Marked digoxin-like immunoreactive factor interference with an enzyme immunoassay.
A case in which digoxin-like immunoreactive factors (DLIF) interfered with an enzyme immunoassay in a patient with renal insufficiency is reported. A 79-year-old woman was found to have a serum digoxin concentration (SDC) determined by enzyme immunoassay of 5.0 ng/ml. Although all subsequent SDC determined by the enzyme immunoassay system were elevated, identical samples run on a fluorescence polarization immunoassay revealed SDC within the therapeutic range. Marked DLIF-related assay interference has been reported to occur with some digoxin assays; however, the enzyme immunoassay methods have never been reported to cross-react to the magnitude seen in this case.
Karboski
J A
JA
College of Pharmacy University of Texas, Austin 78712.
Godley
P J
PJ
Frohna
P A
PA
Horton
M W
MW
Reitmeyer
W J
WJ
D000368:Aged; D001798:Blood Proteins / Q000032:analysis*; D002298:Cardenolides; D004077:Digoxin / Q000097:blood* / Q000276:immunology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D012503:Saponins
D001798:Blood Proteins; D002298:Cardenolides; D012503:Saponins; C034504:digoxin-like factors; D004077:Digoxin