Interference by Human Anti-mouse Antibodies in Immunoassays: Falsely Elevated Cardiac Troponins Leading to Negative Coronary Angiograms

Abstract

Cardiac Troponins are an extremely important indicator of myocardial injury and American College of Cardiology (ACC) and American Heart Association (AHA) guidelines include Cardiac Troponins as one of the major diagnostic criteria for myocardial damage. However in some instances the presence of heterophilic antibodies like Human Anti-Mouse Antibodies (HAMA) may interfere with the sandwich assays used for the detection and quantification of cardiac troponins giving false results which can have a major impact on the management of an individual suspected to have myocardial injury. We present a case of a 56 year old Caucasian male who had negative coronary angiogram 2 years ago presenting with acute chest pain and significantly elevated levels of Cardiac Troponin I (cTnI). He underwent cardiac catheterization which again turned out to be completely normal. His cTnI levels continued to be consistently elevated for months after cardiac catheterization. The reason for elevated cTnI levels was due to high levels of HAMA antibodies that caused heterophilic antibody interference in the assay of cTnI, resulting in falsely elevated levels of cTnI.