Interference of circulating endogenous antibodies on the Dimension® DGNA digoxin immunoassay: elimination with a heterophilic blocking reagent.

Only two cases have been previously described about circulating endogenous antibodies interference on the immunochemical determination of digoxin. In an elderly patient with history of social cat handling was observed a moderate positive interference (about 0.8 ng/mL) on the Dimension® DGNA digoxin immunoassay (capture rabbit antibody), which was eliminated treating the serum samples with a heterophilic blocking reagent. The Architect® immunoassay was not affected.