Figure 2From: Synovial histopathology of psoriatic arthritis, both oligo- and polyarticular, resembles spondyloarthropathy more than it does rheumatoid arthritisSynovial expression of S100A12 in psoriatic arthritis (PsA), nonpsoriatic spondyloarthropathy (SpA; ankylosing spondylitis [AS] + undifferentiated spondyloarthropathy [USpA]) and rheumatoid arthritis (RA). (a) PsA: lining = 0, sublining = 1 (original magnification 640Ć); (b) nonpsoriatic SpA: lining = 0, sublining = 2 (original magnification 640Ć); and (c) RA: lining = 0, sublining = 2 (original magnification 640Ć).Back to article page