HLA Correlations with Clinical Phenotypes and Risk of Metabolic Comorbidities in Singapore Chinese Psoriasis Patients

Introduction Psoriasis is a systemic, chronic inflammatory disease that not only afflicts the skin but is also associated with cardiovascular disease and metabolic syndrome. The strongest susceptibility loci for the disease is within the human leukocyte antigen (HLA) complex, though specific HLA allelic associations vary between populations. Objective Our objective was to investigate HLA associations with clinical phenotypes of psoriasis and metabolic syndrome in Chinese psoriasis cases. Methods We conducted an observational case–control study in Singapore with a cohort of psoriasis cases consecutively recruited from an outpatient specialist dermatological center ( n = 120) compared with 130 healthy controls. Results Significant HLA associations with psoriasis were observed with HLA-A*02:07, B*46:01, C*01:02, and C*06:02. The three-locus haplotype of A*02:07-C*01:02-B*46:01 was also significant (odds ratio [OR] 3.07; p = 9.47 × 10 −5 ). We also observed an association between nail psoriasis and HLA-A*02:07 carriers (OR 4.50; p = 0.002), whereas C*06:02 carriers were less prone to have nail involvement (OR 0.16; p = 0.004). HLA-A*02:07 was also identified as a possible risk allele for hypertension (OR 2.90; p < 0.05), and C*01:02 was a possible risk allele for dyslipidemia (OR 3.36; p < 0.05), both known to be common comorbidities in patients with psoriasis. Conclusion Our results demonstrate the growing importance of discerning population-specific clinical phenotypes and their association with certain HLA alleles in psoriasis.