Paupitz J A, Lima G L, Alvarenga J C, Oliveira R M, Bonfa E, Pereira R M R
Bone Metabolism Laboratory, Rheumatology Division, Faculdade de Medicina da Universidade de São Paulo, Av Dr Arnaldo, 455, 3° Andar, Sala 3193, Sao Paulo, SP, 01246-903, Brazil.
RDO Diagnosticos Medicos, Sao Paulo, Brazil.
Osteoporos Int. 2016 May;27(5):1839-48. doi: 10.1007/s00198-015-3461-y. Epub 2015 Dec 22.
High-resolution peripheral quantitative computed tomography (HR-pQCT) analysis of female juvenile-onset systemic lupus erythematosus (JoSLE) patients revealed trabecular/cortical bone damage and reduced bone strength primarily at the distal radius compared to healthy controls. We demonstrated for the first time that JoSLE patients with vertebral fracture (VF) present trabecular impairment at the distal radius.
This study investigated the volumetric bone mineral density (vBMD), microarchitecture, and biomechanical features at the distal radius and tibia using HR-pQCT and laboratory bone markers in JoSLE patients compared to controls to determine whether this method discriminates JoSLE patients with or without VF.
We compared 56 female JoSLE patients to age- and Tanner-matched healthy controls. HR-pQCT was performed at the distal radius and tibia. Serum levels of the amino-terminal pro-peptide of type I collagen, the C-terminal telopeptide of type I collagen, intact parathormone, sclerostin, and 25-hydroxyvitamin D (25OHD) were evaluated. VFs were analyzed using VFA-dual-energy X-ray absorptiometry (DXA) (Genant's method).
Reduced density and strength parameters and microarchitecture alterations of cortical and trabecular bones were observed in JoSLE patients compared to controls, primarily at the distal radius (p < 0.05). Patients with VF exhibited a significant decrease in trabecular bone parameters solely at the distal radius (Total.BMD, p = 0.034; Trabecular.BMD [Tb.BMD], p = 0.034; bone volume (BV)/trabecular volume (TV), p = 0.034; apparent modulus, p = 0.039) and higher scores for disease damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR-DI), p = 0.002). Bone metabolism markers were similar in all groups. Logistic regression analysis of parameters that were significant in univariate analysis revealed that Tb.BMD (OR 0.98, 95 % CI 0.95-0.99, p = 0.039) and SLICC/ACR-DI (OR 7.37, 95 % CI 1.75-30.97, p = 0.006) were independent risk factors for VF.
In conclusion, this study is the first demonstration of bone microstructure and strength deficits in JoSLE patients, particularly at the distal radius. Our results demonstrated that VF was associated with trabecular radius alteration and emphasized the potential detrimental effect of disease damage on this condition.
对女性青少年型系统性红斑狼疮（JoSLE）患者进行的高分辨率外周定量计算机断层扫描（HR-pQCT）分析显示，与健康对照相比，小梁/皮质骨损伤以及骨强度降低主要发生在桡骨远端。我们首次证明，患有椎体骨折（VF）的JoSLE患者在桡骨远端存在小梁损伤。
本研究使用HR-pQCT和实验室骨标志物，对JoSLE患者与对照组的桡骨远端和胫骨的骨体积密度（vBMD）、微结构和生物力学特征进行了研究，以确定该方法能否区分有无VF的JoSLE患者。
我们将56名女性JoSLE患者与年龄和坦纳分期相匹配的健康对照进行了比较。在桡骨远端和胫骨处进行HR-pQCT检查。评估了血清I型胶原蛋白氨基端前肽、I型胶原蛋白羧基末端肽、完整甲状旁腺激素、硬化蛋白和25-羟基维生素D（25OHD）的水平。使用椎体骨折评估双能X线吸收法（VFA-DXA）（Genant法）分析椎体骨折。
与对照组相比，JoSLE患者的皮质骨和小梁骨密度和强度参数降低，微结构改变，主要发生在桡骨远端（p < 0.05）。患有VF的患者仅在桡骨远端的小梁骨参数显著降低（总体骨密度，p = 0.034；小梁骨密度 [Tb.BMD]，p = 0.034；骨体积（BV）/小梁体积（TV），p = 0.034；表观模量，p = 0.039），且疾病损伤评分更高（系统性红斑狼疮国际协作临床诊所/美国风湿病学会损伤指数（SLICC/ACR-DI），p = 0.002）。所有组的骨代谢标志物相似。对单变量分析中具有显著性的参数进行逻辑回归分析显示，Tb.BMD（比值比0.98，95%置信区间0.95 - 0.99，p = 0.039）和SLICC/ACR-DI（比值比7.37，95%置信区间1.75 - 30.97，p = 0.006）是VF的独立危险因素。
总之，本研究首次证明了JoSLE患者存在骨微结构和强度缺陷，尤其是在桡骨远端。我们的结果表明，VF与小梁半径改变有关，并强调了疾病损伤对这种情况的潜在有害影响。
