目的 筛选辅助检查儿童过敏性紫癜(HSP)的生物学标志物,并用ROC 曲线评价各生物学标志物对诊断HSP 的价值。方法 选取2012 年4 月至2014 年3 月诊断为HSP 的127例患儿为研究对象,另选取健康儿童127 例为对照组,检测两组儿童血清淀粉样蛋白A(SAA)、白细胞介素(IL)-6、免疫球蛋白(Ig)A、IgG、IgM、IgE、C 反应蛋白(CRP)、白细胞(WBC)计数、补体(C3、C4)、抗链球菌溶血素O(ASO)和血清铁蛋白(Fer)等12 项生物学指标水平。受试者工作特征曲线(ROC)分析所筛选标志物对HSP 的诊断价值。结果 HSP 患者SAA、IL-6、CRP、WBC、IgA 和IgM 等6 项指标水平显著高于对照组(P<0.05)。其中5 项指标(SAA、IL-6、WBC、IgA 和IgM)的ROC 曲线下面积(AUC)均>0.7,且差异有统计学意义(P<0.05)。当SAA 最佳临界值为3.035 μg/mL 时,敏感度为95.1%,特异度为90.2%;当IgA 为1 579.5 mg/L 时,敏感度为75.6%,特异度为85.4%;当 IgM 为922.5 mg/L 时,敏感度为72.3%,特异度为82.4%;当WBC 计数为8.850×109/L 时,敏感度为78.0%,特异度为70.7%;当IL-6 为7.035 pg/mL 时,敏感度为63.4%,特异度为80.5%。结论 SAA、IL-6、WBC、IgA 和IgM 对诊断HSP 具有一定的诊断价值,SAA 的诊断价值最高。

Objective To screen biomarkers which can be used as an auxiliary method in the diagnosis of Henoch-Schönlein purpura (HSP) and to evaluate their diagnostic values by receiver operating characteristic (ROC) curve analysis.Methods A total of 127 children diagnosed with HSP between April 2012 and March 2014 were included in the HSP group and an equal number of healthy children were included in the control group. Twelve parameters, i.e., serum amyloid protein A (SAA), interleukin-6 (IL-6), immunoglobulins (IgA, IgG, IgM, and IgE), C-reactive protein (CRP), white blood cell (WBC) count, complements C3 and C4, anti-streptolysin O, and ferritin, were analyzed. The values of the screened biomarkers for diagnosis of HSP were assessed by ROC curve analysis.Results The HSP group had significantly higher levels of SAA, IL-6, CRP, WBC, IgA, and IgM than the control group (P<0.05). The areas under the ROC curve of SAA, IL-6, WBC, IgA, and IgM for the diagnosis of HSP were higher than 0.7 (P<0.05). The optimal cut-off values of SAA, IgA, IgM, WBC, and IL-6 for the diagnosis of HSP were 3.035 μg/mL, 1 579.5 mg/L, 922.5 mg/L, 8.850×109/L, and 7.035 pg/mL, respectively; the corresponding sensitivities of the optimal cut-off values for the diagnosis of HSP were 95.1%, 75.6%, 72.3%, 78.0%, and 63.4%, respectively, and the corresponding specificities were 90.2%, 85.4%, 82.4%, 70.7%, and 80.5%, respectively.Conclusions SAA, IgA, IgM, WBC, and IL-6 are valuable biomarkers for clinical diagnosis of HSP and among them SAA seems to be the best one.