Reduced risk of uncomplicated malaria episodes in children with a⁺-thalassemia in northeastern Tanzania

TY - JOUR

T1 - Reduced risk of uncomplicated malaria episodes in children with a+-thalassemia in northeastern Tanzania

AU - Enevold, Anders

AU - Lusingu, John P

AU - Mmbando, Bruno

AU - Alifrangis, Michael

AU - Lemnge, Martha M

AU - Bygbjerg, Ib C

AU - Theander, Thor G

AU - Vestergaard, Lasse S

N1 - Keywords: Anemia; Child; Child, Preschool; DNA; Female; Genotype; Glucosephosphate Dehydrogenase Deficiency; Hemoglobins; Homozygote; Humans; Malaria, Falciparum; Male; Polymorphism, Single Nucleotide; Sickle Cell Trait; Tanzania; alpha-Thalassemia

PY - 2008

Y1 - 2008

N2 - The prevalence of human red blood cell (RBC) polymorphisms is high in areas of intense Plasmodium falciparum transmission, and individuals carrying these genetic traits are believed to be partially protected against severe malaria. However, it remains uncertain how RBC polymorphisms affect the susceptibility to uncomplicated malaria. We compared the risk of suffering from febrile, uncomplicated malaria between individuals carrying three common RBC polymorphisms (sickle cell trait, alpha(+)-thalassemia, and glucose-6-phosphate-dehydrogenase deficiency) and controls. The study was performed in an area of intense malaria transmission where 202 individuals 0-19 years of age were monitored clinically for a period of 6 months. RBC polymorphisms were assessed with molecular methods, and plasma antibodies to P. falciparum variant surface antigens (anti-VSA IgG) and glutamate-rich protein (anti-GLURP IgG) were measured with flow cytometry and ELISA assays, respectively. Regression analyses showed that alpha(+)-thalassemia was associated with a reduced risk of uncomplicated malaria episodes and that this advantageous effect seemed to be more predominant in children older than 5 years of age, but was independent of levels of antibodies to VSA and GLURP.

AB - The prevalence of human red blood cell (RBC) polymorphisms is high in areas of intense Plasmodium falciparum transmission, and individuals carrying these genetic traits are believed to be partially protected against severe malaria. However, it remains uncertain how RBC polymorphisms affect the susceptibility to uncomplicated malaria. We compared the risk of suffering from febrile, uncomplicated malaria between individuals carrying three common RBC polymorphisms (sickle cell trait, alpha(+)-thalassemia, and glucose-6-phosphate-dehydrogenase deficiency) and controls. The study was performed in an area of intense malaria transmission where 202 individuals 0-19 years of age were monitored clinically for a period of 6 months. RBC polymorphisms were assessed with molecular methods, and plasma antibodies to P. falciparum variant surface antigens (anti-VSA IgG) and glutamate-rich protein (anti-GLURP IgG) were measured with flow cytometry and ELISA assays, respectively. Regression analyses showed that alpha(+)-thalassemia was associated with a reduced risk of uncomplicated malaria episodes and that this advantageous effect seemed to be more predominant in children older than 5 years of age, but was independent of levels of antibodies to VSA and GLURP.

M3 - Journal article

C2 - 18458302

SN - 0002-9637

VL - 78

SP - 714

EP - 720

JO - American Journal of Tropical Medicine and Hygiene

JF - American Journal of Tropical Medicine and Hygiene

IS - 5

ER -