(154 days)
Cyto-Chex® BCT™ is intended for collection and storage of blood specimens for immunophenotyping of WBC by flowcytometry. Recovery of lymphocyte subset cell markers of the HIV panel can be accomplished over a 14-day period following collection.
Cyto-Chex BCT consists of a standard 13 x 75mm glass blood collection tube containing 75.8ul of sterile KJEDTA anti-coagulant and WBC preservative. It is manufactured with a vacuum to draw 5ml of blood by venipuncture.
Here's a breakdown of the acceptance criteria and the study that demonstrates the device meets these criteria, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Clinically important HIV markers (CD3, CD4, and CD8) are stable in samples collected in Cyto-Chex BCT. | Confirmed. CD3, CD4, and CD8 showed agreement with reference values (fresh K2EDTA samples within 6 hours). |
| Agreement of values with fresh samples: trendline slope better than 0.90 (preferably 0.95), R^2 values of 0.85 or better. | Values for CD3, CD4, and CD8 from Cyto-Chex BCT stabilized samples confirmed through calculated correlation statistics meeting acceptance criteria. (Specific slope and R^2 values are not explicitly given, but the text states they meet the criteria). |
| Recovery of CD3, CD4 and CD8 markers well within the acceptance criteria for absolute cell count. | Confirmed in both HIV-positive and healthy donors. |
| Preservation of HIV markers for a 14-day period following collection. | Confirmed for CD3, CD4, and CD8 in both HIV-positive and healthy donors. |
| CD19 stability. | Showed "some deterioration at 14 days" but the report suggests "additional patient sampling would probably improve the results." (This indicates it may not have fully met the criteria or was a borderline finding that Streck believes could be improved with more data, but was deemed acceptable for the intended use of CD3/CD4/CD8). |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size: The text states "multiple healthy donors" and "samples from HIV positive patients." Specific numerical sample sizes for either group are not provided.
- Data Provenance: Not explicitly stated, but it implies a prospective clinical study where fresh blood samples were collected and then split into different tubes and analyzed over time. The mention of "resource-poor countries" in the conclusion suggests a global relevance, but doesn't specifically state the origin of the study participants. The study tested both healthy and HIV-positive individuals.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- Number of Experts: Not mentioned.
- Qualifications of Experts: Not mentioned. The ground truth was established by laboratory analysis using flow cytometry, a standardized method. The expertise would lie in the technicians performing and interpreting these tests, but their specific qualifications are not detailed.
4. Adjudication Method for the Test Set:
- Adjudication Method: Not applicable. This device is a blood collection tube for sample preservation, not an AI diagnostic tool requiring expert adjudication of image interpretations or similar subjective assessments. The "ground truth" was derived from direct laboratory measurements (flow cytometry results of fresh samples).
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:
- MRMC Study: No. This is not an imaging or diagnostic device that involves human interpretation of results. Therefore, an MRMC study is not relevant.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
- Standalone Performance: No. This is a medical device (blood collection tube) that is designed to preserve biological samples. Its performance is assessed by how well it maintains the integrity of the sample, not as an algorithm performing a task autonomously.
7. The Type of Ground Truth Used:
- Type of Ground Truth: The ground truth was established by direct laboratory measurement from fresh samples (specifically, flow cytometric data for lymphocyte subset cell-surface markers from K2EDTA blood collection tubes analyzed within 6 hours of draw). This serves as the "reference value" against which the Cyto-Chex BCT preserved samples were compared.
8. The Sample Size for the Training Set:
- Sample Size for Training Set: Not applicable. This is not an AI/ML device that requires training. The device's performance is based on its physical properties and chemical composition to preserve blood samples.
9. How the Ground Truth for the Training Set Was Established:
- Ground Truth for Training Set: Not applicable, as there is no training set for this type of device.
§ 862.1675 Blood specimen collection device.
(a)
Identification. A blood specimen collection device is a device intended for medical purposes to collect and to handle blood specimens and to separate serum from nonserum (cellular) components prior to further testing. This generic type device may include blood collection tubes, vials, systems, serum separators, blood collection trays, or vacuum sample tubes.(b)
Classification. Class II.