Effect of variability of plasma interferences on the accuracy of drug immunoassays.
Ther Drug Monit
; 19(2): 212-8, 1997 Apr.
Article
en En
| MEDLINE
| ID: mdl-9108653
ABSTRACT
Most immunoassays applied to drugs in human plasma do not use an extraction of analyte. To compensate for interferences due to plasma proteins or salts, standards are prepared in drug-free plasma. Because the concentration of plasma components varies from one subject to another, it is likely that the drug-free plasma is not representative of the potential interference in each plasma. Using two immunoassays, for a steroid (nomegestrol acetate) and a heptapeptide (BN 52080), the authors have shown that tracer binding to the antibody may vary significantly between plasma from different subjects. Intersubject variability of tracer-antibody binding was 21.6% (coefficient of variation for 25 subjects) for nomegestrol acetate. When the same plasma were spiked with the steroid at a concentration corresponding to the central part of the standard curve, the recovery was between 39 and 215%. Intersubject variability in tracer binding was lower (7.7%) for the peptide immunoassay, but still affected accuracy. The authors show that this problem is common to direct immunoassays for other drugs and must be solved in assay development.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plasma
/
Inmunoensayo
Límite:
Humans
Idioma:
En
Revista:
Ther Drug Monit
Año:
1997
Tipo del documento:
Article
País de afiliación:
Francia