Sensitive and quantitative detection of Cardiac Troponin I with upconverting nanoparticle lateral flow test with minimized interference

Measurement of cardiac troponin I (cTnI) should be feasible for point-of-care testing (POCT) to diagnose acute myocardial infarction (AMI). Lateral flow immunoassays (LFIAs) have been long implemented in POCT and clinical settings. However, sensitivity, matrix effect and quantitation in lateral flow immunoassays (LFIAs) have been major limiting factors. The performance of LFIAs can be improved with upconverting nanoparticle (UCNP) reporters. Here we report a new methodological approach to quantify cTnI using UCNP-LFIA technology with minimized plasma interference. The performance of the developed UCNP-LFIA was evaluated using clinical plasma samples (n = 262). The developed UCNP-LFIA was compared to two reference assays, the Siemens Advia Centaur assay and an in-house well-based cTnI assay. By introducing an anti-IgM scrub line and dried EDTA in the LFIA strip, the detection of cTnI in plasma samples was fully recovered. The UCNP-LFIA was able to quantify cTnI concentrations in patient samples within the range of 30–10,000 ng/L. The LoB and LoD of the UCNP-LFIA were 8.4 ng/L and 30 ng/L. The method comparisons showed good correlation (Spearman’s correlation 0.956 and 0.949, p </p

Advances in routine measurement of cardiac damage and cardiovascular risk markers

Abstract The development of commercially available assays from the measurement of enzyme activity to mass concentrations of proteins, especially the assays of cardiac troponin I and T, has been the most important innovation in the field of cardiovascular laboratory diagnostics over the decade. The availability of a simple, rapid test using whole blood to facilitate processing and to reduce the turnaround time could improve the management of patients presenting with chest pain. The aim of this study was to evaluate the analytical and clinical performance of a new time-resolved fluorometry-based immunology technology using the cardiac marker and high-sensitivity C-reactive protein assays. In addition, the use of high-sensitivity C-reactive protein assay for the investigation of patients with acute atrial fibrillation and the influence of heparin for cardiac marker assays were studied. The levels of precision attained with pooled serum and plasma samples and control materials were acceptable. The assays were found to be linear within the ranges tested. The correlation coefficient between the Innotrac Aio! 1st generation cTnI and Abbott AxSYM cTnI assays was 0.960, and the slope was 0.07. The correlations between the 2nd generation Innotrac Aio!, Access AccuTnI and Abbott AxSYM assays were good, but there were biases between the methods. The correlation coefficients between the Innotrac Aio! and Abbott AxSYM CK-MB and myoglobin assays were 0.995 and 0.971, respectively, but the Innotrac Aio! CK-MB assay yielded about 9% higher values than the Abbott assay. The correlations between Innotrac Aio! usCRP and Cobas Integra CRP latex and between Innotrac Aio! usCRP and Hitachi CRP (Latex ) HS were good. Furthermore, the sample material correlation studies showed no significant differences when the Innotrac Aio! System was used. However, the mean Abbott AxSYM CK-MB values and the cTnI values for heparin plasma samples were 17% higher and about 15% lower than for serum samples, respectively. In the investigation of CRP levels in patients with acute atrial fibrillation CRP tended to be higher in the patients with acute FA, and there was a positive correlation between the concentrations of CRP and IL-6. The results demonstrate the excellent analytical performance of the Innotrac Aio! 2nd generation cTnI, myoglobin, CK-MB and usCRP assays, and all the matrices, including serum, plasma and whole blood, are suitable sample matrices to be used with these methods without further standardization

Sensitive and quantitative detection of cardiac troponin I with upconverting nanoparticle lateral flow test with minimized interference

Abstract Measurement of cardiac troponin I (cTnI) should be feasible for point-of-care testing (POCT) to diagnose acute myocardial infarction (AMI). Lateral flow immunoassays (LFIAs) have been long implemented in POCT and clinical settings. However, sensitivity, matrix effect and quantitation in lateral flow immunoassays (LFIAs) have been major limiting factors. The performance of LFIAs can be improved with upconverting nanoparticle (UCNP) reporters. Here we report a new methodological approach to quantify cTnI using UCNP-LFIA technology with minimized plasma interference. The performance of the developed UCNP-LFIA was evaluated using clinical plasma samples (n = 262). The developed UCNP-LFIA was compared to two reference assays, the Siemens Advia Centaur assay and an in-house well-based cTnI assay. By introducing an anti-IgM scrub line and dried EDTA in the LFIA strip, the detection of cTnI in plasma samples was fully recovered. The UCNP-LFIA was able to quantify cTnI concentrations in patient samples within the range of 30–10,000 ng/L. The LoB and LoD of the UCNP-LFIA were 8.4 ng/L and 30 ng/L. The method comparisons showed good correlation (Spearman’s correlation 0.956 and 0.949, p &lt; 0.0001). The developed UCNP-LFIA had LoD suitable for ruling in AMI in patients with elevated cTnI levels and was able to quantify cTnI concentrations in patient samples. The technology has potential to provide simple and rapid assay for POCT in ED setting