Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome and has a varied genetic background. The polymorphism of interferon regulatory factor 5 gene (IRF5) was reported to be associated with susceptibility to macrophage activation syndrome. IRF5 acts as a master transcription factor in the activation of pro-inflammatory cytokines. We assessed associations of IRF5 gene polymorphisms with susceptibility to secondary HLH.
Three IRF5 single nucleotide polymorphisms (rs729302, rs2004640, and rs2280714) were genotyped using TaqMan assays in 82 secondary HLH patients and 188 control subjects.
There was a significant association of the GT/TT genotype at rs2004640 with secondary HLH susceptibility (p < 0.01). The IRF5 haplotype (rs729302 A, rs2004640 T, and rs2280714 T) was associated with secondary HLH susceptibility (p < 0.01).
These findings indicate that IRF5 is a genetic factor influencing the susceptibility to secondary HLH and that the IRF5-associated immune response contributes to the pathogenesis of HLH.