Zhang Guo-Ming, Hu Zhi-De
Department of Laboratory Medicine, Shuyang People's Hospital, Shuyang, China.
Department of Laboratory Medicine, the General Hospital of Ji'nan Military Command Region, Ji'nan, Shandong, China.
J Clin Lab Anal. 2018 Feb;32(2). doi: 10.1002/jcla.22233. Epub 2017 May 19.
Total, unconjugated and conjugated bilirubin levels are usually ordered together in health check-up populations. The aim of this study was to investigate whether using increased total bilirubin (TBIL) as a reflex test can reduce conjugated bilirubin (CBIL) test.
Medical records of 8433 males and 4496 females who visited Shuyang People's Hospital for health check-ups were retrospectively reviewed and the fasting serum TBIL, unconjugated bilirubin (UBIL) and CBIL of patients were extracted. Reference intervals for TBIL, UBIL, CBIL and C/TBIL were established using Q to Q . The relationship between TBIL and CBIL was analyzed by Spearman's approach. Receiver operating characteristics (ROC) curve analysis was used to evaluate the predictive accuracy of TBIL for abnormal CBIL and UBIL.
The reference intervals for TBIL in males and females were 6.9-29.3 μmol/L and 6.1-23.8 μmol/L, respectively. For CBIL, the reference intervals were 1.9-10.4 μmol/L and 1.6-8.8 μmol/L for males and females, respectively. CBIL was significantly positively correlated with TBIL, either in males (r=.75) or females (r=.73). Area under curve (AUC) of TBIL for predicting abnormal CBIL was 0.99 in both male and females. The optimal threshold of TBIL for predicting abnormal CBIL and UBIL were 21.0 μmol/L in males and 17.0 μmol/L in females. At these thresholds, <2% of subjects with abnormal CBIL or CBIL might be missed, but approximately 87% of the CBIL test could be eliminated.
Conjugated bilirubin measurement is not needed for the apparently healthy males with TBIL <21.0 μmol/L or females with TBIL <17.0 μmol/L.
在健康体检人群中，总胆红素、非结合胆红素和结合胆红素水平通常一起检测。本研究的目的是调查将总胆红素（TBIL）升高作为一项筛查试验是否可以减少结合胆红素（CBIL）检测。
回顾性分析8433名男性和4496名女性在沭阳县人民医院进行健康体检的病历，提取患者的空腹血清TBIL、非结合胆红素（UBIL）和CBIL。采用四分位数间距法确定TBIL、UBIL、CBIL和结合胆红素与总胆红素比值（C/TBIL）的参考区间。采用Spearman方法分析TBIL与CBIL之间的关系。采用受试者工作特征（ROC）曲线分析评估TBIL对异常CBIL和UBIL的预测准确性。
男性和女性TBIL的参考区间分别为6.9～29.3 μmol/L和6.1～23.8 μmol/L。CBIL的参考区间男性为1.9～10.4 μmol/L，女性为1.6～8.8 μmol/L。CBIL与TBIL显著正相关，男性（r = 0.75）和女性（r = 0.73）均如此。TBIL预测异常CBIL的曲线下面积（AUC）在男性和女性中均为0.99。男性和女性预测异常CBIL和UBIL的TBIL最佳阈值分别为21.0 μmol/L和17.0 μmol/L。在这些阈值下，CBIL异常或UBIL异常的受试者漏检率<2%，但约87%的CBIL检测可被排除。
对于TBIL<21.0 μmol/L的健康男性或TBIL<17.0 μmol/L的健康女性，无需检测结合胆红素。
