A new integral enthesial-comorbididity index of psoriatic arthritis activity

Abstract

Aim. To develop an integral index of psoriatic arthritis (PsA) activity. Materials and methods. 117 patients with PsA (M/F 63/54) were included. Patients age 4411 years, psoriasis (Ps) duration 213153 months, PsA duration 73.478.5 months. Patients underwent standard clinical examination of PsA activity: tender (out of 68) and swollen (out of 66) joint counts (TJC, SJC), LEI, tenderness of the plantar fascia (PF), skin lesion severity (BSA), presence of nail Ps, body mass index (BMI), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), DAPSA, FACIT-F. Parametric and nonparametric statistic methods, correlation and ROC analysis were used. Results. Mean DAPSA was 3821, TJC 14.210.6, SJC 10.68.3, ESR 30.529.5 mm/h, CRP 23.329 mg/l, LEI 1.21.5, FACIT-F 3211, BMI 27.46.2 kg/m2. The following significant positive correlations were revealed: between DAPSA and BMI, patients age, ESR, PsA and Ps duration, TJC, SJC, LEI, presence of PF enthesitis, skin lesion severity, presence of nail Ps. A negative correlation between FACIT-F and male sex was found. Based on the predictive model of parameters, the Entesial-Comorbid Index of PsA (ECIPsA) was created: 3.81LEI+13.72PF+0.54Age-0.25FACIT-F+7.36BSA+7.94PsA duration+5.5Nail Ps+0.32BMI-3.52, namely LEI Leeds Enthesial Index; PF pain in the PF; patients age; FACIT-F fatigue scale; BSA3%=0, 3%=1; PsA duration2 years=0, 2 years=1; presence of nail Ps=1, absence=0; ECIPsA28 corresponds with high PsA activity according to DAPSA28. ROC analysis of sensitivity and specificity of the prognostic model demonstrated high correctness of the index: the area under the ROC curve was 0.768, 95% confidence interval (0.6240.913). Conclusion. The new PsA activity index corresponds to the existing ones and takes into consideration the clinical heterogeneity and comorbidity of the disease.