title: FcgammaRIIa (CD32) polymorphism and anti-malarial IgG subclass pattern among Fulani and sympatric ethnic groups living in eastern Sudan.
abstract: BACKGROUND
  A SNP at position 131, in the FcgammaRIIa gene, affects the binding of the different IgG subclasses and may influence the clinical variation seen in patients with falciparum malaria. This study confirms and extends previous findings, analysing the FcgammaRIIa (CD32) polymorphism in relation to the IgG subclass distribution seen among two sympatric tribes living in eastern Sudan, characterized by marked differences in susceptibility to Plasmodium falciparum malaria.
  
  
  METHODS
  Two hundred and fifty Fulani subjects living in an area of meso-endemic P. falciparum malaria infection were genotyped for the FcgammaRIIa-131 polymorphism. For comparison, 101 non-Fulani donors - (Masaleit, Hausa and Four) - living in the same study area, were genotyped. The levels of plasma antibodies (IgG and subclasses) to four malaria antigens (AMA-1, MSP 2 - 3D7 & FC27, Pf332-C231) were measured using indirect enzyme-linked immunosorbent assays.
  
  
  RESULTS
  The FcgammaRIIa-H/H131 genotype was found to be significantly more prevalent in the Fulani as compared to the non-Fulani ethnic groups (36.0% for Fulani versus 17.8% for non-Fulani, adjusted OR 3.10, 95% CI 1.61-5.97, P value < 0.001). The Fulani showed lower anti-malarial IgG1 and IgG3 antibody levels as compared to the non-Fulani and higher levels of IgG2 antibodies.
  
  
  CONCLUSIONS
  The FcgammaRIIa-H/H131 genotype and H131 allele is at higher frequency in the Fulani ethnic group. The H/H131 genotype was consistently associated with higher levels of anti-malarial IgG2 and IgG3 antibodies, while the R/R131 genotype was associated with higher levels of IgG1 antibodies.
authors.affiliation: Department of Microbiology and Molecular-Biology, Faculty of Science and Technology, Al-Neelain University, Khartoum, Sudan. amre@imun.su.se
authors.forename: Amre
authors.initials: A
authors.lastname: Nasr
authors.forename: Nnaemeka C
authors.initials: NC
authors.lastname: Iriemenam
authors.forename: Hayder A
authors.initials: HA
authors.lastname: Giha
authors.forename: Halima A
authors.initials: HA
authors.lastname: Balogun
authors.forename: Robin F
authors.initials: RF
authors.lastname: Anders
authors.forename: Marita
authors.initials: M
authors.lastname: Troye-Blomberg
authors.forename: Gehad
authors.initials: G
authors.lastname: ElGhazali
authors.forename: Klavs
authors.initials: K
authors.lastname: Berzins
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D000818:Animals; D044383:Black People / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D016054:DNA, Protozoan / Q000235:genetics / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000145:classification* / Q000276:immunology; D016015:Logistic Models; D016778:Malaria, Falciparum / Q000208:ethnology / Q000235:genetics* / Q000469:parasitology; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D020641:Polymorphism, Single Nucleotide; D017452:Receptors, IgG / Q000235:genetics*; D013397:Sudan
chemical_list: D016054:DNA, Protozoan; C080568:Fc gamma receptor IIA; D007074:Immunoglobulin G; D017452:Receptors, IgG