(283 days)
The AutoDELFIA® Neonatal 17a-OH-progesterone kit is intended for the quantitative determination of human 17a-OH-progesterone in blood specimens dried on filter paper as an aid in screening newborns for congenital adrenal hyperplasia (CAH) using the 1235 AutoDELFIA® automatic immunoassay system.
The AutoDELFIA Neonatal 17α-OH-progesterone (17-OHP) assay is a solid phase, time-resolved fluoroimmunoassay based on the competitive reaction between europium-labeled 17-OHP and sample 17-OHP for a limited amount of binding sites on 17-OHP specific polyclonal antibodies (derived from rabbit). Danazol facilitates the release of 17-OHP from the binding proteins. A second antibody, directed against rabbit IgG, is coated to the solid phase, giving convenient separation of the antibody-bound and free antigen. Enhancement Solution dissociates europium ions from the labeled antigen into solution where they form highly fluorescent chelates with components of the Enhancement Solution. The fluorescence in each well is then measured. The fluorescence of each sample is inversely proportional to the concentration of 17-OHP in the sample.
Here's a summary of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Device: AutoDELFIA® Neonatal 17α-OH-progesterone kit (B024)
Intended Use: Quantitative determination of human 17α-OH-progesterone in blood specimens dried on filter paper as an aid in screening newborns for congenital adrenal hyperplasia (CAH) using the 1235 AutoDELFIA® automatic immunoassay system.
1. Table of Acceptance Criteria and Reported Device Performance
The document describes the proposed device (B024) as substantially equivalent to a predicate device (K042425, B015) and highlights differences in performance characteristics. The acceptance criteria are implicitly defined by demonstrating similar or improved performance compared to the predicate device, especially regarding cross-reactivity and screening efficacy.
| Characteristic | Acceptance Criteria (Implied by Predicate) | Reported Proposed Device (B024) Performance |
|---|---|---|
| Antibody Cross-Reactions | Lower cross-reactivity with physiologically important steroids in neonates than predicate device. | 17α-OH pregnenolone sulfate: 0.78 % (Predicate: 2.0 %) |
| 11-Deoxycortisol: 0.62 % (Predicate: 1.82 %) | ||
| 17α-OH pregnenolone: 0.83 % (Predicate: 1.20 %) | ||
| Progesterone: 0.37 % (Predicate: 0.47 %) | ||
| Analytical Sensitivity / Limit of Blank (LoB) | 1.3 ng/mL serum (Predicate) | 0.37 ng/mL serum (Improved) |
| Analytical Sensitivity / Limit of Detection (LoD) | Not explicitly stated for predicate in table, but overall analytical sensitivity is desired to be good. | 0.84 ng/mL serum (Improved over predicate's LoB) |
| Analytical Sensitivity / Limit of Quantitation (LoQ) | Not explicitly stated for predicate in table. | 1.4 ng/mL serum |
| Precision (Total Variation, full calibration curve) | CV% values for various concentrations (e.g., 13.2% for 25.9 ng/mL, 10.8% for 53.0 ng/mL, 10.9% for 114 ng/mL) | Range of CV% values (e.g., 13.0% for 2.12 ng/mL, 9.8% for 4.69 ng/mL, 14.8% for 7.52 ng/mL, 8.3% for 27.0 ng/mL, 9.2% for 54.4 ng/mL, 10.8% for 109 ng/mL, 9.1% for 182 ng/mL) |
| Precision (Total Variation, one calibration curve per 4 plates) | CV% values for various concentrations (e.g., 14.0% for 25.8 ng/mL, 12.4% for 52.9 ng/mL, 11.8% for 115 ng/mL) | Range of CV% values (e.g., 14.0% for 2.25 ng/mL, 12.0% for 4.89 ng/mL, 15.8% for 7.79 ng/mL, 9.7% for 27.7 ng/mL, 10.5% for 55.7 ng/mL, 12.7% for 113 ng/mL, 11.3% for 188 ng/mL) |
| Screening Efficacy (CAH case detection) | Must detect known CAH cases similarly or better than predicate device. | Detected all known CAH cases in studies at appropriate cut-off with one exception for very high percentiles. For instance, in Study 1, ≥ 2250 g, 90th percentile, 13 out of 13 CAH cases were detected. In Study 2, ≥ 2250 g, 90th percentile, 13 out of 13 CAH cases were detected. (See * below for exception) |
| Median Values in Newborn Screening | Comparable patterns to predicate, potentially with lower absolute values due to reduced cross-reactivity. | For Studies 1 & 2, median values for various weight categories were consistently lower for B024 compared to B015, supporting the claim of reduced cross-reactivity and increased specificity. |
*In Study 1,
§ 862.1395 17-Hydroxyprogesterone test system.
(a)
Identification. A 17-hydroxyprogesterone test system is a device intended to measure 17-hydroxyprogesterone (a steroid) in plasma and serum. Measurements of 17-hydroxyprogesterone are used in the diagnosis and treatment of various disorders of the adrenal glands or the ovaries.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 862.9.