[Determination of digoxin by enzyme immunoassay and radioimmunoassay (author's transl)]

The results of parallel determinations of digoxin in the sera of non selected patients (n = 104) by enzyme immunoassay (EMIT-EIA) and radioimmunoassay (J-125 labeled RIA) were compared with each other. The determinations revealed considerably different concentrations; the values determined by EIA were statistical lower (for EIA 1.09 +/- 0.99 ng/ml, for RIA 1.34 +/- 1.01 ng/ml, p less than 0.01). In sera with hemolysis and in sera of patients with hyperlipidemia and uremia false-negative results were found by EIA. After elimination of these sera an exact concordation of the values of both the methods was obtained (for EIA 1.12 +/- 1.01 ng/ml, for RIA 1.12 +/- 1.02 ng/ml, r = 0.95).