胱抑素C早期诊断造影剂肾病的临床研究

Clinical Research of Cystatin C in Early Diagnosis of Contrast Induced Nephropathy

目的:探讨血浆胱抑素C(Cys C)在造影剂肾病(CI N)早期诊断中的临床意义。方法:选择使用非离子型低渗造影剂进行血管造影的130例患者为研究对象,所有患者分别于造影前24 h内、造影后8 h、24 h和48 h抽血检测Cys C、肌酐(Scr)、尿素氮(BUN)、尿酸(UA)以及根据公式推算的肾小球滤过率(eGFR),根据患者在造影后48 h内是否发生造影剂肾病(CI N),分为CI N组和非CI N组。结果:(1)CI N的发生率为12.3%。(2)CI N组血浆Cys C浓度造影后8 h明显升高,24 h达最高峰,48 h有所降低,但均明显高于造影前以及非CI N组相应时间点的水平,差异均有统计学意义(P<0.05)。而CI N组Scr造影后8 h无明显变化,24 h开始升高,48 h达最高值,只有48 h的值明显高于造影前以及非CI N组相应时间点的水平,差异有统计学意义(P<0.05)。非CI N组造影前后各时间点Cys C、Scr等各项指标比较差异无统计学意义(P>0.05)。(3)患者造影前Cys C与Scr(r=0.431)呈明显正相关,与eGFR(r=-0.392)呈明显负相关。(4)若以造影后8 h和24 h内血浆Cys C浓度较造影前基础值上升25%作为诊断CI N的标准,其敏感性分别为83.2%和89.2%,特异性分别为74.1%和80.5%。阳性预测值分别为45.6%和51.3%,阴性预测值分别为92.5%和94.2%。结论:造影后8 h和24 h的血浆Cys C浓度对CI N的早期诊断有一定的价值,能较Scr更早反映肾功能的变化。

Objective：To study clinical value of cystatin C in early diagnosis of contrast induced nephropathy（CIN）.Methods：Total 130 patients with angiography enrolled in the study were divided into CIN group and non-CIN group according to appearance of CIN in 48 hour after angiography.The serum creatinine（Scr）,nitrogen（BUN）,uric acid（UA） and estimated glomerular filtration rate（eGFR） were measured in the patients in 24 h before and 8 h,24 h,48 h after the angiography,respectively.Results：（1）The prevalence of CIN was 12.3%（16/130）.（2）The serum Cys C level in CIN group significantly rose in 8 h,which reached the peak in 24 h and began to decrease in 48 h after the angiography and it was significantly higher than those before contrast injection of CIN group and those in 8,24,48 h after contrast injection of non-CIN group,respectively（P〈0.05）.The serum creatinine levels in 8 h after contrast injection were similar to those before contrast injection,which began to rise in 24 h and reached the peak in 48 h in CIN group and only those in 48 h had significantly difference in statistics between the two groups（P〈0.05）.There was no significant difference between the serum Cys C and Scr levels before and after contrast injection at 8 h,24 h,48 h in non-CIN group（P〈0.05）.（3）Serum Cys C before angiography was related to serum creatinine（r=0.431,P0.01） and eGFR（calculated by MDRD formula）（r=-0.392,P〈0.01）.（4）When CIN was defined as an increase in cystatin C by 25% of the baseline level in 8 h and 24 h after contrast exposure,the sensitivity was 83.2% and 89.6%,respectively.The specificity was 74.1% and 80.5%.Positive predictive value was 45.6% and 51.3%.The negative predictive value was 92.5% and 94.2%.Conclusion：Serum cystatin C values of 8 h and 24 h after the angiography may be good biomarkers for early diagnosis of CIN and they can reflect the change of renal function after contrast injection earlier than serum creatinine.