CCQM-P58.1: Immunoassay Quantitation of Human Cardiac Troponin I.

Abstract

The CCQM study P58.1 assessed the equivalence of immunoassay measurements between participating NMIs. The aim of P58.1 was to demonstrate the equivalence of immunoassay measurements to determine the mass concentration of the clinically-relevant protein human cardiac troponin I (cTnI) present at low concentration relative to the protein concentration of the sample matrix. The measurement equivalence was assessed using traceability to a common certified reference material. To quantify cTnI, participants used a homogeneous sandwich-based immunoassay with an enzymatic amplification step. The antibody format consisted of a single capture and single detection antibody (referred to as 1 + 1), both were supplied to study participants. In the previous P58 study, ELISA measurement results were compared between laboratories which all used common ELISA reagents (including 96-well plates), samples, a standard for the production of calibrants, and a detailed ELISA protocol, which were supplied by a single laboratory. The P58.1 study only utilized common samples, a standard of the production of calibrants, and a set of monoclonal antibodies (mAbs). Because much of the experimental procedure for the P58 study was essentially standardized across participating labs, the study primarily highlighted between-laboratory differences in plate sampling designs and in plate reader response. As the participants in the P58.1 study had to produce most of their own analytical reagents and develop their own measurement procedure, the study provides a better evaluation of the equivalence of ELISA measurements between the participating laboratories.Main text.To reach the main text of this paper, click on Final ReportThe final report has been peer-reviewed and approved for publication by CCQM.