Identification of disease-associated proteins by proteomic analysis in ankylosing spondylitis with uveitis

Shang-Yi Chiang^1,2, Ming-Ling Tsai², Jiann-Torng Chen², Hao-Ai Shui¹

¹Graduate Institute of Medical Science, National Defense Medical Center, Taipei, Taiwan
²Department of Ophthalmology, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan

Purpose: Ankylosing spondylitis (AS) is a chronic systemic inflammatory disorder of the axial skeleton and shows significant inherited susceptibility. Auto-immune responses have been traditionally considered as a putative pathogenetic event in AS. About 90% of the patients express the HLA- B27 genotype. However, rare consistent self-antigen has been identified to responsible for the disorders in AS until now.

Method: In this study, serum protein profiles of AS patients with HLA-B27 positive, HLA-B27 negative and healthy controls were investigated by two dimensional electrophoresis analysis. Proteins in gel were determined by silver stain, and the separation profiles were analyzed to assess spot density changes between these three groups. These spots in gel were isolated and identified by mass spectrometry and coupled with a database search.

Results: Eight proteins were found to vary in relation to AS groups compared with control samples. A group of four highly expressed protein spots was observed in AS patients' profiles with HLA-B27 positive.

Conclusion: The protein composition in serum was significantly different between both groups (disease and control). The identified proteins could be a potential biomarker for AS and the expression in AS may play a role in the mechanism and may contribute to some of the clinical manifestations of this disease.