目的: 探讨初发系统性红斑狼疮(systemic lupus erythematosus, SLE)患者骨密度及血清骨转化因子的变化情况。方法: 选取在北京大学人民医院风湿免疫科住院的初发SLE患者80例,正常健康志愿者80例,入组研究时所有SLE患者均未开始服用糖皮质激素、免疫抑制剂及活性维生素D。使用双光能X线吸收法检测前臂、髋部、腰椎骨密度,使用ELISA方法检测血清抗酒石酸酸性磷酸酶(tartaric acid phosphatase 5b,TRAP5b)、骨碱性磷酸酶(bone alkaline phosphatase,BAP)和25羟维生素D3(25-dihydroxy-vitamin D3,25-OH-VD3)水平。通过Logistic回归分析寻找SLE患者骨密度下降的可能因素。结果: SLE患者平均年龄(32.8±12.4)岁,育龄期女性68例,年龄未超过50岁的男性12例;健康对照组平均年龄(30.0±2.9)岁,育龄期女性70例,年龄未超过50岁的男性10例。SLE患者前臂、腰椎、髋部平均骨密度均显著低于正常对照组,总体骨密度减低发生率为20%。血清骨转化因子方面,SLE患者血清BAP浓度与同年龄的健康对照相似,血清TRAP5b水平显著低于正常对照(P=0.001),血清25-OH-VD3水平显著低于正常对照[(46.1±12.3) nmol/L vs. (25.4±11.2) nmol/L, P<0.001]。存在肾炎的SLE患者血清25-OH-VD3显著低于不存在肾炎的SLE患者(P=0.04)。上述指标同SLE病情活动度的关系提示,血清25-OH-VD3水平与SLE疾病活动指数(SLE disease activity index, SLEDAI)负相关(r=-0.3, P=0.001),血清TRAP5b浓度与SLEDAI正相关(r=0.435, P=0.003)。Logistic回归分析显示,年龄(P=0.058)及SLEDAI评分(P=0.085)可能与SLE患者骨密度减低有关。结论: 初发SLE患者骨密度值较正常对照下降,疾病相关的慢性炎症可能是参与SLE骨密度减低的危险因素。

Objective: To investigate the changes of bone mineral density (BMD) and serum bone turnover factor in newly diagnosed systemic lupus erythematous (SLE) patients.Methods:Eighty newly diagnosed SLE patients and 80 age and gender matched healthy controls were enrolled. None of the SLE patients had ever received glucocorticoid,immunosuppressive agents or vitamin D. BMD was measured at radius,lumbar spine and hip by dual X ray absorptiometry (DXA). Bone turnover markers including se-rum levels of tartrate-resistant acid phosphatase 5b (TRAP5b),bone alkaline phosphatase (BAP) and 25-hydroxy vitamin D3 (25-OH-VD3) were measured by enzyme-linked immunosorbent assay (ELISA). Logistic regression was employed to analyze the risk factors associated with decreased BMD.Results:Mean age of the SLE patients was (32.8±12.4) years,and 85% were female,none of whom were post-menopausal. BMD was significantly reduced in all the measured sites,compared with the healthy controls. Sixteen (20%) of the patients were osteopenic in at least one site measured locations. The serum levels of 25-OH-VD3 were markedly reduced in the newly diagnosed SLE patients than those of the normal controls [(46.1+12.3) nmol/L vs. (25.4+11.2) nmol/L,P<0.001)]. The serum levels of 25-OH-VD3 in the SLE patients with nephritis were much lower than those without nephritis (P=0.04). A significant negative correlation was demonstrated between the serum concentration of 25-OH-VD3 and the disease activity scores as measured by SLE disease activity index (SLEDAI) (r=-0.3,P=0.001). The serum TRAP5b concentration was positively correlated with SLEDAI (r=0.435,P=0.003). Age (P=0.058) and SLEDAI (P=0.085) were probably associated with decreased BMD in Logistic regression analysis.Conclusion:The study showed reduced BMD in untreated SLE patients. The role of chro-nic inflammation was of probable importance in bone metabolism.