Pigment epithelium-derived factor: as a potential marker in differentiation of axial psoriatic arthritis from peripheral psoriatic arthritis

Background Psoriatic arthritis (PsA) is an inflammatory disorder that affects both spinal and peripheral joints. Distinguishing axial PsA (axPsA) from peripheral PsA (pPsA) remains diagnostically challenging. Pigment epithelium-derived factor (PEDF), a glycoprotein exhibiting antiangiogenic and immunoregulatory activities, represents a potential biomarker for differentiating PsA subtypes. Objective To measure serum PEDF levels in PsA patients and assess their utility in differentiating axial from peripheral disease presentations. Patients and methods We conducted a case–control study including 60 PsA patients (30 axPsA, 30 pPsA) and 30 matched healthy controls. Participants underwent a comprehensive clinical assessment incorporating disease activity measures (DAS-28-ESR and CRP, DAPSA, BASDAI), PASI scoring, and radiographic evaluation. Serum PEDF quantification employed enzyme-linked immunosorbent assay, with correlations to disease activity parameters were analyzed. Results PEDF concentrations were substantially higher in axPsA patients (89.73±28.55 μg/ml) compared to pPsA (23.54±7.78 μg/ml) and controls (6.25±2.60 μg/ml, P <0.001). Receiver operating characteristic analysis determined a PEDF threshold of 36.01 μg/ml, achieving 100% sensitivity and specificity for distinguishing axPsA from pPsA. PEDF concentrations demonstrated strong correlations with age, disease duration, DAS-28 CRP, DAPSA, and BASDAI. Conclusion PEDF shows promise as a biomarker for differentiating axPsA from pPsA. Elevated PEDF concentrations associate with heightened disease activity, which may facilitate earlier diagnosis and optimized PsA management.