Intra-individual variation in creatinine and cystatin C.
BACKGROUND
Serum creatinine and cystatin C are measured in the assessment of glomerular filtration rate. Biological variation of an analyte is an important determinant of its usefulness. Intra-individual variation in serum creatinine and cystatin C in healthy subjects was determined in this study.


METHODS
Weekly blood samples were taken from 10 healthy subjects and analysed for creatinine (kinetic Jaffe method) and for cystatin C (by nephelometry).


RESULTS
Intra-individual variations for serum creatinine and cystatin C were 6.1% and 4.55%, respectively. Index of individuality values were similar for the analytes (0.35 for both).


CONCLUSIONS
Intra-individual variations for serum creatinine and cystatin C were similar in healthy subjects.
Bandaranayake
Niluka
N
Department of Chemical Pathology, St. Thomas' Hospital, London, UK.
Ankrah-Tetteh
Thelma
T
Wijeratne
Sethsiri
S
Swaminathan
Ramasamyiyer
R
D000328:Adult; D001774:Blood Chemical Analysis / Q000379:methods*; D002624:Chemistry, Clinical / Q000379:methods*; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D012016:Reference Values; D015203:Reproducibility of Results
C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D003404:Creatinine