E149 Counting without correlation: the inflammatory ratios that failed to reflect psoriatic disease burden

Background/Aims Psoriatic disease encompasses a spectrum of chronic inflammatory conditions, including psoriasis and psoriatic arthritis, characterised by skin manifestations and joint involvement. Traditional inflammatory markers such as erythrocyte sedimentation rate and C-reactive protein have shown variable correlations with disease activity. Recent studies have explored neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio as potentially accessible biomarkers for assessing disease burden. However, their clinical utility in psoriatic conditions remains debatable. This study aimed to evaluate the relationship between these haematological ratios and validated disease activity indices in patients with psoriatic disease. Methods This hospital-based observational study was conducted at Department of Rheumatology and Clinical Immunology, ESIC Medical College and Hospital, Sanathnagar. The study enrolled 83 patients with psoriatic disease (43 with psoriasis and 40 with psoriatic arthritis). Complete blood counts were analysed to calculate neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte ratios (PLR). Disease severity was assessed using the Psoriasis Area and Severity Index scores (PASI) for cutaneous involvement, while articular disease activity was measured through Disease Activity Score-28 (DAS28) and Disease Activity in Psoriatic Arthritis scores (DAPSA) indices. Statistical analyses included correlation studies using Spearman’s method, group comparisons, and receiver operating characteristic curve analysis. Results In psoriasis patients (n = 43, mean age 42.1±13.5 years), neither NLR (mean 2.58±1.10, ρ = 0.065, p = 0.678) nor PLR (mean 173.29±107.48, ρ=-0.009, p = 0.953) correlated significantly with PASI (mean 3.87±4.23). Similarly, in psoriatic arthritis patients (n = 40, mean age 44.0±10.3 years), no significant associations emerged between these ratios and DAS28 (mean 2.77±1.39; NLR: ρ = 0.046, p = 0.777; PLR: ρ=-0.056, p = 0.731) or DAPSA (mean 12.37±10.69; NLR: ρ = 0.006, p = 0.970; PLR: ρ = 0.028, p = 0.865) (Table 1). Receiver operating characteristic analysis demonstrated poor discriminatory ability (AUC: NLR=0.507, PLR=0.640). Conclusion This investigation found no clinically meaningful relationships between NLR or PLR and disease activity parameters in either psoriasis or psoriatic arthritis. These findings suggest limited practical value of these inflammatory indices as sole biomarkers for monitoring disease severity in psoriatic conditions. Disclosure C.G. Vijay: None. V. Prasanna Parimi: None.