1. Investigación

Aims-. This study evaluated the influence of pharmacogenetics in psoriatic patients treated with adalimumab and/or infliximab. Materials and methods-. Prospective observational study evaluating the association of 124 polymorphisms with the response to adalimumab or infliximab (PASI75) in patients with moderate-to-severe plaque psoriasis at 3 months (N=95) and 6 months of treatment (N=90). Significant SNPs for univariate analysis were subjected to multivariate analysis. Results/Conclusions-. Five SNPs were associated with PASI75 at 3 months: rs6661932 (IVL), rs2546890 (IL12B), rs2145623 (NFKBIA), rs9304742 (ZNF816A) and rs645544 (SLC9A8). Furthermore, rs1061624 (TNFR1B) was associated with PASI75 at 6 months. Nevertheless, these biomarkers should be validated in large-scale studies before implementation in clinical practice.

While anti-TNF therapies are effective against psoriasis, 30%–50% of patients do not show an adequate response to these rugs. Different candidate-gene pharmacogenetics studies have identified single nucleotide polymorphisms that may predict anti-TNF drugs response in psoriasis. Nevertheless, only one paper has undertaken a pharmacogenomic approach failing to find significant biomarkers of biological drug response along the whole genome. Furthermore, most of the pharmacogenetic candidate biomarkers identified previously have not been confirmed in a different cohort of patients. The objective of this study was to find biomarkers that could predict anti-TNF drugs response along the whole genome and validate biomarkers identified previously. A genome-wide association study (GWAS) was performed using the Human Omni Express-8 v1.2 Beadchips in 243 psoriasis patients treated with anti-TNF drugs. This study was multicentric and did not interfere with clinical practice. Associations between single nucleotide polymorphisms (SNP) and PASI75 (a 75% reduction with respect to baseline PASI) at 3 months were evaluated. Imputation was performed using SNPs with R2 > 0.7. There were two SNPs located in NPFFR2 that were close to the significant threshold of 5 × 10−8. These data suggest that NPFFR2 might be associated with anti-TNF drug response. However, further studies involving a larger cohort of patients are needed in order to confirm these results.