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Yeo TW, Lampah DA, Kenangalem E, Tjitra E, Price RN, Weinberg JB, Hyland K, Granger DL, Anstey NM. Impaired systemic tetrahydrobiopterin bioavailability and increased dihydrobiopterin in adult falciparum malaria: association with disease severity, impaired microvascular function and increased endothelial activation. PLoS Pathog 2015; 11:e1004667. [PMID: 25764397 PMCID: PMC4357386 DOI: 10.1371/journal.ppat.1004667] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 01/07/2015] [Indexed: 12/22/2022] Open
Abstract
Tetrahydrobiopterin (BH₄) is a co-factor required for catalytic activity of nitric oxide synthase (NOS) and amino acid-monooxygenases, including phenylalanine hydroxylase. BH4 is unstable: during oxidative stress it is non-enzymatically oxidized to dihydrobiopterin (BH₂), which inhibits NOS. Depending on BH₄ availability, NOS oscillates between NO synthase and NADPH oxidase: as the BH₄/BH₂ ratio decreases, NO production falls and is replaced by superoxide. In African children and Asian adults with severe malaria, NO bioavailability decreases and plasma phenylalanine increases, together suggesting possible BH₄ deficiency. The primary three biopterin metabolites (BH₄, BH₂ and B₀ [biopterin]) and their association with disease severity have not been assessed in falciparum malaria. We measured pterin metabolites in urine of adults with severe falciparum malaria (SM; n=12), moderately-severe malaria (MSM, n=17), severe sepsis (SS; n=5) and healthy subjects (HC; n=20) as controls. In SM, urinary BH₄ was decreased (median 0.16 ¼mol/mmol creatinine) compared to MSM (median 0.27), SS (median 0.54), and HC (median 0.34)]; p<0.001. Conversely, BH₂ was increased in SM (median 0.91 ¼mol/mmol creatinine), compared to MSM (median 0.67), SS (median 0.39), and HC (median 0.52); p<0.001, suggesting increased oxidative stress and insufficient recycling of BH2 back to BH4 in severe malaria. Overall, the median BH₄/BH₂ ratio was lowest in SM [0.18 (IQR: 0.04-0.32)] compared to MSM (0.45, IQR 0.27-61), SS (1.03; IQR 0.54-2.38) and controls (0.66; IQR 0.43-1.07); p<0.001. In malaria, a lower BH₄/BH₂ ratio correlated with decreased microvascular reactivity (r=0.41; p=0.03) and increased ICAM-1 (r=-0.52; p=0.005). Decreased BH4 and increased BH₂ in severe malaria (but not in severe sepsis) uncouples NOS, leading to impaired NO bioavailability and potentially increased oxidative stress. Adjunctive therapy to regenerate BH4 may have a role in improving NO bioavailability and microvascular perfusion in severe falciparum malaria.
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Affiliation(s)
- Tsin W. Yeo
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
- Institute of Infectious Disease and Epidemiology, Tan Tock Seng Hospital, Singapore
| | - Daniel A. Lampah
- Menzies School of Health Research-National Institute of Health Research and Development Research Program, and District Ministry of Health, Timika, Papua, Indonesia
| | - Enny Kenangalem
- Menzies School of Health Research-National Institute of Health Research and Development Research Program, and District Ministry of Health, Timika, Papua, Indonesia
| | - Emiliana Tjitra
- National Institute of Health Research and Development, Jakarta, Indonesia
| | - Ric N. Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - J. Brice Weinberg
- Duke University and VA Medical Centers, Durham, North Carolina, United States of America
| | - Keith Hyland
- Medical Neurogenetics LLC, Atlanta, Georgia, United States of America
| | - Donald L. Granger
- Division of Infectious Diseases, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah, United States of America
| | - Nicholas M. Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, Northern Territory, Australia
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Rubach MP, Mukemba J, Florence S, Lopansri BK, Hyland K, Volkheimer AD, Yeo TW, Anstey NM, Weinberg JB, Mwaikambo ED, Granger DL. Impaired systemic tetrahydrobiopterin bioavailability and increased oxidized biopterins in pediatric falciparum malaria: association with disease severity. PLoS Pathog 2015; 11:e1004655. [PMID: 25764173 PMCID: PMC4357384 DOI: 10.1371/journal.ppat.1004655] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 01/05/2015] [Indexed: 12/17/2022] Open
Abstract
Decreased bioavailability of nitric oxide (NO) is a major contributor to the pathophysiology of severe falciparum malaria. Tetrahydrobiopterin (BH4) is an enzyme cofactor required for NO synthesis from L-arginine. We hypothesized that systemic levels of BH₄ would be decreased in children with cerebral malaria, contributing to low NO bioavailability. In an observational study in Tanzania, we measured urine levels of biopterin in its various redox states (fully reduced [BH₄] and the oxidized metabolites, dihydrobiopterin [BH₂] and biopterin [B₀]) in children with uncomplicated malaria (UM, n = 55), cerebral malaria (CM, n = 45), non-malaria central nervous system conditions (NMC, n = 48), and in 111 healthy controls (HC). Median urine BH4 concentration in CM (1.10 [IQR:0.55-2.18] μmol/mmol creatinine) was significantly lower compared to each of the other three groups - UM (2.10 [IQR:1.32-3.14];p<0.001), NMC (1.52 [IQR:1.01-2.71];p = 0.002), and HC (1.60 [IQR:1.15-2.23];p = 0.005). Oxidized biopterins were increased, and the BH4:BH2 ratio markedly decreased in CM. In a multivariate logistic regression model, each Log10-unit decrease in urine BH4 was independently associated with a 3.85-fold (95% CI:1.89-7.61) increase in odds of CM (p<0.001). Low systemic BH4 levels and increased oxidized biopterins contribute to the low NO bioavailability observed in CM. Adjunctive therapy to regenerate BH4 may have a role in improving NO bioavailability and microvascular perfusion in severe falciparum malaria.
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Affiliation(s)
- Matthew P. Rubach
- Department of Medicine, Duke University and VA Medical Centers, Durham, North Carolina, United States of America
| | - Jackson Mukemba
- Department of Pediatrics, Hubert Kairuki Memorial University, Dar es Salaam, United Republic of Tanzania
| | - Salvatore Florence
- Department of Pediatrics, Hubert Kairuki Memorial University, Dar es Salaam, United Republic of Tanzania
| | - Bert K. Lopansri
- Department of Medicine, Intermountain Healthcare, Salt Lake City, Utah, United States of America
- Department of Medicine, University of Utah School of Medicine and VA Medical Center, Salt Lake City, Utah, United States of America
| | - Keith Hyland
- Neurochemistry Division, Medical Neurogenetics, Atlanta, Georgia, United States of America
| | - Alicia D. Volkheimer
- Department of Medicine, Duke University and VA Medical Centers, Durham, North Carolina, United States of America
| | - Tsin W. Yeo
- Global and Tropical Health Division, Menzies School for Health Research and Charles Darwin University, Darwin, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, Northern Territory, Australia
- Department of Medicine, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Nicholas M. Anstey
- Global and Tropical Health Division, Menzies School for Health Research and Charles Darwin University, Darwin, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - J. Brice Weinberg
- Department of Medicine, Duke University and VA Medical Centers, Durham, North Carolina, United States of America
| | - Esther D. Mwaikambo
- Department of Pediatrics, Hubert Kairuki Memorial University, Dar es Salaam, United Republic of Tanzania
| | - Donald L. Granger
- Department of Medicine, University of Utah School of Medicine and VA Medical Center, Salt Lake City, Utah, United States of America
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Anyona SB, Kempaiah P, Raballah E, Davenport GC, Were T, Konah SN, Vulule JM, Hittner JB, Gichuki CW, Ong'echa JM, Perkins DJ. Reduced systemic bicyclo-prostaglandin-E2 and cyclooxygenase-2 gene expression are associated with inefficient erythropoiesis and enhanced uptake of monocytic hemozoin in children with severe malarial anemia. Am J Hematol 2012; 87:782-9. [PMID: 22730036 DOI: 10.1002/ajh.23253] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 04/26/2012] [Indexed: 11/09/2022]
Abstract
In holoendemic Plasmodium falciparum transmission areas, severe malaria primarily occurs in children aged <48 months and manifests as severe malarial anemia [SMA; hemoglobin (Hb) < 6.0 g/dL]. Induction of high levels of prostaglandin-E(2) (PGE(2)) through inducible cyclooxygenase-2 (COX-2) is an important host-defense mechanism against invading pathogens. We have previously shown that COX-2-derived PGE(2) levels are reduced in children residing in hyperendemic transmission regions with cerebral malaria and in those with mixed sequelae of anemia and hyperparasitemia. Our in vitro studies further demonstrated that reduced PGE(2) was due to downregulation of COX-2 gene products following phagocytosis of malarial pigment (hemozoin, PfHz). However, as COX-2-PGE(2) pathways and the impact of naturally acquired PfHz on erythropoietic responses have not been determined in children with SMA, plasma and urinary bicyclo-PGE(2)/creatinine and leukocytic COX-2 transcripts were determined in parasitized children (<36 months) stratified into SMA (n = 36) and non-SMA (Hb ≥ 6.0 g/dL; n = 38). Children with SMA had significantly reduced plasma (P = 0.001) and urinary (P < 0.001) bicyclo-PGE(2)/creatinine and COX-2 transcripts (P = 0.007). There was a significant positive association between Hb and both plasma (r = 0.363, P = 0.002) and urinary (r = 0.500, P = 0.001)] bicyclo-PGE(2)/creatinine. Furthermore, decreased systemic bicyclo-PGE(2)/creatinine was associated with inefficient erythropoiesis (i.e., reticulocyte production index; RPI < 2.0, P = 0.026). Additional analyses demonstrated that plasma (P = 0.031) and urinary (P = 0.070) bicyclo-PGE(2)/creatinine and COX-2 transcripts (P = 0.026) progressively declined with increasing concentrations of naturally acquired PfHz by monocytes. Results presented here support a model in which reduced COX-2-derived PGE(2), driven in part by naturally acquired PfHz by monocytes, promotes decreased erythropoietic responses in children with SMA.
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Affiliation(s)
- Samuel B Anyona
- Laboratories of Parasitic and Viral Diseases, Centre for Global Health Research, Kenya Medical Research Institute, University of New Mexico, Kisumu, Kenya
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Ugwuja EI, Ugwu NC. Abnormal findings on dipstick urinalysis of out-patients with malaria in Abakaliki, Nigeria. J Vector Borne Dis 2011; 48:205-209. [PMID: 22297281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
BACKGROUND & OBJECTIVES Malaria, one of the major health challenges of the tropics affecting about 500 million people, particularly the children and pregnant women have been associated with changes in urine compositions. The present study was undertaken to document the urinary abnormalities in malaria patients based on malaria species and the level of malaria parasitaemia. METHODS Febrile patients (n = 365) with positive Giemsa - stained blood films for malaria recruited from Outpatient Department of Ebonyi State University Teaching Hospital, Abakaliki participated in the study. Patients were classified into two categories (+ and ++) based on parasite density. Apparently healthy individuals (n = 81), without malaria parasite on both thick and thin films of comparable age and gender acted as control group. Urine sample (10 ml) was collected from each participant and analysed using standard laboratory methods and techniques. RESULTS Seventy - four (20.3%) of the patients had Plasmodium falciparum malaria. Although all the urine parameters were higher in the malarial patients in comparison to the control, only bilirubinuria and urobilinogenuria were statistically significant (p <0.05). Also, bilirubinuria, urobilinogenuria, haematuria and proteinuria were significantly (p < 0.05) higher in P. falciparum infection than in infections with other malaria species, but only in P. falciparum infection, bilirubinuria and urobilinogenuria were significantly (p < 0.05) higher at higher parasitaemia. CONCLUSION Even though positive blood film for malaria parasite remains the gold standard for the diagnosis of malaria, urinary abnormalities, such as bilirubinuria, urobilinogenuria, proteinuria and haematuria may aid in identifying patients with severe malaria parasitaemia, especially the falciparum malaria.
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Affiliation(s)
- E I Ugwuja
- Department of Chemical Pathology, Faculty of Clinical Medicine, Ebonyi State University, Abakaliki, Nigeria.
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Tobón Castaño A, del Mar Cortina A, Felipe Miranda A, Blair Trujillo S. [Dark urine and jaundice as warning signs in Plasmodium falciparum malaria in Colombia]. Rev Cubana Med Trop 2010; 62:28-35. [PMID: 23431634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
INTRODUCTION early recognition of warning signs in malarial patients allows timely identification of the patient at risk of severe malaria and provides opportune treatment. Jaundice and dark urine are frequent signs that can alert to the occurrence of severe malaria. OBJECTIVE to study the relationship between jaundice and dark urine with impaired liver and/or kidney function and anemia in malarial patients, and explore their role as warning signs. METHOD clinical and laboratory data from 199 patients with Plasmodium falciparum malaria, belonging to a case control study conducted in Colombia, were analyzed, the association between dark urine and jaundice with impairment in the urine analysis, the hepatic and renal function test, and hemoglobin were studied. RESULTS there was association between dark urine and hemoglobinuria (OR = 236, 63-867), hematuria (OR = 3.2, 1.6-6.6), proteinuria (OR = 2.3, 1-5.3) and bilirubinuria (OR = 2.1, 1-4.4). Jaundice was present in 31 % of patients who had renal dysfunction (OR = 2.7, 1.1-6.4) and in 22 % of those with liver dysfunction (OR = 2.1, 0.9-4.5). Jaundice was more likely in patients with total bilirubin > 25.6 micromol/L (OR = 6.1, 2.7-13.4) and blood ureic nitrogen > 7.14 mmol/L (OR = 3.5, 1.4-8.5). CONCLUSIONS jaundice in patients with malaria may be considered as a warning sign associated with liver and kidney dysfunction. Dark urine was not associated with kidney or liver dysfunction, but was related to bilirubinuria, hematuria and proteinuria, which can be early indicators of failure; dark urine must be studied to clarify its relationship with liver and kidney failure in malaria.
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Ayoya MA, Stoltzfus RJ, Spiekermann-Brouwer GM, Nemeth E, Traoré AK, Ganz T, Garza C. [Hepcidin and Plasmodium falciparum malaria in anemic school children in Mali]. Bull Soc Pathol Exot 2009; 102:219-220. [PMID: 19950537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Hepcidin is a peptide produced by hepatocytes and detectable in blood and urine. Urinary hepcidin excretion appeared to be significantly increasing in humans with acute and chronic infections or inflammatory diseases. However, the effects of common tropical parasitic infections on hepcidin have not been sufficiently examined. We carried out a study in school children from Mali living in a neighborhood where Plasmodium falciparum malaria and Schistosoma haematobium infections are prevalent. Anemia (hemoglobin < 120 g/l) prevalence was very high among these children (68%); 24% had iron deficiency anemia. The prevalence of infections was also high (65% had at least one infection and 41% had C-reactive protein (CRP) levels > 10 mg/L). S. haematobium was diagnosed in 64%. We assessed first morning urine hepcidin excretion in a sub-sample of 15 children with either S. haematobium, P. falciparum malaria or none; 14 of these 15 children were included in the analyses. Children with P. falciparum malaria excreted significantly higher levels of hepcidin than those with S. haematobium (chi2 = 3.86; p = 0.05) or without any infection (chi2 = 5.95; p = 0.01). Urinary hepcidin correlated significantly with CRP (Spearman's r = 0.59; p = 0.001) and serum ferritin (Spearman's r = 0.73; p = 0.003). Our study confirms the still limited evidence of an association between human malaria and increased urinary hepcidin and points out the need for further studies to define the contribution of hepcidin to anemia associated with this disease.
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Affiliation(s)
- M A Ayoya
- UNICEF, 73 Lodi Estate, New Delhi 110-003, India.
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Tobón A. [Danger signs in the malaria patient]. Biomedica 2009; 29:320-329. [PMID: 20128356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Danger signs are clinical indicators of severity and are useful to predict complications or death. In the malaria patient, clinical or parasitological signs can be easily be recognized during the acute phase of the illness that indicate serious complications. Danger signs include neurological change, abnormal breathing pattern, persistent vomiting and diarrhea, jaundice, bleeding, dark urine, delayed capillary refill, intense pallor, hyperpyrexia, hyperparasitemia and schizontemia. Timely recognition of these signs can lead to a decrease in cases with complications and deaths.
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MESH Headings
- Acute Disease
- Adult
- Child
- Child, Preschool
- Dehydration/etiology
- Diarrhea/etiology
- Female
- Fever/etiology
- Hematuria/etiology
- Hemorrhage/etiology
- Humans
- Infant
- Jaundice/etiology
- Malaria, Falciparum/blood
- Malaria, Falciparum/complications
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/urine
- Malaria, Vivax/blood
- Malaria, Vivax/complications
- Malaria, Vivax/parasitology
- Malaria, Vivax/urine
- Nervous System Diseases/etiology
- Pallor/etiology
- Parasitemia/parasitology
- Plasmodium falciparum/growth & development
- Plasmodium falciparum/isolation & purification
- Plasmodium vivax/isolation & purification
- Pregnancy
- Pregnancy Complications, Infectious/parasitology
- Respiration Disorders/etiology
- Vomiting/etiology
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Affiliation(s)
- Alberto Tobón
- Grupo de Malaria, Universidad de Antioquia, Medellín, Colombia.
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Howard CT, McKakpo US, Quakyi IA, Bosompem KM, Addison EA, Sun K, Sullivan D, Semba RD. Relationship of hepcidin with parasitemia and anemia among patients with uncomplicated Plasmodium falciparum malaria in Ghana. Am J Trop Med Hyg 2007; 77:623-626. [PMID: 17978060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023] Open
Abstract
The pathogenesis of malarial anemia is incompletely understood. Hepcidin, a recently discovered peptide hormone, is a major regulator of iron metabolism and is thought to play a central role in the anemia of chronic inflammation. The specific aim of the study was to characterize the association between urinary hepcidin, hemoglobin, and parasitemia in 199 patients presenting for evaluation of Plasmodium falciparum malaria in Ghana. Urinary hepcidin was semi-quantitatively assessed using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Urinary hepcidin (intensity/mmol creatinine) was associated with log parasitemia in 86 children (beta = 0.086, standard error [SE] = 0.035, P < 0.017), 31 pregnant women (beta = 0.218, SE = 0.085, P < 0.016), and 82 adults (beta = 0.184, SE =0.043, P < 0.0001). Urinary hepcidin was not significantly associated with hemoglobin or anemia. Urinary hepcidin is more strongly associated with parasitemia than hemoglobin or anemia among patients with acute P. falciparum malaria in Ghana.
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Affiliation(s)
- Caitlin T Howard
- Johns Hopkins Medical Institutions, Baltimore, Maryland 21205, USA
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LYKE KIRSTENE, DICKO ALASSANE, DABO ABDOULAYE, SANGARE LANSANA, KONE ABDOULAYE, COULIBALY DRISSA, GUINDO ANDO, TRAORE KARIM, DAOU MODIBO, DIARRA ISSA, SZTEIN MARCELOB, PLOWE CHRISTOPHERV, DOUMBO OGOBARAK. Association of Schistosoma haematobium infection with protection against acute Plasmodium falciparum malaria in Malian children. Am J Trop Med Hyg 2005; 73:1124-30. [PMID: 16354824 PMCID: PMC2738948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
Plasmodium falciparum and Schistosoma haematobium are co-endemic parasitic diseases with worldwide distribution. Evidence suggests interactions occur between helminthic and malaria infections, although it is unclear whether this effect is beneficial or harmful to the host. Malian children 4-14 years of age with asymptomatic S. haematobium infection (SP) (n = 338) were prospectively matched by age, sex, and residence to children without schistosomiasis (SN) (n = 338) who were cleared of occult intestinal parasites, and followed-up for one malaria transmission season (25 weeks). The time to the first clinical malaria infection, incidence of malaria episodes, and parasitemia were recorded. Age associated protection from malaria in children with schistosomiasis was observed. SP children (4-8 years of age) compared with SN children demonstrated delayed time to first clinical malaria infection (74 versus 59 days; P = 0.04), fewer numbers of malaria episodes (1.55 versus 1.81 infections; P = 0.03) and lower geometric mean parasite densities (6,359 versus 9,874 asexual forms/mm(3); P = 0.07) at first infection. No association between schistosomiasis and P. falciparum malaria was observed in children 9-14 years of age. We conclude that underlying schistosomiasis is associated with protection against clinical falciparum malaria in an age-dependent manner.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - CHRISTOPHER V. PLOWE
- Address correspondence to Christopher V. Plowe, Center for Vaccine Development, University of Maryland School of Medicine, 685 West Baltimore Street, HSF I, Room 480, Baltimore, MD 21201. E-mail:
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Ilett KF, Ethell BT, Maggs JL, Davis TME, Batty KT, Burchell B, Binh TQ, Thu LTA, Hung NC, Pirmohamed M, Park BK, Edwards G. Glucuronidation of dihydroartemisinin in vivo and by human liver microsomes and expressed UDP-glucuronosyltransferases. Drug Metab Dispos 2002; 30:1005-12. [PMID: 12167566 DOI: 10.1124/dmd.30.9.1005] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to elucidate the metabolic pathways for dihydroartemisinin (DHA), the active metabolite of the artemisinin derivative artesunate (ARTS). Urine was collected from 17 Vietnamese adults with falciparum malaria who had received 120 mg of ARTS i.v., and metabolites were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Human liver microsomes were incubated with [12-(3)H]DHA and cofactors for either glucuronidation or cytochrome P450-catalyzed oxidation. Human liver cytosol was incubated with cofactor for sulfation. Metabolites were detected by HPLC-MS and/or HPLC with radiochemical detection. Metabolism of DHA by recombinant human UDP-glucuronosyltransferases (UGTs) was studied. HPLC-MS analysis of urine identified alpha-DHA-beta-glucuronide (alpha-DHA-G) and a product characterized as the tetrahydrofuran isomer of alpha-DHA-G. DHA was present only in very small amounts. The ratio of the tetrahydrofuran isomer, alpha-DHA-G, was highly variable (median 0.75; range 0.09-64). Nevertheless, alpha-DHA-G was generally the major urinary product of DHA glucuronidation in patients. The tetrahydrofuran isomer appeared to be at least partly a product of nonenzymic reactions occurring in urine and was readily formed from alpha-DHA-G by iron-mediated isomerization. In human liver microsomal incubations, DHA-G (diastereomer unspecified) was the only metabolite found (V(max) 177 +/- 47 pmol min(-1) mg(-1), K(m) 90 +/- 16 microM). Alpha-DHA-G was formed in incubations of DHA with expressed UGT1A9 (K(m) 32 microM, V(max) 8.9 pmol min(-1) mg(-1)) or UGT2B7 (K(m) 438 microM, V(max) 10.9 pmol mg(-1) min(-1)) but not with UGT1A1 or UGT1A6. There was no significant metabolism of DHA by cytochrome-P450 oxidation or by cytosolic sulfotransferases. We conclude that alpha-DHA-G is an important metabolite of DHA in humans and that its formation is catalyzed by UGT1A9 and UGT2B7.
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Affiliation(s)
- Kenneth F Ilett
- Department of Pharmacology, University of Western Australia, Crawley, Western Australia.
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Abstract
In areas of drug-resistant malaria, control programs may restrict chemotherapy until malaria has been confirmed via microscopy to contain costs and toxicity. In Brazil, patients travel to centralized laboratory posts (FNS) at great cost for diagnosis and treatment. A program was established through the bars of a mining town offering free dipstick diagnosis and mefloquine treatment on a 24-hr basis; falciparum malaria dipstick tests are accurate and easy to use. Outcomes were compared with historical data and results of a neighboring non-intervention village. Guidelines for dipstick use and treatment were followed for 98% of visits. The number of FNS visits was reduced from 2,316 (expected) to 1,097 (observed) with 626 dipstick tests applied. Ninety-five percent of those who visited the FNS experienced onset of malaria symptoms in the town where the FNS was located. There was an unexpected doubling of the malaria hospital admission rate. We demonstrate that dipstick testing can be used in a sustainable, community-based program that should be applicable in a wide variety of settings.
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Affiliation(s)
- M L Cunha
- Health Sciences Department, Federal University of Brasilia, Brazil
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Genton B, Paget S, Beck HP, Gibson N, Alpers MP, Hii J. Diagnosis of Plasmodium falciparum infection using ParaSight(R)-F test in blood and urine of Papua New Guinean children. Southeast Asian J Trop Med Public Health 1998; 29:35-40. [PMID: 9740265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Rapid, simple, accurate and cheap methods are required for the diagnosis of malaria in endemic areas. The ParaSight(R)-F test, which is based on qualitative detection by monoclonal antibody of the Plasmodium falciparum (Pf) histidin-rich protein-II in the blood, showed promising results. As some antigens of Pf have been detected in the urine, we assessed the efficiency of the ParaSight(R)-F test in the whole blood and in the urine using microscopy and PCR as gold standards. One hundred and twelve children living in the East Sepik Province of Papua New Guinea (PNG) were recruited during a cross-sectional community survey. When using microscopy as reference, the ParaSight(R)-F test applied to whole blood had 84% sensitivity and 77% specificity. The semi-quantitative assessment showed that the intensity of the color on the wick correlated with parasite density. The ParaSight(R)-F test performed on urine had 81% sensitivity but only 26% specificity. Very similar results for blood and urine were obtained when using PCR as reference. The present evaluation of the ParaSight(R)-F test applied to blood compares well with findings in endemic areas of Africa or Asia, and confirms its usefulness to diagnose Pf infection in endemic areas of the South Pacific. Because of the lack of specificity, the ParaSight(R)-F test performed on urine cannot be recommended.
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Affiliation(s)
- B Genton
- Papua New Guinea Institute of Medical Research, Madang.
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Mberu EK, Wansor T, Sato H, Nishikawa Y, Watkins WM. Japanese poor metabolizers of proguanil do not have an increased risk of malaria chemoprophylaxis breakthrough. Trans R Soc Trop Med Hyg 1995; 89:658-9. [PMID: 8594689 DOI: 10.1016/0035-9203(95)90434-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- E K Mberu
- Kenya Medical Research Institute, Nairobi, Kenya
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14
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Weller RE, Málaga CA, Buschbom RL, Ragan HA. Urinary enzyme concentrations in the owl monkey (Aotus nancymae). J Med Primatol 1993; 22:340-7. [PMID: 8138983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The activity of three urinary enzymes, alkaline phosphatase (ALP), aspartate aminotransferase (AST), and N-acetyl-beta-D-glucosaminidase (NAG), was evaluated in 71 adult owl monkeys. Fifty-six animals had normal renal function, while 15 had evidence of renal dysfunction. Urinary enzyme: urinary creatinine ratios (UE: UCr) were also determined. The activity for NAG was similar to that of other species, while ALP and AST were higher. Regression analyses revealed that urinary enzymes and UE:UCr were significantly correlated (P < or = 0.0001) with indices of renal damage and could identify active renal disease.
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Affiliation(s)
- R E Weller
- Battelle Pacific NW Laboratories, Richland, WA 99352
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15
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Chaulet JF, Robet Y, Prevosto JM, Grelaud G, Renard C, Bellemin-Magninot P, Lemontey Y. [Simple methods of chloroquine determination in urine and their adaptation in the field]. Med Trop (Mars) 1993; 53:241-51. [PMID: 8412595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Field malaria studies require often the on site detection of chloroquine in urine for monitoring chemoprophylaxis and treatment compliance, investigating drug-use patterns and screening prospective subjects for in vitro and in vivo chemosensitivity tests. The field adapted methods are described, analytical characteristics are compared and different approaches to field adapted assay of chloroquine are discussed.
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Affiliation(s)
- J F Chaulet
- Hôpital d'Instruction des Armées Desgenettes, Services pharmaceutiques et chimiques, Lyon
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16
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Areekul S, Churdchu K, Wilairatana P, Charoenlarp P. Increased circulating levels of transcobalamin II in malarial patients with renal involvement. Ann Trop Med Parasitol 1993; 87:17-22. [PMID: 8346988 DOI: 10.1080/00034983.1993.11812735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Vitamin B12 and its binding proteins were measured in the serum and urine of four patients with Plasmodium falciparum who had renal insufficiency. The results showed that these patients had elevated serum transcobalamin II (TCII) levels which decreased to the normal level after recovery from azotaemia. There were direct relationships between serum TCII levels and blood urea-nitrogen or creatinine concentrations. The clearance and urinary excretion of vitamin B12 and TCII were significantly lower in the patients' group than in normal subjects. All these findings indicated that elevated serum TCII could occur in P. falciparum patients with renal insufficiency. This is probably caused by a reduction in renal plasma flow and glomerular filtration rate (GFR), secondary to a low or ineffective blood volume. The reduced GFR, in turn, reduces the TCII-B12 that filters through the glomeruli, resulting in decreased TCII-B12 uptake by the renal tubules, and thus slows down the TCII degradation by lysosomal enzymes. The decreased TCII catabolism therefore prolongs the TCII survival in the circulation and probably stimulates TCII synthesis and secretion in a feedback mechanism.
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Affiliation(s)
- S Areekul
- Department of Tropical Radioisotopes, Faculty of Tropical Medicine, Mahidol University, Phaya Thai, Bangkok, Thailand
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17
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Brown AE, Herrington DA, Webster HK, Clyde DF, Sztein MB, Davis JR, Beier MS, Edelman R. Urinary neopterin in volunteers experimentally infected with Plasmodium falciparum. Trans R Soc Trop Med Hyg 1992; 86:134-6. [PMID: 1440769 DOI: 10.1016/0035-9203(92)90539-o] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
To investigate the kinetics of monocyte/macrophage activation in falciparum malaria we determined urinary neopterin values serially in experimentally infected volunteers. Three subjects who had been immunized with irradiated sporozoites via mosquito bites served as controls. These individuals remained aparasitaemic, afebrile and without a rise in neopterin after challenge by infective mosquitoes. Four non-immune subjects developed Plasmodium falciparum parasitaemia, fever (3 of 4) and sharp rises in neopterin. Parasite densities reached 10-100 parasitized erythrocytes per microliter before elevations in temperature or neopterin levels were detected. Onset of fever preceded the rise in neopterin excretion by one day. Prompt chemotherapy was associated with the clearance of parasites from the blood and the return of temperature and neopterin levels to normal.
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Affiliation(s)
- A E Brown
- Department of Immunology, Armed Forces Research Institute for Medical Sciences, Bangkok, Thailand
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18
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Katzin AM, Kimura ES, Alexandre CO, Ramos AM. Detection of antigens in urine of patients with acute falciparum and vivax malaria infections. Am J Trop Med Hyg 1991; 45:453-62. [PMID: 1951853 DOI: 10.4269/ajtmh.1991.45.453] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Using an antigen-capture, dot-blot assay, antigens were detected in the urine of 50 patients infected with Plasmodium falciparum. Antigens were also detected in 12/15 patients who had no detectable parasitemias 1-2 weeks after chemotherapy. By Western blotting and immunoprecipitation, four predominant antigens were identified with the following molecular masses (Mr) and isoelectric points (pI): antigen 1, 200 kDa, pI 6.4-6.27; antigen 2, 180 kDa, pI 5.2-4.8; antigen 3, 150 kDa, pI 5.5; antigen 4, 96 kDa, pI 5.1-4.8. These antigens were heat stable to 100 degrees C for 5 min. Antigens were also detected in the urine of 35 patients with acute P. vivax infections by Western blotting and dot-blot analysis and 10/10 patients three weeks following chemotherapy. The antigens had Mr of 200, 170, and 130 kDa.
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Affiliation(s)
- A M Katzin
- Departamento de Parasitologia, Universidad de Sao Paulo, Brazil
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