%0 Journal Article %1 citeulike:489658 %A Menys, V. C. %A Liu, Y. %A Mackness, M. I. %A Caslake, M. J. %A Kwok, S. %A Durrington, P. N. %C Department of Medicine, Manchester Royal Infirmary, Oxford Road, M13 9WL, Manchester, UK. Valentine.Menys@CMMC.nhs.uk %D 2003 %J Clinica Chimica Acta %K elisa apob %N 1-2 %P 95--106 %R 10.1016/S0009-8981(03)00231-6 %T Measurement of plasma small-dense LDL concentration by a simplified ultracentrifugation procedure and immunoassay of apolipoprotein B. %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12867279 %V 334 %X BACKGROUND: Existing methods for detecting small-dense low-density lipoprotein (SD-LDL) are either semiquantitative (e.g., gradient gel electrophoresis) or require specialised laboratory methods (e.g., density-gradient ultracentrifugation, DGU). METHODS: We report a method in which plasma was adjusted to a density (D) of 1.044 and 1.060 g/ml, respectively, in two tubes, both of which underwent ultracentrifugation (UC). A measure of SD-LDL apolipoprotein B (apo B) was obtained by subtraction of the apo B concentration in D>1.060 g/ml lipoproteins from that in D>1.044 g/ml lipoproteins to correct for apo B associated with lipoprotein (a) Lp(a). This procedure was evaluated in paired plasma samples in healthy men (n=62) and in age-matched healthy women (n=74) and in age-matched primary dyslipidaemic men (n=72) and women (n=29) and compared with an established density-gradient ultracentrifugation (DGU) method. RESULTS: The dyslipidaemic patients had either decreased high-density lipoprotein cholesterol (HDL-C) and/or increased triglycerides. In dyslipidaemic men, SD-LDL apo B level (23 5-77 mg/dl) was significantly higher than in healthy men (P<0.001). In dyslipidaemic women, the SD-LDL apo B levels (11 4-71 mg/dl) were significantly higher than in healthy women (7 1-45 mg/dl; P<0.005). The concentration of SD-LDL apo B correlated inversely with HDL-C in both women (r=-0.280: P<0.005) and men (r=-0.464; P<0.0001) and positively with triglyceride concentration in both women (r=0.213; P<0.05) and men (r=0.592: P<0.0001). Correction for apo B in Lp(a) increased the analytical variation, which was 12% for apo B at D=1.044-1.060 g/ml and 9% for apo B measured at D>1.044 g/ml. Although the correlation between the new method and DGU results was high (r=0.830; P<0.0001, n=43), the concentration of apo B at D>1.044 g/ml correlated strongly with both corrected results (r=0.978; P<0.0001; n=237) and also with SD-LDL isolated using the DGU method (r=0.832; P<0.0001). Results at D>1.044 g/ml showed the expected correlations both with HDL-C (r=-0.465: P<0.0001) and triglycerides (r=0.526; P<0.0001). CONCLUSIONS: The new method gave results consistent with earlier published findings using other techniques. Further simplification of the method using a single-density spin at D>1.044 g/ml appears feasible and may provide an easier quantitative method for clinical use.

@article{citeulike:489658, abstract = {BACKGROUND: Existing methods for detecting small-dense low-density lipoprotein (SD-LDL) are either semiquantitative (e.g., gradient gel electrophoresis) or require specialised laboratory methods (e.g., density-gradient ultracentrifugation, DGU). METHODS: We report a method in which plasma was adjusted to a density (D) of 1.044 and 1.060 g/ml, respectively, in two tubes, both of which underwent ultracentrifugation (UC). A measure of SD-LDL apolipoprotein B (apo B) was obtained by subtraction of the apo B concentration in D>1.060 g/ml lipoproteins from that in D>1.044 g/ml lipoproteins to correct for apo B associated with lipoprotein (a) [Lp(a)]. This procedure was evaluated in paired plasma samples in healthy men (n=62) and in age-matched healthy women (n=74) and in age-matched primary dyslipidaemic men (n=72) and women (n=29) and compared with an established density-gradient ultracentrifugation (DGU) method. RESULTS: The dyslipidaemic patients had either decreased high-density lipoprotein cholesterol (HDL-C) and/or increased triglycerides. In dyslipidaemic men, SD-LDL apo B level (23 [5-77] mg/dl) was significantly higher than in healthy men (P<0.001). In dyslipidaemic women, the SD-LDL apo B levels (11 [4-71] mg/dl) were significantly higher than in healthy women (7 [1-45] mg/dl; P<0.005). The concentration of SD-LDL apo B correlated inversely with HDL-C in both women (r=-0.280: P<0.005) and men (r=-0.464; P<0.0001) and positively with triglyceride concentration in both women (r=0.213; P<0.05) and men (r=0.592: P<0.0001). Correction for apo B in Lp(a) increased the analytical variation, which was 12% for apo B at D=1.044-1.060 g/ml and 9% for apo B measured at D>1.044 g/ml. Although the correlation between the new method and DGU results was high (r=0.830; P<0.0001, n=43), the concentration of apo B at D>1.044 g/ml correlated strongly with both corrected results (r=0.978; P<0.0001; n=237) and also with SD-LDL isolated using the DGU method (r=0.832; P<0.0001). Results at D>1.044 g/ml showed the expected correlations both with HDL-C (r=-0.465: P<0.0001) and triglycerides (r=0.526; P<0.0001). CONCLUSIONS: The new method gave results consistent with earlier published findings using other techniques. Further simplification of the method using a single-density spin at D>1.044 g/ml appears feasible and may provide an easier quantitative method for clinical use.}, added-at = {2006-07-07T01:10:50.000+0200}, address = {Department of Medicine, Manchester Royal Infirmary, Oxford Road, M13 9WL, Manchester, UK. Valentine.Menys@CMMC.nhs.uk}, author = {Menys, V. C. and Liu, Y. and Mackness, M. I. and Caslake, M. J. and Kwok, S. and Durrington, P. N.}, biburl = {https://www.bibsonomy.org/bibtex/2389ce8f9c6e17e2cfdc3541d28da891f/biblio24}, citeulike-article-id = {489658}, doi = {10.1016/S0009-8981(03)00231-6}, interhash = {335e3598be87eeda75f4d66a61bc3a05}, intrahash = {389ce8f9c6e17e2cfdc3541d28da891f}, issn = {0009-8981}, journal = {Clinica Chimica Acta}, keywords = {elisa apob}, month = {August}, number = {1-2}, pages = {95--106}, priority = {2}, timestamp = {2006-07-07T01:10:50.000+0200}, title = {Measurement of plasma small-dense LDL concentration by a simplified ultracentrifugation procedure and immunoassay of apolipoprotein B.}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=pubmed\&dopt=Abstract\&list_uids=12867279}, volume = 334, year = 2003 }