(23 days)
Rx Only
For in vitro diagnostic use only
The ALB test within the VITROS XT Chemistry Products ALB-TP Slides quantitatively measures albumin (ALB) concentration in serum and plasma using the VITROS XT 7600 Integrated System. Albumin measurements are used in the diagnosis and treatment of numerous diseases involving primarily the liver or kidneys.
The new device, the VITROS XT Chemistry Products ALB-TP Slides is a single device that contains both an albumin test and a total protein test side by side separated by a plastic barrier sealed within a single slide frame. In this format, individual reactions occur and test results are generated for each analyte independently of the other analyte.
The ALB test is a multilayered, analytical element coated on a polyester support.
For the albumin measurement, a drop of patient sample is deposited on the slide and is evenly distributed by the spreading layer to the underlying layers. When the fluid penetrates the reagent layer, the bromcresol green (BCG) dye diffuses to the spreading layer and binds to albumin in the sample. This binding results in a shift in wavelength of the reflectance maximum of the free dye. The color complex that forms is measured by reflectance spectrophotometry. The amount of albumin-bound dye is proportional to the concentration of albumin in the sample.
The provided document describes the analytical performance of the VITROS XT Chemistry Products ALB-TP Slides for measuring albumin (ALB) concentration, and its substantial equivalence to a predicate device.
Here's an analysis of the acceptance criteria and study data:
1. A table of acceptance criteria and the reported device performance
The document does not explicitly state formal "acceptance criteria" for each performance metric in a dedicated table. Instead, performance is demonstrated through studies and compared against established clinical laboratory guidelines (CLSI protocols) or by showing strong correlation to the predicate device. For some metrics, an implied acceptance based on clinical relevance and comparison to the predicate can be inferred.
Here's a table summarizing the reported device performance, with inferred acceptance criteria based on the context of the studies:
| Performance Metric | Inferred Acceptance Criteria (Contextual) | Reported Device Performance |
|---|---|---|
| Method Comparison | Strong correlation (e.g., correlation coefficient close to 1, slope close to 1, intercept close to 0) with the predicate device, following CLSI EP09-A3. | Correlation for ALB (g/dL): |
- N: 127
- Slope: 1.00
- Intercept: -0.03
- Correlation Coeff.: 0.999
- Test Range: 1.0 - 5.9
- Measuring Range: 1.0 - 6.0 |
| Matrix Comparison | Acceptable performance across different sample types (serum, plasma) compared to a reference serum type (red top plastic serum tube), with slopes near 1 and intercepts near 0, demonstrating equivalence. | Regression results vs. Serum Plastic: - Na Hep: Slope 0.96, Intercept 0.098
- Li Hep: Slope 0.96, Intercept 0.088
- PST: Slope 0.95, Intercept 0.107
- SST: Slope 0.99, Intercept 0.033
- Serum Glass: Slope 1.00, Intercept -0.007 |
| Precision | Meets performance guidelines for precision (e.g., CLSI EP05-A3), demonstrating low variability (low SD and %CV) across different concentrations and over time (repeatability, within-day, within-lab). Specific criteria for SD/CV are not explicitly given but are generally expected to be within clinically acceptable limits. | Representative Lot Precision (g/dL Albumin): - Mean Conc. 1.6: Repeatability %CV 1.2, Within Lab %CV 1.4
- Mean Conc. 2.7: Repeatability %CV 0.9, Within Lab %CV 1.2
- Mean Conc. 3.4: Repeatability %CV 0.8, Within Lab %CV 1.1
- Mean Conc. 4.1: Repeatability %CV 1.0, Within Lab %CV 1.3
- Mean Conc. 4.4: Repeatability %CV 0.7, Within Lab %CV 0.9
- Mean Conc. 5.2: Repeatability %CV 0.9, Within Lab %CV 1.2 |
| Detection Limits (LoQ)| LoQ determined based on pre-defined Total Error (TE) goals, with a specific goal of ≤ 0.2 g/dL. | ALB (g/dL): - LOB: 0.24
- LOD: 0.27
- LOQ: 0.60
- Claimed LOQ: 1.0 (This implies the device achieves a tighter LoQ than the claimed range allows) |
| Linearity | Supports the claimed measuring range (1.0 - 6.0 g/dL), demonstrated by a linear response across a wider range (e.g., 0.5 - 7.1 g/dL) with a high correlation (R close to 1) and appropriate slope/intercept. Follows CLSI EP06-A. | ALB: - Measuring Range: 1.0 - 6.0 g/dL
- Linear Range: 0.5 - 7.1 g/dL
- Least Squares Regression: y = 1.01x - 0.19 with R = 1.00 |
| Specificity (Interference) | Bias -0.38; 4 g/dL (4.8 g/dL ALB) -> -0.58 - Hemoglobin: 300 mg/dL (3.8 g/dL ALB) -> 0.32; 200 mg/dL (4.6 g/dL ALB) -> 0.37
47 test substances found not to interfere (bias
§ 862.1035 Albumin test system.
(a)
Identification. An albumin test system is a device intended to measure the albumin concentration in serum and plasma. Albumin measurements are used in the diagnosis and treatment of numerous diseases involving primarily the liver or kidneys.(b)
Classification. Class II.