Pathological manifestation of sacroiliitis in spondyloarthropathies / 中华风湿病学杂志

ABSTRACT

Objective To study pathological feature of sacroiliitis of spondyloarthropathies (SpA) in different stages,and improve the threshold of early diagnosis of SpA.Method Samples of sacroiliac joints (SIJ) of 8 patients with ankylosing spondylitis (AS) and 5 patients with undifferential spondyloarthropathies (uSpA) were taken when SIJ steroid injection was performed.The pathological feature was studied.Results Synovitis,including lining cell hyperplasia and inflammatory cell infiltration in looseconnective tissue,local cartilage degeneration,fibrosis and inflammatory cell infiltration in subchondral bony plate and marrow cave were found in 6 (86%,6/7) samples in patients with normal/suspectable SIJ CT scan.In the CT Ⅱ and Ⅲ degree sacroiliitis,marked degeneration and fibrosis of cartilage,inflammatory cell infiltration,pannus formation and subchondral bony plate destruction were increasingly prominent.In the advanced sacroiliitis (CT Ⅳ degree),destruction and calcification of cartilage and subchondral bony plate were the major feature.Eosinopil (EO) was increased in the infiltration cells of synovium and subchrodral bony plate in 3 samples.Conclusion Synovitis,including hyperplasia of lining cell and the infiltration of inflammatory cell in loose connective tissue,and local cartilage degeneration and inflammatory cell infiltration,and destruction of subchondral bony plate are the early changes identified in sacroiliitis.Pathological examination can improve the threshold of early diagnosis of sacroiliitis in case it cannot be confirmed with CT scan.