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Lancet. 2004 Jan 24;363(9405):283-9.

Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria.

Author information

1
Centre for Medical Parasitology at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet) and Institute for Medical Microbiology and Immunology, University of Copenhagen, Copenhagen, Denmark.

Abstract

BACKGROUND:

Pregnancy-associated malaria caused by Plasmodium falciparum adherence to chondroitin sulfate A in the placental intervillous space is a major cause of low birthweight and maternal anaemia in areas of endemic P falciparum transmission. Adhesion-blocking antibodies that specifically recognise parasite-encoded variant surface antigens (VSA) are associated with resistance to pregnancy-associated malaria. We looked for a possible relation between VSA-specific antibody concentrations, placental infection, and protection from low birthweight and maternal anaemia.

METHODS:

We used flow cytometry to measure VSA-specific IgG concentrations in plasma samples taken during child birth from 477 Kenyan women selected from a cohort of 910 women on the basis of HIV-1 status, gravidity, and placental histology. We measured VSA expressed by one placental P falciparum isolate and two isolates selected or not selected for chondroitin sulfate A adhesiveness in-vitro.

FINDINGS:

Concentrations of plasma IgG specific for VSA, expressed by chondroitin sulfate A-adhering parasites (VSA in pregnancy-associated malaria or vsa-pam), increased with gravidity and were associated with placental histological findings. Women with chronic pregnancy-associated malaria and low or absent VSA-PAM-specific IgG had lower haemoglobin values (reduced by 17 g/L; 95% CI 8.1-25.2) and delivered smaller babies (birthweight reduced by 0.26 kg; 0.10-0.55) than did corresponding women with high VSA-PAM-specific IgG. No such relation was shown for concentrations of IgG with specificity for non-pregnancy-associated malaria VSA.

INTERPRETATION:

VSA-PAM-specific IgG protects against low birthweight and maternal anaemia. Our data indicate an important mechanism of clinical protection against malaria and raise hope for the clinical effectiveness of a potential VSA-based vaccine against pregnancy-associated malaria.

PMID:
14751701
DOI:
10.1016/S0140-6736(03)15386-X
[Indexed for MEDLINE]

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