Focal Fat Lesions at Vertebral Corners on Magnetic Resonance Imaging Predict the Development of New Syndesmophytes in Ankylosing Spondylitis
Focal Fat Lesions at Vertebral Corners on Magnetic Resonance Imaging Predict the Development of New Syndesmophytes in Ankylosing Spondylitis
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DOI：
10.1002/art.30393
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发表时间：
2011-08-01
影响因子：
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通讯作者：
Maksymowych, Walter P.
中科院分区：
文献类型：
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作者：
Chiowchanwisawakit, Praveena;Lambert, Robert G. W.;Maksymowych, Walter P.
Objective.强直性脊柱炎（AS）患者的脊柱磁共振成像（MRI）上经常可见局灶性脂肪浸润，可能反映了炎症后组织化生。为了支持炎症和新骨形成之间耦合的概念，我们检验了这样一个假设，即椎体角的局灶性脂肪浸润更可能演变为新生韧带联合。在基线时获得MRI扫描，并在基线和2年时获得来自2个队列的100例AS患者的X线片：临床试验队列（n = 38）和观察性队列（n = 62）。在临床试验队列中，患者随机接受抗肿瘤坏死因子（抗TNF）治疗或安慰剂治疗12-24周，然后接受开放标签治疗2年。在观察性队列中，患者接受标准治疗（n = 36）或抗TNF治疗（n = 26）2年。由对影像学检查结果不知情的阅片者对椎角炎症和脂肪浸润进行独立评估。在临床试验（10.2%）和观察（6.5%）队列中，与基线MRI上无任何特征的患者相比（分别为3.1% [P = 0.008]和1.4% [P = 0.0002]），在有脂肪的椎体角中出现新的韧带赘生物的频率显著更高。调整患者内基础韧带赘生物/关节强直的变化，脂肪阳性/炎症阳性的椎体角显著预测新的韧带赘生物，比值比（OR）为7.6（95%置信区间[95% CI] 1.5-38.5 [P = 0.01]），而包括脂肪和炎症的基线变化的模型显示OR为5.8炎症的OR为1.9（95%CI 2.2-15.3 [P < 0.001]），脂肪的OR为1.9（95%CI 0.9-4.1 [P = 0.1]）。结论。我们的数据支持炎症病变通过组织化生（包括脂肪浸润）演变成新骨的假设。
Objective. Focal fat infiltration is frequently visible on magnetic resonance imaging (MRI) of the spine in patients with ankylosing spondylitis (AS) and likely reflects postinflammatory tissue metaplasia. To support the concept of coupling between inflammation and new bone formation, we tested the hypothesis that focal fat infiltration at a vertebral corner is more likely to evolve into a de novo syndesmophyte.Methods. MRI scans were obtained at baseline and radiographs were obtained at baseline and 2 years in 100 AS patients from 2 cohorts: a clinical trial cohort (n = 38) and an observational cohort (n = 62). In the clinical trial cohort, patients were randomized to receive anti-tumor necrosis factor (anti-TNF) therapy or placebo for 12-24 weeks and then open-label treatment for 2 years. In the observational cohort, patients received either standard therapy (n = 36) or anti-TNF therapy (n = 26) for 2 years. Vertebral corner inflammation and fat infiltration were assessed independently by pairs of readers who were blinded with regard to the radiographic findings.Results. New syndesmophytes developed significantly more frequently in vertebral corners with fat in both the clinical trial (10.2%) and the observational (6.5%) cohort as compared to those without either feature on baseline MRI (3.1% [P = 0.008] and 1.4% [P = 0.0002], respectively). Adjusting for within-patient variations in baseline syndesmophytes/ankylosis, vertebral corners that were fat-positive/inflammation-positive significantly predicted new syndesmophytes, with an odds ratio (OR) of 7.6 (95% confidence interval [95% CI] 1.5-38.5 [P = 0.01]), while a model that included baseline variations in both fat and inflammation showed an OR of 5.8 (95% CI 2.2-15.3 [P < 0.001]) for inflammation and an OR of 1.9 (95% CI 0.9-4.1 [P = 0.1]) for fat.Conclusion. Our data lend support to the hypothesis that inflammatory lesions evolve into new bone through a process of tissue metaplasia that includes fat infiltration.