Lack of Interference by Rheumatoid Factor on Immunoassay of Cardiac Troponin I in Serum

A number of endogenous antibodies including rheumatoid factor (RF) and other auto-antibodies have been known to cause interferences in immunoassay systems for various analytes. For this reason, we set out to investigate if seropositive RF specimens exert any effects on immunoassay-based determination of cardiac troponin I (cTn I) performed by Beckman/ Coulter Access 2 Analyzer. Included in this study were sera obtained from one-hundred patients with seropositive RF values ranging from 35 up to 4,400IU/ml, and none of these had an episode of acute coronary event. When these specimens were subjected to cTn I determination, none of them showed value exceeding that of the cut-off range (0.04ng/ml). These data clearly demonstrate that the RF is not an interferent for the immunological determination of cTn I. Thus, immunological quantification of cTn I by Beckman Coulter Access 2 may be a method of choice for the obviation of interference by the presence of RE.