The relationship of Plasmodium falciparum humeral immunity with HIV-1 immunosuppression and treatment efficacy in Zambia.
BACKGROUND
HIV-1 infection affects malaria humeral immunity during pregnancy, but data for non-pregnant adults are lacking. This study reports the impact of HIV-1 infection and other variables on the level of malaria humeral immunity in adults with clinical malaria and whether humeral immune suppression was a risk factor for treatment failure.


METHODS
Sera of 224 HIV-1 infected and 115 uninfected adults were compared for IgG to merozoite antigens AMA-1 and MSP2 (3D7 and FC27 types) determined by ELISA, and for IgG to the Variant Surface Antigens (VSA) of three different parasite line E8B, A4 and HCD6 determined by flow cytometry.


RESULTS
Compared to HIV-1 uninfected adults, AMA-1 IgG was lower in HIV-1 infected (P = 0.02) and associated with low CD4 count AMA-1 IgG (P = 0.003). Low IgG to all three merozoite antigens was associated with less anemia (P = 0.03). High parasite load was associated with low MSP2 IgG 3D7 and FC27 types (P = 0.02 and P = 0.08). Antibody levels to VSA did not differ between HIV-1 infected and uninfected adults. However, low VSA IgGs were associated with high parasite load (P <or= 0.002 for each parasite line) and with treatment failure (P <or= 0.04 for each parasite line).


CONCLUSIONS
HIV-1 affects humeral responses to AMA-1, but seems to marginally or not affect humeral responses to other merozoite antigens and VSAs. The latter were important for controlling parasite density and predict treatment outcome.
Van Geertruyden
Jean-Pierre
JP
Unit International Health, Epidemiology and Social Medicine, Antwerp University, Belgium. jean-pierre.vangeertruyden@ua.ac.be
Van Eijk
Erika
E
Yosaatmadja
Francisca
F
Kasongo
Webster
W
Mulenga
Modest
M
D'Alessandro
Umberto
U
Rogerson
Stephen
S
D000293:Adolescent; D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D000962:Antimalarials / Q000494:pharmacology / Q000627:therapeutic use*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000150:complications* / Q000276:immunology; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D016867:Immunocompromised Host; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D016778:Malaria, Falciparum / Q000150:complications / Q000188:drug therapy* / Q000276:immunology / Q000469:parasitology; D008297:Male; D020066:Merozoite Surface Protein 1 / Q000276:immunology; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000276:immunology* / Q000469:parasitology; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult; D015024:Zambia
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D000962:Antimalarials; D007074:Immunoglobulin G; D020066:Merozoite Surface Protein 1