Annals of Rehabilitation Medicine

Original Article: J Korean Acad Rehabil Med. 2007;31(2):220-227.; HLA-B27 Positive and HLA-B27 Negative Ankylosing Spondylitis: A Comparative Study in Diagnostic Process and Clinical Features.; Sung, Duk Hyun , Yoon, Young Cheol , Kim, Eun Jin , Park, Kwang Hong; ¹Department of Physical Medicine and Rehabilitation, Sungkyunkwan University School of Medicine, Korea. dhsung@smc.samsung.co.kr
²Department of Radiology, Sungkyunkwan University School of Medicine, Korea.
³Department of Physical Medicine and Rehabilitation, The Armed Forces Capital Hospital, Korea.

Abstract: Objective
To investigate the differences in clinical and radiologic features between HLA-B27 positive ankylosing spondylitis (AS) and HLA B27 negative AS. Method: Ninety-nine consecutive patients who were suspected as AS in initial diagnostic process were studied. HLA-B27 was examined with microlymphocytotoxicity method in all patients. A radiologist and a physiatrist re- read plain pelvis radiographies of all patients. Difference in onset age and C-reactive protein (CRP) depending on HLA B27 status and an association between HLA B27 status and clinical and radiologic features were tested. Results: Sacroiliitis (≥bilateral grade 2) was identified in 63 of 77 patients with HLA B27 and 7 of 22 patients without HLA B27 through the re-reading process. Ten percent of definite AS was HLA B27 negative AS. Five of 22 patients without HLA B27 were diagnosed as diffuse idiopathic skeletal hyperostosis. There was a significant association between sacroiliitis (≥bilateral grade 2) and HLA B27 (p＜0.05) in re-reading process. No significant difference was found in onset age, and CRP depending on HLA B27 status. No significant association was noted between HLA B27 and gender, clinical and radiologic features. Conclusion: HLA B27 is useful in diagnosing AS in patients with clinical features of AS and sacroiliitis (≥unilateral grade 1). None of clinical and radiologic parameters are associated with HLA B27 status. It does not make difference in onset age of AS. To make a more concrete conclusion, a study of a much larger number of HLA B27 negative AS patients will be necessary. (J Korean Acad Rehab Med 2007; 31: 220-227)

Keywords :Ankylosing spondylitis, Spondyloarthropathy, Sacroiliitis, Human leukocyte antigen, Diffuse idiopathic skeletal hyperostosis