Psoriasis vulgaris is a chronic inflammatory disease of skin, which affects 2% of world population. The cutaneous manifestations of psoriasis are obvious and have a negative impact on quality of life of patients.
Family studies have demonstrated that psoriasis has a genetic and multifactorial basis in most of cases. In fact, there is a clear association between psoriasis and HLA genes. More specifically, HLA-C*06 group of alleles has been identified as the main psoriasis marker which gives more susceptibility to suffer this disease.
In addition, several studies have demonstrated a significant increasing response to Ustekinumab treatment in HLA-C*06 positive patients: HLA-C*06 positive patients respond faster and to a greater extent to Ustekinumab than HLA-C*06 negative ones.
All of the above highlights the role of HLA-C*06 not only as a psoriasis susceptibility marker, but also as a pharmacogenetic marker of Ustekinumab response in psoriasis.