Maternal peripheral blood level of IL-10 as a marker for inflammatory placental malaria

Background: Placental malaria (PM) is an important cause of maternal and foetal mortality in tropical areas, and severe sequelae and mortality are related to inflammation in the placenta. Diagnosis is difficult because PM is often asymptomatic, peripheral blood smear examination detects parasitemia as few as half of PM cases, and no peripheral markers have been validated for placental inflammation. Methods: In a cohort of Tanzanian parturients, PM was determined by placental blood smears and placental inflammation was assessed by histology and TNF mRNA levels. Maternal peripheral blood levels of several immune mediators previously implicated in PM pathogenesis, as well as ferritin and leptin were measured. The relationship between the levels of these soluble factors to PM and placental inflammation was examined. Results: Peripheral levels of TNF, TNF-RI, TNF-RII, IL-1, IL-10, and ferritin were elevated during PM, whereas levels of IFN-[gamma], IL-4, IL-5 and IL-6 were unchanged and levels of leptin were decreased. In receiver operating characteristic curve analysis, IL-10 had the greatest area under the curve, and would provide a sensitivity of 60% with a false positive rate of 10%. At a cut off level of 15 pg/mL, IL-10 would detect PM with a sensitivity of 79.5% and a specificity of 84.3%. IL-10 levels correlated with placental inflammatory cells and placental TNF mRNA levels in first time mothers. Conclusion: These data suggest that IL-10 may have utility as a biomarker for inflammatory PM in research studies, but that additional biomarkers may be required to improve clinical diagnosis and management of malaria during pregnancy.This work was supported by grants from Bill and Melinda Gates Foundation (grant 29202), NIH (R01 AI52059 and TW05509) and Puget Sound Partners for Global Health to P.E.D

Reliability of Rapid Diagnostic Tests in Diagnosing Pregnancy-Associated Malaria in North-Eastern Tanzania.

Accurate diagnosis and prompt treatment of pregnancy-associated malaria (PAM) are key aspects in averting adverse pregnancy outcomes. Microscopy is the gold standard in malaria diagnosis, but it has limited detection and availability. When used appropriately, rapid diagnostic tests (RDTs) could be an ideal diagnostic complement to microscopy, due to their ease of use and adequate sensitivity in detecting even sub-microscopic infections. Polymerase chain reaction (PCR) is even more sensitive, but it is mainly used for research purposes. The accuracy and reliability of RDTs in diagnosing PAM was evaluated using microscopy and PCR. A cohort of pregnant women in north-eastern Tanzania was followed throughout pregnancy for detection of plasmodial infection using venous and placental blood samples evaluated by histidine rich protein 2 (HRP-2) and parasite lactate dehydrogenase (pLDH) based RDTs (Parascreen™) or HRP-2 only (Paracheck Pf® and ParaHIT®f), microscopy and nested Plasmodium species diagnostic PCR. From a cohort of 924 pregnant women who completed the follow up, complete RDT and microscopy data was available for 5,555 blood samples and of these 442 samples were analysed by PCR. Of the 5,555 blood samples, 49 ((proportion and 95% confidence interval) 0.9% [0.7 -1.1]) samples were positive by microscopy and 91 (1.6% [1.3-2.0]) by RDT. Forty-six (50.5% [40.5 - 60.6]) and 45 (49.5% [39.4 - 59.5]) of the RDT positive samples were positive and negative by microscopy, respectively, whereas nineteen (42.2% [29.0 - 56.7]) of the microscopy negative, but RDT positive, samples were positive by PCR. Three (0.05% [0.02 - 0.2]) samples were positive by microscopy but negative by RDT. 351 of the 5,461 samples negative by both RDT and microscopy were tested by PCR and found negative. There was no statistically significant difference between the performances of the different RDTs. Microscopy underestimated the real burden of malaria during pregnancy and RDTs performed better than microscopy in diagnosing PAM. In areas where intermittent preventive treatment during pregnancy may be abandoned due to low and decreasing malaria risk and instead replaced with active case management, screening with RDT is likely to identify most infections in pregnant women and out-performs microscopy as a diagnostic tool

Chloroquine as weekly chemoprophylaxis or intermittent treatment to prevent malaria in pregnancy in Malawi: a randomised controlled trial.

BACKGROUND: Sulfadoxine-pyrimethamine resistance threatens efficacy of intermittent preventive treatment of malaria during pregnancy, and alternative regimens need to be identified. With the return of chloroquine efficacy in southern Africa, we postulated that chloroquine either as an intermittent therapy or as weekly chemoprophylaxis would be more efficacious than intermittent sulfadoxine-pyrimethamine for prevention of malaria in pregnancy and associated maternal and newborn adverse outcomes. METHODS: We did an open-label, single-centre, randomised controlled trial at Ndirande Health Centre, Blantyre, in southern Malawi. We enrolled pregnant women (first or second pregnancy) at 20-28 weeks' gestation who were HIV negative. Participants were randomly assigned in a 1:1:1 ratio using a computer-generated list to either intermittent sulfadoxine-pyrimethamine (two doses of 1500 mg sulfadoxine and 75 mg pyrimethamine, 4 weeks apart), intermittent chloroquine (two doses of 600 mg on day 1, 600 mg on day 2, and 300 mg on day 3), or chloroquine prophylaxis (600 mg on day 1 then 300 mg every week). The primary endpoint was placental malaria in the modified intent-to-treat population, which consisted of participants who contributed placental histopathology data at birth. Secondary outcomes included clinical malaria, maternal anaemia, low birthweight, and safety. This trial is registered with ClinicalTrials.gov, number NCT01443130. FINDINGS: Between February, 2012, and May, 2014, we enrolled and randomly allocated 900 women, of whom 765 contributed histopathological data and were included in the primary analysis. 108 (14%) women had placental malaria, which was lower than the anticipated prevalence of placental malaria infection. Protection from placental malaria was not improved by chloroquine as either prophylaxis (30 [12%] of 259 had positive histopathology; relative risk [RR] 0·75, 95% CI 0·48-1·17) or intermittent therapy (39 [15%] of 253; RR 1·00, 0·67-1·50) compared with intermittent sulfadoxine-pyrimethamine (39 [15%] of 253). In protocol-specified analyses adjusted for maternal age, gestational age at enrolment, bednet use the night before enrolment, anaemia at enrolment, and malaria infection at enrolment, women taking chloroquine as prophylaxis had 34% lower placental infections than did those allocated intermittent sulfadoxine-pyrimethamine (RR 0·66, 95% CI 0·46-0·95). Clinical malaria was reported in nine women assigned intermittent sulfadoxine-pyrimethamine, four allocated intermittent chloroquine (p=0·26), and two allocated chloroquine prophylaxis (p=0·063). Maternal anaemia was noted in five women assigned intermittent sulfadoxine-pyrimethamine, 15 allocated intermittent chloroquine (p=0·038), and six assigned chloroquine prophylaxis (p>0·99). Low birthweight was recorded for 31 babies born to women allocated intermittent sulfadoxine-pyrimethamine, 29 assigned intermittent chloroquine (p=0·78), and 41 allocated chloroquine prophylaxis (p=0·28). Four women assigned intermittent sulfadoxine-pyrimethamine had adverse events possibly related to study product compared with 94 women allocated intermittent chloroquine (p<0·0001) and 26 allocated chloroquine prophylaxis (p<0·0001). Three women had severe or life-threatening adverse events related to study product, of whom all were assigned intermittent chloroquine (p=0·25). INTERPRETATION: Chloroquine administered as intermittent therapy did not provide better protection from malaria and related adverse effects compared with intermittent sulfadoxine-pyrimethamine in a setting of high resistance to sulfadoxine-pyrimethamine. Chloroquine chemoprophylaxis might provide benefit in protecting against malaria during pregnancy, but studies with larger sample sizes are needed to confirm these results. FUNDING: US National Institutes of Health

Pregnancy outcomes and risk of placental malaria after artemisinin-based and quinine-based treatment for uncomplicated falciparum malaria in pregnancy: a WorldWide Antimalarial Resistance Network systematic review and individual patient data meta-analysis.

Malaria in pregnancy, including asymptomatic infection, has a detrimental impact on foetal development. Individual patient data (IPD) meta-analysis was conducted to compare the association between antimalarial treatments and adverse pregnancy outcomes, including placental malaria, accompanied with the gestational age at diagnosis of uncomplicated falciparum malaria infection. A systematic review and one-stage IPD meta-analysis of studies assessing the efficacy of artemisinin-based and quinine-based treatments for patent microscopic uncomplicated falciparum malaria infection (hereinafter uncomplicated falciparum malaria) in pregnancy was conducted. The risks of stillbirth (pregnancy loss at ≥ 28.0 weeks of gestation), moderate to late preterm birth (PTB, live birth between 32.0 and &lt; 37.0 weeks), small for gestational age (SGA, birthweight of &lt; 10th percentile), and placental malaria (defined as deposition of malaria pigment in the placenta with or without parasites) after different treatments of uncomplicated falciparum malaria were assessed by mixed-effects logistic regression, using artemether-lumefantrine, the most used antimalarial, as the reference standard. Registration PROSPERO: CRD42018104013. Of the 22 eligible studies (n = 5015), IPD from16 studies were shared, representing 95.0% (n = 4765) of the women enrolled in literature. Malaria treatment in this pooled analysis mostly occurred in the second (68.4%, 3064/4501) or third trimester (31.6%, 1421/4501), with gestational age confirmed by ultrasound in 91.5% (4120/4503). Quinine (n = 184) and five commonly used artemisinin-based combination therapies (ACTs) were included: artemether-lumefantrine (n = 1087), artesunate-amodiaquine (n = 775), artesunate-mefloquine (n = 965), and dihydroartemisinin-piperaquine (n = 837). The overall pooled proportion of stillbirth was 1.1% (84/4361), PTB 10.0% (619/4131), SGA 32.3% (1007/3707), and placental malaria 80.1% (2543/3035), and there were no significant differences of considered outcomes by ACT. Higher parasitaemia before treatment was associated with a higher risk of SGA (adjusted odds ratio [aOR] 1.14 per 10-fold increase, 95% confidence interval [CI] 1.03 to 1.26, p = 0.009) and deposition of malaria pigment in the placenta (aOR 1.67 per 10-fold increase, 95% CI 1.42 to 1.96, p &lt; 0.001). The risks of stillbirth, PTB, SGA, and placental malaria were not different between the commonly used ACTs. The risk of SGA was high among pregnant women infected with falciparum malaria despite treatment with highly effective drugs. Reduction of malaria-associated adverse birth outcomes requires effective prevention in pregnant women

Differential gene expression mediated by 15-hydroxyeicosatetraenoic acid in LPS-stimulated RAW 264.7 cells

<p>Abstract</p> <p>Background</p> <p>Given the immuno-modulatory activity of native haemozoin (Hz), the effects of constitutive Hz components on immune response are of interest. Recently, gene expression changes mediated by HNE and the synthetic analogue of Hz, beta-haematin (BH), were identified and implicated a significant role for lipid peroxidation products in Hz's activity. The study presented herein examines gene expression changes in response to 15(S)-hydroxyeicosatetraenoic acid (HETE) in a model macrophage cell line.</p> <p>Methods</p> <p>LPS-stimulated RAW 264.7 macrophage-like cells were treated with 40 μM 15(S)-HETE for 24 h, and microarray analysis was used to identify global gene expression alterations. Fold changes were calculated relative to LPS-stimulated cells and those genes altered at least 1.8-fold (<it>p </it>value ≤ 0.025) were considered to be differentially expressed. Expression levels of a subset of genes were assessed by qRT-PCR and used to confirm the microarray results.</p> <p>Results</p> <p>Network analysis revealed that altered genes were primarily associated with "lipid metabolism" and "small molecule biochemistry". While several genes associated with PPAR-gamma receptor-mediated signaling were differentially expressed, a number of genes indicated the activation of secondary signaling cascades. Genes related to cytoadherence (cell-cell and cell-matrix), leukocyte extravasation, and inflammatory response were also differentially regulated by treatment, supporting a potential role for 15(S)-HETE in malaria pathogenesis.</p> <p>Conclusion</p> <p>These results add insight and detail to 15-HETE's effects on gene expression in macrophage-like cells. Data indicate that while 15-HETE exerts biological activity and may participate in Hz-mediated immuno-modulation, the gene expression changes are modest relative to those altered by the lipid peroxidation product HNE.</p

Diagnosis of placental malaria in poorly fixed and processed placental tissue

Abstract Background Placental histopathology has been considered the gold standard for diagnosis of malaria during pregnancy. However, in under-resourced areas placental tissue is often improperly fixed and processed; the resulting formalin pigment is difficult to distinguish from malaria pigment. This study examines two alternative diagnostic methods: polymerase chain reaction (PCR) and a novel immunohistochemistry (IHC)-based method using an antibody against histidine-rich protein 2 (HRP2). Methods Placental histopathology from 151 pregnant women in Kinshasa was assessed by two blinded microscopists and compared with peripheral blood PCR and IHC for HRP2. The Cohen’s kappa coefficients were calculated to assess the test agreement. The sensitivity and specificity of individual tests were calculated using PCR or IHC as the reference standard as well as latent class analysis (LCA). Results PCR and IHC correlated fairly well. The correlation between the two blinded microscopists was poor, as there was widespread formalin pigment. Using LCA, all of the tests had high specificities. The most sensitive test was IHC (67.7 %), with PCR as second-best (56.1 %). Conclusions PCR and/or IHC are suitable diagnostics when the presence of formalin pigment substantially compromises placental histopathology

Reductions in malaria in pregnancy and adverse birth outcomes following indoor residual spraying of insecticide in Uganda.

BACKGROUND: Indoor residual spraying of insecticide (IRS) is a key intervention for reducing the burden of malaria in Africa. However, data on the impact of IRS on malaria in pregnancy and birth outcomes is limited. METHODS: An observational study was conducted within a trial of intermittent preventive therapy during pregnancy in Tororo, Uganda. Women were enrolled at 12-20 weeks of gestation between June and October 2014, provided with insecticide-treated bed nets, and followed through delivery. From December 2014 to February 2015, carbamate-containing IRS was implemented in Tororo district for the first time. Exact spray dates were collected for each household. The exposure of interest was the proportion of time during a woman's pregnancy under protection of IRS, with three categories of protection defined: no IRS protection, >0-20 % IRS protection, and 20-43 % IRS protection. Outcomes assessed included malaria incidence and parasite prevalence during pregnancy, placental malaria, low birth weight (LBW), pre-term delivery, and fetal/neonatal deaths. RESULTS: Of 289 women followed, 134 had no IRS protection during pregnancy, 90 had >0-20 % IRS protection, and 65 had >20-43 % protection. During pregnancy, malaria incidence (0.49 vs 0.10 episodes ppy, P = 0.02) and parasite prevalence (20.0 vs 8.9 %, P 20-43 % IRS protection (1.6 %, P = 0.006). Compared to women with no IRS protection, those with >20-43 % IRS protection had a lower risk of LBW (20.9 vs 3.1 %, P = 0.002), pre-term birth (17.2 vs 1.5 %, P = 0.006), and fetal/neonatal deaths (7.5 vs 0 %, P = 0.03). CONCLUSION: In this setting, IRS was temporally associated with lower malaria parasite prevalence during pregnancy and at delivery, and improved birth outcomes. IRS may represent an important tool for combating malaria in pregnancy and for improving birth outcomes in malaria-endemic settings. Trial Registration Current Controlled Trials Identifier NCT02163447

Pregnancy outcomes and risk of placental malaria after artemisinin-based and quinine-based treatment for uncomplicated falciparum malaria in pregnancy: a WorldWide Antimalarial Resistance Network systematic review and individual patient data meta-analysis.

BACKGROUND: Malaria in pregnancy, including asymptomatic infection, has a detrimental impact on foetal development. Individual patient data (IPD) meta-analysis was conducted to compare the association between antimalarial treatments and adverse pregnancy outcomes, including placental malaria, accompanied with the gestational age at diagnosis of uncomplicated falciparum malaria infection. METHODS: A systematic review and one-stage IPD meta-analysis of studies assessing the efficacy of artemisinin-based and quinine-based treatments for patent microscopic uncomplicated falciparum malaria infection (hereinafter uncomplicated falciparum malaria) in pregnancy was conducted. The risks of stillbirth (pregnancy loss at ≥ 28.0 weeks of gestation), moderate to late preterm birth (PTB, live birth between 32.0 and < 37.0 weeks), small for gestational age (SGA, birthweight of < 10th percentile), and placental malaria (defined as deposition of malaria pigment in the placenta with or without parasites) after different treatments of uncomplicated falciparum malaria were assessed by mixed-effects logistic regression, using artemether-lumefantrine, the most used antimalarial, as the reference standard. Registration PROSPERO: CRD42018104013. RESULTS: Of the 22 eligible studies (n = 5015), IPD from16 studies were shared, representing 95.0% (n = 4765) of the women enrolled in literature. Malaria treatment in this pooled analysis mostly occurred in the second (68.4%, 3064/4501) or third trimester (31.6%, 1421/4501), with gestational age confirmed by ultrasound in 91.5% (4120/4503). Quinine (n = 184) and five commonly used artemisinin-based combination therapies (ACTs) were included: artemether-lumefantrine (n = 1087), artesunate-amodiaquine (n = 775), artesunate-mefloquine (n = 965), and dihydroartemisinin-piperaquine (n = 837). The overall pooled proportion of stillbirth was 1.1% (84/4361), PTB 10.0% (619/4131), SGA 32.3% (1007/3707), and placental malaria 80.1% (2543/3035), and there were no significant differences of considered outcomes by ACT. Higher parasitaemia before treatment was associated with a higher risk of SGA (adjusted odds ratio [aOR] 1.14 per 10-fold increase, 95% confidence interval [CI] 1.03 to 1.26, p = 0.009) and deposition of malaria pigment in the placenta (aOR 1.67 per 10-fold increase, 95% CI 1.42 to 1.96, p < 0.001). CONCLUSIONS: The risks of stillbirth, PTB, SGA, and placental malaria were not different between the commonly used ACTs. The risk of SGA was high among pregnant women infected with falciparum malaria despite treatment with highly effective drugs. Reduction of malaria-associated adverse birth outcomes requires effective prevention in pregnant women

Oxygen isotope heterogeneity of the mantle beneath the Canary Islands : insights from olivine phenocrysts

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Contributions to Mineralogy and Petrology 162 (2011): 349-363, doi:10.1007/s00410-010-0600-5.A relatively narrow range of oxygen isotopic ratios (δ18O = 5.05.4‰) is preserved in olivine of mantle xenoliths, mid-ocean ridge (MORB) and most ocean island basalts (OIB). The values in excess of this range are generally attributed either to the presence of a recycled component in the Earth’s mantle or to shallow level contamination processes. A viable way forward to trace source heterogeneity is to find a link between chemical (elemental and isotopic) composition of the earlier crystallized mineral phases (olivine) and the composition of their parental magmas, then using them to reconstruct the composition of source region. The Canary hotspot is one of a few that contains ~1-2 Ga old recycled ocean crust that can be traced to the core-mantle boundary using seismic tomography and whose origin is attributed to the mixing of at least three main isotopically distinct mantle components i.e., HIMU, DMM and EM. This work reports ion microprobe and single crystal laser fluorination oxygen isotope data of 148 olivine grains also analyzed for major and minor elements in the same spot. The olivines are from 20 samples resembling the most primitive shield stage picrite through alkali basalt to basanite series erupted on Gran Canaria, Tenerife, La Gomera, La Palma and El Hierro, Canary Islands, for which shallow level contamination processes were not recognized. A broad range of δ18Oolivine values from 4.6 to 6.1‰ was obtained and explained by stable, long-term oxygen isotope heterogeneity of crystal cumulates present under different volcanoes. These cumulates are thought to have crystallized from mantle derived magmas uncontaminated at crustal depth, representing oxygen isotope heterogeneity of source region. A relationship between Ni×FeO/MgO and δ18Oolivine values found in one basanitic lava erupted on El Hierro, the westernmost island of the Canary Archipelago, was used to estimate oxygen isotope compositions of partial melts presumably originated from peridotite (HIMU-type component inherited its radiogenic isotope composition from ancient, ~12 Ga, recycled ocean crust) and pyroxenite (young, <1 Ga, recycled oceanic crust preserved as eclogite with depleted MORB-type isotopic signature) components of the Canary plume. The model calculations yield 5.2 and 5.9±0.3‰ for peridotite and pyroxenite derived melts, respectively, which appeared to correspond closely to the worldwide HIMU-type OIB and upper limit N-MORB δ18O values. This difference together with the broad range of δ18O variations found in the Canarian olivines cannot be explained by thermodynamic effects of oxygen isotopic fractionation and are believed to represent true variations in the mantle, due to oceanic crust and continental lithosphere recycling.This work was supported by the CNRS “poste rouge” grant to AG, the NSF EAR-CAREER-0844772 grant to IB and the CRPG-CNRS and at its initial stage by the DFG (grant SCHM 250/64) and the Alexander von Humboldt Foundation (Wolfgang Paul Award to A.V. Sobolev who provided access to the electron microprobe at the Max Planck Institute, Mainz, Germany)

Relationships between infection with Plasmodium falciparum during pregnancy, measures of placental malaria, and adverse birth outcomes.

BACKGROUND: Malaria in pregnancy has been associated with maternal morbidity, placental malaria, and adverse birth outcomes. However, data are limited on the relationships between longitudinal measures of malaria during pregnancy, measures of placental malaria, and birth outcomes. METHODS: This is a nested observational study of data from a randomized controlled trial of intermittent preventive therapy during pregnancy among 282 participants with assessment of placental malaria and delivery outcomes. HIV-uninfected pregnant women were enrolled at 12-20 weeks of gestation. Symptomatic malaria during pregnancy was measured using passive surveillance and monthly detection of asymptomatic parasitaemia using loop-mediated isothermal amplification (LAMP). Placental malaria was defined as either the presence of parasites in placental blood by microscopy, detection of parasites in placental blood by LAMP, or histopathologic evidence of parasites or pigment. Adverse birth outcomes assessed included low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA) infants. RESULTS: The 282 women were divided into three groups representing increasing malaria burden during pregnancy. Fifty-two (18.4%) had no episodes of symptomatic malaria or asymptomatic parasitaemia during the pregnancy, 157 (55.7%) had low malaria burden (0-1 episodes of symptomatic malaria and < 50% of samples LAMP+), and 73 (25.9%) had high malaria burden during pregnancy (≥ 2 episodes of symptomatic malaria or ≥ 50% of samples LAMP+). Women with high malaria burden had increased risks of placental malaria by blood microscopy and LAMP [aRR 14.2 (1.80-111.6) and 4.06 (1.73-9.51), respectively], compared to the other two groups combined. Compared with women with no malaria exposure during pregnancy, the risk of placental malaria by histopathology was higher among low and high burden groups [aRR = 3.27 (1.32-8.12) and aRR = 7.07 (2.84-17.6), respectively]. Detection of placental parasites by any method was significantly associated with PTB [aRR 5.64 (1.46-21.8)], and with a trend towards increased risk for LBW and SGA irrespective of the level of malaria burden during pregnancy. CONCLUSION: Higher malaria burden during pregnancy was associated with placental malaria and together with the detection of parasites in the placenta were associated with increased risk for adverse birth outcomes. Trial Registration Current Controlled Trials Identifier NCT02163447