Since interleukin-1 receptor-associated kinase (IRAK-1)/nuclear factor-kappa B (NF-kappa B) pathway plays an essential role in the pathogenesis of autoimmune diseases, the aim of the present study was to explore the role of polymorphisms in three genes, named IRAK1 (rs3027898), NFKBIA (rs696) and NFKB1 (-94ATTG insertion/deletion variant, - rs28362491), in PV susceptibility.