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The Dimension® CSAE Cyclosporine Extended Range Calibrator is an in vitro diagnostic product intended to be used to calibrate the CSAE Cyclosporine Extended range method for the Dimension® clinical chemistry system.

The Dimension® CSAE Cyclosporine Extended Range Calibrator contains cyclosporine in a preserved whole blood hemolysate. The kit consists of 2 sets of the following: one vial of sample diluent (0.0 ng/ml of cyclosporine) and one vial of levels 1 through 5. The target concentrations for the five calibrator levels are approximately 200, 400, 800, 1400 and 2000 ng/ml of cyclosporine. Level 0 is included for dilution of over-range samples (>2000 ng/mL) in order to obtain a result; it is not used in calibration. Levels 1 thru 5 are used for calibration of the CSAE method. Refer to the method insert sheet for instructions on calibration and making appropriate manual dilutions.

The provided document describes the acceptance criteria and a study to prove the Dimension® Extended Range Cyclosporine Calibrator meets these criteria.

Acceptance Criteria and Reported Device Performance

Study Details

Due to the nature of the device (a calibrator material) and the provided 510(k) summary, the study described is not a typical clinical performance study involving human readers or patient outcomes, but rather a stability and value assignment study to ensure the calibrator's accuracy and reliability.

1. Sample size used for the test set and the data provenance:

   • Sample Size: The document mentions that the product (calibrator) was tested at various time points (0, 7, 14, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 390 days) during its testing cycle. The control material was tested at the same frequency. These time points represent the "samples" for the stability study. The calibrator itself consists of 5 levels (plus a diluent level 0), meaning each "sample" involves testing these 5 levels at each time point.
   • Data Provenance: Not explicitly stated but implied to be generated in-house through laboratory testing by Dade Behring Inc. The study is prospective in nature, as it involves real-time monitoring of the product's stability over an extended period.

2. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

   • This question is less applicable to a calibrator device. The "ground truth" for calibrators is primarily established through analytical and metrological traceability, not expert consensus on diagnostic interpretation.
   • Traceability: The document states that Novartis Pharmaceutical Grade CSA powder was used to formulate a reference stock solution, and its concentration was assigned by HPLC. A reference lot was then formulated and assigned by LC/MS/MS. This establishes the highly accurate "ground truth" values for the cyclosporine concentrations.
   • Qualifications: While not explicitly mentioned for the individual performing the HPLC or LC/MS/MS, these are standard analytical chemistry techniques that would be performed by qualified laboratory scientists with expertise in these methods.

3. Adjudication method (e.g. 2+1, 3+1, none) for the test set:

   • Not applicable. Adjudication methods like 2+1 or 3+1 are used in studies involving human interpretation (e.g., radiology reads) where there might be disagreement among experts. For an analytical calibrator, the ground truth is established chemically and instrumentally, not through subjective human interpretation requiring adjudication.

4. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:

   • Not applicable. This device is a calibrator for a clinical chemistry system, not an AI-assisted diagnostic tool that would involve human readers interpreting cases.

5. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

   • Yes, in a sense. The "standalone performance" of the calibrator is its ability to maintain its assigned values over time (stability) and for its assigned values to be accurate (traceability and value assignment). The performance characteristics section (L) directly addresses this for the calibrator itself, independent of operator interaction after its initial formulation and validation.

6. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

   • The ground truth for the calibrator's concentrations is established through analytical and metrological techniques, specifically:
     • HPLC (High Performance Liquid Chromatography) for the initial stock solution concentration.
     • LC/MS/MS (Liquid Chromatography-Mass Spectrometry/Mass Spectrometry) for assigning the reference lot values.
     • Gravimetric procedures for preparing the cyclosporine stock solution.

7. The sample size for the training set:

   • Not applicable in the conventional sense of an AI/machine learning model's training set. For a calibrator, the "training" analogous process is its initial development, formulation, and rigorous characterization to ensure its stability and accurate value assignment. The document describes the process of preparing stock solutions and calibrator levels using controlled methods, which is a form of "training" or establishment of the product.

8. How the ground truth for the training set was established:

   • As mentioned above, the "ground truth" (i.e., the target concentrations of cyclosporine for each calibrator level) was established through:
     • Preparation of a cyclosporine stock solution using standard gravimetric procedures.
     • Confirmation of the stock solution concentration using HPLC.
     • Aliquots of this stock solution were then added to measured amounts of calibrator matrix (preserved whole blood hemolysate) to achieve the desired concentrations for each calibrator level.
     • The recovery of these levels was verified against a control calibrator lot and a frozen reference lot, with the reference lot assigned by LC/MS/MS.

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