Cytophilic antibodies to Plasmodium falciparum glutamate rich protein are associated with malaria protection in an area of holoendemic transmission.
BACKGROUND
Several studies conducted in areas of medium or low malaria transmission intensity have found associations between malaria immunity and plasma antibody levels to glutamate rich protein (GLURP). This study was conducted to analyse if a similar relationship could be documented in an area of intense malaria transmission.


METHODS
A six month longitudinal study was conducted in an area of holoendemic malaria transmission in north-eastern Tanzania, where the incidence of febrile malaria decreased sharply by the age of three years, and anaemia constituted a significant part of the malaria disease burden. Plasma antibodies to glutamate rich protein (GLURP) were analysed and related with protection against malaria morbidity in models correcting for the effect of age.


RESULTS
The risk of febrile malaria episodes was reduced significantly in children with measurable anti-GLURP IgG1 antibodies at enrollment [adjusted odds ratio: 0.39 (95% CI: 0.15, 0.99); P = 0.047]. Interestingly, there was an inverse relationship between the plasma anti-GLURP IgG1 and IgG3 levels and the levels of parasitaemia at enrollment. However, anti-GLURP IgG2 and IgG4 levels were not associated with reduction in parasite density. Similarly, antibody levels were not associated with haemoglobin levels or anaemia risk.


CONCLUSIONS
Cytophilic IgG1 and IgG3 antibodies against R0-GLURP may contribute to the control of parasite multiplication and reduction in febrile malaria incidence in children living in an area of intense malaria transmission.
Lusingu
John P A
JP
National Institute for Medical Research, Amani Medical Research Centre, Tanga & Headquarters, Dar es Salaam, Tanzania. jpalusingu@yahoo.co.uk
Vestergaard
Lasse S
LS
Alifrangis
Michael
M
Mmbando
Bruno P
BP
Theisen
Michael
M
Kitua
Andrew Y
AY
Lemnge
Martha M
MM
Theander
Thor G
TG
D000293:Adolescent; D000328:Adult; D000740:Anemia / Q000209:etiology; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D016778:Malaria, Falciparum / Q000150:complications / Q000276:immunology* / Q000635:transmission; D010963:Plasmodium falciparum / Q000378:metabolism*; D015800:Protozoan Proteins / Q000276:immunology* / Q000378:metabolism; D012307:Risk Factors; D013636:Tanzania / Q000453:epidemiology
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D015800:Protozoan Proteins; C072492:glutamate-rich protein, Plasmodium