Abstract
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Tropical Medicine & International Health |
| Vol/bind | 10 |
| Udgave nummer | 12 |
| Sider (fra-til) | 1286-97 |
| Antal sider | 11 |
| ISSN | 1360-2276 |
| DOI | |
| Status | Udgivet - 2005 |
Bibliografisk note
Keywords: Adult; Anemia; Antibodies, Protozoan; Antigens, Surface; Chondroitin Sulfates; Dietary Supplements; Double-Blind Method; Female; Ghana; Gravidity; Humans; Immunoglobulin G; Malaria, Falciparum; Placenta Diseases; Pregnancy; Pregnancy Complications, Parasitic; Risk Factors; Vitamin A; Vitamin A DeficiencyAdgang til dokumentet
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I: Tropical Medicine & International Health, Bind 10, Nr. 12, 2005, s. 1286-97.
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review
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TY - JOUR
T1 - Maternal vitamin A supplementation and immunity to malaria in pregnancy in Ghanaian primigravids
AU - Cox, Sharon E
AU - Staalsoe, Trine
AU - Arthur, Paul
AU - Bulmer, Judith N
AU - Tagbor, Harry
AU - Hviid, Lars
AU - Frost, Chris
AU - Riley, Eleanor M
AU - Kirkwood, Betty R
N1 - Keywords: Adult; Anemia; Antibodies, Protozoan; Antigens, Surface; Chondroitin Sulfates; Dietary Supplements; Double-Blind Method; Female; Ghana; Gravidity; Humans; Immunoglobulin G; Malaria, Falciparum; Placenta Diseases; Pregnancy; Pregnancy Complications, Parasitic; Risk Factors; Vitamin A; Vitamin A Deficiency
PY - 2005
Y1 - 2005
N2 - BACKGROUND: Vitamin A supplementation is believed to enhance immune responses to infection but few studies have assessed its effects on anti-malarial immunity, especially during pregnancy when women are at increased risk from both vitamin A deficiency and pregnancy-associated malaria. The pathological effects of malaria in pregnancy are believed to be due to the sequestration of parasites in the placenta mediated via binding of variant surface antigens (VSA) expressed on the surface of P. falciparum infected red blood cells to placental chondroitin sulphate A (CSA). METHODS: We conducted a randomized double-blind controlled trial of vitamin A supplementation in 98 primigravid Ghanaian women to investigate the effects of vitamin A supplementation on levels of IgG antibodies binding to VSA of a clinical, P. falciparum placental isolate and to two isolates selected (or not) for adherence to CSA in vitro (anti-VSACSA IgG or anti-VSA IgG). Placental malarial infection was determined by placental blood smear and histology. RESULTS: Vitamin A supplementation was non-significantly associated with a decreased risk of active or chronic-active placental malarial infection compared to past, resolved infection at delivery, as determined by histology (OR=0.42, P=0.13--adjusted for level of education). After adjustment for differences in baseline values, levels of anti-VSACSA IgG to a placental, CSA-adherent isolate (EJ-24) but not to two isolates selected for CSA-adhesion in vitro (FCR3CSA and BusuaCSA), were significantly lower in women receiving vitamin A supplementation than in women receiving placebo (P=0.002). There was no apparent effect of vitamin A supplementation to levels of Ab to non-CSA-adherent parasite isolates. CONCLUSIONS: The data suggest that the reduction in the levels of anti-VSACSA antibodies to the known placental malaria isolate may reflect reduced intensity or duration of placental parasitaemia in women receiving vitamin A supplementation. These observations are of potential public health significance and deserve further investigation.
AB - BACKGROUND: Vitamin A supplementation is believed to enhance immune responses to infection but few studies have assessed its effects on anti-malarial immunity, especially during pregnancy when women are at increased risk from both vitamin A deficiency and pregnancy-associated malaria. The pathological effects of malaria in pregnancy are believed to be due to the sequestration of parasites in the placenta mediated via binding of variant surface antigens (VSA) expressed on the surface of P. falciparum infected red blood cells to placental chondroitin sulphate A (CSA). METHODS: We conducted a randomized double-blind controlled trial of vitamin A supplementation in 98 primigravid Ghanaian women to investigate the effects of vitamin A supplementation on levels of IgG antibodies binding to VSA of a clinical, P. falciparum placental isolate and to two isolates selected (or not) for adherence to CSA in vitro (anti-VSACSA IgG or anti-VSA IgG). Placental malarial infection was determined by placental blood smear and histology. RESULTS: Vitamin A supplementation was non-significantly associated with a decreased risk of active or chronic-active placental malarial infection compared to past, resolved infection at delivery, as determined by histology (OR=0.42, P=0.13--adjusted for level of education). After adjustment for differences in baseline values, levels of anti-VSACSA IgG to a placental, CSA-adherent isolate (EJ-24) but not to two isolates selected for CSA-adhesion in vitro (FCR3CSA and BusuaCSA), were significantly lower in women receiving vitamin A supplementation than in women receiving placebo (P=0.002). There was no apparent effect of vitamin A supplementation to levels of Ab to non-CSA-adherent parasite isolates. CONCLUSIONS: The data suggest that the reduction in the levels of anti-VSACSA antibodies to the known placental malaria isolate may reflect reduced intensity or duration of placental parasitaemia in women receiving vitamin A supplementation. These observations are of potential public health significance and deserve further investigation.
U2 - 10.1111/j.1365-3156.2005.01515.x
DO - 10.1111/j.1365-3156.2005.01515.x
M3 - Journal article
C2 - 16359410
SN - 1360-2276
VL - 10
SP - 1286
EP - 1297
JO - Tropical Medicine & International Health
JF - Tropical Medicine & International Health
IS - 12
ER -