Determinants of variant surface antigen antibody response in severe Plasmodium falciparum malaria in an area of low and unstable malaria transmission

TY - JOUR

T1 - Determinants of variant surface antigen antibody response in severe Plasmodium falciparum malaria in an area of low and unstable malaria transmission

AU - A-Elgadir, T M E

AU - Theander, T G

AU - Elghazali, G

AU - Nielsen, M A

AU - A-Elbasit, I E

AU - Adam, I

AU - Troye-Blomberg, M

AU - Elbashir, M I

AU - Giha, H A

N1 - Keywords: Adolescent; Age Factors; Anemia; Animals; Antibodies, Protozoan; Antibody Formation; Antibody Specificity; Antigen-Antibody Reactions; Antigens, Protozoan; Antigens, Surface; Child; Child, Preschool; Disease Transmission; Humans; Malaria, Cerebral; Malaria, Falciparum; Plasmodium falciparum

PY - 2006

Y1 - 2006

N2 - The variant surface antigens (VSA) of infected erythrocytes are important pathogenic markers, a set of variants (VSA(SM)), were assumed to be associated with severe malaria (SM), while SM constitutes clinically diverse forms, such as, severe malarial anemia (SMA) and cerebral malaria (CM). This study was conducted in Eastern Sudan, an area of seasonal and unstable malaria transmission. Parasites and plasma were obtained from patients with different clinical grades of malaria, and flow cytometry was used for analysis of VSA antibody (Ab) response. We found that individuals recognized a broader range of isolates had a higher level of VSA Ab against the recognized isolates (correlation coefficient, 0.727, P<0.001). Unexpectedly, at the time of malaria diagnosis, plasma from patients with CM recognized a significantly larger number of isolates than did the plasma from patients with SMA (P<0.001). Parasites obtained from patients with SMA or from children were better recognized than isolates obtained from patients with uncomplicated malaria or from adults, P<0.001, P=0.021, respectively. Taken together, the above findings suggest that the limitations in the VSA immunoglobulin G repertoire were most probably contributing to the pathogenesis of SMA but not to that of CM.

AB - The variant surface antigens (VSA) of infected erythrocytes are important pathogenic markers, a set of variants (VSA(SM)), were assumed to be associated with severe malaria (SM), while SM constitutes clinically diverse forms, such as, severe malarial anemia (SMA) and cerebral malaria (CM). This study was conducted in Eastern Sudan, an area of seasonal and unstable malaria transmission. Parasites and plasma were obtained from patients with different clinical grades of malaria, and flow cytometry was used for analysis of VSA antibody (Ab) response. We found that individuals recognized a broader range of isolates had a higher level of VSA Ab against the recognized isolates (correlation coefficient, 0.727, P<0.001). Unexpectedly, at the time of malaria diagnosis, plasma from patients with CM recognized a significantly larger number of isolates than did the plasma from patients with SMA (P<0.001). Parasites obtained from patients with SMA or from children were better recognized than isolates obtained from patients with uncomplicated malaria or from adults, P<0.001, P=0.021, respectively. Taken together, the above findings suggest that the limitations in the VSA immunoglobulin G repertoire were most probably contributing to the pathogenesis of SMA but not to that of CM.

U2 - 10.1111/j.1365-3083.2006.01732.x

DO - 10.1111/j.1365-3083.2006.01732.x

M3 - Journal article

C2 - 16499577

SN - 0300-9475

VL - 63

SP - 232

EP - 240

JO - Scandinavian Journal of Immunology

JF - Scandinavian Journal of Immunology

IS - 3

ER -