Absence of Association ofInterleukin-18Gene Polymorphisms with Primary Immune Thrombocytopenia in a Chinese Han Population

Abstract

Interleukin-18 (IL-18) is an inflammatory cytokine that plays an important role in autoimmune disease by inducing interferon-g secretion. Considering the abnormal serum concentration of IL-18 in primary immune thrombocytopenia (ITP) patients and the regulated effect of IL-18 gene polymorphisms on its production, the aim of this study was to investigate a possible association between the IL-18 promoter polymorphisms ( -137 G/C and -607 C/A sites) and genetic susceptibility to ITP in a Chinese Han population. A total of 181 ITP patients and 163 healthy controls were included in this study; IL-18 gene promoter polymorphisms were analyzed by a polymerase chain reaction with sequence-specific primers. No significant differences in genotype ( -607: w 2 = 0.307, p = 0.858; -137: w 2 = 0.378, p = 0.828) and allele frequencies ( -607: w 2 = 0.004, p = 0.949; -137: w 2 = 0.307, p = 0.858) were found between total ITP patients and normal controls. We further analyzed the association of IL-18 polymorphisms with clinical parameters of ITP patients, including first onset age and clinical therapy response to glucocorticoids, and no difference was revealed. In conclusion, IL-18 promoter polymorphisms may not be associated with genetic susceptibility to ITP in a Chinese Han population.

Impact of serum immunoglobulins level and IL-18 promoter gene polymorphism among Egyptian patients with idiopathic thrombocytopenic purpura

“…23,24 In our study, we found that there was no significant difference between the ITP patients and the control group as regard to the IL-18 genotype polymorphism. This in agreement with Zhao et al 25 and Li et al 26 who stated that there is no association between IL-18 promotor polymorphism and occurrence of primary thrombocytopenia.…”