Significance of association of HLA-C and HLA-E with psoriatic arthritis

Psoriatic arthritis (PsA) is a complex genetic disorder that results from an interplay between multiple genetic and environmental factors. The aim of the study was to assess the significance of the association between the HLA-C and HLA-E allelic groups and PsA. Our results confirm the association between HLA-C∗06 and PsA (OR = 5.16, p < 0.0001). Furthermore, HLA-C∗06-positive patients develop more severe disease (p < 0.01) and more frequently present with polyarticular pattern of PsA (p = 0.08). Additionally our study revealed that the HLA-C∗02 allele was more frequently observed in PsA patients (OR = 5.40, p < 0.0005) and also that the HLA-E∗01:01 allele was significantly over-represented among HLA-C∗02-negative patients in comparison to healthy individuals (OR = 6.44, p = 0.045). Therefore these results suggest that the HLA-E and HLA-C∗02 molecules may also play an important role in determination immune response contributing to the PsA development.