HLA polymorphism among Chinese patients with chronic plaque psoriasis: subgroup analysis.

Background: HLA-Cw*06 has a strong influence on the clinical features and the susceptibility to psoriasis in different ethnicities. It is also used as a biomarker to predict the therapeutic efficacy of biologics, with inconsistent results. Additionally, most Asian patients with psoriasis do not carry HLA-Cw*06.
Objectives: To determine additional HLA alleles which confer susceptibility or affect the severity of psoriasis in Chinese Han individuals. In addition, the potential of using HLA to predict treatment outcomes was also investigated.
Methods: We conducted a case-control association study in 199 Chinese patients with psoriasis and 200 unrelated healthy controls. HLA-B and HLA-C genotyping was performed and correlated with the therapeutic efficacy of the biologics, including alefacept, efalizumab, etanercept and ustekinumab. Patients with psoriasis were divided into group A (high-need patients with moderate to severe psoriasis) and B (general patients with psoriasis).
Results: The frequencies of HLA-B*60, HLA-B*75, HLA-Cw*06 and HLA-Cw*10 were significantly increased in patients with psoriasis compared with the healthy controls. However, the prevalence of HLA-Cw*06 was lower in group A compared with group B (6% vs. 17%, Pc=0·04). HLA-B*46 was found to be strongly associated with group A but not with group B patients with psoriasis. HLA-Cw*01/HLA-B*46 was also identified as a risk haplotype for Chinese patients with psoriasis, compatible with the results in Thais. Significant differences in response to biologics were observed between HLA-Cw*01+ and HLA-Cw*01- individuals in the alefacept treatment group, and between HLA-B*37+ and HLA-B*37-, and HLA-B*58+ and HLA-B*58- individuals in the efalizumab treatment group.
Conclusions: In addition to HLA-Cw*06, the HLA-Cw*01/HLA-B*46 haplotype was also increased in Chinese patients with psoriasis. High-need patients with psoriasis had a lower frequency of HLA-Cw*06 but a higher prevalence of HLA-B*46 compared with general patients with psoriasis in our population.
(© 2011 The Authors. BJD © 2011 British Association of Dermatologists.)