Biological Variation and Reference Change Value Data for Serum Neuron-Specific Enolase in a Turkish Population.
BACKGROUND
Neuron-specific enolase (NSE) is a recognized biomarker for the assessment of cerebral injury in neurological disorders. This study aims to report a definitive assessment of the biological variation (BV) components of this biomarker, including within-subject BV (CVI), between-subject BV (CVG), index of individuality (II), and reference change value (RCV), in a cohort of Turkish participants using an experimental protocol.


METHODS
Six blood specimens were collected from each of the 13 apparently healthy volunteers (seven women, six men; ranging in age from 23 to 36) on the same day, every 2 weeks for 2 months. Serum specimens were stored at -20°C until analysis. Neuron-specific enolase levels were evaluated in serum samples using an electrochemiluminescence (ECLIA) immunoassay kit with a Roche Cobas e 411 auto-analyser. ANOVA test was used to calculate the variations.


RESULTS
The CVI and CVG for NSE were 21.5% and 28.8%, respectively. Analytical variation (CVA) was calculated as 10.2%. Additionally, II and RCV were calculated as 0.74 and 66% (95% confident interval, CI), respectively.


CONCLUSIONS
As the performance index (PI) was found to be less than 2 (PI = 0.95), it is concluded that the NSE measurements have a desirable performance for analytical imprecision. Since the II was found to be less than 1 (II: 0.74), the reference values will be of little use. Thus, RCV would provide better information for deciding whether a significant change has occurred.
Central Laboratory, Medical Faculty, Balcali Hospital, Cukurova University, Adana, Turkey. selcukmatyar@yahoo.com.
Selcuk
S
Matyar
Department of Clinical Biochemistry, Medical Faculty, Cukurova University, Adana, Turkey.
Ozlem
O
Goruroglu Ozturk
Department of Clinical Biochemistry, Medical Faculty, Cukurova University, Adana, Turkey.
Esin
E
Ziyanoglu Karacor
Central Laboratory, Medical Faculty, Balcali Hospital, Cukurova University, Adana, Turkey.
Sedefgul
S
Yuzbasioglu Ariyurek
Department of Clinical Biochemistry, Medical Faculty, Cukurova University, Adana, Turkey.
Gulhan
G
Sahin
Department of Clinical Microbiology, Medical Faculty, Cukurova University, Adana, Turkey.
Filiz
F
Kibar
Department of Clinical Microbiology, Medical Faculty, Cukurova University, Adana, Turkey.
Akgun
A
Yaman
Department of Clinical Biochemistry, Medical Faculty, Cukurova University, Adana, Turkey.
Tamer
T
Inal
D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D010751:Phosphopyruvate Hydratase / Q000097:blood*; D012016:Reference Values; D013997:Time Factors; D014421:Turkey; D055815:Young Adult
D015415:Biomarkers; D010751:Phosphopyruvate Hydratase
analytical variation; between-subject BV; index of individuality; neuron-specific enolase; reference change value; within-subject BV