IL12B rs3213094 as a Predictor of Early Response to Biologic Therapy in Psoriasis: A Real-World Study in a Romanian...

Background and Objectives: Psoriasis is a chronic immune-mediated inflammatory disease characterized by heterogeneous clinical presentation and variable response to biologic therapy. Genetic variation within the IL-23/Th17 inflammatory pathway may influence treatment outcomes. This study evaluated the association between IL12B rs3213094 and IL23R rs11209026 single-nucleotide polymorphisms (SNPs) and response to biologic therapy in patients with moderate-to-severe psoriasis. Materials and Methods: We conducted a multicenter observational study including 92 Romanian patients with moderate-to-severe psoriasis vulgaris receiving their first biologic therapy (anti-TNF, anti-IL-17, or anti-IL-23 monoclonal antibodies). Clinical response was assessed using the Psoriasis Area and Severity Index (PASI) at baseline and weeks 12, 24, 36, and 48. Early response was defined as achieving PASI75 at week 12. Patient-reported disease impact was assessed using the Dermatology Life Quality Index (DLQI) at the same time points. Genotyping of IL12B rs3213094 and IL23R rs11209026 was performed using TaqMan assays. Longitudinal PASI dynamics were analyzed using repeated-measures ANOVA, while multivariable logistic regression was used to identify independent predictors of PASI75 at week 12. Results: A significant reduction in PASI scores over time was observed (p < 0.001). The IL12B rs3213094 genotype was associated with differences in early response kinetics, with T-allele carriers showing significantly greater PASI improvement at week 12 compared with CC homozygotes (90.0% vs. 65.7%, p = 0.003). This effect was limited to early treatment and attenuated at later time points. In multivariable analysis, the IL12B rs3213094 CT + TT genotype was independently associated with PASI75 achievement at week 12 (OR = 4.285, 95% CI 1.500-12.239, p = 0.007). Treatment with anti-IL-17 agents was also an independent predictor of early response (OR = 3.946, 95% CI 1.416-10.998, p = 0.009). No significant association was observed between IL23R rs11209026 and treatment response. DLQI scores improved significantly over time (p < 0.001), without genotype-dependent differences. Conclusions: IL12B rs3213094 SNP is significantly associated with early biologic treatment response in psoriasis, supporting its potential role as a pharmacogenetic biomarker of treatment responsiveness. These findings may inform the integration of genetic markers into personalized therapeutic strategies, particularly in underrepresented populations such as those from Eastern Europe. Further studies in larger cohorts are warranted to validate these results.