(30 days)
The Prodesse ProFlu™+ Assay is a multiplex Real-Time PCR (RT-PCR) in vitro diagnostic test for the rapid and qualitative detection and discrimination of Influenza A Virus. Influenza B Virus, and Respiratory Syncytial Virus (RSV) nucleic acids isolated and purified from nasopharyngeal (NP) swab specimens obtained from symptomatic patients. This test is intended for use to aid in the differential diagnosis of Influenza A. Influenza B and RSV viral infections in humans and is not intended to detect Influenza C.
Negative results do not preclude influenza or RSV virus infection and should not be used as the sole basis for treatment or other management decisions. Conversely, positive results do not rule-out bacterial infection or co-infection with other viruses. The agent detected may not be the definite cause of disease. The use of additional laboratory testing and clinical presentation must be considered in order to obtain the final diagnosis of respiratory viral infection.
Performance characteristics for Influenza A Virus were established when Influenza A/H3 and A/H1 were the predominant Influenza A viruses in circulation (2006 - 2007 respiratory season). Performance characteristics for Influenza A were confirmed when Influenza A/H1, Influenza A/H3, and Influenza A/2009 H1N1 were the predominant Influenza A viruses in circulation (2008 and 2009). When other Influenza A viruses are emerging, performance characteristics may vary.
If infection with a novel Influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent Influenza viruses and sent to state or local health department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
The ProFlu+ Assay enables detection and discrimination of Influenza A Virus, Influenza B Virus, RSV and universal internal control nucleic acid. Nasopharyngeal swab specimens are collected from patients with signs and symptoms of a respiratory infection using a polyester, rayon or nylon tipped swab and placed into viral transport medium. A Universal Internal Control (UIC) is added to each sample prior to nucleic acid isolation to monitor for inhibitors present in the specimens. The isolation and purification of the nucleic acids is performed using either a MagNA Pure LC Instrument (Roche) and the MagNA Purc Total Nucleic Acid Isolation Kit (Roche) or a NucliSENS® easyMAG™ System (bioMérieux) and the Automated Magnetic Extraction Reagents (bioMérieux). The purified nucleic acids are added to Influenza B/RSV Mix along with enzymes included in the ProFlu+ Assay Kit. The Influenza A/Influenza B/RSV Mix contains oligonucleotide primers and target-specific oligonucleotide probes. The primers are complementary to highly conserved regions of genetic sequences for these respiratory viruses. The probes are dual-labeled with a reporter dye attached to the 5'-end and a quencher dye attached to the 3'-end. Reverse transcription of the RNA in the sample into complementary DNA (cDNA) and subsequent amplification of DNA is performed in a Cepheid SmartCycler® II instrument. In this process, the probe anneals specifically to the template followed by primer extension and amplification. The ProFity- Assay is based on Tagman chemistry, which utilizes the 5 - 3 exonuclease activity of the Taq polymerase to cleave the probe thus separating the reporter dye from the quencher. This generates an increase in fluorescent signal upon excitation from a light source. With each cycle, additional reporter dye molecules are cleaved from their respective probes, further increasing fluorescent signal. The amount of fluorescence at any given cycle is dependent on the amount of amplification products present at that time. Fluorescent intensity is monitored during each PCR cycle by the SmartCyclerII instrument.
The provided document describes a 510(k) premarket notification for a modified in vitro diagnostic device, the Prodesse ProFlu™+ Assay. As such, the information typically associated with acceptance criteria and a detailed study proving device performance against those criteria in the context of AI/ML or image processing devices is not present. This document focuses on demonstrating substantial equivalence to a predicate device, rather than proving performance against specific acceptance criteria with detailed statistical results.
However, I can extract the relevant information based on the prompt's request, interpreting "acceptance criteria" as the claimed performance or non-inferiority that the modification verification studies aimed to confirm.
Here's a breakdown of the requested information, acknowledging the limitations of a 510(k) submission for a molecular diagnostic device:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state numerical "acceptance criteria" in the format typically seen for sensitivity/specificity for algorithms. Instead, the modifications were verified to ensure the fundamental scientific technology and clinical performance remained unchanged from the predicate device. The "acceptance criteria" were met if these aspects were confirmed.
| Aspect Tested | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Universal Internal Control (UIC) Impact | - Ability to detect target organisms at LOD. |
- Clinical performance remains consistent with the current ProFlu+ Assay. | - The UIC did not affect the ability of the ProFlu+ Assay to detect target organisms at the limit of detection (LOD) as evinced by results of Analytical Sensitivity, IC Interference, Extractor Equivalency, and Sample Stability studies.
- A retrospective clinical comparison study demonstrated the modified ProFlu+ Assay with UIC continues to meet the performance claims for the current ProFlu+ Assay. |
| Modified Positive Controls | - Stability claims are met. - Continued ability to monitor for global assay failures. | - Stability studies demonstrated current stability claims are met.
- Clinical validation of the modified positive controls demonstrated their continued ability to monitor for global assay failures. |
| Influenza A H3N2v and H7N9 Reactivity | - Ability to detect specific strains (A/Indiana/10/2011 (H3N2v) and A/Anhui/1/2013 (H7N9)). | - Results of the Reactivity Study demonstrated the ability of the ProFlu+ Assay to detect A/Indiana/10/2011 (H3N2v) and A/Anhui/1/2013 (H7N9) nucleic acids at concentrations near the limit of detection of the assay. |
| Increased Freeze-Thaw Cycles (M-MLV RT & RNase II) | - Assay performance is not affected by 10 freeze-thaw cycles. | - Stability studies demonstrated that ProFlu+ Assay performance was not affected when the MMLV Reverse Transcriptase and the RNase Inhibitor II underwent 10 freeze-thaw cycles. |
2. Sample Size Used for the Test Set and Data Provenance
The document mentions a "retrospective clinical comparison study" for the UIC impact. However, the specific sample size used for this test set is not provided. The geographic provenance (e.g., country of origin) of the data is also not specified. The study is described as "retrospective."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
For this type of molecular diagnostic device, ground truth is typically established by laboratory testing methods (e.g., gold standard PCR, sequencing, or culture) rather than expert human interpretation of images or clinical data, especially for a retrospective study focused on assay performance. Therefore, the concept of "number of experts" and their "qualifications" for establishing ground truth as one might consider for imaging devices does not directly apply in this context. The "ground truth" would be the result of a reference laboratory method.
4. Adjudication Method for the Test Set
Given that ground truth is likely based on objective laboratory methods, an "adjudication method" involving multiple human readers (e.g., 2+1, 3+1) is not applicable here.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was Done
No, a Multi Reader Multi Case (MRMC) comparative effectiveness study was not done. This type of study is relevant for evaluating the impact of AI assistance on human reader performance, which is not applicable to a non-AI molecular diagnostic assay validation.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
The ProFlu™+ Assay is a molecular diagnostic test. The entire assay system (reagents, instrumentation, and protocol) constitutes the "algorithm" in a broad sense. The verification studies assess the performance of this system directly. Therefore, the "standalone" performance is what was evaluated in the analytical and clinical studies described, as there isn't a separate "human-in-the-loop" component in the direct interpretation of the PCR results for this device. The user performs the test and interprets the results based on predefined thresholds, but the core detection is algorithmic.
7. The Type of Ground Truth Used
The ground truth for the verification studies would likely be established through:
- Reference molecular methods: Such as a validated laboratory-developed test (LDT), sequencing, or other nucleic acid amplification tests (NAATs) that are considered the gold standard for detecting the target viruses.
- Viral culture: For confirmation of viable virus.
- Analytical spiking: For analytical sensitivity and reactivity studies, where known concentrations of target nucleic acids are used.
While the document doesn't explicitly state the exact "ground truth" method for the clinical comparison, for a molecular diagnostic, it would invariably involve a highly accurate reference laboratory test.
8. The Sample Size for the Training Set
This submission describes modifications to an existing device and its verification, not the development of a de novo algorithm requiring a "training set" in the context of machine learning. Therefore, the concept of a "training set" does not apply here. The initial development of the predicate ProFlu+ Assay would have involved studies to establish its design parameters.
9. How the Ground Truth for the Training Set Was Established
As noted in point 8, the concept of a "training set" is not relevant to this type of device modification submission.
§ 866.3980 Respiratory viral panel multiplex nucleic acid assay.
(a)
Identification. A respiratory viral panel multiplex nucleic acid assay is a qualitative in vitro diagnostic device intended to simultaneously detect and identify multiple viral nucleic acids extracted from human respiratory specimens or viral culture. The detection and identification of a specific viral nucleic acid from individuals exhibiting signs and symptoms of respiratory infection aids in the diagnosis of respiratory viral infection when used in conjunction with other clinical and laboratory findings. The device is intended for detection and identification of a combination of the following viruses:(1) Influenza A and Influenza B;
(2) Influenza A subtype H1 and Influenza A subtype H3;
(3) Respiratory Syncytial Virus subtype A and Respiratory Syncytial Virus subtype B;
(4) Parainfluenza 1, Parainfluenza 2, and Parainfluenza 3 virus;
(5) Human Metapneumovirus;
(6) Rhinovirus; and
(7) Adenovirus.
(b)
Classification. Class II (special controls). The special controls are:(1) FDA's guidance document entitled “Class II Special Controls Guidance Document: Respiratory Viral Panel Multiplex Nucleic Acid Assay;”
(2) For a device that detects and identifies Human Metapneumovirus, FDA's guidance document entitled “Class II Special Controls Guidance Document: Testing for Human Metapneumovirus (hMPV) Using Nucleic Acid Assays;” and
(3) For a device that detects and differentiates Influenza A subtype H1 and subtype H3, FDA's guidance document entitled “Class II Special Controls Guidance Document: Testing for Detection and Differentiation of Influenza A Virus Subtypes Using Multiplex Nucleic Acid Assays.” See § 866.1(e) for the availability of these guidance documents.