Development and Validation of an Enzymatic Method for Total Cholesterol Analysis Using Whole Blood Spot.
BACKGROUND
High serum cholesterol represents a risk factor for cardiovascular disease. This study aims to quantify total cholesterol in dried blood spot (DBS) by direct enzymatic method.


METHODS
Three hundred seventeen blood samples with serum cholesterol level ranging from 81 to 337 mg/dl were collected. DBS were manually prepared, cholesterol was extracted using methanol and analyzed by a manual enzymatic method. DBS cholesterol method was validated for imprecision and extraction efficacy. DBS cholesterol values were correlated (training test) with serum values measured by automated enzymatic method (reference method). The obtained correlation was used for predicting serum cholesterol from DBS analysis of a new sample group (validation test, n = 58).


RESULTS
Within-day and between-day coefficient of variation (CV%) were lower than 7.69 and 6.32, respectively. Residual cholesterol in DBS after extraction was 16%. DBS cholesterol and serum cholesterol showed a linear correlation (slope = 0.5217; r = 0.9139) and a bias of -28%. Furthermore, DBS cholesterol values of validation test (n = 58), converted using the training test correlation, were not statistically different compared to the corresponding plasma values (P = 0.9487), and the comparison by Passing and Bablok showed a linear regression with a slope of 1.068 (r = 0.611) and a bias of -0.22%.


CONCLUSIONS
The results show that this enzymatic method is suitable to analyze cholesterol in DBS and it could be automated and used for population screening of total blood cholesterol.
Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy. gaetano.corso@unifg.it.
Gaetano
G
Corso
Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy.
Francesco
F
Papagni
Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.|Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy.
Monica
M
Gelzo
Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy.
Monica
M
Gallo
Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy.
Rosalba
R
Barone
Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy.
Maria
M
Graf
Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy.
Nicola
N
Scarpato
Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy. antonio.dellorusso@unina.it.
Antonio
A
Dello Russo
D002784:Cholesterol / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D059788:Dried Blood Spot Testing; D005260:Female; D006801:Humans; D008297:Male; D012044:Regression Analysis; D015203:Reproducibility of Results; D012737:Sex Factors; D053719:Tandem Mass Spectrometry; D013997:Time Factors
D002784:Cholesterol
chronic degenerative diseases; dried blood spot; total blood cholesterol