Determination of apolipoprotein B-48 in plasma by a competitive ELISA.
BACKGROUND
Apolipoprotein B-48 (apoB-48) is produced by the small intestine, as part of chylomicrons, and appears to be a suitable marker for clinical studies of postprandial lipoproteins and related cardiovascular risk. Our aim was to develop, for routine analysis, an assay to quantify apoB-48 in plasma samples.


METHODS
A microtiter plate was coated with a C-terminal apoB-48-specific heptapeptide. Plasma samples were incubated with appropriate detergent to allow competition between immobilized antigen and plasma apoB-48. Appropriate calibration curves were obtained in the ELISA, using calibrated lymph and chylomicrons.


RESULTS
Treatment of plasma samples with the mild detergent Triton X-100 allowed an efficient competition between immobilized antigen and plasma apoB-48. No cross-reactivity was found with apoB-100, as checked by ELISA and Western blot analysis. Intra- and interassay CVs were 5.4% and 5. 5%, respectively. In healthy subjects, apoB-48 concentrations markedly increased in the postprandial state, in parallel with triglycerides.


CONCLUSIONS
This new ELISA allows determination of the concentration of apoB-48 in normolipidemic plasma.
Lorec
A M
AM
Laboratoire Central, Hôpital Sainte-Marguerite, 270 Bd Sainte-Marguerite BP 29, 13274 Marseille Cedex 09, France.
Juhel
C
C
Pafumi
Y
Y
Portugal
H
H
Pauli
A M
AM
Lairon
D
D
Defoort
C
C
D053283:Apolipoprotein B-48; D001055:Apolipoproteins B / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D003429:Cross Reactions; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D017830:Octoxynol; D019518:Postprandial Period; D012016:Reference Values; D012680:Sensitivity and Specificity
D053283:Apolipoprotein B-48; D001055:Apolipoproteins B; D015415:Biomarkers; D003902:Detergents; D017830:Octoxynol