Clinical and Imaging Signs of Spondyloarthritis in First-Degree Relatives of HLA-B27-Positive Ankylosing Spondylitis Patients: The Pre-Spondyloarthritis (Pre-SpA) Cohort Study.
Arthritis Rheumatol 2017;
68:2444-55. [PMID:
27214232 DOI:
10.1002/art.39766]
[Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 05/19/2016] [Indexed: 12/27/2022]
Abstract
OBJECTIVE
To investigate whether seemingly healthy first-degree relatives of patients with ankylosing spondylitis (AS) have clinical, laboratory, or imaging features of spondyloarthritis (SpA).
METHODS
First-degree relatives (ages 18-40 years) of HLA-B27-positive AS patients were included in the pre-spondyloarthritis (Pre-SpA) cohort, a prospective inception cohort study. Clinical, biologic, and imaging features were recorded. First-degree relatives were classified according to several sets of SpA classification criteria.
RESULTS
We report baseline features of 51 first-degree relatives included in this study. Twenty-nine (57%) had back pain, 2 (4%) had psoriasis, 1 (2%) had inflammatory bowel disease, and 1 (2%) had uveitis. Three (6%) had low-grade sacroiliitis, 1 (2%) had cervical syndesmophytes on radiography, and 10 (20%) had bone marrow edema on magnetic resonance imaging of the sacroiliiac joints. Seventeen of 51 first-degree relatives (33%) fulfilled SpA classification criteria: 7 (14%) fulfilled both Assessment of SpondyloArthritis international Society (ASAS) axial SpA and European Spondylarthropathy Study Group (ESSG) classification criteria, 6 (12%) fulfilled only ASAS axial SpA classification criteria, and 4 (8%) fulfilled only ESSG classification criteria; 3 (6%) also fulfilled the Amor criteria. None fulfilled other SpA classification criteria. First-degree relatives fulfilling the ASAS axial SpA and/or ESSG classification criteria had more frequent inflammatory back pain, had a higher level of disease activity, and had more psoriasis. No differences were found in parameters of inflammation, peripheral and extraarticular disease other than psoriasis, and HLA-B27 positivity between those who did and those who did not fulfill the ASAS axial SpA and/or ESSG classification criteria. Four first-degree relatives (12%) who did not fulfill the ASAS axial SpA and/or ESSG classification criteria had imaging abnormalities suggestive of SpA.
CONCLUSION
A substantial proportion of seemingly healthy first-degree relatives of HLA-B27-positive AS patients have clinical and/or imaging abnormalities suggestive of SpA. Thirty-three percent could be classified as having SpA. Further follow-up will show which first-degree relatives will develop clinically manifest SpA.
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