The occurrence of sacroiliitis in HLA-B*35-positive patients with undifferentiated spondyloarthritis. A cross sectional MRI study.
Clin Rheumatol 2020;
39:2299-2306. [PMID:
32107663 DOI:
10.1007/s10067-020-04999-4]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 02/07/2020] [Accepted: 02/14/2020] [Indexed: 02/07/2023]
Abstract
OBJECTIVE
To investigate possible association between sacroiliitis and HLA-B*35 positivity.
METHOD
After excluding patients with axial spondyloarthritis and HLA-B*27 positivity, psoriasis inflammatory bowel disease, preceding infections, or juvenile type of spondyloarthritis, 110 patients were recruited with a diagnosis of undifferentiated axial spondyloarthritis. All of them had inflammatory back pain of short duration (3 months to 2 years) and 72 were HLA-B*35 positive. In order to determine if there is a possible association of sacroiliitis and HLA-B*35 positivity, all patients underwent MRI of sacroiliac joints.
RESULTS
A statistically significant association between the detection of bone marrow edema at sacroiliac joints on MRI and HLA-B*35 positivity (χ2 = 6.25; p = 0.022) was found. A logistic regression analysis revealed that the presence of HLA-B*35 allele was associated with a 6 times greater chance of identifying bone marrow edema at sacroiliac joints on MRI (OR 6, 95% CI 1.3-27, p = 0.021). HLA-B*35 positivity was also associated with a 4.7 times greater chance of finding elevated CRP (OR 4.7, 95% CI 1-11.9, p = 0.047) and a 5 times greater chance of finding peripheral joint synovitis (OR 5, 95% CI 1.75-14.3, p = 0.003). HLA-B*35-positive patients had high disease activity (mean ± SD of Bath Ankylosing Spondylitis Disease Activity Index 6.1 ± 1.72 and Ankylosing Spondylitis Disease Activity Score C-reactive protein Index 3 ± 0.64) with a high degree of functional limitations (mean ± SD of Bath Ankylosing Spondylitis Functional Index 5.3 ± 2.16).
CONCLUSION
The data clearly show the association between bone marrow edema on MRI at sacroiliac joints and HLA-B*35 allele in patients with undifferentiated spondyloarthritis. Further work is needed to understand how much this result may influence follow-up of these patients. Key Points • HLA-B*35 allele was associated with a 6 times greater chance of identifying bone marrow edema at sacroiliac joints on MRI in un-axSpa patients. • HLA-B*35 allele was also associated with a 4.7 times greater chance of finding elevated CRP and a 5 times greater chance of finding peripheral joint synovitis in un-axSpa patients. • HLA-B*35 allele could be a potential risk factor for developing sacroiliitis and axSpA.
Collapse