Anti-Phosphatidylserine/Prothrombin antibodies in patients with Polyarteritis Nodosa

Anti-phosphatidylserine/prothrombin (aPS/PT) antibodies have been described in cutaneous Polyarteritis Nodosa (PAN) in association with specific manifestations. To determine aPS/PT antibodies in patients with PAN and its correlation with clinical manifestations. Cross-sectional comparative study including PAN patients and 20 controls (10 Microscopic Polyangiitis [MPA] and 10 Behçet's disease [BD]). Clinical and demographic variables, treatment, serological markers, prognosis, activity and damage indexes were evaluated. aPS/PT, anti-cardiolipin (aCL), anti-beta 2 glycoprotein 1 (anti-B2GP1) antibodies, and lupus anticoagulant (LA) were determined. Fourteen patients with PAN were included, 11 (79%) women, with disease duration of 207 months, and mostly inactive disease. Only one patient with PAN and one with BD were positive for aPS/PT IgG. LA was the most frequent antibody identified. One patient with MPA and one with BD were positive for aCL IgM; one with MPA for anti-B2GP1 IgG, and one with PAN for anti-B2GP1 IgM. aPS/PT antibodies are not frequent in patients with longstanding inactive PAN.