Toll-like receptor 9 promoter polymorphism as a predictive factor of narrow-band UVB phototherapy response in patients with psoriasis.

BACKGROUND: Prediction of response to ultraviolet B (UVB) phototherapy in psoriatic patients mainly relies on clinical criteria, although some genetic predictors have been identified. Toll-like receptors (TLRs) have been involved in psoriasis pathogenesis through activation of the innate immune system. Their polymorphisms may condition not only the clinical profile of psoriasis but also the response to therapy.
METHODS: We analyzed the role of functional single-nucleotide polymorphisms (SNPs) of TLR2, 5, 4, and 9 in clinical response to a standard narrow-band UVB (NBUVB) therapy in 39 patients with moderate to severe psoriasis.
RESULTS: We found a significant relationship between TLR9-1486T/C SNP variants and a better response to NBUVB phototherapy. Patients with TC and CC genotype showed a higher improvement of Psoriasis Area and Severity Index (PASI) than patients with TT genotype. Results of multivariate analysis indicate that the differences in PASI improvement at the end of phototherapy attributed to TRL9 SNP genotype were not dependent on the patients' phototype, age, gender, body mass index, basal PASI, or disease evolution.
CONCLUSIONS: We describe a functional genetic variant in TLR9 gene that might affect the susceptibility to antipsoriatic treatment. The search of genetic predictive factors may be helpful in therapy selection and optimization of therapeutic regimes in psoriatic patients.