Distribution of FCR Polymorphism in Children Endemic Population of Burkina and Effect of this Polymorphism on IgG and his Subclass Production

Aims: Malaria is one of disease which caused many deaths every year. Many studies try to understand why since it apparition, malaria is still endemic in certain regions. It appear that some FCR polymorphism may impact on susceptibility to malaria. The present study aimed to determine the distribution of certain FCR polymorphism and their effect on antibodies production.

Study Design: Two cross-sectional surveys were carried out at Saponé.

Place and Duration of Study: Sampling was done at Saponé during low (January 2007) and high (September 2007) malaria transmissions seasons and laboratories activities were done at the department of Molecular Biosciences, the Wenner-Gren Institute, Stockholm University, Sweden. Methodology: During each cross-sectional survey, 5 ml of venous blood in a tube containing EDTA was collected from each child for antibodies assessment by ELISA and FCR genotyping by PCR. Thick and thin blood films were also prepared from finger prick for microscopy diagnosis of malaria.

Results: 622 children from Mossi tribes participated in this study. Three mutants allele were present in pupation with Frequencies of the mutant alleles of FCGR2C (rs3933769), FCGR3A (rs396991) and FCGR2B (rs1050519) 15.43%, 66.24% and 37.94% respectively. Regarding the SNPs, they are contribute to malaria pathogenesis. Carriers of the mutant allele of FcγRIIB (rs1050519) harboured more parasites than the parasites harboured by non-carriers (P=.002). However, the mutant alleles of FCγRIIC (rs3933769) and FCγRIIIA (rs396991) harboured less parasite than wild alleles (P=.001) for all of them. SNPs are associated to total IgG responses. The FCγRIIB (rs 1050519) SNP (permutation of G to T) was negatively associated with IgG responses. Children with allele GG (Wild type) produced more antibodies against MSP3 than children with GT (Heterozygous) and TT (Mutant). The difference was statically significant (P= 0.05). However the FcRIIB mutation was positively associated with cytophilic IgG production against MSP2B, GLURP R0 and GLURP R2. The difference was statistically significant for MSP2A (P<0.001).

Conclusion: FCR2b, FCR2c and FCR3a are present in or study population. Malaria antibodies seem to be affected by FCR mutations.