Interleukin-10 gene polymorphism reflects the severity of chronic immune thrombocytopenia in Japanese patients.

INTRODUCTION:T-helper cell type 1 (Th1) polarization of the immune response has been documented in patients with chronic immune thrombocytopenia (ITP). Interleukin (IL)-10 is the most important factor regulating Th1 and T-helper type 2 cytokine synthesis. This study evaluated the impact of IL-10 polymorphisms on both susceptibility to, and severity of, chronic ITP. METHODS:We analyzed -1082(G/A), -812(C/T), and -592(C/A) IL-10 polymorphisms in 90 patients with adult chronic ITP and 202 race- and sex-matched healthy controls. RESULTS:No significant differences in the genotype or haplotype frequencies were observed between the patient with chronic ITP and the control group. However, more patients with the -592AA genotype showed a severe thrombocytopenic state (platelet count <10 x 10⁹/l) than those with the -592CC/CA genotypes (44.1%vs. 19.6%, P = 0.01). Furthermore, more patients with the ATA/ATA haplotype showed a severe thrombocytopenic state than those without the ATA/ATA haplotype (44.1%vs. 19.6%, P = 0.01). CONCLUSION:According to our data, patients with low producer type of IL-10 polymorphisms have more severe thrombocytopenia, suggesting that IL-10 gene polymorphisms may reflect the severity of ITP.