title: Overestimation of nuclear matrix protein 22 in concentrated urine.
abstract: OBJECTIVE
  To confirm the hypothesis that nuclear matrix protein 22 (NMP22) is overestimated in concentrated urine, we compared the NMP22 values measured at different dietary states.
  
  
  METHODS
  We retrospectively reviewed 531 healthy subjects who had had abnormal urinary NMP22 values ≥ 10 U/mL at the first test and underwent a second NMP22 test within 2 weeks. The first NMP22 test was performed after overnight fasting, and the second was performed with no dietary restrictions. We compared the NMP22 values between the 2 measurements and investigated the relationship between the NMP22 value and urine specific gravity.
  
  
  RESULTS
  At the second test, 504 subjects (94.9%) had a normal NMP22 value of <10 U/mL and only 27 subjects (5.1%) persistently had an abnormal NMP22 value of ≥ 10 U/mL. Both NMP22 and urine specific gravity at the first test were significantly higher than at the second test (P <.0001). Subjects with an abnormal NMP22 value tended to have a more concentrated urine with a greater urine specific gravity than did the subjects with a normal NMP22 value. This difference was significant in the subgroup undergoing bowel preparation for colonoscopy (P <.001).
  
  
  CONCLUSIONS
  NMP22 will be overestimated in concentrated urine after overnight fasting. When interpreting the NMP22 value, we should consider the overestimation of NMP22 in concentrated urine.
authors.affiliation: Center for Prostate Cancer, National Cancer Center, Goyang, Korea.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Joung
authors.forename: Sohee
authors.initials: S
authors.lastname: Park
authors.forename: Hyekyoung
authors.initials: H
authors.lastname: Yoon
authors.forename: Whi-An
authors.initials: WA
authors.lastname: Kwon
authors.forename: In-Chang
authors.initials: IC
authors.lastname: Cho
authors.forename: Ho Kyung
authors.initials: HK
authors.lastname: Seo
authors.forename: Jinsoo
authors.initials: J
authors.lastname: Chung
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Hwang
authors.forename: Chan Wha
authors.initials: CW
authors.lastname: Lee
authors.forename: Kang Hyun
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000652:urine*; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000652:urine*; D011237:Predictive Value of Tests; D012016:Reference Values; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013046:Specific Gravity; D016482:Urinalysis / Q000379:methods*; D001749:Urinary Bladder Neoplasms / Q000652:urine
chemical_list: D014408:Biomarkers, Tumor; D009687:Nuclear Proteins; C100379:nuclear matrix protein 22