Frequencies of Anti-Troponin I vs Anti-Troponin T Autoantibodies and Degrees of Interference on Troponin Assays

Objective: Presence of autoantibodies against troponin I (cTnI) or T (cTnT) has been reported to interfere with troponin assays. However, the extent of the interference with the measurement has not been explored sufficiently. The aims of this study were to examine the frequencies of autoantibodies against troponin I and troponin T and how much these antibodies would affect the measurement.

Methods: The study comprised 52 subjects who visited Hokkaido University Hospital with suspected ischemic heart diseases. To evaluate the presence of autoantibodies, we calculated the recoveries of cTnI or cTnT after immunoglobulin G depletion, and the distributions of peaks reactive with cTnI or cTnT by high-performance liquid chromatography were examined.

Results: Autoantibodies against cTnI and cTnT were identified in 8 subjects (15.4%) and 1 subject (1.9%), respectively. Although the greatest difference between cTnI and cTnT was 32-fold, the distributions of cTnI-to-cTnT ratios in groups with and without anti-cTnI were not statistically different.

Conclusion: Autoantibodies against cTnI were more frequent by several fold than those against cTnT. Their presence did not significantly expand the discrepancy between cTnI and cTnT assays.