Bone Metabolism Laboratory, Rheumatology Division, Faculdade de Medicina FMUSP Universidade de Sao Paulo, Av. Dr. Arnaldo 455, 3° andar, sala 3105, Sao Paulo, 01246-903, Brazil.
Rheumatology Division, Hospital das Clinicas HCFMUSP, Faculdade de Medicina FMUSP Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
BMC Musculoskelet Disord. 2021 Jan 25;22(1):109. doi: 10.1186/s12891-021-03992-5.
Rheumatoid arthritis (RA) is a chronic autoimmune disease depicted by synovial inflammation leading to local and systemic bone loss. The aim of this study was to evaluate by a HR-pQCT (High Resolution Peripheral Quantitative Computed Tomography) study which parameters are associated with volume of bone erosions including bone mineral density (BMD) around erosions (VOI 1 to 4 = volume of interest), BMD of metacarpophalangeal (MCP) head, BMD of radius, presence of osteophytes and joint space width (JSW).
Fifty female RA patients (18-50 years) were enrolled in this study. Demographic and disease-specific data, laboratory inflammatory parameters and handgrip test were performed. All patients underwent HR-pQCT of 2nd and 3rd MCP joints and distal radius, according to established protocols. The volume of bone erosions was evaluated by MIAF (Medical Image Analysis Framework) software. Osteophytes were analyzed by manual method.
The mean of age and disease duration were 40.0 ± 6.0 yrs. and 10.8 ± 4.8 yrs., respectively. According to DAS-28 (Disease Activity Score), 54% (27) of the sample were in remission. However, when SDAI (Simplified Disease Activity Index) was used, only 18% (9) were under remission. The mean of HAQ (Health Assessment Questionnaire), ESR (Erythrocyte sedimentation rate) and CRP (C reactive protein) were 0.9 ± 0.7, 13.9 ± 12.2 mm and 5.6 ± 7.5 mg/mL, respectively. Forty-six bone erosions (0.9 ± 1.2 erosion/patient) and 14 osteophytes (0.3 ± 0.7 osteophyte/patient) were found in 2nd MCP head. The median (IQR-Interquartile range) of volume of erosion and volume of osteophytes were 14.9 (5.7;35.9)mm and 3.1 (2.1, 4.3)mm, respectively. The mean of JSW was 80.5 ± 34.2 mm. The volume of bone erosions was negatively correlated with BMD of 2nd MCP head, VOI-4 and JSW; and it was positively correlated with osteophytes number. Regarding absence or presence of erosion in 2nd MCP head, a significant difference was found between BMD of MCP head, osteophyte number and JSW. Multiple linear regression analysis showed that only BMD of 2nd MCP head was independently associated with volume of bone erosions.
BMD of MCP head was independently associated with volume of bone erosion, suggesting that this parameter should be used to analyze and monitoring bone destruction, as well as to evaluate treatment response in RA patients.
类风湿关节炎（RA）是一种慢性自身免疫性疾病，表现为滑膜炎症导致局部和全身骨质流失。本研究旨在通过高分辨率外周定量计算机断层扫描（HR-pQCT）研究评估哪些参数与骨侵蚀体积相关，包括侵蚀周围的骨矿物质密度（BMD）（VOI 1 至 4=感兴趣体积）、掌指骨（MCP）头部的 BMD、桡骨的 BMD、骨赘的存在和关节间隙宽度（JSW）。
本研究纳入了 50 名女性 RA 患者（18-50 岁）。进行了人口统计学和疾病特异性数据、实验室炎症参数和握力测试。所有患者均根据既定方案接受了第 2 和第 3 掌指关节和远端桡骨的 HR-pQCT 检查。使用 MIAF（医学图像分析框架）软件评估骨侵蚀体积。通过手动方法分析骨赘。
平均年龄和疾病持续时间分别为 40.0±6.0 岁和 10.8±4.8 岁。根据 DAS-28（疾病活动评分），54%（27）的样本处于缓解状态。然而，当使用 SDAI（简化疾病活动指数）时，只有 18%（9）的患者处于缓解状态。HAQ（健康评估问卷）、ESR（红细胞沉降率）和 CRP（C 反应蛋白）的平均值分别为 0.9±0.7、13.9±12.2mm 和 5.6±7.5mg/mL。在第 2 掌指关节头发现了 46 个骨侵蚀（0.9±1.2 个侵蚀/患者）和 14 个骨赘（0.3±0.7 个骨赘/患者）。侵蚀和骨赘体积的中位数（IQR-四分位距）分别为 14.9（5.7；35.9）mm 和 3.1（2.1，4.3）mm。JSW 的平均值为 80.5±34.2mm。骨侵蚀体积与第 2 掌指关节头的 BMD、VOI-4 和 JSW 呈负相关；与骨赘数量呈正相关。关于第 2 掌指关节头是否存在侵蚀，MCP 头部的 BMD、骨赘数量和 JSW 之间存在显著差异。多元线性回归分析表明，只有第 2 掌指关节头的 BMD 与骨侵蚀体积独立相关。
MCP 头的 BMD 与骨侵蚀体积独立相关，表明该参数应用于分析和监测骨质破坏，并评估 RA 患者的治疗反应。
