Department of Rehabilitation Medicine and Rheumatology, University Hospital Centre Split, Split, Croatia.
Department of Health Studies, University of Split, Split, Croatia.
Clin Rheumatol. 2020 Aug;39(8):2299-2306. doi: 10.1007/s10067-020-04999-4. Epub 2020 Feb 27.
To investigate possible association between sacroiliitis and HLA-B*35 positivity.
After excluding patients with axial spondyloarthritis and HLA-B27 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-B35 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.
A statistically significant association between the detection of bone marrow edema at sacroiliac joints on MRI and HLA-B35 positivity (χ2 = 6.25; p = 0.022) was found. A logistic regression analysis revealed that the presence of HLA-B35 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-B35 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-B35-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).
The data clearly show the association between bone marrow edema on MRI at sacroiliac joints and HLA-B35 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-B35 allele was associated with a 6 times greater chance of identifying bone marrow edema at sacroiliac joints on MRI in un-axSpa patients. • HLA-B35 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-B35 allele could be a potential risk factor for developing sacroiliitis and axSpA.
研究中轴型脊柱关节炎患者存在的中轴型脊柱关节炎和 HLA-B*35 阳性之间可能存在的关联。
排除存在中轴型脊柱关节炎和 HLA-B27 阳性、银屑病、炎症性肠病、前驱感染或青少年型脊柱关节炎的患者后，共纳入 110 例未分化中轴型脊柱关节炎患者。所有患者均有持续时间短（3 个月至 2 年）的炎症性腰背疼痛，其中 72 例 HLA-B35 阳性。为了确定骶髂关节炎与 HLA-B*35 阳性之间是否存在关联，所有患者均接受了骶髂关节 MRI 检查。
MRI 显示骶髂关节骨髓水肿与 HLA-B35 阳性存在统计学显著关联（χ2 = 6.25；p = 0.022）。逻辑回归分析显示，HLA-B35 等位基因的存在与 MRI 显示骶髂关节骨髓水肿的几率增加 6 倍相关（OR 6，95%CI 1.3-27，p = 0.021）。HLA-B35 阳性还与 CRP 升高的几率增加 4.7 倍相关（OR 4.7，95%CI 1-11.9，p = 0.047），与外周关节滑膜炎的几率增加 5 倍相关（OR 5，95%CI 1.75-14.3，p = 0.003）。HLA-B35 阳性患者疾病活动度高（Bath 强直性脊柱炎疾病活动指数平均 ± 标准差为 6.1 ± 1.72，强直性脊柱炎疾病活动评分 C 反应蛋白指数为 3 ± 0.64），功能受限程度高（Bath 强直性脊柱炎功能指数平均 ± 标准差为 5.3 ± 2.16）。
数据清楚地显示了未分化脊柱关节炎患者骶髂关节 MRI 骨髓水肿与 HLA-B35 等位基因之间的关联。需要进一步研究以了解这一结果对这些患者的随访可能有多大影响。关键点：• HLA-B35 等位基因与未分化脊柱关节炎患者骶髂关节 MRI 骨髓水肿的几率增加 6 倍相关。• HLA-B35 等位基因还与 CRP 升高的几率增加 4.7 倍相关，与外周关节滑膜炎的几率增加 5 倍相关。• HLA-B35 等位基因可能是发生骶髂关节炎和中轴型脊柱关节炎的潜在危险因素。
