PfEMP1-specific IgG reactivity among Beninese pregnant women with sickle cell trait

Abstract Background Sickle cell trait (HbAS) protects against severe Plasmodium falciparum malaria, but not against placental malaria (PM). In this study, PfEMP1-specific antibodies were measured in HbAA and HbAS Beninese pregnant women as a proxy of exposure to specific PfEMP1 variants. Methods Plasma samples collected at delivery from 338 HbAA and 63 HbAS women were used to measure IgG levels to six recombinant PfEMP1 proteins and three corresponding native proteins expressed on the infected erythrocyte (IE) surface. IgG-mediated inhibition of VAR2CSA + IEs adhesion to CSA was also tested. Results Levels of PfEMP1-specific IgG were similar in the two groups, except for native IT4VAR09 on IEs, where IgG levels were significantly higher in HbAS women. Adjusted odds ratios for women with positive IgG to HB3VAR06 and PFD1235w suggest a lower risk of infection with these virulent variants among HbAS individuals. The percentage of IEs binding to CSA did not differ between HbAA and HbAS women, but correlated positively with levels of anti-VAR2CSA and parity. Women with PM had lower levels of anti-VAR2CSA-specific IgG and lower IgG-mediated inhibition of IE adhesion to CSA. Conclusions The findings support similar malaria exposure in HbAA and HbAS women and a lack of HbAS-dependent protection against placental infection among pregnant women.

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IgG Responses to the Plasmodium falciparum Antigen VAR2CSA in Colombia Are Restricted to Pregnancy and Are Not Induced by Exposure to Plasmodium vivax

Infection and Immunity ◽

10.1128/iai.00136-18 ◽

2018 ◽

Vol 86 (8) ◽

Cited By ~ 6

Author(s):

Mary Lopez-Perez ◽

Mads Delbo Larsen ◽

Rafael Bayarri-Olmos ◽

Paulina Ampomah ◽

Liz Stevenson ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Pregnant Women ◽

Plasmodium Vivax ◽

Insect Cells ◽

Chinese Hamster ◽

Full Length ◽

Content Type ◽

Native Proteins ◽

Malaria Exposure ◽

Specific Igg

ABSTRACT Clinical immunity to malaria is associated with the acquisition of IgG specific for members of the Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family of clonally variant antigens on the surface of infected erythrocytes (IEs). The VAR2CSA subtype of PfEMP1 mediates IE binding in the placenta. VAR2CSA-specific IgG is normally acquired only after exposure to placental parasites. However, it was recently reported that men and children from Colombia often have high levels of functional VAR2CSA-specific IgG. This potentially undermines the current understanding of malaria immunity in pregnant women, and we thus conducted a study to assess further the levels of VAR2CSA-specific IgG in pregnant and nonpregnant Colombians. Plasma IgG against two full-length recombinant PfEMP1 proteins (one of the VAR2CSA type and one not) produced in baculovirus-transfected insect cells was detected frequently among Colombian men, children, and pregnant women with acute or previous malaria exposure. In contrast, IgG reactivity to a homologous full-length VAR2CSA-type protein expressed in Chinese hamster ovary (CHO) cells was low and infrequent among the Colombian plasma samples, as was reactivity to both corresponding native PfEMP1 proteins. Moreover, human and rabbit antibodies specific for Plasmodium vivax Duffy-binding protein (PvDBP), a protein with some homology to PfEMP1, did not react with VAR2CSA-type recombinant or native proteins, although the mouse monoclonal and PvDBP-specific antibody 3D10 was weakly reactive with recombinant proteins expressed in baculovirus-transfected insect cells. Our data indicate that the previously reported Colombian IgG reactivity to recombinant VAR2CSA is not malaria specific and that the acquisition of VAR2CSA-specific IgG is restricted to pregnancy, in Colombia and elsewhere.

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A perspective of the epidemiology of malaria and anaemia and their impact on maternal and perinatal outcomes in Sudan

The Journal of Infection in Developing Countries ◽

10.3855/jidc.1282 ◽

2010 ◽

Vol 5 (02) ◽

pp. 83-87 ◽

Cited By ~ 24

Author(s):

Ishag Adam ◽

Elhassan M Elhassan ◽

Abd Elrahium D Haggaz ◽

Abdel Aziem A Ali ◽

Gamal K Adam

Keyword(s):

Risk Factor ◽

Pregnant Women ◽

Placental Malaria ◽

Vitamin B12 Deficiency ◽

Perinatal Outcomes ◽

Plasmodium Falciparum Malaria ◽

Malaria Prevention ◽

Bed Nets ◽

Case Control Studies ◽

Cross Sectional

Introduction: Both malaria and anaemia have adverse effects on maternal and perinatal outcomes. Thus there is an urgent need to investigate the co-epidemiology of malaria and anaemia and their combined impact on maternal and perinatal outcomes in the different regions of Sudan Methodology: Various cross-sectional and case control studies conducted during the years 2003-2010 to investigate the epidemiology of malaria and anaemia and their impact on maternal and perinatal outcomes in different regions of Sudan were compared. Results: While 13.7% of antenatal attendants in New Halfa had peripheral microscopically detected Plasmodium falciparum malaria, placental malaria (using histological examinations) was prevalent in 32.0-40% and 19.5% of parturient women in New Halfa and Gadarif Hospitals, respectively. Malaria was a risk factor for anaemia in New Halfa and for stillbirths in Omdurman Maternity Hospital. Anaemia was present in 52.5%, 62.6% and 80.2% of pregnant women in Medani, New Halfa, and Gadarif Hospitals, respectively. In Gadarif, 57.3% of pregnant women had a folate deficiency, while 1% had a vitamin B12, deficiency. In Medani, zinc and copper deficiencies were detected in 45.0% and 4% of pregnant women, respectively. Anaemia was a risk factor for low birth weight in Al-Fashir, for fetal anaemia in New Halfa, and for stillbirth in Kassala Hospital. Conclusion: More care should be taken to ensure proper nutrition and malaria prevention such as bed nets and intermittent preventive treatments to avoid these diseases and their effects on maternal and perinatal outcomes.

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Plasmodium falciparum malaria: association of sickle cell trait in the reduction of parasite density in symptomatic Fulani tribe living in sympatry in Mali, West Africa

International Journal of Infectious Diseases ◽

10.1016/j.ijid.2016.02.750 ◽

2016 ◽

Vol 45 ◽

pp. 348

Author(s):

B. Maiga

Keyword(s):

Plasmodium Falciparum ◽

West Africa ◽

Falciparum Malaria ◽

Sickle Cell ◽

Parasite Density ◽

Sickle Cell Trait ◽

Plasmodium Falciparum Malaria

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P357 Perinatal and maternal outcomes in pregnant women with sickle cell disease and sickle cell trait

International Journal of Gynecology & Obstetrics ◽

10.1016/s0020-7292(09)61848-8 ◽

2009 ◽

Vol 107 ◽

pp. S516-S516

Author(s):

K. Tosta ◽

R. Nomura ◽

A. Igai ◽

G. Fonseca ◽

S. Gualandro ◽

...

Keyword(s):

Sickle Cell Disease ◽

Pregnant Women ◽

Sickle Cell ◽

Sickle Cell Trait ◽

Maternal Outcomes ◽

Cell Disease

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Hypertensive Disorders and Birth Weight in Pregnant Women With Sickle Cell Trait [9H]

Obstetrics and Gynecology ◽

10.1097/01.aog.0000483919.75741.3f ◽

2016 ◽

Vol 127 ◽

pp. 68S

Author(s):

Shannon Sullivan ◽

Jeanne Darbinian ◽

Mara B. Greenberg

Keyword(s):

Birth Weight ◽

Pregnant Women ◽

Sickle Cell ◽

Sickle Cell Trait ◽

Hypertensive Disorders

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Evidence for both innate and acquired mechanisms of protection from Plasmodium falciparum in children with sickle cell trait

Blood ◽

10.1182/blood-2011-08-371062 ◽

2012 ◽

Vol 119 (16) ◽

pp. 3808-3814 ◽

Cited By ~ 41

Author(s):

Lauren Gong ◽

Catherine Maiteki-Sebuguzi ◽

Philip J. Rosenthal ◽

Alan E. Hubbard ◽

Chris J. Drakeley ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Relative Density ◽

Sickle Cell ◽

Sickle Cell Trait ◽

Plasmodium Falciparum Malaria ◽

Force Of Infection ◽

Symptomatic Malaria ◽

Molecular Force ◽

High Parasite Density ◽

Within Subjects

AbstractSickle cell trait (HbAS) is known to be protective against Plasmodium falciparum malaria, but it is unclear when during the course of infection this protection occurs and whether protection is innate or acquired. To address these questions, a cohort of 601 children 1-10 years of age were enrolled in Kampala, Uganda, and followed for 18 months for symptomatic malaria and asymptomatic parasitemia. Genotyping was used to detect and follow individual parasite clones longitudinally within subjects. Children with HbAS were protected against the establishment of parasitemia, as assessed by the molecular force of infection at older but not younger ages (at 2 years of age: incidence rate ratio [IRR] = 1.16; 95% confidence interval [95% CI], 0.62-2.19; P = .6; at 9 years of age: IRR = 0.50; 95% CI, 0.28-0.87; P = .01), suggesting an acquired mechanism of protection. Once parasitemic, children with HbAS were less likely to progress to symptomatic malaria, with protection again being the most pronounced at older ages (at 2 years of age: relative risk [RR] = 0.92; 95% CI, 0.77-1.10; P = .3; at 9 years of age: RR = 0.68; 95% CI, 0.51-0.91; P = .008). Conversely, the youngest children were best protected against high parasite density (at 2 years of age: relative density = 0.24; 95% CI, 0.10-0.54; P = .001; at 9 years of age: relative density = 0.59; 95% CI, 0.30-1.19; P = .14), suggesting an innate mechanism of protection against this end point.

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Screening on prenatal infections in the South and Southwest macro-regions in the State of Bahia, Brazil: detected on paper filter

Revista Brasileira de Saúde Materno Infantil ◽

10.1590/1806-93042019000300011 ◽

2019 ◽

Vol 19 (3) ◽

pp. 681-690

Author(s):

Simone Andrade Porto São Pedro ◽

Carlos Alberto Lima da Silva ◽

Mônica Cardozo Rebouças ◽

Maria de Fátima Dias Costa

Keyword(s):

Pregnant Women ◽

Sickle Cell ◽

Sickle Cell Trait ◽

The State ◽

Screening Tests ◽

The South ◽

Prenatal Infections ◽

Paper Filter ◽

The Mean ◽

Epidemiological Profile

Abstract Objectives: to estimate the detection rate on prenatal screening pathologies on paper filter in the South and Southwest in the State of Bahia, as well as to delineate the epidemiological profile of these pregnant women, calculate and estimate the rate of adherence and the coverage of the Program. Methods: a descriptive study was carried out from August 2013 to August 2015, and the data were obtained from the Labimuno/ICS/UFBA. Results: 64,743 pregnant women were included; the mean ages were 25 years for the Southwest macro-region and 23 for the South. The results on the screening tests showed positivity of 0.13% and 0.29% for HBsAg, 0.17% and 0.22% for cytomegalovirus, 0.07% and 0.09% for HCV, 0.13% and 0.38% for HTLV, 0.04% and 0.19% for HIV, 1.2% and 2.84% for syphilis, and 0.54% and 0.73% for toxoplasmosis in the Southwest and South macro-regions, respectively. The estimates on coverage were considered satisfactory. Sickle cell anemia showed positivity of 0.02% and of 0.04% and 5% and 6.3% presented sickle cell trait in the Southwest and South macro-regions, respectively. Conclusions: the frequencies of infections in maternal-fetal health were considered low, highlighting on syphilis and the presence for sickle cell trait.

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