title: [Significance of apolipoprotein A1 as biomarker for early diagnosis and classification of bladder urothelial carcinoma].
abstract: OBJECTIVE
  To investigate the significance of apolipoprotein (Apo)-A1 in urine as a biomarker for early diagnosis and classification of bladder urothelial carcinoma (BUC).
  
  
  METHODS
  Urine samples were divided into four groups: normal control group, benign bladder disease group, low-grade malignant BUC group, and high-grade malignant BUC group. Apo-A1, which showed significantly different expression among the four groups, was selected according to the two-dimensional electrophoresis (2-DE) images of the four groups, and enzyme-linked immunosorbent assay (ELISA) was used to quantify Apo-A1 in the four groups. A receiver operating characteristic (ROC) curve was generated, and the optimal operating points on the ROC curve were found to determine the critical concentrations of Apo-A1 for early diagnosis of BUC and differentiation of low-grade and high-grade malignant BUC. The results were verified clinically, and the specificity and sensitivity were calculated.
  
  
  RESULTS
  The 2-DE images showed that that the level of Apo-A1 increased from the normal control grouP to high-grade malignant BUC group. The ELISA showed that there was no significant difference in Apo-A1 level between the normal control grouP and benign bladder disease group, but the Apo-A1 level was significantly higher in the BUC groups than in the normal control grouP and benign bladder disease grouP (P < 0.01); the high-grade BUC grouP had a significantly higher Apo-A1 level than the low-grade BUC grouP (P < 0.01). The BUC patients and those without BUC could be differentiated with an Apo-A1 concentration of 18.22 ng/ml, while the low-grade and high-grade malignant BUC could be differentiated with an Apo-A1 concentration of 29.86 ng/ml. When used as a biomarker, Apo-A1 had a sensitivity of 91.6% (98/107) and a specificity of 85.7% (42/49) for diagnosis of BUC and had a sensitivity of 83.7% (41/49) and a specificity of 89.7% (52/58) for BUC classification.
  
  
  CONCLUSIONS
  Apo-A1 may be a biomarker for early diagnosis and classification of BUC and shows promise for clinical application.
authors.affiliation: Tianjin key Laboratory of Urology, Tianjin Institute of Urology, Second Hospital of Tianjin Medical University, Tianjin 300211, China.
authors.forename: Chang-ying
authors.initials: CY
authors.lastname: Li
authors.forename: Hong-jie
authors.initials: HJ
authors.lastname: Li
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.forename: Hong-sheng
authors.initials: HS
authors.lastname: Gao
authors.forename: Ji-wu
authors.initials: JW
authors.lastname: Chang
authors.forename: Xiu-li
authors.initials: XL
authors.lastname: Men
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.forename: Jian-min
authors.initials: JM
authors.lastname: Li
mesh_terms: D000368:Aged; D016632:Apolipoprotein A-I / Q000652:urine*; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000652:urine
chemical_list: D016632:Apolipoprotein A-I