title: Parity and placental infection affect antibody responses against Plasmodium falciparum during pregnancy.
abstract: Women are at higher risk of Plasmodium falciparum infection when pregnant. The decreasing risk of malaria with subsequent pregnancies is attributed to parity-dependent acquisition of antibodies against placental parasites expressing variant surface antigens, VAR2CSA, that mediate placental sequestration through adhesion to chondroitin sulfate A (CSA). However, modulation of immunity during pregnancy may also contribute to increase the risk of malaria. We compared antibody responses among 30 Mozambican primigravidae and 60 multigravidae at delivery, 40 men, and 40 children. IgG levels were measured against the surface antigens of erythrocytes infected with P. falciparum isolated from 12 pregnant women (4 placental and 8 peripheral blood isolates) and 26 nonpregnant hosts. We also measured IgG levels against merozoite recombinant antigens and total IgG. Placental P. falciparum infection was associated with increased levels of total IgG as well as IgG levels against merozoite antigens and parasite isolates from pregnant and nonpregnant hosts. We therefore stratified comparisons of antibody levels by placental infection. Compared to multigravidae, uninfected primigravidae had lower total IgG as well as lower levels of IgGs against peripheral blood isolates from both pregnant and nonpregnant hosts. These differences were not explained by use of bed nets, season at delivery, neighborhood of residence, or age. Compared to men, infected primigravidae had higher levels of IgGs against isolates from pregnant women and CSA-binding lines but not against other isolates, supporting the concept of a pregnancy-specific development of immunity to these parasite variants. Results of this study show that parity and placental infection can modulate immune responses during pregnancy against malaria parasites.
authors.affiliation: Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain. agmayor@clinic.ub.es
authors.forename: Alfredo
authors.initials: A
authors.lastname: Mayor
authors.forename: Eduard
authors.initials: E
authors.lastname: Rovira-Vallbona
authors.forename: Sonia
authors.initials: S
authors.lastname: Machevo
authors.forename: Quique
authors.initials: Q
authors.lastname: Bassat
authors.forename: Ruth
authors.initials: R
authors.lastname: Aguilar
authors.forename: Llorenç
authors.initials: L
authors.lastname: Quintó
authors.forename: Alfons
authors.initials: A
authors.lastname: Jiménez
authors.forename: Betuel
authors.initials: B
authors.lastname: Sigauque
authors.forename: Carlota
authors.initials: C
authors.lastname: Dobaño
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Kumar
authors.forename: Bijender
authors.initials: B
authors.lastname: Singh
authors.forename: Puneet
authors.initials: P
authors.lastname: Gupta
authors.forename: Virander S
authors.initials: VS
authors.lastname: Chauhan
authors.forename: Chetan E
authors.initials: CE
authors.lastname: Chitnis
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Alonso
authors.forename: Clara
authors.initials: C
authors.lastname: Menéndez
mesh_terms: D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood* / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D002675:Child, Preschool; D004912:Erythrocytes / Q000276:immunology / Q000469:parasitology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007223:Infant; D016778:Malaria, Falciparum / Q000097:blood / Q000276:immunology*; D008297:Male; D010298:Parity; D010920:Placenta / Q000276:immunology / Q000469:parasitology; D010922:Placenta Diseases / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D010963:Plasmodium falciparum / Q000276:immunology; D011247:Pregnancy / Q000276:immunology*; D011248:Pregnancy Complications / Q000097:blood / Q000276:immunology*; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G