Reference Interval for the Axis-Shield Clinical Chemistry Heparin-Binding Protein Assay

Establishing reliable reference intervals is essential for interpreting clinical chemistry assays. Prior research has shown that heparin-binding protein (HBP) is a potential biomarker for sepsis and other inflammatory conditions. However, no prior work had resolved the specific reference interval for HBP using the Axis-Shield assay. This gap motivated the current investigation into the analytical performance and reference range of this new automated platform. It was already known that HBP levels vary with infection severity, but the exact normal range remained undefined. This study aimed to address that uncertainty by evaluating the Axis-Shield HBP assay. No prior work had resolved the need for a standardized RI for this particular assay. The study sought to provide a foundation for clinical interpretation of HBP measurements. This effort is part of broader efforts to improve sepsis diagnostics through automated biomarker assays.

The study aimed to determine a reference interval for HBP using the Axis-Shield assay and to assess its analytical performance. This effort was driven by the need for a standardized normal range to interpret HBP measurements accurately. The researchers proposed that the new assay could support clinical decision-making in sepsis management. No prior work had resolved the need for an RI specific to this automated platform. The study focused on establishing a population-based reference range. It also sought to evaluate precision, linearity, and carry-over. This work is part of broader efforts to improve diagnostic accuracy in infectious disease settings. The researchers proposed that the Axis-Shield assay could be a valuable tool in routine clinical practice.

The study used 212 sodium citrated plasma samples to establish a reference interval. The non-parametric method was applied to calculate the 2.5th and 97.5th percentiles. Precision was evaluated using low- and high-concentration controls. Linearity was assessed by measuring HBP concentrations across a range. Carry-over was tested according to CLSI guidelines. The researchers followed standardized protocols for each analytical step. No prior work had resolved the need for a fully automated HBP assay. The study design allowed for direct comparison with existing manual methods.

The reference interval for HBP was found to be between 5.3 ng/mL and 171.0 ng/mL. This range was consistent across age and gender groups. Repeatability and within-laboratory precision were 4.9% and 6.3% for low-concentration controls. For high-concentration controls, the %CVs were 1.6% and 3.0%. Linearity was excellent with an R² of 0.99. Carry-over was negligible at 0.05%. These findings suggest the assay has strong analytical performance. The results support the use of this assay in routine clinical settings.

The study established a reference interval for HBP using the Axis-Shield assay. The authors proposed that this interval could be used regardless of age or gender. The analytical performance met acceptable standards for precision and linearity. The carry-over rate was below the threshold for concern. This is the first study to report on this fully automated HBP assay. The researchers proposed that the assay could be used in routine clinical practice. Further studies are needed to evaluate the clinical utility of HBP measurements. The findings suggest that this assay could support sepsis diagnostics.