Research Information System
Archives of Dermatological Research, vol.318, no.1, 2026 (SCI-Expanded, Scopus)
While methotrexate (MTX) modulates systemic inflammation in psoriasis, its effects on novel hematologic indices and their clinical utility remain underexplored. To investigate MTX-induced changes in systemic inflammatory markers and their clinical correlations in psoriasis. This retrospective study analyzed 70 adults with moderate-to-severe psoriasis receiving subcutaneous MTX (15-25 mg/week) for 3 months. We evaluated changes in CBC-derived indices including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI), acute-phase reactants C-reactive protein(CRP), erythrocyte sedimentation rate(ESR), and their associations with PASI75 response. Subgroup analyses assessed psoriatic arthritis and regional involvement (scalp, nail, genital) effects. Primary endpoint was the percent change in the systemic immune-inflammation index (SII) from baseline to Month 3; secondary endpoints included percent changes in NLR, PLR, SIRI, ESR, and CRP, and their correlations with clinical response (PASI and PASI75). At Month 3, PASI decreased from median 7.45 (IQR 4.80–10.82) to 2.75 (IQR 1.20-5.28) (p<0.001). NLR (p=0.029), SII (p=0.031), ESR (p<0.001), and CRP (p=0.004) declined. PASI% change correlated weakly with SII% change (ρ=0.255, p=0.033). Compared with non-responders, PASI75 responders showed a greater SII reduction (−9.89% vs +7.38%; p=0.041). Genital involvement was associated with pronounced decreases in NLR (−21.0%, p=0.030), SII (−24.1%, p=0.016), and PLR (−23.3%, p=0.001), while psoriatic arthritis attenuated ESR reduction (p=0.049). This study identifies SII as a responsive hematologic marker of MTX efficacy in psoriasis, correlating with clinical improvement and showing greater reductions in treatment responders. The differential inflammatory marker changes observed across disease phenotypes highlight the potential for tailored monitoring approaches using routine CBC indices.