Paradoxical psoriasiform reactions to anti-TNFα drugs are associated with genetic polymorphisms in patients with psoriasis.

Paradoxical psoriasiform reactions to anti-tumor necrosis factor α (TNFα) agents have been described. We aimed to study the association between these reactions and polymorphisms in genes previously associated with psoriasis or other autoimmune diseases. A total of 161 patients with plaque-type psoriasis treated with anti-TNFα drugs were genotyped for 173 single-nucleotide polymorphisms (SNPs) using the Illumina Veracode genotyping platform. Among the 161 patients, 25 patients developed a paradoxical psoriasiform reaction consisting of a change in morphology, mostly to guttate psoriasis (88%). These lesions developed 9.20±13.52 months after initiating treatment, mainly with etanercept (72%). Psoriasis type and a Psoriasis Area and Severity Index (PASI) 75 response to treatment were not associated with lesions. Multivariate logistic regression revealed that five SNPs (rs11209026 in IL23R, rs10782001 in FBXL19, rs3087243 in CTLA4, rs651630 in SLC12A8 and rs1800453 in TAP1) were associated with paradoxical reactions. This is the first study to show an association between genetic polymorphisms and paradoxical reactions in patients with psoriasis treated with anti-TNFα drugs.The Pharmacogenomics Journal advance online publication, 21 July 2015; doi:10.1038/tpj.2015.53.