Measurement of cholesterol in plasma and other body fluids

Abstract

Measurement of cholesterol has become increasingly important with recognition of its predictive association with cardiovascular diseases. Government and professional groups in the United States and other countries have developed consensus guidelines for using cholesterol and the lipoproteins in identifying patients at risk and in managing therapies. Accuracy in the measurements is essential not only for reliable classification of patients, but also in public health/wellness programs and in research. Laboratory experts have developed requisite analytical performance targets and guidelines for measurements. Manufacturers of diagnostic reagents and laboratories can assure accuracy by accessing the Cholesterol Reference Method Laboratory Network, which offers reference methods for total, high-density lipoprotein, and low-density lipoprotein cholesterol. Recommendations for controlling pre-analytical sources of variation and uniform interpretation of patient results facilitate reliable classification of patients. Driven by increasing workloads and the need for increased efficiency in laboratory testing, dramatic improvements have been made in recent years in automating laboratory analyzers, as well as the methods used for lipoprotein analysis. Newer technology allows multiple sequential measurements in the same cuvette, as well as point-of-care measurements, using strip tests and compact analyzers. Efforts continue to develop reliable, minimally invasive tests in body fluids other than serum.

Lipid profile and long‐term outcome in premature myocardial infarction

“…The diagnosis FCHL was based on a nomogram as described previously. 20 Immunoturbidimetric assays were utilized for measurement of ApoB100, Apo A-I, and Lp (a). Patients were assigned a "FCHL phenotype" if the probability of FCHL exceeded a value of 60%.…”

“…In cases of severe hypertriglyceridaemia (Tg ≥ 400 mg/dL), LDL-C was measured directly. 20 Immunoturbidimetric assays were utilized for measurement of ApoB100, Apo A-I, and Lp (a). 21 The Apo B100 measurement was standardized using the WHO-IFCC SP3-07 reference standard.…”

Standardization of total cholesterol measurement in population surveys--pre-analytic sources of variation and their effect on the prevalence of hypercholesterolaemia

“…The control of analytic as well as pre-analytic sources of variation is important [10,[37][38][39], since the latter can account for as much as 60% of the total variation in cholesterol measurement [39].…”

Transferência simultânea de lipídeos de um modelo artificial de lipoproteína (LDE) para a lipoproteína de alta densidade (HDL)

“…Quando separada por eletroforese em gel de poliacrilamida, que usa o tamanho e a carga da partícula como base para a separação, a fração da HDL previamente separada por ultracentrifugação pode ser dividida em cinco subfrações distintas (RAINWATER, 1998;RAINWATER et aI., 1997;WARNICK;REMALEY, 2001). As subfrações separadas por ordem decrescente de tamanho são a HDL 2b (diâmetro .…”

“…As partículas conhecidas como pré-~1 HDL são na verdade moléculas de apo A-I ou partículas discóides formadas por uma ou duas moléculas de apo A-I complexada(s) com fosfolipídeos e possivelmente uma pequena quantidade de colesterol não esterificado. A fração gama é constituída de partículas que contêm apenas apo E e não apo A-I (BARTER et aI., 2003;WARNICK;REMALEY, 2001).…”