Immunoluminometric assays for the quantification of apolipoproteins A-I, B, C-II, apolipoprotein(a) and lipoprotein(a).
Immunoluminometric assays were developed for apolipoproteins A-I, B, C-II (as the apolipoprotein C-II: apolipoprotein B complex), apolipoprotein(a) and lipoprotein(a). The assays were evaluated clinically and methodologically. The results for apolipoprotein A-I, apolipoprotein B and lipoprotein(a) were compared with those obtained by turbidimetric assays. No comparison was possible for apolipoprotein C-II. Sample predilution was necessary for apolipoprotein A-I, apolipoprotein B, apolipoprotein(a) and lipoprotein(a). Not all antibody combinations gave rise to assays with acceptable recovery rates. This was especially the case for lipoprotein(a). These assays for apolipoprotein(a) and lipoprotein(a) had relatively low detection limit (< 5 mg/l) and measuring ranges up to 800 mg/l (using a 1:10 sample dilution), and were suitable for routine use, especially for longer series. Assay times were all less than 3 h, each assay using the streptavidin-biotin technique and being based on a coated-ball technology. The median intra-assay coefficients of variation for all assays lay between 2.9 and 5.9% in the range of interest, expressed in terms of precision profiles. Inter-assay (im)precision lay between 6.2 and 12.2%, calculated in the accepted way. Correlations between turbidimetric and immunoluminometric assays for apolipoprotein A-I and apolipoprotein B were statistically acceptable, although the correlation coefficients were mediocre (apolipoprotein A-I - r = 0.65, apolipoprotein B - r = 0.83) and the slope of the regression line differed from unity. This was most probably due to standardisation and differences in assay design (one-site competitive versus two-site immunometric assays).(ABSTRACT TRUNCATED AT 250 WORDS)
Institut für Klinische Laboratoriumsdiagnostik, Klinikum der Hansestadt Stralsund, Federal Republic of Germany.
A
A
Kessler
M
M
Schumacher
W G
WG
Wood
D016632:Apolipoprotein A-I / Q000378:metabolism; D053304:Apolipoprotein C-II; D001053:Apolipoproteins / Q000378:metabolism*; D001056:Apolipoproteins C / Q000378:metabolism; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000592:standards; D017270:Lipoprotein(a) / Q000097:blood*; D008163:Luminescent Measurements; D009391:Nephelometry and Turbidimetry; D012015:Reference Standards; D015203:Reproducibility of Results
D016632:Apolipoprotein A-I; D053304:Apolipoprotein C-II; D001053:Apolipoproteins; D001056:Apolipoproteins C; D017270:Lipoprotein(a)