The potential association of tumor necrosis factor-βeta (252 G/A) cytokine gene polymorphism with immune thrombocytopenic purpura among Egyptian children

Abstract

ABSTRACTObjectives: The main objective of this study was to study tumor necrosis factor beta (TNFB) + 252G/A gene polymorphism, known to be related to autoimmunity, in immune thrombocytopenia (ITP) patients. We also aimed to investigate the association between TNFB + 252G/A polymorphism and susceptibility to develop persistent/chronic ITP.Methods: One hundred pediatric ITP patients, as well as 50 age- and sex-matched healthy Egyptian subjects, were included. Genotyping of TNF-β gene (G252A) was done using the PCR-RFLP method.Results: TNFB allele B2 frequency was (64%, 64/100) in controls, (69%, 138/200) in ITP patients, while the frequency of the variant allele B1 was 36% (36/100) in controls, (31%, 62/200) in ITP patients. TNFB genotype frequency in ITP patients showed equal frequency for B2B2 and B1B2 genotypes, (46%, 46/100), while B1B1 frequency was 8% (8/100). Among controls, frequencies of B2B2, B1B2 and B1B1 genotypes were 36% (18/50), 56% (28/50), and 8% (4/50), respectively. Odds ratio for the risk of developing ITP revealed no statistically significant risk, associated with any allele or genotype. No association was encountered between different genotypes and age, hematological parameters, gender, stage of the disease or response to treatment.Discussion: Comparison between ITP patients and controls as regards TNFB allele and genotype frequencies showed no statistically significant difference. No increased risk for developing ITP was associated with any allele/genotype.Conclusion: The risk of developing ITP was not related to the studied polymorphism.