(28 days)
ACCURUN™ 135 Toxoplasma IgG Positive Control is a human blood based single analyte run control designed to be used as an independent run control with tests for the detection of IgG antibodies to Toxoplasma gondii. This control is not intended as a substitute for controls provided with test kits. ACCURUN™ 135 control is intended to estimate laboratory testing precision and can be used to detect errors in laboratory testing procedures. This product is not FDA cleared for use in testing blood or plasma donors. This product will be made available to clinical laboratory professionals in public health laboratories and clinical laboratories for use with in vitro diagnostic tests for the detection of IgG antibodies to Taxoplasma gondii in human serum.
ACCURUN™ 135 Toxoplasma IgG Positive Control is manufactured from human serum or plasma containing IgG antibodies to Toxoplasma gondii, but is nonreactive for antibodies to Human Immunodeficiency Virus Types 1 and 2 (HIV 1 and 2), antibodies to Human T-Lymphotropic Virus Type I (HTLV I) and antibodies to Hepatitis C (HCV). This control contains stabilizers (EDTA, buffering agents) and 0.1% ProClin™ as preservative. The manufacturer recommends that the user observe the Centers for Disease Control (CDC) recommended Universal Precautions for handling ACCURUN™ 135 and all human blood. This product will be made available to clinical laboratory professionals in public health laboratories and clinical laboratories for use with in vitro diagnostic tests for the detection of IgG antibodies to Toxoplasma gondii in human serum and plasma. This control is supplied as 1 x 1 ml vial or 1 x 5 ml vial. ACCURUN™ 135 should be stored at 2-8°C. Once opened, ACCURUN™ 135 should be discarded after 60 days.
The provided document describes the safety and effectiveness summary for the ACCURUN™ 135 Toxoplasma IgG Positive Control. This device is a quality control material, not a diagnostic test itself, so the acceptance criteria and study design are focused on its stability and consistency as a control rather than diagnostic accuracy metrics like sensitivity or specificity.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state quantitative acceptance criteria for the ACCURUN™ 135 Toxoplasma IgG Positive Control's performance. Instead, it describes general claims of stability and effectiveness, which implicitly serve as the performance goals.
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| Stability at 2-8°C (vialed form): The control should remain stable when stored at recommended temperatures. | "The data suggest that ACCURUN™ 135 can be stored at 2-8°C in its vialed form..." |
| Resistance to multiple freeze-thaw cycles: The control's integrity should not be compromised by freeze-thaw events. | "...and is not affected by multiple freeze-thaw cycles." |
| Stability at ambient temperatures (short period): The control should tolerate temporary exposure to room temperature. | "ACCURUN™ 135 is stable at ambient temperatures... for a short period of time with no adverse effects." |
| Stability under heat stress (short period): The control should tolerate temporary exposure to elevated temperatures. | "...and under heat stress for a short period of time with no adverse effects." |
| Open vial stability (at 2-8°C for at least 60 days): The control should remain stable for a specified period after opening and refrigerated storage. | "ACCURUN™ 135 remains stable even after the vials have been repeatedly opened and stored at 2-8℃ for at least 60 days." |
| Consistency and performance as an independent run control: The device should consistently perform as an effective independent run control across different laboratories and lots. | "The clinical trial data demonstrate that ACCURUN™ 135 is safe and effective in three different laboratories with three manufactured ACCURUN™ 135 lots, and under various conditions of stress." |
2. Sample Size for Test Set and Data Provenance
- Sample Size for Test Set: The document does not specify exact "sample sizes" in terms of number of patient samples. For stability studies, it refers to "five types of stability studies" (real time, ambient temperature, heat stress, freeze-thaw, and open vial) and implies multiple vials or aliquots were tested under these conditions. For clinical evaluations, it states that "three manufactured ACCURUN™ 135 lots" were evaluated.
- Data Provenance: The studies were performed "at BBI [Boston Biomedica, Inc.] and at two clinical laboratories." This suggests data was collected both internally and externally. The country of origin is implicitly the United States, as BBI is located in Massachusetts and the submission is to the US FDA. The studies appear to be prospective evaluations designed to test the stability and consistency of the manufactured control lots.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
This section is not applicable to this device. The ACCURUN™ 135 is a positive control, not a diagnostic device intended to differentiate disease states or interpret findings. Therefore, explicit "ground truth" as established by experts for a test set (e.g., patient diagnosis confirmed by radiologists) is not relevant for this type of product. The "ground truth" here is the expected behavior of the control, which is to provide a positive signal for Toxoplasma IgG antibodies in a consistent manner. This is assessed by laboratory testing against established methodologies.
4. Adjudication Method for the Test Set
This section is not applicable for the same reasons as point 3. Adjudication methods like 2+1 or 3+1 are used to resolve disagreements among multiple experts when establishing a diagnostic ground truth for patient cases. Since this is a quality control device without a patient diagnostic "test set" requiring expert interpretation for ground truth, such adjudication is not performed. The "adjudication" in this context would be the internal quality control review of the test results for consistency and adherence to predefined specifications.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
An MRMC comparative effectiveness study was not done. This type of study investigates the impact of a device (e.g., AI assistance) on the performance of human readers in interpreting medical images or diagnostic tests. Since ACCURUN™ 135 is a laboratory control product and not an interpretative diagnostic device involving human readers for case diagnosis, an MRMC study is not relevant.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
A standalone study was not done in the context of an "algorithm only" performance. ACCURUN™ 135 is a biological reagent control; it does not involve a software algorithm that operates independently. Its "performance" is measured by its chemical/biological stability and its consistent reactivity in standard laboratory assays, which inherently involve human technicians and laboratory equipment.
7. Type of Ground Truth Used
The "ground truth" for the ACCURUN™ 135 control is its pre-defined positive status for Toxoplasma IgG antibodies and its consistency in performance over time and under various conditions. This is established through:
- Known composition/manufacturing: The control is manufactured from human serum/plasma known to contain IgG antibodies to Toxoplasma gondii.
- Laboratory testing parameters: The "ground truth" of its stability and effectiveness is determined by its consistent reactivity in various in vitro diagnostic tests for Toxoplasma gondii IgG, within acceptable ranges.
- Experimental data: The stability studies (real-time, ambient, heat stress, freeze-thaw, open vial) generate data that confirm the control continues to perform within expected parameters, thus validating its "ground truth" as a stable positive control.
Essentially, the "ground truth" is the empirically validated performance characteristics of the control itself, rather than external patient outcome data or expert consensus on clinical cases.
8. Sample Size for the Training Set
This section is not applicable. ACCURUN™ 135 is a laboratory reagent control, not a machine learning or AI-based diagnostic device that requires a "training set" to develop an algorithm.
9. How the Ground Truth for the Training Set Was Established
This section is not applicable for the same reasons as point 8.
§ 866.3780
Toxoplasma gondii serological reagents.(a)
Identification. Toxoplasma gondii serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies toToxoplasma gondii in serum. Additionally, some of these reagents consist of antisera conjugated with a fluorescent dye (immunofluorescent reagents) used to identifyToxoplasma gondii from clinical specimens. The identification aids in the diagnosis of toxoplasmosis caused by the parasitic protozoanToxoplasma gondii and provides epidemiological information on this disease. Congenital toxoplasmosis is characterized by lesions of the central nervous system, which if undetected and untreated may lead to brain defects, blindness, and death of an unborn fetus. The disease is characterized in children by inflammation of the brain and spinal cord.(b)
Classification. Class II (performance standards).