IP-10 and MCP-1 gene polymorphisms in Chinese patients with chronic immune thrombocytopenia

Aberrant Th1/Th2 polarization is considered to play a crucial role in the abnormal immune state of primary immune thrombocytopenia (ITP). IFN-γ-inducible protein of 10 kilodaltons (IP-10) and Monocyte chemoattractant protein-1 (MCP-1) gene are involved in enhancing the Th1 and Th2 immune response, respectively. In this study we investigated the distributions of IP-10 (-201 G/A) and MCP-1 (-2518 A/G) polymorphisms in 323 patients with chronic ITP and 255 healthy controls by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). The IP-10 and MCP-1 levels of blood serum from 79 adult ITP patients and 43 healthy controls were detected with ELISA. The frequency of AG + AA genotype in IP-10 (-201 G/A) was significantly higher in ITP patients than in controls, especially in female and adult patients. ITP patients showed higher IP-10 levels than normal controls. Moreover, both IP-10 (-201 G/A) heterozygote (GA) and homozygote minor allele (AA) patients had significantly increased IP-10 levels compared to homozygote genotype (GG) patients at diagnosis. No significant differences were revealed in genotypes and allele distributions of MCP-1 (-2518 A/G) between ITP patients and normal controls, as well as the MCP-1 levels. In conclusion, the -201 G/A polymorphism of IP-10 gene may be associated with the susceptibility of ITP in Chinese population.