The Value of Systemic Inflammatory Parameters (Neutrophil-Lymphocyte Ratio and C-Reactive Protein) Combined with Psoriasis Area Severity Index in Predicting the Development of Arthritic Symptoms in Patients with Psoriasis

Abstract

Background/Aims: This study aimed to assess the utility of the neutrophil‑to‑lymphocyte ratio (NLR), C‑reactive protein (CRP), and skin lesion severity for identifying arthritic manifestations in individuals with psoriasis. Materials and Methods: A total of 102 patients with psoriasis vulgaris (PsV), 74 with psoriatic arthritis (PsA), and 60 healthy controls were enrolled. Demographic and laboratory data were systematically examined. Skin lesion severity, measured by the Psoriasis Area and Severity Index (PASI), was compared between PsV and PsA groups. Correlation analysis, receiver operating characteristic (ROC) curves, and multivariate regression were performed to evaluate the associative strength of various indicators with PsA and their role in risk stratification. Results: No significant intergroup differences were found in age, sex, BMI, smoking/alcohol history, or family history of psoriasis (all P > .05). The PsA group exhibited higher WBC, NEU, CRP, and NLR than the PsV and control groups (all P < .001). Platelet‑to‑lymphocyte ratio (PLR) was higher in PsA than in PsV (P = .017), whereas PLT did not differ across groups (P = .296). Joint symptom frequency (arthralgia, synovial thickening, etc) and PASI score were higher in PsA than in PsV (all P < .05). Correlation analysis showed positive associations of NLR and CRP with arthritic symptoms and PASI (all P < .05). ROC analysis revealed that NLR (area under the curve [AUC] = .739), CRP (AUC = .787), and PASI (AUC = .783) had moderate individual discriminative value; the combination NLR+CRP+PASI yielded the highest performance (AUC = .891, sensitivity 82.43%, specificity 83.33%). Multivariate regression indicated that NLR and CRP were independently associated with PsA (both P < .001). Conclusion: NLR, CRP, and PASI are closely linked to arthritic symptoms in psoriasis patients. As independent correlates of PsA, NLR and CRP, along with skin lesion severity, may offer a clinical reference for early arthritis detection and risk assessment. Cite this article as: Liu Y, Qi H, Bian X, et al. The Value of Systemic Inflammatory Parameters (Neutrophil-Lymphocyte Ratio and C-Reactive Protein) Combined with Psoriasis Area Severity Index in Predicting the Development of Arthritic Symptoms in Patients with Psoriasis. ArchRheumatol. Published online September 09, 2026. doi: 10.5152/ArchRheumatol.2026.25145.