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Powell NR, Geck RC, Lai D, Shugg T, Skaar TC, Dunham M. Functional Analysis of G6PD Variants Associated With Low G6PD Activity in the All of Us Research Program. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.04.12.24305393. [PMID: 38645242 PMCID: PMC11030488 DOI: 10.1101/2024.04.12.24305393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Glucose-6-phosphate dehydrogenase (G6PD) protects red blood cells against oxidative damage through regeneration of NADPH. Individuals with G6PD polymorphisms (variants) that produce an impaired G6PD enzyme are usually asymptomatic, but at risk of hemolytic anemia from oxidative stressors, including certain drugs and foods. Prevention of G6PD deficiency-related hemolytic anemia is achievable through G6PD genetic testing or whole-genome sequencing (WGS) to identify affected individuals who should avoid hemolytic triggers. However, accurately predicting the clinical consequence of G6PD variants is limited by over 800 G6PD variants which remain of uncertain significance. There also remains significant variability in which deficiency-causing variants are included in pharmacogenomic testing arrays across institutions: many panels only include c.202G>A, even though dozens of other variants can also cause G6PD deficiency. Here, we seek to improve G6PD genotype interpretation using data available in the All of Us Research Program and using a yeast functional assay. We confirm that G6PD coding variants are the main contributor to decreased G6PD activity, and that 13% of individuals in the All of Us data with deficiency-causing variants would be missed if only the c.202G>A variant were tested for. We expand clinical interpretation for G6PD variants of uncertain significance; reporting that c.595A>G, known as G6PD Dagua or G6PD Açores, and the newly identified variant c.430C>G, reduce activity sufficiently to lead to G6PD deficiency. We also provide evidence that five missense variants of uncertain significance are unlikely to lead to G6PD deficiency, since they were seen in hemi- or homozygous individuals without a reduction in G6PD activity. We also applied the new WHO guidelines and were able to classify two synonymous variants as WHO class C. We anticipate these results will improve the accuracy, and prompt increased use, of G6PD genetic tests through a more complete clinical interpretation of G6PD variants. As the All of Us data increases from 245,000 to 1 million participants, and additional functional assays are carried out, we expect this research to serve as a template to enable complete characterization of G6PD deficiency genotypes. With an increased number of interpreted variants, genetic testing of G6PD will be more informative for preemptively identifying individuals at risk for drug- or food-induced hemolytic anemia.
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Affiliation(s)
- Nicholas R Powell
- Indiana University School of Medicine, Department of Medicine, Division of Clinical Pharmacology, Indianapolis IN
| | - Renee C Geck
- University of Washington, Department of Genome Sciences, Seattle WA
| | - Dongbing Lai
- Indiana University School of Medicine, Department of Medical and Molecular Genetics, Indianapolis IN
| | - Tyler Shugg
- Indiana University School of Medicine, Department of Medicine, Division of Clinical Pharmacology, Indianapolis IN
| | - Todd C Skaar
- Indiana University School of Medicine, Department of Medicine, Division of Clinical Pharmacology, Indianapolis IN
| | - Maitreya Dunham
- University of Washington, Department of Genome Sciences, Seattle WA
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Brito M, Rufatto R, Murta F, Sampaio V, Balieiro P, Baía-Silva D, Castro V, Alves B, Alencar A, Duparc S, Grewal Daumerie P, Borghini-Fuhrer I, Jambert E, Peterka C, Edilson Lima F, Carvalho Maia L, Lucena Cruz C, Maciele B, Vasconcelos M, Machado M, Augusto Figueira E, Alcirley Balieiro A, Menezes A, Ataídes R, Batista Pereira D, Lacerda M. Operational feasibility of Plasmodium vivax radical cure with tafenoquine or primaquine following point-of-care, quantitative glucose-6-phosphate dehydrogenase testing in the Brazilian Amazon: a real-life retrospective analysis. Lancet Glob Health 2024; 12:e467-e477. [PMID: 38365417 PMCID: PMC10882209 DOI: 10.1016/s2214-109x(23)00542-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 11/07/2023] [Accepted: 11/10/2023] [Indexed: 02/18/2024]
Abstract
BACKGROUND To achieve malaria elimination, Brazil must implement Plasmodium vivax radical cure. We aimed to investigate the operational feasibility of point-of-care, quantitative, glucose-6-phosphate dehydrogenase (G6PD) testing followed by chloroquine plus tafenoquine or primaquine. METHODS This non-interventional, observational study was done at 43 health facilities in Manaus (Amazonas State) and Porto Velho (Rondônia State), Brazil, implementing a new P vivax treatment algorithm incorporating point-of-care quantitative G6PD testing to identify G6PD status and single-dose tafenoquine (G6PD normal, aged ≥16 years, and not pregnant or breastfeeding) or primaquine (intermediate or normal G6PD, aged ≥6 months, not pregnant, or breastfeeding >1 month). Following training of health-care providers, we collated routine patient records from the malaria epidemiological surveillance system (SIVEP-Malaria) retrospectively for all consenting patients aged at least 6 months with parasitologically confirmed P vivax malaria mono-infection or P vivax plus P falciparum mixed infection, presenting between Sept 9, 2021, and Aug 31, 2022. The primary endpoint was the proportion of patients aged at least 16 years with P vivax mono-infection treated or not treated appropriately with tafenoquine in accordance with their G6PD status. The trial is registered with ClinicalTrials.gov, NCT05096702, and is completed. FINDINGS Of 6075 patients enrolled, 6026 (99·2%) had P vivax mono-infection, 2685 (44·6%) of whom were administered tafenoquine. G6PD status was identified in 2685 (100%) of 2685 patients treated with tafenoquine. The proportion of patients aged at least 16 years with P vivax mono-infection who were treated or not treated appropriately with tafenoquine in accordance with their G6PD status was 99·7% (95% CI 99·4-99·8; 4664/4680). INTERPRETATION Quantitative G6PD testing before tafenoquine administration was operationally feasible, with high adherence to the treatment algorithm, supporting deployment throughout the Brazilian health system. FUNDING Brazilian Ministry of Health, Municipal and State Health Secretariats; Fiocruz; Medicines for Malaria Venture; Bill & Melinda Gates Foundation; Newcrest Mining; and the UK Government. TRANSLATION For the Portuguese translation of the abstract see Supplementary Materials section.
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Affiliation(s)
- Marcelo Brito
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
| | - Rosilene Rufatto
- Centro de Pesquisa em Medicina Tropical de Rondônia, Porto Velho, Brazil
| | - Felipe Murta
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
| | - Vanderson Sampaio
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
| | - Patrícia Balieiro
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
| | - Djane Baía-Silva
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil; Universidade do Estado do Amazonas, Manaus, Brazil; Instituto Leônidas & Maria Deane, Fiocruz, Manaus, Brazil; Universidade Nilton Lins, Manaus, Brazil
| | | | - Brenda Alves
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
| | - Aline Alencar
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
| | | | | | | | | | | | | | | | | | - Bruna Maciele
- Centro de Pesquisa em Medicina Tropical de Rondônia, Porto Velho, Brazil
| | | | | | | | | | | | | | | | - Marcus Lacerda
- Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil; Instituto Leônidas & Maria Deane, Fiocruz, Manaus, Brazil; University of Texas Medical Branch, Galveston, TX, USA.
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Cardoso MA, Lourenço BH, Matijasevich A, Castro MC, Ferreira MU. Prevalence and correlates of childhood anemia in the MINA-Brazil birth cohort study. Rev Saude Publica 2024; 57Suppl 2:6s. [PMID: 38422335 PMCID: PMC10897962 DOI: 10.11606/s1518-8787.2023057005637] [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: 06/26/2023] [Accepted: 11/08/2023] [Indexed: 03/02/2024] Open
Abstract
OBJECTIVE This study aimed to describe the prevalence and predictors of childhood anemia in an Amazonian population-based birth cohort study. METHODS Prevalence of maternal anemia was estimated at delivery (hemoglobin [Hb] concentration < 110 g/L) in women participating in the MINA-Brazil birth cohort study and in their children, examined at ages one, two (Hb < 110 g/L), and five (Hb < 115 g/L). Moreover, ferritin, soluble transferrin receptor, and C-reactive protein concentrations were measured in mothers at delivery and in their 1- and 2-year-old children to estimate the prevalence of iron deficiency and its contribution to anemia, while adjusting for potential confounders by multiple Poisson regression analysis (adjusted relative risk [RRa]). RESULTS The prevalence 95% confidence interval (CI) of maternal anemia, iron deficiency, and iron-deficiency anemia at delivery were 17.3% (14.0-21.0%), 42.6% (38.0-47.2%), and 8.7% (6.3-11.6)%, respectively (n = 462). At one year of age (n = 646), 42.2% (38.7-45.8%) of the study children were anemic, 38.4% (34.6-42.3%) were iron-deficient, and 26.3 (23.0-29.9) had iron-deficiency anemia. At two years of age (n = 761), these values decreased to 12.8% (10.6-15.2%), 18.1% (15.5-21.1%), and 4.1% (2.8-5.7%), respectively; at five years of age (n = 655), 5.2% (3.6-7.2%) were anemic. Iron deficiency (RRa = 2.19; 95%CI: 1.84-2.60) and consumption of ultra-processed foods (UPF) (RRa = 1.56; 95%CI: 1.14-2.13) were significant contributors to anemia at 1 year, after adjusting for maternal schooling. At 2 years, anemia was significantly associated with maternal anemia at delivery (RRa: 1.67; 95%CI: 1.17-2.39), malaria since birth (2.25; 1.30-3.87), and iron deficiency (2.15; 1.47-3.15), after adjusting for children's age and household wealth index. CONCLUSIONS Anemia continues to be highly prevalent during pregnancy and early childhood in the Amazon. Public health policies should address iron deficiency, UPF intake, maternal anemia, and malaria to prevent and treat anemia in Amazonian children.
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Affiliation(s)
- Marly A Cardoso
- Universidade de São PauloFaculdade de Saúde PúblicaDepartamento de NutriçãoSão PauloSPBrasilUniversidade de São Paulo. Faculdade de Saúde Pública. Departamento de Nutrição. São Paulo, SP, Brasil
| | - Bárbara H. Lourenço
- Universidade de São PauloFaculdade de Saúde PúblicaDepartamento de NutriçãoSão PauloSPBrasilUniversidade de São Paulo. Faculdade de Saúde Pública. Departamento de Nutrição. São Paulo, SP, Brasil
| | - Alicia Matijasevich
- Universidade de São PauloFaculdade de MedicinaDepartamento de Medicina PreventivaSão PauloSPBrasilUniversidade de São Paulo. Faculdade de Medicina. Departamento de Medicina Preventiva. São Paulo, SP, Brasil
| | - Marcia C Castro
- Harvard T.H. Chan School of Public HealthDepartment of Global Health and PopulationBostonMAUnited States of AmericaHarvard T.H. Chan School of Public Health. Department of Global Health and Population. Boston, MA, United States of America
| | - Marcelo U Ferreira
- Universidade de São PauloInstituto de Ciências BiomédicasDepartamento de ParasitologiaSão PauloSPBrasilUniversidade de São Paulo, Instituto de Ciências Biomédicas. Departamento de Parasitologia. São Paulo, SP, Brasil
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Habtamu K, Petros B, Yan G. Plasmodium vivax: the potential obstacles it presents to malaria elimination and eradication. Trop Dis Travel Med Vaccines 2022; 8:27. [PMID: 36522671 PMCID: PMC9753897 DOI: 10.1186/s40794-022-00185-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022] Open
Abstract
Initiatives to eradicate malaria have a good impact on P. falciparum malaria worldwide. P. vivax, however, still presents significant difficulties. This is due to its unique biological traits, which, in comparison to P. falciparum, pose serious challenges for malaria elimination approaches. P. vivax's numerous distinctive characteristics and its ability to live for weeks to years in liver cells in its hypnozoite form, which may elude the human immune system and blood-stage therapy and offer protection during mosquito-free seasons. Many malaria patients are not fully treated because of contraindications to primaquine use in pregnant and nursing women and are still vulnerable to P. vivax relapses, although there are medications that could radical cure P. vivax. Additionally, due to CYP2D6's highly variable genetic polymorphism, the pharmacokinetics of primaquine may be impacted. Due to their inability to metabolize PQ, some CYP2D6 polymorphism alleles can cause patients to not respond to treatment. Tafenoquine offers a radical treatment in a single dose that overcomes the potentially serious problem of poor adherence to daily primaquine. Despite this benefit, hemolysis of the early erythrocytes continues in individuals with G6PD deficiency until all susceptible cells have been eliminated. Field techniques such as microscopy or rapid diagnostic tests (RDTs) miss the large number of submicroscopic and/or asymptomatic infections brought on by reticulocyte tropism and the low parasitemia levels that accompany it. Moreover, P. vivax gametocytes grow more quickly and are much more prevalent in the bloodstream. P. vivax populations also have a great deal of genetic variation throughout their genome, which ensures evolutionary fitness and boosts adaptation potential. Furthermore, P. vivax fully develops in the mosquito faster than P. falciparum. These characteristics contribute to parasite reservoirs in the human population and facilitate faster transmission. Overall, no genuine chance of eradication is predicted in the next few years unless new tools for lowering malaria transmission are developed (i.e., malaria elimination and eradication). The challenging characteristics of P. vivax that impede the elimination and eradication of malaria are thus discussed in this article.
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Affiliation(s)
- Kassahun Habtamu
- Department of Microbial, Cellular & Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
- Menelik II Medical & Health Science College, Addis Ababa, Ethiopia
| | - Beyene Petros
- Department of Microbial, Cellular & Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Guiyun Yan
- Program in Public Health, University of California at Irvine, Irvine, CA 92697 USA
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