Comparison of an immunoprecipitation method for direct measurement of LDL- cholesterol with beta-quantification (ultracentrifugation)

I. Jialal, S. V. Hirany, S. Devaraj, T. A. Sherwood

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

A direct LDL cholesterol assay was evaluated using immunoprecipitation (Sigma Diagnostics, St. Luis, MO) with beta-quantification obtained by ultracentrifugation. Excellent intra- and interassay coefficients of variation were obtained (<4.5%). There was a good correlation (r = 0.88, P < .0001) between the two methods for low-density lipoprotein cholesterol (LDL- C) in 249 samples with triglyceride levels ranging from 13 mg/dL to 2,236 mg/dL and LDL cholesterol levels ranging from 28 mg/dL to 290 mg/dL. Similar correlations were seen for patients with triglyceride levels < 400 mg/dL (r = 0.89, n = 174) and ≥400 mg/dL (r = 0.89, n = 75). However, using the Friedewald equation, there was a good correlation only in samples with triglyceride levels < 4011 mg/dL. No significant differences were found between LDL-C quantitated by the direct LDL assay and beta quantification for patients with dysbetalipoproteinemia (Type III disorder). However, calculated LDL values using the Friedewald equation were found to be significantly higher when compared to beta-quantification in patients with the Type III disorder. There was a slight but significant decrease in LDL-C determined by direct LDL cholesterol assay for non-fasting versus fasting serum (4.7%) despite a strong correlation between these samples (r = 0.98, P < .0001). In addition, freezing samples for 30 days resulted in a significant decrease in levels (15.1%). Thus, this direct LDL cholesterol assay is recommended in place of beta-quantification in hypertriglyceridemic samples (TG ≥400 mg/dL) and to monitor LDL cholesterol levels in patients with Type III dyslipidemia, because it is less time consuming, more cost-effective and can be adapted to the clinical laboratory.

Original languageEnglish (US)
Pages (from-to)76-81
Number of pages6
JournalAmerican Journal of Clinical Pathology
Volume104
Issue number1
StatePublished - 1995
Externally publishedYes

Fingerprint

Ultracentrifugation
Immunoprecipitation
LDL Cholesterol
Triglycerides
Hyperlipoproteinemia Type III
Dyslipidemias
Freezing
Fasting
Costs and Cost Analysis
Serum
oxidized low density lipoprotein

Keywords

  • Beta- quantification
  • Coronary heart disease
  • Direct LDL cholesterol assay
  • Friedewald equation
  • Low-density lipoprotein cholesterol

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

Cite this

Comparison of an immunoprecipitation method for direct measurement of LDL- cholesterol with beta-quantification (ultracentrifugation). / Jialal, I.; Hirany, S. V.; Devaraj, S.; Sherwood, T. A.

In: American Journal of Clinical Pathology, Vol. 104, No. 1, 1995, p. 76-81.

Research output: Contribution to journalArticle

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