Assessment of FOXP3 gene polymorphisms and serum interleukin-10 and their clinical significance in adult patients with chronic immune thrombocytopenia

Background
The association between single nucleotide polymorphisms (SNPs) in the regulatory regions of the FOXP3 gene, specifically in the promoter regions, and several autoimmune disorders has been established. It is unclear how the two FOXP3 polymorphisms are related to immune thrombocytopenia (ITP).


Aim
In order to investigate the potential association between these functional polymorphisms and ITP, as well as their correlation with interleukin-10 (IL-10) levels and their relationship with other clinical manifestations in adult ITP patients, an exploration is warranted.


Methods
Sixty patients with chronic ITP were enrolled in this study and 60 age- and sex-matched healthy volunteers served as a comparison group. Real-time polymerase chain reaction was used to genotype FOXP3 at the 3279 A/C and 924 A/G loci and ELISA to assess human serum interleukin10 level.


Results
The mean IL-10 in chronic ITP patients was 54.33± 10.7, while in controls, it had a mean of 18.37±6.34. Significantly elevated levels of IL-10 were found in the ITP case compared to the control (P<0.001). Regarding FOXP3 gene polymorphisms, 48.3% of ITP patients expressed the AA genotype of rs3761548 SNP, 30% of them expressed the CA genotype, and 21.7% expressed the CC genotype. Meanwhile, 20% of the control group expressed the AA genotype, 26.7% of them expressed the CA genotype, and 53.3% expressed the CC genotype by a substantial difference in genotype among patients with chronic ITP and controls (P=0.005). The rs3761548 SNP was significantly linked to IL-10 (P=0.019) as the CC genotype had significantly higher IL-10. Also, rs2232365 SNP and IL-10 were significantly related (P<0.001), as the AA genotype had significantly higher IL-10 compared to the AG and GG genotypes.


Conclusion
FOXP3 gene polymorphisms (rs2232365 and rs3761548) were significantly associated with ITP. Also, there was a significant relation between IL-10 and FOXP3 gene polymorphisms (rs2232365 and rs3761548).