Attention should be paid to false-positive results due to heterophilic antibodies interfering with Abbott high-sensitivity cardiac troponin I assay

Abstract

Objectives In recent years, chemiluminescent microparticle immunoassay (CMIA) has been widely used for determination of high-sensitivity troponin I (hs-cTnI). However, a CMIA analysis is usually affected by the presence of some endogenous or exogenous substances. This case-report aims to unveil the essence of the reoccurrence of false-positive results due to heterophilic antibodies interference with Abbott high-sensitivity cardiac troponin I assay, although the assay method applied a chimeric antibody. Case presentation A 28-year-old female misdiagnosed with myocarditis due to falsely elevated hs-cTnI with an initial test result of 595.0 ng/L considered as critical value was reported. And the false critical value of hs-cTnI reoccurred five times after admission. The heterophilic blocking tube (HBT) procedure caused a decrease in troponin concentrations within the reference values, which suggests the presence of interference from heterophilic antibodies. Conclusions It requires a close and strong collaboration between clinicians and laboratorians to manage the similar case on the interference from heterophilic antibodies. To prevent false-positive results caused by interferences from being used in clinical practice, the clinicians are suggested to contact the laboratorians whenever the clinical picture, historical data and laboratory values are not conclusive.