目的 评价血清补体C3在成人still病（AOSD）和脓毒症中的鉴别诊断价值。方法 收集江苏省人民医院2016年至2019年AOSD患者58例、脓毒症患者50例，并选取50名江苏省人民医院体检中心健康体检者作为健康对照。检测三组血清中补体C3水平，并比较AOSD患者和脓毒症患者的其他实验室指标有无差异性，运用单因素和多因素分析各变量与AOSD鉴别诊断的关系，并采用ROC曲线探讨补体C3与血清铁蛋白水平对AOSD和脓毒症的诊断效能。结果 AOSD组补体C3水平（1.49±0.24）显著高于脓毒症组C3（1.00±0.37），两组数据中高密度脂蛋白、铁蛋白、补体C3差异具有统计学意义。多因素分析显示铁蛋白≥472.20ng/ml（OR 56.968，95%CI 2.218~1463.439，P＜0.05），补体C3 ≥1.20g/L（OR 27.801，95%CI 3.217~240.277,P＜0.01），高密度脂蛋白≥0.82mmol/L（OR 13.335，95%CI 1.009~176.293,P＜0.05）与AOSD发生的可能性独立相关。血清C3鉴别诊断AOSD和脓毒症患者的曲线下面积（AUC）为0.81（95%CI 0.63~1.00），当C3临界值为1.21时，诊断灵敏度为0.90，特异度为0.73，此时可达最大的诊断效能，然而当C3联合铁蛋白鉴别诊断时，AUC则为0.86（95%CI 0.75~0.96）。结论 血清C3可作为AOSD和脓毒症的鉴别诊断指标，对AOSD的诊断具有临床价值。
objective To evaluate the differential diagnosis value of serum complement C3 in Adult-onset Still’s disease (AOSD) and sepsis. Methods 58 patients with AOSD and 50 patients with sepsis were collected from Jiangsu Provincial People's Hospital from 2016 to 2019. 50 physical examinees of Jiangsu Provincial People's Hospital were selected as health control. Serum complement C3 levels in the three groups were detected, and differences in other laboratory indicators between AOSD patients and sepsis patients were compared. Univariate and multivariate factors were used to analyze the relationship between each variable and the occurrence of AOSD. ROC curve was used to explore the diagnostic efficacy of complement C3 and serum ferritin levels on AOSD and sepsis. Results AOSD group C3 level (1.49±0.24) is significantly higher than sepsis group (1.00±0.37), in addition, two groups of data in the high density lipoprotein cholesterol, ferritin, C3 differences statistically significant.In multivariate analysis,ferritin≥472.20ng/ml(OR56.968,95%CI2.218~1463.439,P<0.05),C3≥1.20g/L（OR27.801，95%CI3.217~240.277,P<0.01）and high density lipoprotein cholesterol≥0.82mmol/L（OR13.335，95%CI 1.009~176.293,P<0.05） independently suggested sepsis more than AOSD. The area under the curve (AUC) of serum C3 in the differential diagnosis of AOSD and sepsis was 0.81 (95% CI 0.63~1.00), and the diagnostic sensitivity and specificity were 0.90 and 0.73 when C3 critical value was 1.21, which reached the maximum diagnostic efficacy. However, when C3 combined with ferritin was used for differential diagnosis, the AUC was 0.86 (95%CI 0.75~0.96). Conclusion Serum C3 can be used as a differential diagnostic index of AOSD and sepsis, and has clinical value in the diagnosis of AOSD.