血清非磷酸化MGP蛋白(dpMGP)对强直性脊柱炎的诊断意义

Significance of detecting circulating non-phosphorylated matrix Gla protein(dpMGP) in ankylosing spondylitis

目的研究强直性脊柱炎(AS)患者血清dpMGP浓度水平及其诊断价值,探索dpMGP与AS炎症与骨化病程的关系。方法将82例AS病人及75例健康对照纳入该横断性研究。评估AS病人各项临床指标(年龄、性别、病程、疾病活动度)以及反映骨代谢或炎症的生物标记(血沉(ESR)、C反应蛋白(CRP)、骨钙素(OC)、骨碱性磷酸酶(BALP))。疾病活动度依据BASDAI评分标准。利用竞争性ELISA法检测AS病人dpMGP血清浓度。将上述指标与对照组进行比较性分析。利用ROC曲线回归分析dpMGP作为AS诊断指标的价值。通过运用统计学相关分析的方法,研究dpMGP及AS炎症与骨重建病程关联。结果 AS患者dpMGP浓度(mean(SD),9.2(2)nmol/l)低于对照组(mean(SD),13.7(4.5)),P<0.01。同样结果见于20-40岁(mean(SD),9.6(2)nmol/l)及40-60岁(mean(SD),9(2.1)nmol/l)年龄组。两年龄组dpMGP浓度比较差异并不明显。ROC曲线回归分析显示dpMGP=11.5nmol/l(截断点)时诊断特异性及敏感性分别为83%、88%,youden指数为0.56,AUC为0.81,其诊断效力可为中级。炎症相关生物标记ESR、CRP,以及骨重建相关生物标志BALP、OC与dpMGP关联性并不明显。结论 AS病人血清dpMGP可作为一种新的血清诊断指标及反映骨化进展的生物标志。

Objective To evaluate serum dpMGP level in patients with ankylosing spondylitis（AS） and its diagnostic utility,to investigate its relation to inflammation and bone remodelling process in AS.Methods 82 patients with AS and 75 heathy controls were enrolled in cross-sectional study.We measured clinical characteristics（age,gender,disease duration,disease activity,radiographic progress,eta） and a panel of biomarkers reflecting bone turnover or inflammation（C-reactive protein（CRP）,erythrocyte sedimentation rate（ESR）,bone-specific alkaline phosphatase（BALP）,osteocalcin（OC））about these two groups and made contrast.Disease activity was assesed with Bath Ankylosing Spondylitis Disease Activity Index（BASDAI）.A competive-ELISA assay was developed to determine circulating dpMGP of these two groups to evaluate it＇s diagnostic value.Patients with AS were divided into two groups,A group（20-40 years）,B group（40-60 years）,with segmentation of the range of age.Finally,through correlation analysis,the relation between dpMGP and clinical parameters,biomarkers was investigated.Results Serum level of dpMGP in AS patients[mean（SD）,9.2（2） nmol/l] was significantly lower than control[mean（SD）13.7（4.5） nmol/l]（P0.01）,which were also seen for A（mean（SD）,9.6（2）nmol/l） and B（mean（SD）,9.6（2）nmol/l） groups than control.There is no difference between A and B group.ROC analysis revealed dpMGP（cutoff 11.5 nmol/l;AUC（0.81）as a median diagnostic indicator（youden index（0.56））.There was no correlation between dpMGP and clinical parameters,biomarkers reflecting inflammation and bone remodeling.Conclusion The serum level of dpMGP as a potential biomarker may serve to diagnose AS,independent of age.DpMGP may involve in the process of inflammation and bone remodeling in AS.