TNF-a, TGF-b1, IL-10, IL-6 and IFN-y polymorphisms in patients with idiopathic thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterized by the presence of autoantibodies against platelet membrane glycoproteins (GPs), such as GPIIa/IIIa and GPIb/IX. Single nucleotid polymorphism (SNPs) of inflammatory cytokine genes were examined in 71 adult patients with chronic ITP and 71 healthy controls. The examined SNPs examined were within the genes were: tumour necrosis factor (TNF)-?(-308), transforming growth factor(TGF) TGF- ? 1(codons 10), TGF- ? 1 (codons 25), interleukine (IL) IL-10 (-1082), IL-10 (-819), IL-10 (-592), İL (-174) and interferone (IFN) IFN- ? (+874). Of these SNPs, frequency of the TNF-? (-308) AG phenotype and IFN- ? (+874) AA phenotypes were significiantly higher in ITP patients than in healthy controls (OR:0.342 95% CI:0.149-0.787, p=0.016), (OR:4.993 95% CI:1.586-15.721, p<0.05). Frequency of the TGF- ? 1 (codons 10) TT was significiantly lower in ITP patients than inhealthy controls (OR:0.342 95% CI:0.149-0.787, p=0.016). TNF- ?(308) AG phenotype was significantly higher in steroid-refractory and splenectomized cases relative to steroid?responsive (complete response and remission) ones at the end of the one year (OR:4.137 95% CI:1.156-14.807, p<0.05). When we compared the steroid responsive cases, which is at first steroid course, to the 12 cases who were in remission, however, in whom a complete response were not achieved, we found in IFN- ? (+874) AA genotype 12 (20.3 %) and 6 (50 %); respectively (OR:0.082 95% CI:0.009-0.793, p<0.05).With these findings, TNF-?(-308) AG , TGF- ? 1(codon 10) TT, IFN- ? (+874) TT genotypes were detected as the genes that posses tendency to ITP. On the other hand genotypes of TNF-?(-308) AG and IFN- ? (+874) AA might be important in steroid treatment.Key words: Immune thrombocytopenic purpura, Single nucleotid polymorphism