title: Assessment of the trueness and inter-laboratory precision of routine uric acid assays using 4 frozen pooled serum samples measured by the Japan Society of Clinical Chemistry's HPLC method.
abstract: BACKGROUND
  Reference procedures are required for evaluating the accuracy of routine analytical systems for uric acid (UA). External quality assessment (EQA) for UA has only been conducted with quality controls in China, and the results have not been published. This study was designed to investigate both the trueness and inter-laboratory precision of UA measurements among routine analytical systems using a candidate reference method.
  
  
  METHODS
  We performed the HPLC method recommended by the Japan Society of Clinical Chemistry (JSCC). Next, we evaluated its analytical performance and validated its trueness. The performance of 4 routine analytical systems (5 instruments per system, n=20) for UA was assessed by using 4 frozen pooled serum samples measured by the HPLC method according to biologically relevant quality goals.
  
  
  RESULTS
  Within-run, between-run, inter-day, and total CV of the method were less than 0.3%, 0.4%, 1.8%, and 2.6%, respectively. The UA measurements were consistent with the target values of standard reference material (SRM) 909b, the sixth ring trial for Reference Laboratories (RELA-2008) specimen, and national primary reference materials. The 4 frozen pooled serum samples were homogeneous, stable, and commutable. All routine systems achieved the desirable performance goal (total error <11.9%).
  
  
  CONCLUSIONS
  We successfully reproduced the JSCC's HPLC method, which was simple, specific, precise, and accurate. We recommend this method as a reference method for UA measurement in human serum. Four routine analytical systems for UA measurement had acceptable traceability, and their UA results showed good concordance.
authors.affiliation: Department of Clinical Laboratory, Peking University First Hospital, Beijng, China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of Clinical Laboratory, Tsinghua University First Hospital, Beijng, China.
authors.forename: Ou
authors.initials: O
authors.lastname: Liu
authors.affiliation: Department of Clinical Laboratory, Peking University First Hospital, Beijng, China.
authors.forename: Guobing
authors.initials: G
authors.lastname: Xu
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000592:standards; D005615:Freezing; D006801:Humans; D007564:Japan; D007753:Laboratories / Q000592:standards; D012015:Reference Standards; D012955:Societies, Medical; D014527:Uric Acid / Q000097:blood* / Q000592:standards
chemical_list: D014527:Uric Acid
keywords: HPLC; Standardization; Uric acid