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Woolley SD, Grigg MJ, Marquart L, Gower JSE, Piera K, Nair AS, Amante FM, Rajahram GS, William T, Frazer DM, Chalon S, McCarthy JS, Anstey NM, Barber BE. Longitudinal changes in iron homeostasis in human experimental and clinical malaria. EBioMedicine 2024; 105:105189. [PMID: 38851058 DOI: 10.1016/j.ebiom.2024.105189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 05/23/2024] [Accepted: 05/23/2024] [Indexed: 06/10/2024] Open
Abstract
BACKGROUND The interaction between iron status and malaria is incompletely understood. We evaluated longitudinal changes in iron homeostasis in volunteers enrolled in malaria volunteer infection studies (VIS) and in Malaysian patients with falciparum and vivax malaria. METHODS We retrieved data and samples from 55 participants (19 female) enrolled in malaria VIS, and 171 patients (45 female) with malaria and 30 healthy controls (13 female) enrolled in clinical studies in Malaysia. Ferritin, hepcidin, erythropoietin, and soluble transferrin receptor (sTfR) were measured by ELISA. FINDINGS In the VIS, participants' parasitaemia was correlated with baseline mean corpuscular volume (MCV), but not iron status (ferritin, hepcidin or sTfR). Ferritin, hepcidin and sTfR all increased during the VIS. Ferritin and hepcidin normalised by day 28, while sTfR remained elevated. In VIS participants, baseline ferritin was associated with post-treatment increases in liver transaminase levels. In Malaysian patients with malaria, hepcidin and ferritin were elevated on admission compared to healthy controls, while sTfR increased following admission. By day 28, hepcidin had normalised; however, ferritin and sTfR both remained elevated. INTERPRETATION Our findings demonstrate that parasitaemia is associated with an individual's MCV rather than iron status. The persistent elevation in sTfR 4 weeks post-infection in both malaria VIS and clinical malaria may reflect a causal link between malaria and iron deficiency. FUNDING National Health and Medical Research Council (Program Grant 1037304, Project Grants 1045156 and 1156809; Investigator Grants 2016792 to BEB, 2016396 to JCM, 2017436 to MJG); US National Institute of Health (R01-AI116472-03); Malaysian Ministry of Health (BP00500420).
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Affiliation(s)
- Stephen D Woolley
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia; Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom; Academic Department of Military Medicine, Royal Centre for Defence Medicine, Birmingham, United Kingdom
| | - Matthew J Grigg
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia; Infectious Diseases Society Kota Kinabalu Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Louise Marquart
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia; School of Public Health, University of Queensland, Brisbane, Australia
| | - Jeremy S E Gower
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Kim Piera
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Arya Sheela Nair
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Fiona M Amante
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Giri S Rajahram
- Infectious Diseases Society Kota Kinabalu Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia; Department of Medicine, Queen Elizabeth II Hospital, Kota Kinabalu, Malaysia; Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Malaysia
| | - Timothy William
- Infectious Diseases Society Kota Kinabalu Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia; Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Malaysia; Subang Jaya Medical Centre, Subang Jaya, Malaysia
| | - David M Frazer
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - James S McCarthy
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia; Victorian Infectious Diseases Institute, Peter Doherty Institute, University of Melbourne, Melbourne, Australia
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia; Infectious Diseases Society Kota Kinabalu Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Bridget E Barber
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia; Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia; Infectious Diseases Society Kota Kinabalu Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia; Infectious Diseases Department, Royal Brisbane and Women's Hospital, Brisbane, Australia.
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Brito M, Rufatto R, Brito-Sousa JD, 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, Batista Pereira D, Lacerda M. Operational effectiveness of tafenoquine and primaquine for the prevention of Plasmodium vivax recurrence in Brazil: a retrospective observational study. THE LANCET. INFECTIOUS DISEASES 2024; 24:629-638. [PMID: 38452779 PMCID: PMC7615970 DOI: 10.1016/s1473-3099(24)00074-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/15/2024] [Accepted: 01/25/2024] [Indexed: 03/09/2024]
Abstract
BACKGROUND Prevention of Plasmodium vivax malaria recurrence is essential for malaria elimination in Brazil. We evaluated the real-world effectiveness of an updated treatment algorithm for P vivax radical cure in the Brazilian Amazon. METHODS In this non-interventional observational study, we used retrospective data from the implementation of a P vivax treatment algorithm at 43 health facilities in Manaus and Porto Velho, Brazil. The treatment algorithm consisted of chloroquine (25 mg/kg over 3 days) and point-of-care quantitative glucose-6-phosphate dehydrogenase (G6PD) testing followed by single-dose tafenoquine 300 mg (G6PD normal, aged ≥16 years, not pregnant and not breastfeeding), 7-day primaquine 0·5 mg/kg per day (G6PD intermediate or normal, aged ≥6 months, not pregnant, and not breastfeeding or breastfeeding for >1 month), or primaquine 0·75 mg/kg per week for 8 weeks (G6PD deficient, aged ≥6 months, not pregnant, and not breastfeeding or breastfeeding for >1 month). P vivax recurrences were identified from probabilistic linkage of routine patient records from the Brazilian malaria epidemiological surveillance system. Recurrence-free effectiveness at day 90 and day 180 was estimated using Kaplan-Meier analysis and hazard ratios (HRs) by multivariate analysis. This clinical trial is registered with ClinicalTrials.gov, NCT05096702, and is completed. FINDINGS Records from Sept 9, 2021, to Aug 31, 2022, included 5554 patients with P vivax malaria. In all treated patients of any age and any G6PD status, recurrence-free effectiveness at day 180 was 75·8% (95% CI 74·0-77·6) with tafenoquine, 73·4% (71·9-75·0) with 7-day primaquine, and 82·1% (77·7-86·8) with weekly primaquine. In patients aged at least 16 years who were G6PD normal, recurrence-free effectiveness until day 90 was 88·6% (95% CI 87·2-89·9) in those who were treated with tafenoquine (n=2134) and 83·5% (79·8-87·4) in those treated with 7-day primaquine (n=370); after adjustment for confounding factors, the HR for recurrence following tafenoquine versus 7-day primaquine was 0·65 (95% CI 0·49-0·86; p=0·0031), with similar outcomes between the two treatments at day 180 (log-rank p=0·82). Over 180 days, median time to recurrence in patients aged at least 16 years who were G6PD normal was 92 days (IQR 76-120) in those treated with tafenoquine and 68 days (52-94) in those treated with 7-day primaquine. INTERPRETATION In this real-world setting, single-dose tafenoquine was more effective at preventing P vivax recurrence in patients aged at least 16 years who were G6PD normal compared with 7-day primaquine at day 90, while overall efficacy at 180 days was similar. The public health benefits of the P vivax radical cure treatment algorithm incorporating G6PD quantitative testing and tafenoquine support its implementation in Brazil and potentially across South America. 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
| | | | - 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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Krause PJ, Rogers R, Shah MK, Kang H, Parsonnet J, Kodama R, Vannier E. Tafenoquine for Relapsing Babesiosis: A Case Series. Clin Infect Dis 2024:ciae238. [PMID: 38814096 DOI: 10.1093/cid/ciae238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Indexed: 05/31/2024] Open
Abstract
BACKGROUND Relapsing babesiosis often occurs in highly immunocompromised patients and has been attributed to the acquisition of resistance against drugs commonly used for treatment such as atovaquone, azithromycin, and clindamycin. Tafenoquine, which is approved for malaria prophylaxis and presumptive antirelapse treatment of Plasmodium vivax malaria, has shown activity against Babesia microti in several animal models of acute infection and in a single human case of relapsing babesiosis. Here, we report 5 cases of relapsing babesiosis treated with tafenoquine, including the previous case, and begin to define the conditions for optimal use of tafenoquine in relapsing babesiosis. METHODS A definitive diagnosis of babesiosis was made by microscopic examination of Giemsa-stained thin blood smears or a real-time polymerase chain reaction (PCR) that targets the parasite 18S rRNA gene. Clearance of B. microti infection was ascertained by use of blood smear and real-time PCR. RESULTS Tafenoquine was initiated with a loading dose of 600 mg. A weekly maintenance dose consisted of 200 mg or 300 mg; the lower dose was associated with a delayed clearance of B. microti. In 2 cases, all antimicrobial agents but tafenoquine were discontinued prior to clearance of infection. In 2 other cases, clearance was achieved while tafenoquine was administered along with other antimicrobial agents. In 3 of these 4 cases, tafenoquine was used in combination with atovaquone-proguanil. Other agents included atovaquone, azithromycin, and/or clindamycin. In 1 case, tafenoquine was administered alone and failed to prevent relapse. CONCLUSIONS Tafenoquine can be a useful adjunct for the treatment of highly immunocompromised patients experiencing relapsing babesiosis caused by B. microti.
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Affiliation(s)
- Peter J Krause
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health and Yale School of Medicine, New Haven, Connecticut, USA
| | - Ralph Rogers
- Division of Infectious Diseases, Warrant Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Monika K Shah
- Infectious Diseases Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
- Department of Medicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - HeeEun Kang
- Section of Infectious Diseases and International Health, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Jeffrey Parsonnet
- Section of Infectious Diseases and International Health, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Rich Kodama
- Infectious Diseases Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Edouard Vannier
- Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Boston, Massachusetts, USA
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Barber BE, Webster R, Potter AJ, Llewellyn S, Sahai N, Leelasena I, Mathison S, Kuritz K, Flynn J, Chalon S, Marrast AC, Gobeau N, Moehrle JJ. Characterising the blood-stage antimalarial activity of pyronaridine in healthy volunteers experimentally infected with Plasmodium falciparum. Int J Antimicrob Agents 2024; 64:107196. [PMID: 38734217 DOI: 10.1016/j.ijantimicag.2024.107196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 04/23/2024] [Accepted: 05/03/2024] [Indexed: 05/13/2024]
Abstract
With the spread of artemisinin resistance throughout Southeast Asia and now in Africa, the antimalarial drug pyronaridine is likely to become an increasingly important component of new antimalarial drug regimens. However, the antimalarial activity of pyronaridine in humans has not been completely characterised. This volunteer infection study aimed to determine the pharmacokinetic/pharmacodynamic (PK/PD) relationship of pyronaridine in malaria naïve adults. Volunteers were inoculated with Plasmodium falciparum-infected erythrocytes on day 0 and administered different single oral doses of pyronaridine on day 8. Parasitaemia and concentrations of pyronaridine were measured and standard safety assessments performed. Curative artemether-lumefantrine therapy was administered if parasite regrowth occurred, or on day 47 ± 2. Outcomes were parasite clearance kinetics, PK and PK/PD parameters from modelling. Ten participants were inoculated and administered 360 mg (n = 4), 540 mg (n = 4) or 720 mg (n = 1) pyronaridine. One participant was withdrawn without receiving pyronaridine. The time to maximum pyronaridine concentration was 1-2 h, the elimination half-life was 8-9 d, and the parasite clearance half-life was approximately 5 h. Parasite regrowth occurred with 360 mg (4/4 participants) and 540 mg (2/4 participants). Key efficacy parameters including the minimum inhibitory concentration (5.5 ng/mL) and minimum parasiticidal concentration leading to 90% of maximum effect (MPC90: 8 ng/mL) were derived from the PK/PD model. Adverse events considered related to pyronaridine were predominantly mild to moderate gastrointestinal symptoms. There were no serious adverse events. Data obtained in this study will support the use of pyronaridine in new antimalarial combination therapies by informing partner drug selection and dosing considerations.
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Affiliation(s)
- Bridget E Barber
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia; University of the Sunshine Coast Clinical Trials, Morayfield, QLD, Australia; Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - Rebecca Webster
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Adam J Potter
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Stacey Llewellyn
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Nischal Sahai
- University of the Sunshine Coast Clinical Trials, Morayfield, QLD, Australia
| | - Indika Leelasena
- University of the Sunshine Coast Clinical Trials, Morayfield, QLD, Australia
| | - Susan Mathison
- University of the Sunshine Coast Clinical Trials, Morayfield, QLD, Australia
| | | | - Julia Flynn
- Medicines for Malaria Venture, Geneva, Switzerland
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Woolley SD, Grigg MJ, Marquart L, Gower J, Piera K, Nair AS, Amante FM, Rajahram GS, William T, Frazer DM, Chalon S, McCarthy JS, Anstey NM, Barber BE. Longitudinal changes in iron homeostasis in human experimental and clinical malaria. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.12.19.23300265. [PMID: 38196596 PMCID: PMC10775340 DOI: 10.1101/2023.12.19.23300265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Background The interaction between iron deficiency and malaria is incompletely understood. We evaluated longitudinal changes in iron homeostasis in volunteers enrolled in malaria volunteer infection studies (VIS) and in Malaysian patients with falciparum and vivax malaria. Methods We retrieved samples and associated data from 55 participants enrolled in malaria VIS, and 171 malaria patients and 30 healthy controls enrolled in clinical studies in Malaysia. Ferritin, hepcidin, erythropoietin, and soluble transferrin receptor (sTfR) were measured by ELISA. Results In the VIS, participants' parasitaemia was correlated with baseline mean corpuscular volume (MCV), but not iron status (ferritin, hepcidin or sTfR). Ferritin, hepcidin and sTfR all increased during the VIS. Ferritin and hepcidin normalised by day 28, while sTfR remained elevated. In VIS participants, baseline iron status (ferritin) was associated with post-treatment increases in liver transaminase levels. In Malaysian malaria patients, hepcidin and ferritin were elevated on admission compared to healthy controls, while sTfR increased following admission. Hepcidin normalised by day 28; however, ferritin and sTfR both remained elevated 4 weeks following admission. Conclusion Our findings demonstrate that parasitaemia is associated with an individual's MCV rather than iron status. The persistent elevation in sTfR 4 weeks post-infection in both malaria VIS and clinical malaria may reflect a causal link between malaria and iron deficiency.
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Affiliation(s)
- Stephen D Woolley
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Academic Department of Military Medicine, Royal Centre for Defence Medicine, Birmingham, United Kingdom
| | - Matthew J Grigg
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
- Infectious Diseases Society Kota Kinabalu Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Louise Marquart
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- School of Public Health, University of Queensland, Brisbane, Australia
| | - Jeremy Gower
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Kim Piera
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Arya Sheela Nair
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Fiona M Amante
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Giri S Rajahram
- Infectious Diseases Society Kota Kinabalu Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
- Department of Medicine, Queen Elizabeth II Hospital, Kota Kinabalu, Malaysia
- Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Malaysia
| | - Timothy William
- Infectious Diseases Society Kota Kinabalu Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
- Department of Medicine, Queen Elizabeth II Hospital, Kota Kinabalu, Malaysia
- Subang Jaya Medical Centre, Subang Jaya, Malaysia
| | - David M Frazer
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - James S McCarthy
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Victorian Infectious Diseases Institute, Peter Doherty Institute, University of Melbourne, Melbourne, Australia
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
- Infectious Diseases Society Kota Kinabalu Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Bridget E Barber
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
- Infectious Diseases Society Kota Kinabalu Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
- Infectious Diseases Department, Royal Brisbane and Women's Hospital, Brisbane, Australia
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Mordue DG, Hale SJ, Dennis WE, Vuong CV, Li XM, Yang N, Wormser GP. Plasma Blood Levels of Tafenoquine following a Single Oral Dosage in BALBc Mice with Acute Babesia microti Infection That Resulted in Rapid Clearance of Microscopically Detectable Parasitemia. Pathogens 2023; 12:1113. [PMID: 37764921 PMCID: PMC10534932 DOI: 10.3390/pathogens12091113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/26/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Previous studies of mice infected with Babesia microti have shown that a single dose of tafenoquine administered orally is extremely effective at decreasing microscopically detectable parasitemia. However, a critical limitation of studies to date is the lack of data concerning the plasma levels of tafenoquine that are needed to treat babesiosis. In the current study, we begin to address this gap by examining the plasma levels of tafenoquine associated with the rapid reduction of B. microti patent parasitemia in a mouse model of babesiosis. In the current study, we infected BALB/c mice with 1 × 107B. microti-infected red blood cells. Two days post-infection, mice were treated with 20 mg/kg of tafenoquine succinate or vehicle control administered orally by gavage. Parasitemia and plasma levels of tafenoquine were evaluated every 24 h post-treatment for 96 h. This allowed us to correlate blood plasma levels of tafenoquine with reductions in parasitemia in treated mice. Consistent with previous studies, a single oral dose of 20 mg/kg tafenoquine resulted in a rapid reduction in parasitemia. Plasma levels of tafenoquine 24 h post-administration ranged from 347 to 503 ng/mL and declined thereafter. This blood plasma tafenoquine level is similar to that achieved in humans using the current FDA-approved dose for the prevention of malaria.
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Affiliation(s)
- Dana G. Mordue
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY 10520, USA
| | - Synthia J. Hale
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY 10520, USA
| | - William E. Dennis
- Walter Reed Army Institute of Research, Experimental Therapeutics Branch, Department of Drug Development, Silver Spring, MD 20910, USA; (W.E.D.)
| | - Chau V. Vuong
- Walter Reed Army Institute of Research, Experimental Therapeutics Branch, Department of Drug Development, Silver Spring, MD 20910, USA; (W.E.D.)
| | - Xiu-Min Li
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY 10520, USA
| | - Nan Yang
- General Nutraceutical Technology, LLC, Elmsford, NY 10523, USA;
| | - Gary P. Wormser
- Division of Infectious Diseases, New York Medical College, Valhalla, NY 10520, USA;
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Markus MB. Putative Contribution of 8-Aminoquinolines to Preventing Recrudescence of Malaria. Trop Med Infect Dis 2023; 8:278. [PMID: 37235326 PMCID: PMC10223033 DOI: 10.3390/tropicalmed8050278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/07/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
Enhanced therapeutic efficacy achieved in treating Plasmodium vivax malaria with an 8-aminoquinoline (8-AQ) drug such as primaquine (PQ) together with a partner drug such as chloroquine (CQ) is usually explained as CQ inhibiting asexual parasites in the bloodstream and PQ acting against liver stages. However, PQ's contribution, if any, to inactivating non-circulating, extra-hepatic asexual forms, which make up the bulk of the parasite biomass in chronic P. vivax infections, remains unclear. In this opinion article, I suggest that, considering its newly described mode of action, PQ might be doing something of which we are currently unaware.
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Affiliation(s)
- Miles B. Markus
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of Witwatersrand, Johannesburg 2193, South Africa;
- School of Animal, Plant and Environmental Sciences, Faculty of Science, University of Witwatersrand, Johannesburg 2001, South Africa
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