The comparison between Behcet's disease and spondyloarthritides: Does Behcet's disease belong to the spondyloarthropathy complex?

This study was to clarify whether BehCet's disease (BID) could be classified into the spondyloarthropathy (SpA) complex. It was undertaken on 58 patients with BD (I group), 56 patients with SpA (SpA group), and 3 patients who concurrently satisfied the criteria for BID and SpA (BDSpA group). The clinical parameters and known susceptible HLA antigens were compared between BID group and SpA group. In addition, 3 patients in BDSpA group were reviewed. The prevalence of definitive sacroiliitis (SI) in BID group and SpA group was 46.4% and 5.2%, respectively. However, none had a definitive SI in healthy controls. Enthesitis was observed in 3.4% of BID group and in 50% of SpA group. The patterns of eye involvement were different between these two groups. HLA-B27 was negative in all 49 patients of BID group, whereas it was positive in 67.9% of SpA group. The prevalence of HLA-B51 was 51.7% in BID group, and that in SpA group was 21.4%. One patient in BDSpA group was considered to have concurrent BID and ankylosing spondylitis (AS). Another patient was closer to AS, and the third to BD. Conclusively, it seems that BID could not be classified into the SpA complex.