(29 days)
The Progenika A1AT genotyping kit is a qualitative, polymerase chain reaction (PCR) and hybridization-based in vitro diagnostic test to be used with the Luminent (with xPONENT software) for the simultaneous detection and identification of 14 allelic variants and their associated alleles found in the Alpha-1 antitrypsin (AIAT) codifying gene SERPINA1. The test is intended for use with genomic DNA extracted from human whole blood samples collected as dry blood spots (DBS) or in K2-EDTA or from human saliva samples collected as buccal swabs using ORAcollect Dx OCD-100. The A1AT allelic variant genotypes and associated allele results, when used in conjunction with clinical findings and other laboratory tests, are intended as an aid in the diagnosis of individuals with A1AT deficiency (A1ATD). The kit is indicated for prescription use only.
Alpha 1 antitrypsin (A1AT) Genotyping Test utilizes Luminex xMAP technology. Genomic DNA is extracted from DBS, from human EDTA anticoagulated whole blood or from human saliva samples collected as buccal swabs using ORAcollect-Dx OCD-100. Extracted DNA is amplified and biotinylated by multiplex PCR and PCR products are denatured and hybridized to oligonucleotide probes coupled to color-coded beads. Hybridized DNA is labeled with a fluorescent conjugate and the resulting signal is detected with a Luminex® 200 system. Raw data obtained is processed with the A1AT Genotyping Test ANALYSIS SOFTWARE in order to obtain the final report. The A1AT Genotyping Test ANALYSIS SOFTWARE algorithm converts the allelic variant genotypes into associated alleles, based on the current literature.
The A1AT Genotyping Test Kit is composed of 4 reagent components (A1AT PCR Master Mix, A1AT Beads Master Mix, SAPE, SAPE Dilution Buffer) required to perform all the abovementioned processing steps. The A1AT Genotyping Test ANALYSIS SOFTWARE, instructions for use and other necessary files are uploaded on a Grifols website. Two kit configurations are available: for 48 or 192 tests (different amounts of the same reagent components are provided in each case).
The provided document describes the A1AT Genotyping Test. This 510(k) submission (K211115) is for a modified version of a previously cleared device (K192858), primarily involving a software update. Therefore, much of the performance data refers back to the original submissions (K192858 and K171868).
Here's a breakdown of the acceptance criteria and study information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Predicate or Implied) | Reported Device Performance (Modified A1AT Genotyping Test) |
|---|---|---|
| Lower Limit of Detection (LoD) | Predicate: 0.0310 ng/µl DNA. The modified device's LoD of 0.0215 ng/µl is an improvement, suggesting the acceptance criteria is at least equal to or better than the predicate. | 0.0215 ng/µl DNA (highest LoD among two lots) |
| Precision (Lot-to-Lot Repeatability) | Predicate: Overall correct call rate of 99.7% (one M/S sample provided an incorrect result). For the modified device, the acceptance criteria would be 100% correct calls or similar to the predicate. | 100% correct calls |
| Precision (External Reproducibility) | Predicate: 100% correct calls. The modified device refers to K171868 for this, implying the acceptance criteria is 100% correct calls. | Same as predicate (100% correct calls) |
| Accuracy | Predicate: Accuracy demonstrated with 147 samples using Bi-directional Sanger sequencing as comparator. The modified device refers to K171868 for Method Comparison (whole blood) and K192858 (saliva), suggesting similar high accuracy against a gold standard. The specific acceptance criteria (e.g., % agreement) are not detailed in this section but are implied to be met. | Same as predicate (demonstrated in K171868 and K192858) |
2. Sample Sizes and Data Provenance
- Test Set Sample Size:
- LoD: 20 replicates of nine DNA dilutions for a "Sample Panel" (total of 180 tests per lot, across two lots used).
- Precision (Lot-to-Lot): Five DNA samples ("Sample Panel") tested in triplicate, with three different reagent lots, by two operators, on six non-consecutive days, alternating between two Luminex instruments (5 samples * 3 replicates * 3 lots * 2 operators * 6 days = 540 tests, plus additional factors for instruments).
- Accuracy: For the predicate device, 147 samples were used. The document refers to K171868 and K192858 for specific method comparison data for the modified device, so the exact number for the modified device's accuracy testing isn't explicitly stated but would be similar to or larger than the predicate's 147.
- Data Provenance: Not explicitly stated as "country of origin for data" or "retrospective/prospective." However, the applicant is Progenika Biopharma S.A. based in Spain, suggesting the studies likely occurred in Spain or affiliated regions. The nature of the studies (analytical performance) implies laboratory-based testing, which can be seen as a form of controlled prospective data collection for the device's technical performance.
3. Number of Experts and Qualifications for Ground Truth (Test Set)
- The document does not mention the use of experts to establish ground truth for the test set for the analytical performance studies described (LoD, Precision). These studies focus on the device's ability to consistently and accurately detect specific genetic variants based on known DNA samples.
- For Accuracy (Method Comparison), the ground truth was established by Bi-directional Sanger sequencing. This is considered a gold standard in genetic sequencing, not typically requiring "experts" to interpret the sequence output, but rather highly skilled laboratory personnel and bioinformaticians.
4. Adjudication Method (Test Set)
- Not applicable as the ground truth for analytical performance studies is typically objective (e.g., known DNA concentrations, Sanger sequencing results). The results are compared directly to these objective standards.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC comparative effectiveness study was not done. This device is an in vitro diagnostic (IVD) genetic test, which generates objective results (detection of allelic variants). The performance evaluation focuses on the analytical accuracy and precision of the device itself, rather than human interpretation of complex images or clinical scenarios that would necessitate an MRMC study.
6. Standalone Performance Study (Algorithm Only)
- Yes, a standalone performance study was done. The entire "Performance Data" section (H) describes the analytical studies to determine the device's capabilities (LoD, precision, stability, accuracy). These are evaluations of the algorithm and the assay itself, demonstrating its standalone performance from DNA input to reported genotype. The device includes "A1AT Genotyping Test ANALYSIS SOFTWARE" which processes raw data to obtain the final report, indicating its role as a standalone algorithm in the diagnostic process once the PCR and hybridization steps are completed.
7. Type of Ground Truth Used
- For LoD and Precision: Known DNA samples with established genotypes/concentrations were used.
- For Accuracy (Method Comparison): Bi-directional Sanger sequencing was used as the comparator (a gold standard laboratory method) to establish the ground truth for the samples tested.
8. Sample Size for the Training Set
- The document does not explicitly state the sample size used for the training set. This is a 510(k) submission for a device with a software update (v1.0.8.16 from v1.0.6.1). The software's algorithm for converting allelic variant genotypes into associated alleles is based on current literature. It's possible that the "training" for such an algorithm is not based on a 'training set' in the machine learning sense, but rather on established scientific knowledge and rules coded into the software. If any machine learning components were present, their training data is not disclosed here.
9. How the Ground Truth for the Training Set Was Established
- Given that the document refers to the algorithm converting genotypes into alleles "based on the current literature," the ground truth for the "training" (or more accurately, the ruleset development) of the algorithm would be derived from published scientific literature and established genetic associations between allelic variants and their corresponding alleles for the SERPINA1 gene. There is no indication of a specific "training set" of patient samples with prospectively established ground truth for algorithm development in this context.
§ 866.5130
Alpha -1-antitrypsin immunological test system.(a)
Identification. Analpha -1-antitrypsin immunological test system is a device that consists of the reagents used to measure by immunochemical techniques thealpha -1-antitrypsin (a plasma protein) in serum, other body fluids, and tissues. The measurements aid in the diagnosis of several conditions including juvenile and adult cirrhosis of the liver. In addition,alpha -1-antitrypsin deficiency has been associated with pulmonary emphysema.(b)
Classification. Class II (performance standards).