[Evaluation of the reference range of retinol-binding protein (RBP) levels by the latex turbidimetric immunoassay].
Retinol-binding-protein (RBP) has a short half-life, and a physiological change and intra-individual variation are small, so it is used as nutrition assessment protein. The measurement of RBP levels has nephelometric immunoassay (NIA) and latex turbidimetric immunoassay (LTIA), and the reference range was demanded by NIA, but it is noted it to vary by the LTIA. Thus we found a reference value in the LTIA and estimated intra-individual variation and analytical error by analysis of variance. Therefore we demanded intra-individual variation amplitude and reference range in the turbidimetric immunoassay. As for RBP, the intra-individual variations(with coefficient of variation (CV)) was 4.3% and 13.3% for males and females, respectively. The analytical error (CV) is very small in 1.2% and there are less them than half of the intra-individual variation for evaluation of inaccuracy. The reference range of the RBP was 2.65-6.00 mg/dl (n=525) in male and 1.90-4.61 mg/dl (n=565) in female, respectively. This reference range became the low level in comparison with the value of the NIA which was already reported. As a result of mutual measurement of the calibrator and the control of NIA and LTIA, a tendency similar to the difference of the reference range was found, so it seemed to be due to the difference of the calibrator.
Clinical Laboratory, Nagano Municipal Hospital, Nagano 381-8551, Japan.
Nobuki
N
Miura
Hirofumi
H
Kitamura
Mitsuaki
M
Kameko
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002138:Calibration; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007840:Latex; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry / Q000379:methods; D015596:Nutrition Assessment; D012016:Reference Values; D012177:Retinol-Binding Proteins / Q000032:analysis*; D055815:Young Adult
D015415:Biomarkers; D007840:Latex; D012177:Retinol-Binding Proteins