Prevalence of Plasmodium falciparum infection in pregnant Cameroonian women.

Zhou, Ainong; Megnekou, Rosette; Leke, Robert J. I.; Fogako, Josephine; Metenou, Simon; Trock, Bruce J.; Taylor, Diane Wallace; Leke, Rose G. F.

doi:10.4269/ajtmh.2002.67.566

Cited by 23 publications

(24 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is consistent with the observations that in the placenta, IRBCs sequester predominantly in the intervillous spaces, although some adhere to syncytiotrophoblasts (30,42,43). In pregnant women, the prevalence of parasite infection is highest between 13 and 20 weeks of gestation (7,45), which likely corresponds to the period when IRBCs accumulate in high numbers in the placenta. Thus, for the CSPGs to be the relevant receptor for IRBC binding in the placenta, these molecules must be expressed in the intervillous spaces in significant amounts at the end of the first trimester and the beginning of the second trimester.…”

supporting

confidence: 89%

“…In pregnant women infected with P. falciparum, the peak prevalence of infection occurs at 13 to 20 weeks of gestation (7,45). Since CSPGs are the receptors for the adherence of IRBCs in the intervillous spaces of the human placenta, the CSPGs must be expressed in significant levels toward the end of the first trimester or the beginning of the second trimester of pregnancy.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Chondroitin Sulfate Proteoglycan Expression and Binding ofPlasmodium falciparum-Infected Erythrocytes in the Human Placenta during Pregnancy

et al. 2003

View full text Add to dashboard Cite

A characteristic feature of malaria during pregnancy is the sequestration of Plasmodium falciparum-infected red blood cells (IRBCs) in the intervillous spaces of the placenta. We have recently shown that unusually low-sulfated chondroitin sulfate proteoglycans (CSPGs) present in the intervillous spaces mediate the adherence of IRBCs in the placenta. In areas of endemicity, the prevalence of P. falciparum infection in pregnant women peaks during weeks 13 to 20 and then gradually declines, implying that the placental CSPGs are available for IRBC adhesion early during the pregnancy. However, there is no information on the expression and composition of CSPGs during pregnancy. In this study, the expression pattern of CSPGs during the course of pregnancy was investigated. The CSPGs were purified from placentas of various gestational ages, characterized, and tested for the ability to bind IRBCs. The data demonstrate that the CSPGs are present in the intervillous spaces throughout the second and third trimesters. The levels of CSPGs expressed per unit tissue weight were similar in placentas of various gestational ages. However, the structures of the intervillous-space CSPGs changed considerably during the course of pregnancy. In particular, the molecular weight was decreased, with an accompanying gradual increase in the CSPG size polydispersity, from 16 weeks until 38 weeks. The sulfate content was increased considerably after 24 weeks. Despite these structural changes, the CSPGs of placentas of various gestational ages efficiently supported the binding of IRBCs. These results demonstrate that CSPGs can mediate the sequestration of IRBCs in the intervillous spaces of the placenta during the entire second and third trimesters and possibly during the later part of the first trimester as well.

show abstract

supporting

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Chondroitin Sulfate Proteoglycan Expression and Binding ofPlasmodium falciparum-Infected Erythrocytes in the Human Placenta during Pregnancy

et al. 2003

View full text Add to dashboard Cite

show abstract

“…In Yaoundé, being primigravida and Յ20 years of age are risk factors for placental malaria (44). Thus, the influence of gravidity and age on anti-PfGPI antibodies was investigated.…”

Section: Resultsmentioning

confidence: 99%

Lack of an Association between Antibodies toPlasmodium falciparumGlycosylphosphatidylinositols and Malaria-Associated Placental Changes in Cameroonian Women with Preterm and Full-Term Deliveries

et al. 2004

Self Cite

View full text Add to dashboard Cite

Sequestration of Plasmodium falciparum parasites within the placenta often leads to an accumulation of macrophages within the intervillous space and increased production of tumor necrosis factor alpha (TNF-␣), a cytokine associated with placental pathology and poor pregnancy outcomes. P. falciparum glycosylphosphatidylinositol (GPI) anchors have been shown to be the major parasite component that induces TNF-␣ production by monocytes and macrophages. Antibodies against P. falciparum GPI (anti-PfGPI), however, can inhibit the induction of TNF-␣ and inflammation. Thus, the study was undertaken to determine whether anti-PfGPI antibodies down-regulate inflammatory-type changes in the placentas of women with malaria. Anti-PfGPI immunoglobulin M (IgM) and IgG levels were measured in 380 pregnant women with or without placental malaria, including those who delivered prematurely and at term. Results showed that anti-PfGPI antibody levels increased with gravidity and age and that malaria infection boosted anti-PfGPI antibodies in pregnant women. However, no association was found between anti-PfGPI antibodies and placental TNF-␣ levels or the presence of acute or chronic placental malaria. Furthermore, anti-PfGPI antibody levels were similar in women with preterm and full-term deliveries and were not associated with an increase in infant birth weight. Thus, these results fail to support a strong role for anti-PfGPI antibodies in the prevention of chronic placental malaria infections and malaria-associated poor birth outcomes.

show abstract

“…Malaria transmission is perennial at both sites, but it is considerably lower in urban Yaounde (entomological inoculation rate, 0.1 to 1.1/month) (15) than in rural Etoa (EIR, 0.4 to 2.4/day) (24). The study sites and populations have been described in detail elsewhere (33). We used plasma samples collected from 283 Cameroonian women.…”

Section: Study Sites and Plasma Donorsmentioning

confidence: 99%

Effects of Pregnancy and Intensity of Plasmodium falciparum Transmission on Immunoglobulin G Subclass Responses to Variant Surface Antigens

et al. 2005

Self Cite

View full text Add to dashboard Cite

Placenta-sequestering Plasmodium falciparum involved in the pathogenesis of pregnancy-associated malaria (PAM) in otherwise clinically immune women expresses particular variant surface antigens (VSA PAM ) on the surface of infected erythrocytes that differ from VSA found in parasitized nonpregnant individuals (non-PAM type VSA). We studied levels of immunoglobulin G (IgG) and IgG subclasses with specificity for VSA PAM and for non-PAM type VSA in pregnant and nonpregnant women from two sites with different endemicities in Cameroon. We found that VSA PAM -specific responses depended on the pregnancy status, parity, gestational age, and parasite transmission intensity, whereas only the parasite transmission intensity influenced the levels of IgG specific for non-PAM type VSA. For both types of VSA, the responses were dominated by the cytophilic subclass IgG1, followed by IgG3. In pregnant women, the levels of VSA PAM -specific antibodies either were very low or negative or were very high, whereas the levels of the antibodies specific for non-PAM type VSA were uniformly high. Interestingly, the levels of VSA PAM -specific IgG1 increased with increasing gestational age, while the levels of the corresponding IgG3 tended to decrease with increasing gestational age. The IgG subclass responses with specificity for non-PAM type VSA did not vary significantly with gestational age. Taken together, our data indicate that IgG1 and to a lesser extent IgG3 are the main subclasses involved in acquired VSA PAM -specific immunity to pregnancy-associated malaria.

show abstract

Prevalence of Plasmodium falciparum infection in pregnant Cameroonian women.

Cited by 23 publications

References 16 publications

Chondroitin Sulfate Proteoglycan Expression and Binding ofPlasmodium falciparum-Infected Erythrocytes in the Human Placenta during Pregnancy

Chondroitin Sulfate Proteoglycan Expression and Binding ofPlasmodium falciparum-Infected Erythrocytes in the Human Placenta during Pregnancy

Lack of an Association between Antibodies toPlasmodium falciparumGlycosylphosphatidylinositols and Malaria-Associated Placental Changes in Cameroonian Women with Preterm and Full-Term Deliveries

Effects of Pregnancy and Intensity of Plasmodium falciparum Transmission on Immunoglobulin G Subclass Responses to Variant Surface Antigens

Contact Info

Product

Resources

About