Objective: To analyze the prognostic value and threshold effect of serum C3, C4 in patients with multiple myeloma (MM).
Methods: The clinical data of 146 patients with MM who visited Suqian First People's Hospital from October 2016 to October 2019 were collected. The patients were divided into deceased group (42 cases) and survival group (104 cases) according to their prognosis and survival. The risk factors affecting the prognosis of the patients were analyzed. The correlation of serum C3 and C4 with prognosis was analyzed by threshold effect. The predictive value of serum C3/C4 on the prognosis of MM patients was evaluated by the receiver operating characteristic (ROC) curve. Nomogram model was constructed, and the discrimination and accuracy of the model were evaluated. The nomogram model was internally validated by bootstrap resampling.
Results: Durie-Salmon (DS) stage Ⅲ, decreased low density lipoprotein cholesterol (LDL-C) and apolipoprotein B (Apo B), elevated homocysteine (Hcy), uric acid (UA), and serum C3 and C4 were independent risk factors affecting the prognosis of MM patients (P < 0.05). Curve fitting showed that the mortality probability of MM patients increased with the increase of serum C3 and C4 levels. The threshold effect analysis showed that when serum C3 was higher than 1.2 g/L or serum C4 was higher than 0.37 g/L, the mortality rate of MM patients increased with the increase of the index levels; When serum C3 was lower than 1.2 g/L or serum C4 was lower than 0.37 g/L, the mortality rate of MM patients had no significant correlation with the indexes. Serum C3 and C4 had a good predictive value for the prognosis of MM patients, and the combination of C3 and C4 had a higher predictive value. The validation results showed that the nomogram model constructed in our study had good discrimination and high accuracy.
Conclusion: Elevated levels of serum C3 and C4 are independent risk factors for mortality in patients with MM. The combination of serum C3 and C4 is more valuable in predicting mortality in MM patients than C3 or C4 alone, which can be used as a sensitive index to evaluate the prognosis of MM patients.
题目: 血清C3、C4对多发性骨髓瘤患者预后的预测价值及阈值效应分析.
目的: 分析血清C3、C4对多发性骨髓瘤（MM）患者预后的预测价值及阈值效应。.
方法: 收集2016年10月至2019年10月于宿迁市第一人民医院就诊的146例MM患者的临床资料，根据患者预后生存情况分为死亡组（42例）和存活组（104例）。对影响患者预后的危险因素进行分析。对血清C3、C4与患者预后的关系进行阈值效应分析。采用受试工作者特征（ROC）曲线评估血清C3、C4对患者预后的预测价值。构建列线图模型，并对模型的区分度和准确度进行评价；采用bootstrap重采样对列线图模型进行内部验证。.
结果: DS Ⅲ期，LDL-C、Apo B水平降低，Hcy、UA及血清C3、C4水平升高均为影响患者预后的独立危险因素（P < 0.05）。曲线拟合发现，随着血清C3、C4的升高，MM患者的死亡概率呈上升趋势。阈值效应分析发现，当血清C3>1.2 g/L时或血清C4>0.37 g/L时，患者死亡发生率随着相应指标水平升高而增高；当血清C3<1.2 g/L时或血清C4<0.37 g/L时，患者死亡发生率与指标无明显相关性。血清C3、C4对患者预后有良好的预测价值，二者联合的预测价值更高。验证结果显示，本研究建立的列线图模型区分度较好、准确度较高。.
结论: 血清C3、C4水平升高是影响MM患者预后的独立危险因素，血清C3、C4二者联合对于预测MM患者死亡的价值优于单一指标，二者联合可作为评估患者预后的敏感指标。.
Keywords: serum C3; serum C4; multiple myeloma; prognosis.