Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria.
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 reco...
| Main Authors: | , , , , , |
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| Format: | Journal article |
| Language: | English |
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2004
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| _version_ | 1826260845423755264 |
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| author | Staalsoe, T Shulman, C Bulmer, J Kawuondo, K Marsh, K Hviid, L |
| author_facet | Staalsoe, T Shulman, C Bulmer, J Kawuondo, K Marsh, K Hviid, L |
| author_sort | Staalsoe, T |
| collection | OXFORD |
| description | 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. |
| first_indexed | 2024-03-06T19:12:11Z |
| format | Journal article |
| id | oxford-uuid:172544d7-2e73-4c9f-8d5d-213e91e5d04a |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:12:11Z |
| publishDate | 2004 |
| record_format | dspace |
| spelling | oxford-uuid:172544d7-2e73-4c9f-8d5d-213e91e5d04a2022-03-26T10:35:25ZVariant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:172544d7-2e73-4c9f-8d5d-213e91e5d04aEnglishSymplectic Elements at Oxford2004Staalsoe, TShulman, CBulmer, JKawuondo, KMarsh, KHviid, L 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. |
| spellingShingle | Staalsoe, T Shulman, C Bulmer, J Kawuondo, K Marsh, K Hviid, L Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria. |
| title | Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria. |
| title_full | Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria. |
| title_fullStr | Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria. |
| title_full_unstemmed | Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria. |
| title_short | Variant surface antigen-specific IgG and protection against clinical consequences of pregnancy-associated Plasmodium falciparum malaria. |
| title_sort | variant surface antigen specific igg and protection against clinical consequences of pregnancy associated plasmodium falciparum malaria |
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