Course and Prognosis of AA Amyloidosis in Patients with Psoriatic Arthritis: Report of Three Cases from a Single Center Cohort and Review of the Literature.

Objective: Herein, we aimed to evaluate the frequency and clinical features of AA amyloidosis in patients with PsA followed up in our tertiary referral clinic. Methods: We retrospectively evaluated PsA patients classified according to CASPAR classification criteria followed-up in our tertiary referral clinic for AA amyloidosis. The literature search was also done by three independent researchers using the keywords "psoriatic arthritis AND amyloidosis", "spondyloarthritis AND amyloidosis", "AA amyloidosis", "secondary amyloidosis". Results and conclusions: A total of 253 patients were included into the analysis. Two thirds of (n=162; 64%) the patients were women, and the mean age of the patients was 50.6 ± 13.4 (range, 20-90). We identified three patients with AA amyloidosis in 253 patients with PsA (1.2 %). The frequency of PsA-related amyloidosis in our AA amyloidosis cohort (n=165) was 1.8 %. Literature search revealed only a retrospective cohort study and 17 case reports, and we analysed these 31 cases. Nearly half of the cases were male, mean age of the patients was 50.7±15.3 and mean age of amyloidosis diagnosis was 47.2±16.7 years. Most of these patients had both polyarticular and axial involvement (81.3%). AA amyloidosis is a rare in patients with PsA. It should be kept in mind that patients with PsA who have not received appropriate treatment for a long time and/or have refractory disease may develop AA amyloidosis.