Association between malaria immunity and pregnancy outcomes among Malawian pregnant women receiving nutrient supplementation.
Malaria antibody responses measured at delivery have been associated with protection from maternal anaemia and low birth weight deliveries. Whether malarial antibodies present in the first half of pregnancy may protect from these or other poor birth outcomes is unclear. To determine whether malaria antibodies in the first half of pregnancy predict pregnancy outcomes, antibodies were measured to a range of merozoite antigens and to antigens expressed on the surface of parasitized red blood cells (pRBCs) in plasma samples collected at 14-20 weeks of gestation from Malawian women. The latter antibodies were measured as total IgG to pRBCs, and antibodies promoting opsonic phagocytosis of pRBCs. Associations between antibodies and maternal haemoglobin in late pregnancy or newborn size were investigated, after adjusting for potential covariates.



Antibodies to pRBC surface antigens were associated with higher haemoglobin concentration at 36 weeks. Total IgG to pRBCs was associated with 0.4 g/l [(95% confidence interval (0.04, 0.8)] increase in haemoglobin, and opsonizing antibody with 0.5 (0.05, 0.9) increase in haemoglobin for each 10% increase in antibody. These antibodies were not associated with birthweight, placental malaria, or newborn anthropometrics. Antibodies to merozoite antigens and non-placental-binding IEs were not associated with decreased risk of any of these outcomes. In some instances, they were negatively associated with outcomes of interest.



Antibodies to placental-binding infected erythrocytes may be associated with higher haemoglobin levels in pregnancy, whereas antibodies to other malaria antigens may instead be markers of malaria exposure. Trial registration clinicaltrials.gov NCT01239693. Registered Nov 10, 2010.
Department of Medicine at the Doherty Institute of Infection and Immunity, University of Melbourne, 792 Elizabeth Street, Melbourne, VIC, Australia.
Upeksha P
UP
Chandrasiri
Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Prahran, VIC, Australia.|Department of Epidemiology, Centre for Epidemiology and Biostatistics, University of Melbourne, Melbourne, VIC, Australia.|Department of Preventive Medicine and Infectious Diseases, Monash University, Clayton, VIC, Australia.
Freya J I
FJ
Fowkes
Department of Medicine at the Doherty Institute of Infection and Immunity, University of Melbourne, 792 Elizabeth Street, Melbourne, VIC, Australia.|Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Prahran, VIC, Australia.|Department of Microbiology, Monash University, Clayton, VIC, Australia.
James G
JG
Beeson
Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Prahran, VIC, Australia.|Department of Microbiology, Monash University, Clayton, VIC, Australia.
Jack S
JS
Richards
University of Malawi College of Medicine, Blantyre, Malawi.
Steve
S
Kamiza
Faculty of Public Health and Family Medicine, University of Malawi College of Medicine, Blantyre, Malawi.
Kenneth
K
Maleta
Centre for Child Health Research, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland.|Department of Paediatrics, Tampere University Hospital, Tampere, Finland.
Per
P
Ashorn
Department of Medicine at the Doherty Institute of Infection and Immunity, University of Melbourne, 792 Elizabeth Street, Melbourne, VIC, Australia. sroger@unimelb.edu.au.
Stephen J
0000-0003-4287-1982
SJ
Rogerson
D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood; D019587:Dietary Supplements; D005260:Female; D005502:Food; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008288:Malaria / Q000276:immunology*; D008295:Malawi; D009895:Opsonin Proteins / Q000097:blood; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology*; D011256:Pregnancy Outcome; D055815:Young Adult
D000913:Antibodies, Protozoan; D006454:Hemoglobins; D007074:Immunoglobulin G; D009895:Opsonin Proteins
Anaemia; Birthweight; Malaria in pregnancy; Malawi; Merozoite antigens; Placental malaria and low length-for-age Z score; Pregnancy outcomes; Small for gestational age; Variant surface antigens