The expression of IFN-gamma, IL-4, Foxp3 and perforin genes are not correlated with DNA methylation status in patients with immune thrombocytopenic purpura.

We investigated the relationship between the expression of IFN-gamma, IL-4, Foxp3 and perforin gene and the methylation status of their promoters in immune thrombocytopenic purpura (ITP) patients. Gene expression and DNA methylation were determined by quantitative PCR and bisulfite genomic sequencing, respectively. The expression of IFN-gamma was higher, while the expression of IL-4 was notably lower in ITP patients when compared with the controls. Most importantly, the Th1/Th2 (IFN-gamma/IL-4) was remarkably higher in ITP patients, showing that the ITP patients were mainly in the Th1 polarization response. Although the methylation rate of CpGs located at -409 of perforin was higher (p = 0.0376) and that of IFN-gamma were relatively higher (p = 0.0582) in ITP, we did not find the negative correlation between the expression of those genes and the methylation of their promoters.