Role of HLA-DR Alleles to Increase Genetic Susceptibility to Onychomycosis in Nail Psoriasis

Background: Patients with nail psoriasis have an increased risk of onychomycosis. Previous studies suggest it may be due to structural changes of the nails. However, a genetic predisposition seems to be also at play. Objective: To determine a genetic susceptibility for onychomycosis in nails with changes of psoriasis. Methods: This is a prospective casecontrol study of patients with suggestive changes of nail psoriasis with onychomycosis ( cases) and without onychomycosis ( controls) confirmed by mycological tests. HLA typing was performed in all of them by sequence-specific primers. Results: Twenty-five patients and 20 controls with a mean age of 50 years ( range 37-72 years) were studied. HLA-DRB1*08 was found in 12 cases ( 48%) and only 3 controls ( 15%) [ p < 0.033, odds ratio ( OR) = 3.8, 95% confidence interval ( CI): 0.9-19]. HLA-DR1 was found in 9 cases ( 36%) and only 1 control ( 5%) ( p < 0.023, OR = 8.5, 95% CI: 1-188). Conclusion: HLA-DR*08 and HLA-DR*01 probably increase the susceptibility to fungal infection in psoriasis-affected nails, but larger studies are required to confirm this observation. (C) 2016 S. Karger AG, Basel