title: Standardized Centile Curves and Reference Intervals of Serum Thymidine Kinase 1 Levels in a Normal Chinese Population Using the LMS Method.
abstract: OBJECTIVE
  The aim of the present study was to re-establish a set of normative data for serum thymidine kinase 1 (STK1) for the Chinese population.
  
  
  METHODS
  The study included 14,960 Chinese subjects (9586 males and 5374 females) from 20 to 79 years old. Subjects suffering from diseases that could affect STK1 levels were excluded. STK1 was measured by a sensitive chemiluminescence dot blot assay. The reference intervals were calculated using the LMS method.
  
  
  RESULTS
  Peak thymidine kinase 1 (TK1) serum levels were observed at 20 years of age for both genders. After the age of 20 years, serum TK1 levels decreased slowly from 0.51 to 0.36 pM, reaching a plateau to a mean of 0.35 pM in late adulthood. The mean pretreatment STK1 Z-scores in patients with solid malignant tumors obtained from related studies for cancers were 0.01 ± 0.99 (males, -0.07 ± 0.97; females, 0.09 ± 1.02).
  
  
  CONCLUSIONS
  The present study established age- and gender-specific normative STK1 data for the Chinese population and showed the utility of these references for screening patients with solid malignant tumors.
authors.affiliation: 1 Health Management Center, the Third Xiangya Hospital, Central South University , Changsha, Hunan Province, China .
authors.forename: Xia
authors.initials: X
authors.lastname: Cao
authors.affiliation: 2 Mental Health Institute, the Second Xiangya Hospital, Central South University , Changsha, Hunan Province, China .
authors.forename: Jiansong
authors.initials: J
authors.lastname: Zhou
authors.affiliation: 1 Health Management Center, the Third Xiangya Hospital, Central South University , Changsha, Hunan Province, China .
authors.forename: Zhiheng
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data*; D014408:Biomarkers, Tumor / Q000097:blood; D002681:China; D005260:Female; D006801:Humans; D008163:Luminescent Measurements / Q000379:methods / Q000592:standards; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000175:diagnosis / Q000201:enzymology; D012016:Reference Values; D012737:Sex Factors; D051941:fms-Like Tyrosine Kinase 3 / Q000097:blood*
chemical_list: D014408:Biomarkers, Tumor; C497970:FLT3 protein, human; D051941:fms-Like Tyrosine Kinase 3