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Gomes ARQ, Cunha N, Varela ELP, Brígido HPC, Vale VV, Dolabela MF, de Carvalho EP, Percário S. Oxidative Stress in Malaria: Potential Benefits of Antioxidant Therapy. Int J Mol Sci 2022; 23:ijms23115949. [PMID: 35682626 PMCID: PMC9180384 DOI: 10.3390/ijms23115949] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 01/07/2023] Open
Abstract
Malaria is an infectious disease and a serious public health problem in the world, with 3.3 billion people in endemic areas in 100 countries and about 200 million new cases each year, resulting in almost 1 million deaths in 2018. Although studies look for strategies to eradicate malaria, it is necessary to know more about its pathophysiology to understand the underlying mechanisms involved, particularly the redox balance, to guarantee success in combating this disease. In this review, we addressed the involvement of oxidative stress in malaria and the potential benefits of antioxidant supplementation as an adjuvant antimalarial therapy.
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Affiliation(s)
- Antonio Rafael Quadros Gomes
- Post-Graduate Program in Pharmaceutica Innovation, Institute of Health Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (A.R.Q.G.); (H.P.C.B.); (V.V.V.); (M.F.D.)
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (N.C.); (E.L.P.V.); (E.P.d.C.)
| | - Natasha Cunha
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (N.C.); (E.L.P.V.); (E.P.d.C.)
| | - Everton Luiz Pompeu Varela
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (N.C.); (E.L.P.V.); (E.P.d.C.)
- Post-graduate Program in Biodiversity and Biotechnology (BIONORTE), Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
| | - Heliton Patrick Cordovil Brígido
- Post-Graduate Program in Pharmaceutica Innovation, Institute of Health Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (A.R.Q.G.); (H.P.C.B.); (V.V.V.); (M.F.D.)
| | - Valdicley Vieira Vale
- Post-Graduate Program in Pharmaceutica Innovation, Institute of Health Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (A.R.Q.G.); (H.P.C.B.); (V.V.V.); (M.F.D.)
| | - Maria Fâni Dolabela
- Post-Graduate Program in Pharmaceutica Innovation, Institute of Health Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (A.R.Q.G.); (H.P.C.B.); (V.V.V.); (M.F.D.)
- Post-graduate Program in Biodiversity and Biotechnology (BIONORTE), Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
| | - Eliete Pereira de Carvalho
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (N.C.); (E.L.P.V.); (E.P.d.C.)
- Post-graduate Program in Biodiversity and Biotechnology (BIONORTE), Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
| | - Sandro Percário
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil; (N.C.); (E.L.P.V.); (E.P.d.C.)
- Post-graduate Program in Biodiversity and Biotechnology (BIONORTE), Institute of Biological Sciences, Federal University of Pará, Belém 66075-110, PA, Brazil
- Correspondence:
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Redaelli S, Magliocca A, Malhotra R, Ristagno G, Citerio G, Bellani G, Berra L, Rezoagli E. Nitric oxide: Clinical applications in critically ill patients. Nitric Oxide 2022; 121:20-33. [PMID: 35123061 PMCID: PMC10189363 DOI: 10.1016/j.niox.2022.01.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/19/2022] [Accepted: 01/31/2022] [Indexed: 12/19/2022]
Abstract
Inhaled nitric oxide (iNO) acts as a selective pulmonary vasodilator and it is currently approved by the FDA for the treatment of persistent pulmonary hypertension of the newborn. iNO has been demonstrated to effectively decrease pulmonary artery pressure and improve oxygenation, while decreasing extracorporeal life support use in hypoxic newborns affected by persistent pulmonary hypertension. Also, iNO seems a safe treatment with limited side effects. Despite the promising beneficial effects of NO in the preclinical literature, there is still a lack of high quality evidence for the use of iNO in clinical settings. A variety of clinical applications have been suggested in and out of the critical care environment, aiming to use iNO in respiratory failure and pulmonary hypertension of adults or as a preventative measure of hemolysis-induced vasoconstriction, ischemia/reperfusion injury and as a potential treatment of renal failure associated with cardiopulmonary bypass. In this narrative review we aim to present a comprehensive summary of the potential use of iNO in several clinical conditions with its suggested benefits, including its recent application in the scenario of the COVID-19 pandemic. Randomized controlled trials, meta-analyses, guidelines, observational studies and case-series were reported and the main findings summarized. Furthermore, we will describe the toxicity profile of NO and discuss an innovative proposed strategy to produce iNO. Overall, iNO exhibits a wide range of potential clinical benefits, that certainly warrants further efforts with randomized clinical trials to determine specific therapeutic roles of iNO.
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Affiliation(s)
- Simone Redaelli
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Aurora Magliocca
- Department of Medical Physiopathology and Transplants, University of Milan, Milano, Italy
| | - Rajeev Malhotra
- Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Giuseppe Ristagno
- Department of Medical Physiopathology and Transplants, University of Milan, Milano, Italy; Department of Anesthesiology, Intensive Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Giuseppe Citerio
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy; Neuroscience Department, NeuroIntensive Care Unit, San Gerardo Hospital, ASST Monza, Monza, Italy
| | - Giacomo Bellani
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy; Department of Emergency and Intensive Care, ECMO Center, San Gerardo University Hospital, Monza, Italy
| | - Lorenzo Berra
- Harvard Medical School, Boston, MA, USA; Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Respiratory Care Department, Massachusetts General Hospital, Boston, MA, USA
| | - Emanuele Rezoagli
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy; Department of Emergency and Intensive Care, ECMO Center, San Gerardo University Hospital, Monza, Italy.
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Heme oxygenase-1, carbon monoxide, and malaria – The interplay of chemistry and biology. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Yu B, Ichinose F, Bloch DB, Zapol WM. Inhaled nitric oxide. Br J Pharmacol 2019; 176:246-255. [PMID: 30288739 PMCID: PMC6295404 DOI: 10.1111/bph.14512] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/14/2018] [Accepted: 08/22/2018] [Indexed: 12/18/2022] Open
Abstract
Nitric oxide (NO) is a gas that induces relaxation of smooth muscle cells in the vasculature. Because NO reacts with oxyhaemoglobin with high affinity, the gas is rapidly scavenged by oxyhaemoglobin in red blood cells and the vasodilating effects of inhaled NO are limited to ventilated regions in the lung. NO therefore has the unique ability to induce pulmonary vasodilatation specifically in the portions of the lung with adequate ventilation, thereby improving oxygenation of blood and decreasing intrapulmonary right to left shunting. Inhaled NO is used to treat a spectrum of cardiopulmonary conditions, including pulmonary hypertension in children and adults. However, the widespread use of inhaled NO is limited by logistical and financial barriers. We have designed, developed and tested a simple and economic NO generation device, which uses pulsed electrical discharges in air to produce therapeutic levels of NO that can be used for inhalation therapy. LINKED ARTICLES: This article is part of a themed section on Nitric Oxide 20 Years from the 1998 Nobel Prize. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.2/issuetoc.
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Affiliation(s)
- Binglan Yu
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMAUSA
| | - Fumito Ichinose
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMAUSA
| | - Donald B Bloch
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMAUSA
- Division of Rheumatology, Allergy and Immunology, Department of MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMAUSA
| | - Warren M Zapol
- Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain MedicineMassachusetts General Hospital, Harvard Medical SchoolBostonMAUSA
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Conroy AL, Hawkes M, Hayford K, Hermann L, McDonald CR, Sharma S, Namasopo S, Opoka RO, John CC, Liles WC, Miller C, Kain KC. Methemoglobin and nitric oxide therapy in Ugandan children hospitalized for febrile illness: results from a prospective cohort study and randomized double-blind placebo-controlled trial. BMC Pediatr 2016; 16:177. [PMID: 27814710 PMCID: PMC5097382 DOI: 10.1186/s12887-016-0719-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 10/25/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Exposure of red blood cells to oxidants increases production of methemoglobin (MHb) resulting in impaired oxygen delivery to tissues. There are no reliable estimates of methemoglobinemia in low resource clinical settings. Our objectives were to: i) evaluate risk factors for methemoglobinemia in Ugandan children hospitalized with fever (study 1); and ii) investigate MHb responses in critically ill Ugandan children with severe malaria treated with inhaled nitric oxide (iNO), an oxidant that induces MHb in a dose-dependent manner (study 2). METHODS Two prospective studies were conducted at Jinja Regional Referral Hospital in Uganda between 2011 and 2013. Study 1, a prospective cohort study of children admitted to hospital with fever (fever cohort, n = 2089 children 2 months to 5 years). Study 2, a randomized double-blind placebo-controlled parallel arm trial of room air placebo vs. 80 ppm iNO as an adjunctive therapy for children with severe malaria (RCT, n = 180 children 1-10 years receiving intravenous artesunate and 72 h of study gas). The primary outcomes were: i) masimo pulse co-oximetry elevated MHb levels at admission (>2 %, fever cohort); ii) four hourly MHb levels in the RCT. RESULTS In the fever cohort, 34 % of children admitted with fever had elevated MHb at admission. Children with a history of vomiting, delayed capillary refill, elevated lactate, severe anemia, malaria, or hemoglobinopathies had increased odds of methemoglobinemia (p < 0.05 in a multivariate model). MHb levels at admission were higher in children who died (n = 89) compared to those who survived (n = 1964), p = 0.008. Among children enrolled in the iNO RCT, MHb levels typically plateaued within 12-24 h of starting study gas. MHb levels were higher in children receiving iNO compared to placebo, and MHb > 10 % occurred in 5.7 % of children receiving iNO. There were no differences in rates of study gas discontinuation between trial arms. CONCLUSIONS Hospitalized children with evidence of impaired oxygen delivery, metabolic acidosis, anemia, or malaria were at risk of methemoglobinemia. However, we demonstrated high-dose iNO could be safely administered to critically ill children with severe malaria with appropriate MHb monitoring. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT01255215 (Date registered: December 5, 2010).
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Affiliation(s)
- Andrea L Conroy
- Depatment of Medicine, University of Toronto, Toronto, Canada.,Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada
| | - Michael Hawkes
- Division of Pediatric Infectious Diseases, University of Alberta, Edmonton, Canada
| | - Kyla Hayford
- Depatment of Medicine, University of Toronto, Toronto, Canada.,Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada
| | - Laura Hermann
- Depatment of Medicine, University of Toronto, Toronto, Canada
| | - Chloe R McDonald
- Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, Canada
| | - Suparna Sharma
- Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada
| | - Sophie Namasopo
- Department of Pediatrics, Jinja Regional Referral Hospital, Jinja, Uganda
| | - Robert O Opoka
- Department of Paediatrics and Child Health, Mulago Hospital, Makerere University, Kampala, Uganda
| | - Chandy C John
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - W Conrad Liles
- Department of Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Christopher Miller
- Department of Respiratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Kevin C Kain
- Depatment of Medicine, University of Toronto, Toronto, Canada. .,Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University Health Network-Toronto General Hospital, University of Toronto, Toronto, Canada. .,Institute of Medical Sciences, University of Toronto, Toronto, Canada. .,Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Canada. .,MaRS Centre, TMDT, 10th floor 10-351, Toronto, ON, M5G1L7, Canada.
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Severe malaria: what's new on the pathogenesis front? Int J Parasitol 2016; 47:145-152. [PMID: 27670365 DOI: 10.1016/j.ijpara.2016.08.002] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 08/09/2016] [Accepted: 08/15/2016] [Indexed: 12/25/2022]
Abstract
Plasmodium falciparum causes the most severe and fatal form of malaria in humans with over half a million deaths each year. Cerebral malaria, a complex neurological syndrome of severe falciparum malaria, is often fatal and represents a major public health burden. Despite vigorous efforts, the pathophysiology of cerebral malaria remains to be elucidated, thereby hindering the development of adjunctive therapies. In recent years, multidisciplinary and collaborative approaches have led to groundbreaking progress both in the laboratory and in the field. Here we review the latest breakthroughs in severe malaria pathogenesis, with a specific focus on new pathogenetic mechanisms leading to cerebral malaria. The most recent findings point towards specific parasite phenotypes targeting brain microvasculature, endothelial dysfunction and subsequent oedema-induced brain swelling.
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Hawkes MT, Conroy AL, Opoka RO, Hermann L, Thorpe KE, McDonald C, Kim H, Higgins S, Namasopo S, John C, Miller C, Liles WC, Kain KC. Inhaled nitric oxide as adjunctive therapy for severe malaria: a randomized controlled trial. Malar J 2015; 14:421. [PMID: 26510464 PMCID: PMC4625637 DOI: 10.1186/s12936-015-0946-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 10/21/2015] [Indexed: 05/15/2023] Open
Abstract
BACKGROUND Severe malaria remains a major cause of childhood mortality globally. Decreased endothelial nitric oxide is associated with severe and fatal malaria. The hypothesis was that adjunctive inhaled nitric oxide (iNO) would improve outcomes in African children with severe malaria. METHODS A randomized, blinded, placebo-controlled trial of iNO at 80 ppm by non-rebreather mask versus room air placebo as adjunctive treatment to artesunate in children with severe malaria was conducted. The primary outcome was the longitudinal course of angiopoietin-2 (Ang-2), an endothelial biomarker of malaria severity and clinical outcome. RESULTS One hundred and eighty children were enrolled; 88 were assigned to iNO and 92 to placebo (all received IV artesunate). Ang-2 levels measured over the first 72 h of hospitalization were not significantly different between groups. The mortality at 48 h was similar between groups [6/87 (6.9 %) in the iNO group vs 8/92 (8.7 %) in the placebo group; OR 0.78, 95 % CI 0.26-2.3; p = 0.65]. Clinical recovery times and parasite clearance kinetics were similar (p > 0.05). Methaemoglobinaemia >7 % occurred in 25 % of patients receiving iNO and resolved without sequelae. The incidence of neurologic deficits (<14 days), acute kidney injury, hypoglycaemia, anaemia, and haemoglobinuria was similar between groups (p > 0.05). CONCLUSIONS iNO at 80 ppm administered by non-rebreather mask was safe but did not affect circulating levels of Ang-2. Alternative methods of enhancing endothelial NO bioavailability may be necessary to achieve a biological effect and improve clinical outcome. TRIAL REGISTRATION ClinicalTrials.gov NCT01255215.
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Affiliation(s)
- Michael T Hawkes
- 3-588D Edmonton Clinic Health Academy, University of Alberta, 11405 87 Ave NW, Edmonton, AB, T6G 1C9, Canada.
| | - Andrea L Conroy
- Sandra Rotman Centre for Global Health, MaRS Centre, University of Toronto, 101 College St TMDT 10-360A, Toronto, ON, M5G 1L7, Canada.
| | - Robert O Opoka
- Global Health Uganda, Upper Paediatrics Office, Mulago Hospital, PO Box 33842, Plot 138, Upper Mawanda Road, Kawempe, Kampala, Uganda.
| | - Laura Hermann
- Sandra Rotman Centre for Global Health, MaRS Centre, University of Toronto, 101 College St TMDT 10-360A, Toronto, ON, M5G 1L7, Canada.
| | - Kevin E Thorpe
- Applied Health Research Centre, St Michael's Hospital, 250 Yonge St, 6th Floor, Toronto, ON, M5T 3M7, Canada.
| | - Chloe McDonald
- Sandra Rotman Centre for Global Health, MaRS Centre, University of Toronto, 101 College St TMDT 10-360A, Toronto, ON, M5G 1L7, Canada.
| | - Hani Kim
- Johns Hopkins School of Public Health, International Vaccine Access Center, 615 N Wolfe St, Baltimore, MD, 21205, USA.
| | - Sarah Higgins
- Sandra Rotman Centre for Global Health, MaRS Centre, University of Toronto, 101 College St TMDT 10-360A, Toronto, ON, M5G 1L7, Canada.
| | - Sophie Namasopo
- Jinja Regional Referral Hospital, Plot 7, Nalufenya Road, Jinja, Uganda.
| | - Chandy John
- Department of Pediatrics, Indiana University, 702 Barnhill Dr, Room 5900, Indianapolis, IN, 46202, USA.
| | - Chris Miller
- Division of Infectious Disease, University of British Columbia, Rm D433, HP East, Vancouver Hospital, 2733 Heather Street, Vancouver, BC, V5Z-3J5, Canada.
| | - W Conrad Liles
- Department of Medicine, University of Washington, 1959 NE Pacific Street, HSB RR-511, Box 356420, Seattle, WA, 98195-6420, USA.
| | - Kevin C Kain
- Sandra Rotman Centre for Global Health, MaRS Centre, University of Toronto, 101 College St TMDT 10-360A, Toronto, ON, M5G 1L7, Canada.
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Eisenhut M. The evidence for a role of vasospasm in the pathogenesis of cerebral malaria. Malar J 2015; 14:405. [PMID: 26463364 PMCID: PMC4603731 DOI: 10.1186/s12936-015-0928-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/01/2015] [Indexed: 12/31/2022] Open
Abstract
Due to delay in treatment, cerebral malaria (CM) remains a significant complication of Plasmodium falciparum infection and is a common cause of death from malaria. In addition, more than 10 % of children surviving CM have neurological and long-term cognitive deficits. Understanding the pathogenesis of CM enables design of supportive treatment, reducing neurological morbidity and mortality. Vaso-occlusion and brain swelling appear to be leading to clinical features, neuronal damage and death in CM. It is proposed that parasitized red blood cells (pRBC), due to cytoadhesion to the endothelium and vasospasm induced by reduced bioavailability of nitric oxide, are causes. Stasis of blood flow and accumulation of pRBC may allow, after schizont rupture, for high concentration of products of haemolysis to accumulate, which leads to localized nitric oxide depletion, inducing adhesion molecules and cerebral vasospasm. Features consistent with an involvement of vasospasm are rapid reversibility of neurological symptoms, intermittently increased or absent flow in medium cerebral artery detectable on Doppler ultrasound and hemispheric reversible changes on cerebral magnetic resonance imaging in some patients. Clinical trials of treatment that can rapidly reduce cerebral vasospasm, including nitric oxide donors, inhaled nitric oxide, endothelin or calcium antagonists, or tissue plasminogen activators, are warranted.
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Affiliation(s)
- Michael Eisenhut
- Luton and Dunstable University Hospital NHS Foundation Trust, Lewsey Road, Luton, LU4ODZ, UK.
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Nacer A, Movila A, Sohet F, Girgis NM, Gundra UM, Loke P, Daneman R, Frevert U. Experimental cerebral malaria pathogenesis--hemodynamics at the blood brain barrier. PLoS Pathog 2014; 10:e1004528. [PMID: 25474413 PMCID: PMC4256476 DOI: 10.1371/journal.ppat.1004528] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 10/17/2014] [Indexed: 12/16/2022] Open
Abstract
Cerebral malaria claims the lives of over 600,000 African children every year. To better understand the pathogenesis of this devastating disease, we compared the cellular dynamics in the cortical microvasculature between two infection models, Plasmodium berghei ANKA (PbA) infected CBA/CaJ mice, which develop experimental cerebral malaria (ECM), and P. yoelii 17XL (PyXL) infected mice, which succumb to malarial hyperparasitemia without neurological impairment. Using a combination of intravital imaging and flow cytometry, we show that significantly more CD8(+) T cells, neutrophils, and macrophages are recruited to postcapillary venules during ECM compared to hyperparasitemia. ECM correlated with ICAM-1 upregulation on macrophages, while vascular endothelia upregulated ICAM-1 during ECM and hyperparasitemia. The arrest of large numbers of leukocytes in postcapillary and larger venules caused microrheological alterations that significantly restricted the venous blood flow. Treatment with FTY720, which inhibits vascular leakage, neurological signs, and death from ECM, prevented the recruitment of a subpopulation of CD45(hi) CD8(+) T cells, ICAM-1(+) macrophages, and neutrophils to postcapillary venules. FTY720 had no effect on the ECM-associated expression of the pattern recognition receptor CD14 in postcapillary venules suggesting that endothelial activation is insufficient to cause vascular pathology. Expression of the endothelial tight junction proteins claudin-5, occludin, and ZO-1 in the cerebral cortex and cerebellum of PbA-infected mice with ECM was unaltered compared to FTY720-treated PbA-infected mice or PyXL-infected mice with hyperparasitemia. Thus, blood brain barrier opening does not involve endothelial injury and is likely reversible, consistent with the rapid recovery of many patients with CM. We conclude that the ECM-associated recruitment of large numbers of activated leukocytes, in particular CD8(+) T cells and ICAM(+) macrophages, causes a severe restriction in the venous blood efflux from the brain, which exacerbates the vasogenic edema and increases the intracranial pressure. Thus, death from ECM could potentially occur as a consequence of intracranial hypertension.
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Affiliation(s)
- Adéla Nacer
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Alexandru Movila
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Fabien Sohet
- Department of Anatomy, University of California San Francisco, San Francisco, California, United States of America
| | - Natasha M. Girgis
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Uma Mahesh Gundra
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - P'ng Loke
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
| | - Richard Daneman
- Department of Anatomy, University of California San Francisco, San Francisco, California, United States of America
| | - Ute Frevert
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
- * E-mail:
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10
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Frevert U, Nacer A. Fatal cerebral malaria: a venous efflux problem. Front Cell Infect Microbiol 2014; 4:155. [PMID: 25414834 PMCID: PMC4222339 DOI: 10.3389/fcimb.2014.00155] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 10/13/2014] [Indexed: 12/20/2022] Open
Abstract
Most Plasmodium falciparum-infected children with cerebral malaria (CM) die from respiratory arrest, but the underlying pathology is unclear. Here we present a model in which the ultimate cause of death from CM is severe intracranial hypertension. Dynamic imaging of mice infected with P. berghei ANKA, an accepted model for experimental CM, revealed that leukocyte adhesion impairs the venous blood flow by reducing the functional lumen of postcapillary venules (PCV). The resulting increase in intracranial pressure (ICP) exacerbates cerebral edema formation, a hallmark of both murine and pediatric CM. We propose that two entirely different pathogenetic mechanisms-cytoadherence of P. falciparum-infected erythrocytes in pediatric CM and leukocyte arrest in murine CM-result in the same pathological outcome: a severe increase in ICP leading to brainstem herniation and death from respiratory arrest. The intracranial hypertension (IH) model unifies previous hypotheses, applies to human and experimental CM alike, eliminates the need to explain any selective recognition mechanism Plasmodium might use to target multiple sensitive sites in the brain, and explains how an intravascular parasite can cause so much neuronal dysfunction.
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Affiliation(s)
- Ute Frevert
- Division of Medical Parasitology, Department of Microbiology, New York University School of Medicine New York, NY, USA
| | - Adéla Nacer
- Unité de Biologie des Interactions Hôte-Parasite, Département de Parasitologie et Mycologie, Institut Pasteur Paris, France
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11
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Cabrera A, Neculai D, Kain KC. CD36 and malaria: friends or foes? A decade of data provides some answers. Trends Parasitol 2014; 30:436-44. [PMID: 25113859 DOI: 10.1016/j.pt.2014.07.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 07/16/2014] [Accepted: 07/17/2014] [Indexed: 02/07/2023]
Abstract
The past 10 years have generated new insights into the complex interaction between CD36 (cluster of differentiation 36) and malaria. These range from the crystallization of the CD36 homolog, LIMPII (lysosomal integral membrane protein II), permitting modeling of CD36 and its binding to diverse ligands, to cell biology-based studies of CD36 and large population genetic studies assessing the association of CD36 polymorphisms and malarial disease severity. Collectively these lines of evidence indicate that a receptor other than CD36 is associated with severity. CD36 plays an important role in innate immunity and in the phagocytic uptake of multiple pathogens including malaria. CD36 polymorphisms lack association with severity, and isolates that cause severe disease primarily bind to endothelial protein C receptor (EPCR) rather than to CD36.
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Affiliation(s)
- Ana Cabrera
- Sandra Ann Rotman (SAR) Laboratories, SAR Centre, Toronto General Hospital, University Health Network, Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Dante Neculai
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Kevin C Kain
- Sandra Ann Rotman (SAR) Laboratories, SAR Centre, Toronto General Hospital, University Health Network, Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Hawkes M, Conroy AL, Opoka RO, Namasopo S, Liles WC, John CC, Kain KC. Performance of point-of-care diagnostics for glucose, lactate, and hemoglobin in the management of severe malaria in a resource-constrained hospital in Uganda. Am J Trop Med Hyg 2014; 90:605-8. [PMID: 24591431 DOI: 10.4269/ajtmh.13-0689] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Severe malaria is frequently managed without access to laboratory testing. We report on the performance of point-of-care tests used to guide the management of a cohort of 179 children with severe malaria in a resource-limited Ugandan hospital. Correlation coefficients between paired measurements for glucose (i-STAT and One Touch Ultra), lactate (i-STAT and Lactate Scout), and hemoglobin (Hb; laboratory and i-STAT) were 0.86, 0.85, and 0.73, respectively. The OneTouch Ultra glucometer readings deviated systematically from the i-STAT values by +1.7 mmol/L. Lactate Scout values were systematically higher than i-STAT by +0.86 mmol/L. Lactate measurements from either device predicted subsequent mortality. Hb estimation by the i-STAT instrument was unbiased, with upper and lower limits of agreement of -34 and +34 g/L, and it was 91% sensitive and 89% specific for the diagnosis of severe anemia (Hb < 50 g/L). New commercially available bedside diagnostic tools, although imperfect, may expedite clinical decision-making in the management of critically ill children in resource-constrained settings.
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Affiliation(s)
- Michael Hawkes
- Division of Infectious Diseases, Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada; Department of Medicine and Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada; Department of Paediatrics and Child Health, Mulago Hospital and Makerere University, Kampala, Uganda; Department of Paediatrics, Jinja Regional Referral Hospital, Jinja, Uganda; Department of Medicine, University of Washington, Seattle, Washington; Division of Global Pediatrics, Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota; Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, Toronto, Ontario, Canada; Tropical Disease Unit, University Health Network-Toronto General Hospital, Toronto, Ontario, Canada
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Experimental Models of Microvascular Immunopathology: The Example of Cerebral Malaria. JOURNAL OF NEUROINFECTIOUS DISEASES 2014; 5:134. [PMID: 26430675 PMCID: PMC4586166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Human cerebral malaria is a severe and often lethal complication of Plasmodium falciparum infection. Complex host and parasite interactions should the precise mechanisms involved in the onset of this neuropathology. Adhesion of parasitised red blood cells and host cells to endothelial cells lead to profound endothelial alterations that trigger immunopathological changes, varying degrees of brain oedema and can compromise cerebral blood flow, cause cranial nerve dysfunction and hypoxia. Study of the cerebral pathology in human patients is limited to clinical and genetic field studies in endemic areas, thus cerebral malaria (CM) research relies heavily on experimental models. The availability of malaria models allows study from the inoculation of Plasmodium to the onset of disease and permit invasive experiments. Here, we discuss some aspects of our current understanding of CM, the experimental models available and some important recent findings extrapolated from these models.
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Hawkes M, Conroy AL, Opoka RO, Namasopo S, Liles WC, John CC, Kain KC. Use of a three-band HRP2/pLDH combination rapid diagnostic test increases diagnostic specificity for falciparum malaria in Ugandan children. Malar J 2014; 13:43. [PMID: 24484540 PMCID: PMC3922073 DOI: 10.1186/1475-2875-13-43] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 01/27/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Rapid diagnostic tests (RDTs) for malaria provide a practical alternative to light microscopy for malaria diagnosis in resource-limited settings. Three-band RDTs incorporating two parasite antigens may have enhanced diagnostic specificity, relative to two-band RDTs with a single parasite antigen (typically histidine-rich protein 2 [HRP2]). METHODS Phase 1: 2,000 children, two months to five years of age, admitted to a referral hospital in Jinja, Uganda, with acute febrile illness were enrolled. A WHO highly rated three-band RDT was compared to light microscopy of thick peripheral blood films read by local expert microscopists.Phase 2: the three-band RDT was used as a screening tool for inclusion of patients in a clinical trial, and subjects with three positive RDT bands were tested by microscopy using blood samples drawn in parallel. Discordant results were adjudicated by PCR. RESULTS Phase 1: 1,648 children had both a RDT and peripheral blood smear performed. The specificity of a RDT with all three bands positive was 82% (95% CI: 79-85%) compared to 62% (95% CI: 59-66%) for HRP2 alone. The sensitivity was 88% (95% CI: 85-89%) and 94% (95% CI: 92-95%) for three-band positive RDT and HRP2 antigen, respectively. 119 patients (7.2%) had a positive HRP2 band, but negative parasite lactate dehydrogenase (pLHD) band and negative peripheral smear, and 72 (61%) of these had received pre-treatment with anti-malarials, suggesting a false positive HRP2 result (p = 0.002).Phase 2: the positive predictive value (PPV) of the three-band RDT was 94% (95% CI 89%-97%) using microscopy as the reference standard. However, microscopy-discordant results were shown to be positive for P. falciparum by PCR in all cases, suggesting that the PPV was in fact higher. CONCLUSION The pLDH antigen on three-band RDTs, used in combination with HRP2, provides added diagnostic specificity for malaria parasitaemia and may be useful to distinguish acute infection from recently treated infection. In situations where diagnostic specificity is desirable (e.g., for selection of malaria-infected participants in clinical trials), a three-band RDT should be considered in a sub-Saharan African setting.
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Affiliation(s)
| | | | | | | | | | | | - Kevin C Kain
- Department of Medicine, University of Toronto, Toronto, Canada.
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Abstract
Severe malaria is a medical emergency requiring early intervention to prevent death. This article highlights key aspects of the management of severe malaria syndromes in the intensive care unit, with a focus on individual case management of imported malaria. Key differences in the presentation, management, and outcomes of severe malaria by endemicity and by age group are emphasized. In all groups with severe malaria, intravenous artesunate is the antimalarial agent of choice. This article discusses specific antimalarial therapies, optimal supportive management strategies, differences from strategies for bacterial sepsis, and trials of adjunctive therapy for severe malaria in humans.
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Hawkes M, Elphinstone RE, Conroy AL, Kain KC. Contrasting pediatric and adult cerebral malaria: the role of the endothelial barrier. Virulence 2013; 4:543-55. [PMID: 23924893 PMCID: PMC5359751 DOI: 10.4161/viru.25949] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Malaria affects millions of people around the world and a small subset of those infected develop cerebral malaria. The clinical presentation of cerebral malaria differs between children and adults, and it has been suggested that age-related changes in the endothelial response may account for some of these differences. During cerebral malaria, parasites sequester within the brain microvasculature but do not penetrate into the brain parenchyma and yet, the infection causes severe neurological symptoms. Endothelial dysfunction is thought to play an important role in mediating these adverse clinical outcomes. During infection, the endothelium becomes activated and more permeable, which leads to increased inflammation, hemorrhages, and edema in the surrounding tissue. We hypothesize that post-natal developmental changes, occurring in both endothelial response and the neurovascular unit, account for the differences observed in the clinical presentations of cerebral malaria in children compared with adults.
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Wilson NO, Solomon W, Anderson L, Patrickson J, Pitts S, Bond V, Liu M, Stiles JK. Pharmacologic inhibition of CXCL10 in combination with anti-malarial therapy eliminates mortality associated with murine model of cerebral malaria. PLoS One 2013; 8:e60898. [PMID: 23630573 PMCID: PMC3618178 DOI: 10.1371/journal.pone.0060898] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 03/04/2013] [Indexed: 02/05/2023] Open
Abstract
Despite appropriate anti-malarial treatment, cerebral malaria (CM)-associated mortalities remain as high as 30%. Thus, adjunctive therapies are urgently needed to prevent or reduce such mortalities. Overproduction of CXCL10 in a subset of CM patients has been shown to be tightly associated with fatal human CM. Mice with deleted CXCL10 gene are partially protected against experimental cerebral malaria (ECM) mortality indicating the importance of CXCL10 in the pathogenesis of CM. However, the direct effect of increased CXCL10 production on brain cells is unknown. We assessed apoptotic effects of CXCL10 on human brain microvascular endothelial cells (HBVECs) and neuroglia cells in vitro. We tested the hypothesis that reducing overexpression of CXCL10 with a synthetic drug during CM pathogenesis will increase survival and reduce mortality. We utilized atorvastatin, a widely used synthetic blood cholesterol-lowering drug that specifically targets and reduces plasma CXCL10 levels in humans, to determine the effects of atorvastatin and artemether combination therapy on murine ECM outcome. We assessed effects of atorvastatin treatment on immune determinants of severity, survival, and parasitemia in ECM mice receiving a combination therapy from onset of ECM (day 6 through 9 post-infection) and compared results with controls. The results indicate that CXCL10 induces apoptosis in HBVECs and neuroglia cells in a dose-dependent manner suggesting that increased levels of CXCL10 in CM patients may play a role in vasculopathy, neuropathogenesis, and brain injury during CM pathogenesis. Treatment of ECM in mice with atorvastatin significantly reduced systemic and brain inflammation by reducing the levels of the anti-angiogenic and apoptotic factor (CXCL10) and increasing angiogenic factor (VEGF) production. Treatment with a combination of atorvastatin and artemether improved survival (100%) when compared with artemether monotherapy (70%), p<0.05. Thus, adjunctively reducing CXCL10 levels and inflammation by atorvastatin treatment during anti-malarial therapy may represent a novel approach to treating CM patients.
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Affiliation(s)
- Nana O. Wilson
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Wesley Solomon
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Leonard Anderson
- Cardiovascular Research Institute, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - John Patrickson
- Department of Pathology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Sidney Pitts
- Department of Pathology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Vincent Bond
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Mingli Liu
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Jonathan K. Stiles
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
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Percário S, Moreira DR, Gomes BAQ, Ferreira MES, Gonçalves ACM, Laurindo PSOC, Vilhena TC, Dolabela MF, Green MD. Oxidative stress in malaria. Int J Mol Sci 2012; 13:16346-72. [PMID: 23208374 PMCID: PMC3546694 DOI: 10.3390/ijms131216346] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 11/08/2012] [Accepted: 11/23/2012] [Indexed: 12/16/2022] Open
Abstract
Malaria is a significant public health problem in more than 100 countries and causes an estimated 200 million new infections every year. Despite the significant effort to eradicate this dangerous disease, lack of complete knowledge of its physiopathology compromises the success in this enterprise. In this paper we review oxidative stress mechanisms involved in the disease and discuss the potential benefits of antioxidant supplementation as an adjuvant antimalarial strategy.
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Affiliation(s)
- Sandro Percário
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Danilo R. Moreira
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Bruno A. Q. Gomes
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Michelli E. S. Ferreira
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Ana Carolina M. Gonçalves
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Paula S. O. C. Laurindo
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Thyago C. Vilhena
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Maria F. Dolabela
- Pharmacy Faculty, Institute of Health Sciences, Federal University of Para. Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mail:
| | - Michael D. Green
- US Centers for Disease Control and Prevention, 1600 Clifton Road NE, mailstop G49, Atlanta, GA 30329, USA; E-Mail:
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Abstract
PURPOSE OF REVIEW Artesunate treatment reduces mortality in severe malaria when compared with quinine. Nevertheless, severe malaria is associated with mortality rates between 1.4 and 9.5% after hospitalization. This review puts into context the recent developments in understanding the pathophysiology of malaria and how these may be reflected in renewed attempts at improving adjunct therapies. Identifying new adjunct approaches has been particularly difficult for severe malaria because most interventions have either caused harm or failed to confer benefit. RECENT FINDINGS Imaging and postmortem findings in children with severe and cerebral malaria have given impetus to study new interventions that could be added to antimalarial treatment. Some pilot studies have (re)tested different approaches to improve complications of cerebral malaria such as the use of N-acetyl cysteine or mannitol. Fluids administration, blood transfusions and red cell exchanges in severe malaria are controversial and important areas that are also reviewed with new evidence. Other interventions such as measures to increase nitric oxide, manage acute renal failure or optimize artesunate dosing are discussed. SUMMARY Outcomes with adjunct therapies for severe malaria have been poor, but as insights into pathophysiological processes are deepened it may be possible eventually to reduce mortality further.
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Inhaled nitric oxide reduces endothelial activation and parasite accumulation in the brain, and enhances survival in experimental cerebral malaria. PLoS One 2011; 6:e27714. [PMID: 22110737 PMCID: PMC3218025 DOI: 10.1371/journal.pone.0027714] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 10/22/2011] [Indexed: 01/08/2023] Open
Abstract
The host immune response contributes to the onset and progression of severe malaria syndromes, such as cerebral malaria. Adjunctive immunomodulatory strategies for severe malaria may improve clinical outcome beyond that achievable with artemisinin-based therapy alone. Here, we report that prophylaxis with inhaled nitric oxide significantly reduced systemic inflammation (lower TNF, IFNγ and MCP-1 in peripheral blood) and endothelial activation (decreased sICAM-1 and vWF, and increased angiopoeitin-1 levels in peripheral blood) in an experimental cerebral malaria model. Mice that received inhaled nitric oxide starting prior to infection had reduced parasitized erythrocyte accumulation in the brain, decreased brain expression of ICAM-1, and preserved vascular integrity compared to control mice. Inhaled nitric oxide administered in combination with artesunate, starting as late as 5.5 days post-infection, improved survival over treatment with artesunate alone (70% survival in the artesunate only vs. 100% survival in the artesunate plus iNO group, p = 0.03). These data support the clinical investigation of inhaled nitric oxide as a novel adjunctive therapy in patients with severe malaria.
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