Cardiac markers are used in the diagnosis and risk stratification of patients with chest pain and suspected acute coronary syndrome (ACS). Cardiac troponin is central to the definition of acute myocardial infarction (AMI) in the consensus guidelines from the European Society of Cardiology (ESC) and the American College of Cardiology (ACC).^1–3 In China, guidelines for the diagnosis and treatment of non-ST-segment elevation acute coronary syndrome suggest the use of cardiac troponin for diagnosis and risk stratification. The guidelines also note that cardiac troponin has higher sensitivity and specificity compared with the traditional cardiac markers.⁴

The Pylon approach to an analytical challenge

BNP is secreted from the cardiac ventricle in response to volume and pressure overload. The diagnostic and prognostic value of BNP in improving clinical outcome in heart failure is well established.¹ Yet, accurate measurements can be a challenge because the BNP molecule is small (32 amino acids) and unstable. Studies have shown that the truncated form (without the C- and N-terminus) of BNP and NT-proBNP is the molecular entity present in circulating plasma. As a result, assays that rely on dual epitopes, one of which is in the C-terminus, are likely to underestimate BNP level. To address this issue, the Pylon BNP Immunoassay uses a novel Single Epitope Sandwich (SES™) format requiring only one epitope for antigen detection.^1,2 The capture antibody is specific to the relatively stable ring part of the BNP molecule, which is common to both BNP and NT-proBNP. The detection antibody is specific to the immune complex and not the individual components of the complex.

PCT is a precursor of the hormone calcitonin and is expressed by neuroendocrine cells as part of an inflammatory response to systemic bacterial infections. PCT levels correlate with clinical severity, and thus is useful as a diagnostic and prognostic biomarker to identify patients who can benefit from antimicrobial therapy and monitor treatment progress to determine when it is safe to end therapy. Clinical use of PCT includes:

• Diagnosis and treatment monitoring of sepsis¹
• Diagnosis of infection and prognosis in patients with fever at the ER²
• Identification of lower respiratory tract infections in patients who need antibiotic treatment³
• Guiding treatment of acute respiratory tract infections⁴

Use of PCT in ER⁵

Blood level β-hCG increases during pregnancy, rising rapidly until week 20 when it levels off. After delivery, miscarriage or pregnancy termination, β-hCG levels drop after delivery, miscarriage of pregnancy termination, with a half-life of 24 to 36 hours. Abnormal β-hCG levels are associated with ectopic pregnancy or fetal abnormalities.^1,2 Outside of pregnancy, elevated β-hCG are associated with tumors.²

The Pylon β-hCG assay protocol includes two sequences for each sample: one optimized for high concentration and the other for low-end detection. This avoids having to dilute the sample following an out-of-range assay run and to repeat the analysis, saving the cost and time associated with a rerun.

Overall dynamic range: 1 to 300,000 IU/L