A Quantitative Detection of Cardiotrophin-1 in Chronic Heart Failure by Chemiluminescence Immunoassay

Background: Cardiotrophin-1 (CT-1) is a cytokine that could induce cardiomyocytes hypertrophy and dysfunction. Plasma CT-1 might serve as a cardiac biomarker both in diagnosis, staging, and prognostic assessment of heart failure.

Methods: In this study, a one-step paramagnetic particles-based chemiluminescence immunoassay (MPs-CILA) for rapid and sensitive detection of plasma CT-1 was established. Plasma samples were directly incubated with biotin-labeled anti-CT-1 antibody (bio-Ab) and acridine ester labeled anti-CT-1 antibody (AE-Ab) to form sandwiched complex. The sandwiched CT-1 was then captured by streptavidin modified paramagnetic particles (MPs-SA) for rapid separation and signal generation.

Results: The proposed MPs-CLIA presents a laudable linear relationship ranging from 7.8 pg/mL to 200 ng/mL with a detection limit of 1.0 pg/mL. The recoveries of spiked human plasma samples at low (10pg/mL), medium (100 pg/mL), and high (800 pg/mL) levels of CT-1 were 96%, 104%, and 110% respectively. The intra-analysis coefficient variation (CVs) of the 3 samples was 8.92%, 6.69%, and 3.54%, respectively. And the inter-analysis coefficient variation (CVs) was 9.25%, 10.9%, and 4.3%, respectively. These results strongly indicate high sensitivity, wide linear range, acceptable precision, and applicable reproducibility of the proposed method to detect plasma level of CT-1. Finally, Plasma CT-1 from 140 subjects with or without chronic heart failure was analyzed to assess the clinical application of MPs-CILA.

Conclusions: Noteworthily, the MPs-CLIA method is highly automated such that it is suitable for high-throughput detection of CT-1 in clinical inspection.