(223 days)
The GBI TSH Neonatal Screening Kit is designed for the quantitative determination of Thyroid Stimulating Hormone (TSH) concentrations in neonatal blood samples that have been collected onto Whatman 903 specimen collection paper. The results are used to screen newborns for congenital hypothyroidism.
The GBI TSH Neonatal Screening Kit is an enzyme immunoassay. A highly specific polyclonal goat antihTSH (human) antibody has been immobilized onto each well of the 96-well microplates provided. To begin the assay, sample discs punched from dried whole blood spot standards, controls and neonate specimens are added to the coated wells. An elution buffer is also added. The plate is incubated to elute TSH from the sample disc and to allow capture of the eluted TSH by the antibody immobilized onto the microplate wells. Following incubation the plates are washed to remove the sample discs as well as the eluate. A second antibody, a D-specific anti-hTSH monoclonal that has been conjugated to the enzyme horseradishperoxidase (HRP), is then added to the wells and incubated. The eluted TSH of the sample already captured by the microplate-bound antibody is now also bound by the enzyme-conjugated monoclonal antibody added. An antibody-TSH-antibody bridge, or "sandwich", forms that is bound to the surface of the microplate wells. Any unbound complexes are removed with subsequent plate washings. The final stage of the assay is the detection of the microwell-bound complexes by the addition of a color developing reagent. The enzyme (HRP) portion of the bound "sandwich" reacts with the color developer, 3, 3', 5, 5'-Tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2). The TMB/ H2O2 liquid is converted from colorless to blue. The degree of color change is directly proportional to the amount of TSH antigen that is bound in the well. The color development is terminated with the addition of a color stopper that converts the blue to yellow. The results are measured with a microplate reader at a wavelength of 450 mm. The absorbance measured is directly proportional to the concentration of TSH in the sample. A standard curve is generated by plotting the light absorbance of each standard versus its known TSH concentrations of TSH in the unknown samples are determined by interpolation from this standard curve.
Here's an analysis of the acceptance criteria and study proving the device meets them, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Predicate Device) | Reported Device Performance (GBI TSH Neonatal Screening Kit) |
|---|---|---|
| Analytical Sensitivity | 2.9 uIU/ml | 2.4 uIU/ml |
| Precision (Within-Run) | NA (Specific values for predicate not provided in the same format) | 15 uIU/ml: Sr = 0.9 uIU/ml (cv= 6.2%) |
| 30 uIU/ml: Sr = 1.3 uIU/ml (cv= 4.6%) | ||
| 25+ uIU/ml: Sr = 2.6 uIU/ml (cv= 8.5%) | ||
| 40+ uIU/ml: Sr = 4.2 uIU/ml (cv= 9.1%) | ||
| 80+ uIU/ml: Sr = 6.5 uIU/ml (cv=7.5%) | ||
| Precision (Between-Day) | NA (Specific values for predicate not provided in the same format) | 15 uIU/ml: Sdd = 1.0 uIU/ml (cv= 6.8%) |
| 30 uIU/ml: Sdd = 2.3 uIU/ml (cv= 8.1%) | ||
| 25+ uIU/ml: Sdd = 2.6 uIU/ml (cv= 8.5%) | ||
| 40+ uIU/ml: Sdd = 1.2 uIU/ml (cv= 2.6%) | ||
| 80+ uIU/ml: Sdd = 10.3 uIU/ml (cv= 11.9%) | ||
| Precision (Within-Device) | NA (Not published for predicate) | 15 uIU/ml: ST = 1.2 uIU/ml (cv= 8.2%) |
| 30 uIU/ml: ST = 2.5 uIU/ml (cv= 8.8%) | ||
| 25+ uIU/ml: ST = 3.7 uIU/ml (cv= 12.1%) | ||
| 40+ uIU/ml: ST = 4.4 uIU/ml (cv= 9.5%) | ||
| 80+ uIU/ml: ST = 12.2 uIU/ml (cv= 14.1%) | ||
| Interfering Substances | No interference at highest concentrations tested: Bilirubin (up to 60 mg/dl), Lipids (up to 1000 mg/dl), Hemoglobin (up to 78 g/dl) | No interference with expected values of clinical significance: |
- Bilirubin: no interference up to 20 mg/dl (Note: lower than predicate's stated limit, but the study shows no interference at this level)
- Lipids: no interference up to 1350 mg/dl
- Hemoglobin: no interference up to 80 g/dl
- Specific test results show observed values within +/- 1 SD of control values for lipid, bilirubin (conj/un), and hemoglobin (at various concentrations, including higher ones in an additional study). |
| Cross Reacting Substances | No interference at highest concentrations tested: FSH (up to 500 mIU/ml), LH (up to 500 mIU/ml), HCG (up to 100,000 mIU/ml) | No interference found at highest concentrations tested (values were below the limit of detection for the assay,
§ 862.1690 Thyroid stimulating hormone test system.
(a)
Identification. A thyroid stimulating hormone test system is a device intended to measure thyroid stimulating hormone, also known as thyrotrophin and thyrotrophic hormone, in serum and plasma. Measurements of thyroid stimulating hormone produced by the anterior pituitary are used in the diagnosis of thyroid or pituitary disorders.(b)
Classification. Class II.