Thoughts concerning the early diagnosis of ankylosing spondylitis and related diseases

M.A. Khan 

Case Western Reserve University, Cleveland, Ohio, USA

ABSTRACT
The diagnosis of ankylosing spondylitis is mainly based on a radiograph of the sacroiliac joints. Thus, this is the standard imaging test. However, in the early phase of disease, conventional radiographs are often too insensitive to show sacroiliitis. In this clinical situation, HLA B27 testing and new imaging modalities such as magnetic resonance imaging may be helpful. Early forms of AS can be initially classified as undifferentiated spondyloarthritis. All subsets of spondyloarthritides may evolve later into AS. Since AS in association with psoriasis and chronic inflammatory bowel diseases is often HLA B27-negative, this test is of limited value under these circumstances. The usefulness of testing for HLA B27 and its subtypes differs among ethnic and racial groups. The value of this test for diagnosis depends on the individual pre-test probability in each setting.

Key words
Ankylosing spondylitis, early diagnosis, HLB-27. 

Please address correspondence to: Muhammad Asim Khan, MD, FRCP, FACP, Professor of Medicine, Division of Rheumatology, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, Ohio 44109-7998, USA.

Clin Exp Rheumatol 2002; 20: (Suppl. 28): S6-S10.
© Copyright Clinical and Experimental Rheumatology 2002.