efavirenz and nevirapine, used in the treatment of HIV/AIDS. Variations in the activity of these enzymes due to gene polymorphisms can affect an individual's drug response or may lead to adverse drug reactions. There is an inter-ethnic distribution in the frequency of these polymorphisms, with African populations exhibiting higher genetic diversity compared to other populations. African specific alleles with clinical relevance have also emerged. Given the high prevalence of HIV/AIDS in sub-Saharan Africa, understanding the frequency of pharmacogenetically relevant alleles in populations of African origin, and their impact on efavirenz and nevirapine metabolism, is becoming increasingly critical. This review aims to investigate ethnic variation of CYP2B6, CYP2A6 and UGT2B7, and to understand the pharmacogenetic relevance when comparing frequencies in African populations to other populations worldwide.
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Affiliation(s)
- Antoinette Čolić
- Department of Biochemistry, Faculty of Natural and Agricultural SciencesSchool of Biological Science, University of Pretoria , Pretoria , South Africa and
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18
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Alessandrini M, Pepper MS. Priority pharmacogenetics for the African continent: focus on CYP450. Pharmacogenomics 2014; 15:385-400. [PMID: 24533717 DOI: 10.2217/pgs.13.252] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Countries in Africa have a high burden of communicable disease, and are experiencing an increase in noncommunicable diseases due to the effects of globalization, industrialization and urbanization. The costs incurred through adverse drug reactions and nonresponsiveness to therapy further aggravates the situation, and the application of pharmacogenetic principles is likely to provide some relief. Having undertaken an extensive evaluation of CYP450 reports in Africa, our objective was to map out areas of need based on regional disease burdens. The data confirms a paucity of CYP450 reports and illustrates large regions for which no population information exists. There is a dire need to address the health problems of Africa, and wide-scale pharmacogenetic profiling of these populations will add significantly to improving patient care on the continent. Priority pharmacogenetics for the African continent gives precedence to the profiling of clinically relevant pharmacogenetic biomarkers, and defines the immediate need in the context of disease burden.
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Affiliation(s)
- Marco Alessandrini
- Department of Immunology & The Institute for Cellular & Molecular Medicine, Faculty of Health Sciences, University of Pretoria, South Africa
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19
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Evaluation of an immunoassay for determination of plasma efavirenz concentrations in resource-limited settings. J Int AIDS Soc 2014; 17:18979. [PMID: 24909561 PMCID: PMC4049128 DOI: 10.7448/ias.17.1.18979] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 04/07/2014] [Accepted: 04/17/2014] [Indexed: 11/08/2022] Open
Abstract
Introduction Therapeutic drug monitoring (TDM) may improve antiretroviral efficacy through adjustment of individual drug administration. This could result in reduced toxicity, prevent drug resistance, and aid management of drug–drug interactions. However, most measurement methods are too costly to be implemented in resource-limited settings. This study evaluated a commercially available immunoassay for measurement of plasma efavirenz. Methods The immunoassay-based method was applied to measure efavirenz using a readily available Humastar 80 chemistry analyzer. We compared plasma efavirenz concentrations measured by the immunoassay with liquid chromatography tandem mass spectrometry (LC-MS/MS) (reference method) in 315 plasma samples collected from HIV patients on treatment. Concentrations were categorized as suboptimal<1 µg/ml, normal 1–4 µg/ml or high>4 µg/ml. Agreement between results of the methods was assessed via Bland-Altman plot and κ statistic values. Results The median Interquartile range (IQR) efavirenz concentration was 2.8 (1.9; 4.5) µg/ml measured by the LC–MS/MS method and 2.5 (1.8; 3.9) µg/ml by the immunoassay and the results were well correlated (ρ=0.94). The limits of agreement assessed by Bland–Altman plots were −2.54; 1.70 µg/ml. Although immunoassay underestimated high concentrations, it had good agreement for classification into low, normal or high concentrations (K=0.74). Conclusions The immunoassay is a feasible alternative to determine efavirenz in areas with limited resources. The assay provides a reasonable approximation of efavirenz concentration in the majority of samples with a tendency to underestimate high concentrations. Agreement between tests evaluated in this study was clinically satisfactory for identification of low, normal and high efavirenz concentrations.
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Wake RM, Poulikakos P, Groth J, Harrison TS, Macallan DC. Evaluation of a pro-active strategy for managing tuberculosis-HIV co-infection in a UK tertiary care setting. Int J STD AIDS 2013; 24:263-8. [PMID: 23635810 DOI: 10.1177/0956462412472431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Management of tuberculosis (TB)-HIV co-infection is complicated by interactions between the diseases and their therapies. We developed and evaluated a strategy to (i) treat co-infected patients in a single co-infection clinic, (ii) maximize use of first-line drugs, (iii) delay antiretroviral therapy (ART) until two months post-TB treatment except in severe immunosuppression, (iv) commence efavirenz at 600 mg daily with therapeutic drug monitoring (TDM) and (v) target treatment completion. We conducted a prospective cohort review over 5.5 years in a UK tertiary referral center where 56 HIV-positive patients treated for TB were followed-up for a median 30 months. Main outcome measures were treatment completion, adverse events, immune reconstitution inflammatory syndrome, immunological and virological parameters, and TDM for efavirenz. Treatment completion rates were 88% (49/56); four patients were lost to local follow-up and three (5.4%) died during treatment; no deaths were TB-related. Adverse events were common (55%), but caused no treatment interruptions. Standard doses (600 mg daily) of efavirenz with rifampicin achieved or exceeded therapeutic levels in 25/28 (89%). This study supports combined management for TB-HIV co-infected patients. Delaying ART to two months post-TB treatment did not seem to result in poor clinical outcomes in this well-resourced context. Although efavirenz 600 mg daily usually achieved satisfactory levels, TDM is recommended.
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Affiliation(s)
- R M Wake
- Infection & Immunity Research Centre, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK
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Ngaimisi E, Habtewold A, Minzi O, Makonnen E, Mugusi S, Amogne W, Yimer G, Riedel KD, Janabi M, Aderaye G, Mugusi F, Bertilsson L, Aklillu E, Burhenne J. Importance of ethnicity, CYP2B6 and ABCB1 genotype for efavirenz pharmacokinetics and treatment outcomes: a parallel-group prospective cohort study in two sub-Saharan Africa populations. PLoS One 2013; 8:e67946. [PMID: 23861838 PMCID: PMC3702506 DOI: 10.1371/journal.pone.0067946] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 05/23/2013] [Indexed: 12/30/2022] Open
Abstract
Objectives We evaluated the importance of ethnicity and pharmacogenetic variations in determining efavirenz pharmacokinetics, auto-induction and immunological outcomes in two African populations. Methods ART naïve HIV patients from Ethiopia (n = 285) and Tanzania (n = 209) were prospectively enrolled in parallel to start efavirenz based HAART. CD4+ cell counts were determined at baseline, 12, 24 and 48 weeks. Plasma and intracellular efavirenz and 8-hydroxyefvairenz concentrations were determined at week 4 and 16. Genotyping for common functional CYP2B6, CYP3A5, ABCB1, UGT2B7 and SLCO1B1 variant alleles were done. Result Patient country, CYP2B6*6 and ABCB1 c.4036A>G (rs3842A>G) genotype were significant predictors of plasma and intracellular efavirenz concentration. CYP2B6*6 and ABCB1 c.4036A>G (rs3842) genotype were significantly associated with higher plasma efavirenz concentration and their allele frequencies were significantly higher in Tanzanians than Ethiopians. Tanzanians displayed significantly higher efavirenz plasma concentration at week 4 (p<0.0002) and week 16 (p = 0.006) compared to Ethiopians. Efavirenz plasma concentrations remained significantly higher in Tanzanians even after controlling for the effect of CYP2B6*6 and ABCB1 c.4036A>G genotype. Within country analyses indicated a significant decrease in the mean plasma efavirenz concentration by week 16 compared to week 4 in Tanzanians (p = 0.006), whereas no significant differences in plasma concentration over time was observed in Ethiopians (p = 0.84). Intracellular efavirenz concentration and patient country were significant predictors of CD4 gain during HAART. Conclusion We report substantial differences in efavirenz pharmacokinetics, extent of auto-induction and immunologic recovery between Ethiopian and Tanzanian HIV patients, partly but not solely, due to pharmacogenetic variations. The observed inter-ethnic variations in efavirenz plasma exposure may possibly result in varying clinical treatment outcome or adverse event profiles between populations.
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Affiliation(s)
- Eliford Ngaimisi
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Unit of Pharmacology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Abiy Habtewold
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Department of Pharmacology, School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | - Omary Minzi
- Unit of Pharmacology, School of Pharmacy, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Eyasu Makonnen
- Department of Pharmacology, School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | - Sabina Mugusi
- Venhälsan, Karolinska Institutet, Södersjukhuset, Stockholm, Sweden
- Department of Internal Medicine, Muhimbili National Hospital, Dar es Salaam Tanzania
| | - Wondwossen Amogne
- Department of Medicine, Unit of Infectious Diseases, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden
- Department of Internal Medicine, School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | - Getnet Yimer
- Department of Pharmacology, School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | - Klaus-Dieter Riedel
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| | - Mohammed Janabi
- Department of Internal Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Getachew Aderaye
- Department of Internal Medicine, School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ferdinand Mugusi
- Department of Internal Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Leif Bertilsson
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Eleni Aklillu
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- * E-mail:
| | - Juergen Burhenne
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
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Mukonzo JK, Okwera A, Nakasujja N, Luzze H, Sebuwufu D, Ogwal-Okeng J, Waako P, Gustafsson LL, Aklillu E. Influence of efavirenz pharmacokinetics and pharmacogenetics on neuropsychological disorders in Ugandan HIV-positive patients with or without tuberculosis: a prospective cohort study. BMC Infect Dis 2013; 13:261. [PMID: 23734829 PMCID: PMC3680019 DOI: 10.1186/1471-2334-13-261] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 05/25/2013] [Indexed: 01/01/2023] Open
Abstract
Background HIV infection, anti-tuberculosis and efavirenz therapy are associated with neuropsychological effects. We evaluated the influence of rifampicin cotreatment, efavirenz pharmacokinetics and pharmacogenetics on neuropsychiatric disorders in Ugandan HIV patients with or without tuberculosis coinfection. Methods 197 treatment naïve Ugandan HIV patients, of whom 138 were TB co-infected, enrolled prospectively and received efavirenz based HAART. TB-HIV confected patients received concomitant rifampicin based anti-TB therapy. Genotypes for CYP2B6 (*6, *11), CYP3A5 (*3, *6, *7), ABCB1 (c.3435C>T and c.4036 A/G rs3842), CYP2A6 (*9, *17) and NR1I3 rs3003596 T/C were determined. Efavirenz plasma concentrations were serially quantified at 3rd day, 1st, 2nd, 4th, 6th, 8th and 12th weeks during therapy. Efavirenz neuropsychiatric symptoms were evaluated in terms of sleep disorders, hallucinations and cognitive effects at baseline, at two and twelve weeks of efavirenz treatment using a modified Mini Mental State Examination (MMSE) score. Results During the first twelve weeks of ART, 73.6% of the patients experienced at least one efavirenz related neuropsychiatric symptom. Commonest symptoms experienced were sleep disorders 60.5% (n=124) and hallucination 30.7% (n=63). Neuropsychiatric symptoms during HAART were significantly predicted by efavirenz plasma concentrations consistently. Rifampicin cotreatment reduced plasma efavirenz concentrations significantly only during the first week but not afterwards. There was no significant difference in the incidence of neuropsychiatric symptoms between patients receiving efavirenz with or without rifampicin cotreatment. CYP2B6*6 and ABCB1 c.4036 A/G genotype significantly predicted efavirenz concentrations. The tendency of CYP2B6*6 genotype association with higher incidence of having vivid dream (p=0.05), insomnia (p=0.19) and tactile hallucination (p=0.09) was observed mainly at week-2. Conclusions Efavirenz related neuropsychiatric symptoms are common among Ugandan HIV patients receiving ART and is mainly predicted by higher efavirenz plasma concentrations and CYP2B6 genotype but not by rifampicin based anti-TB co-treatment.
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Affiliation(s)
- Jackson K Mukonzo
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, SE- 141 86, Stockholm, Sweden
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Alessandrini M, Asfaha S, Dodgen TM, Warnich L, Pepper MS. Cytochrome P450 pharmacogenetics in African populations. Drug Metab Rev 2013; 45:253-75. [PMID: 23590174 DOI: 10.3109/03602532.2013.783062] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The Cytochrome P450 (CYP450) family of enzymes is involved in the oxidative metabolism of many therapeutic drugs, carcinogens and various endogenous substrates. These enzymes are highly polymorphic at an inter-individual and inter-ethnic level. Polymorphisms or genetic variations account for up to 30% of inter-individual differences seen in a variety of drug responses. The frequencies of the different metabolizer categories (slow, intermediate, extensive and ultra-rapid), the distribution of genetic variants, genotype-phenotype correlations and the clinical importance of the CYP450 enzymes have been extensively documented in Caucasian and Oriental populations. Limited data exists for African populations, despite the fact that this knowledge is critically important for these populations who experience a heavy burden of communicable and non-communicable diseases. In addition, the costs incurred through adverse drug reactions and non-responsiveness to therapy could be reduced through the wide-scale application of pharmacogenetics. This review provides an overview and investigation of CYP450 genotypic and phenotypic reports published from 1980 to present in African populations. Our findings confirm the high degree of variability that is expected when comparing individuals of African origin to other ethnic groups and also highlight the distribution of clinically relevant CYP450 alleles amongst the various African populations. The notable discordance in genotypic and phenotypic data amongst African populations exemplifies the need for in-depth and well-orchestrated molecular and pharmacological investigations of these populations in the future, for which whole genome sequencing and association studies will be critical.
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Affiliation(s)
- Marco Alessandrini
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
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Radloff R, Gras A, Zanger UM, Masquelier C, Arumugam K, Karasi JC, Arendt V, Seguin-Devaux C, Klein K. Novel CYP2B6 enzyme variants in a Rwandese population: functional characterization and assessment of in silico prediction tools. Hum Mutat 2013; 34:725-34. [PMID: 23418033 DOI: 10.1002/humu.22295] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 02/05/2013] [Indexed: 01/11/2023]
Abstract
Cytochrome P450 CYP2B6 is a highly polymorphic enzyme that metabolizes numerous drugs, pesticides, and environmental toxins. Sequence analysis of a Rwandese population identified eight functionally uncharacterized nonsynonymous variants c.329G>T (p.G110V), c.341T>C (p.I114T), c.444G>T (p.E148D), c.548T>G (p.V183G), c.637T>C (p.F213L), c.758G>A (p.R253H), c.835G>C (p.A279P), and c.1459C>A (p.R487S), and five novel alleles termed CYP2B6*33 to CYP2B6*37 were assigned. Recombinant expression in COS-1 cells and functional characterization using the antidepressant bupropion and the antiretroviral efavirenz (EFV) as substrates demonstrated complete or almost complete loss-of-function for variants p.G110V, p.I114T, p.V183G, and p.F213L, whereas p.E148D, p.R253H, p.A279P, and p.R487S variants were functional. The data were used to assess the predictive power of eight online available functional prediction programs for amino-acid changes. Although none of the programs correctly predicted the functionality of all variants, substrate docking simulation analyses indicated similar conformational changes by all four deleterious mutations within the enzyme's active site, thus explaining lack of enzymatic function for both substrates. Because low-activity alleles of CYP2B6 are associated with impaired EFV metabolism and adverse drug response, these results are of potential utility for personalized treatment strategies in HIV/AIDS therapy.
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Affiliation(s)
- Robert Radloff
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany
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Cytochrome P450 CYP2B6 genotypes and haplotypes in a Colombian population: identification of novel variant CYP2B6 alleles. Pharmacogenet Genomics 2012; 21:773-8. [PMID: 21886015 DOI: 10.1097/fpc.0b013e32834b3efc] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Information on CYP2B6 allele frequencies and detrimental genotypes in mixed human populations is scarce. The aim of this study was to analyze the frequencies and haplotypes of nonsynonymous CYP2B6 single nucleotide polymorphisms (SNPs) in a Colombian population. METHODS One hundred and fifty-two healthy individuals were analyzed for five nonsynonymous CYP2B6 SNPs, namely rs8192709, rs3745274, rs2279343 rs28399499, and rs3211371. RESULTS Besides eight known variant alleles, we identified two as yet unknown variant alleles combining, respectively, the SNPs rs3745274 and rs3211371 and rs8192709 and rs3745274. Comparison of Colombian mestizo individuals with other mestizo population indicates statistically significant differences (P<0.001) for the gain-of-function CYP2B6*4 allele and for combined detrimental CYP2B6 alleles. In addition, we observed a low linkage between the SNPs rs3745274 and rs2279343, which are often assumed as linked. CONCLUSION In conclusion, large interethnic and intraethnic variability exists for CYP2B6 polymorphisms, thus reinforcing the need for tailored genotyping protocols for CYP2B6 testing as a biomarker of drug response.
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Brown C, Oki NO, Hariani G, Motsinger-Reif AA. Research Highlights. Pharmacogenomics 2012; 13:137-8. [DOI: 10.2217/pgs.11.158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Chad Brown
- Bioinformatics Research Center, Department of Statistics, North Carolina State University, Raleigh, NC 27695, USA
| | - Noffisat O Oki
- Bioinformatics Research Center, Department of Statistics, North Carolina State University, Raleigh, NC 27695, USA
| | - Gunjan Hariani
- Bioinformatics Research Center, Department of Statistics, North Carolina State University, Raleigh, NC 27695, USA
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