Cystatin C

K242585 · SENTINEL CH. SpA · NDY · May 16, 2025 · Clinical Chemistry

Device Facts

• Record ID: K242585
• Device Name: Cystatin C
• Applicant: SENTINEL CH. SpA
• Product Code: NDY · Clinical Chemistry
• Decision Date: May 16, 2025
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1225
• Device Class: Class 2

Intended Use

The Cystatin C assay is an in vitro diagnostic test used in the quantitative immunoturbidimetric determination of cystatin C in human serum and plasma on the Alinity c system. Measurement of cystatin C aids in the diagnosis and treatment of renal diseases. For laboratory professional use only.

Device Story

The Cystatin C assay is a particle-enhanced turbidimetric immunoassay (PETIA) designed for use on the Alinity c system. It utilizes latex particles coated with rabbit anti-human cystatin C antibodies. When mixed with a patient serum or plasma sample, the particles agglutinate in the presence of cystatin C; the resulting change in absorbance is measured photometrically and is proportional to the cystatin C concentration. The device is intended for use by laboratory professionals in clinical settings. Results are provided to healthcare providers to assist in the diagnosis and management of renal disease. The assay features an analytical measuring interval of 0.30–10.00 mg/L, with an extended range up to 40.00 mg/L via dilution.

Clinical Evidence

Bench testing only. Performance was validated through precision/reproducibility studies (N=240 per sample), linearity (0.30–10.00 mg/L), and interference testing. Method comparison against the predicate (N=161) showed a correlation coefficient of 1.00 and a Passing-Bablok slope of 1.03. Reference range established using 250 healthy individuals (105 female, 145 male, ages 18–69).

Technological Characteristics

Particle-enhanced turbidimetric immunoassay (PETIA). Reagents: R1 (buffer, stabilizers, sodium azide <0.1%); R2 (latex particles coated with rabbit IgG anti-human cystatin C, buffer, stabilizers, sodium azide <0.1%). Form factor: Cartridge-based for Alinity c system. Standardization: ERM-DA471/IFCC. Connectivity: Integrated with Alinity c system.

Indications for Use

Indicated for the quantitative determination of cystatin C in human serum and plasma to aid in the diagnosis and treatment of renal diseases in adult populations.

Regulatory Classification

Identification

A creatinine test system is a device intended to measure creatinine levels in plasma and urine. Creatinine measurements are used in the diagnosis and treatment of renal diseases, in monitoring renal dialysis, and as a calculation basis for measuring other urine analytes.

Predicate Devices

• Tina-quant Cystatin C Gen.2 (K161817)

Submission Summary (Full Text)

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FDA U.S. FOOD &amp; DRUG ADMINISTRATION

May 16, 2025

SENTINEL CH. S.p.A.
Patricia Dupé
Head of Quality System
Via Robert Koch, 2
Milan (MI), 20152, Italy

Re: K242585
Trade/Device Name: Cystatin C
Regulation Number: 21 CFR 862.1225
Regulation Name: Creatinine Test System
Regulatory Class: Class II
Product Code: NDY
Dated: April 10, 2025
Received: April 10, 2025

Dear Patricia Dupé

We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

U.S. Food &amp; Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov

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K242585 - Patricia Dupé
Page 2

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801 and Part 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.

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K242585 - Patricia Dupé
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For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

Sincerely,

Paula V. Caposino -S

Paula Caposino, Ph.D.
Deputy Director
Division of Chemistry and Toxicology Devices
OHT7: Office of In Vitro Diagnostics
Office of Product Evaluation and Quality
Center for Devices and Radiological Health

Enclosure

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FORM FDA 3881 (8/23)
Page 1 of 1
PSC Publishing Services [phone]
EF

| DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Indications for Use | Form Approved: OMB No. 0910-0120 Expiration Date: 07/31/2026 See PRA Statement below. |
| --- | --- |
| 510(k) Number (if known) K242585 | |
| Device Name Cystatin C | |
| Indications for Use (Describe) The Cystatin C assay is an in vitro diagnostic test used in the quantitative immunoturbidimetric determination of cystatin C in human serum and plasma on the Alinity c system. Measurement of cystatin C aids in the diagnosis and treatment of renal diseases. For laboratory professional use only. | |
| Type of Use (Select one or both, as applicable) ☑ Prescription Use (Part 21 CFR 801 Subpart D) ☐ Over-The-Counter Use (21 CFR 801 Subpart C) | |
| CONTINUE ON A SEPARATE PAGE IF NEEDED. | |
| This section applies only to requirements of the Paperwork Reduction Act of 1995. *DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.* | |
| The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to: Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff [e-mail] | |
| "An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number." | |

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

# Administrative Documentation – 510(k) Summary

This summary of the 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR §807.92.

# I. 510(k) Number

K242585

# II. Applicant Name

SENTINEL CH. S.p.A.
Via Robert Koch, 2
Milano (MI)
20152, Italy
[phone]

Primary contact person for all communications:

Patricia Dupé
Head of Quality System
Phone: [phone]
Fax: [phone]
Email: [e-mail]

Secondary contact person for all communications:

Alessia Moiana
Sr. Regulatory Affairs Specialist
Phone: [phone]
Email: [e-mail]

Date Summary Prepared: May 15, 2025

# III. Device Name and Classification

Trade name: Cystatin C
Device Classification: Class II
Regulation Description: Creatinine test system
Regulation Number: 862.1225
Product Code: NDY

Administrative Documentation – 510(k) Summary
Page 1 of 12

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

## IV. Predicate Device

Tina-quant Cystatin C Gen.2 (K161817)

## V. Description of Device

### A. Principles of the Procedure

The Cystatin C assay is an automated clinical chemistry assay.

Cystatin C is a particle-enhanced turbidimetric immunoassay (PETIA) developed to accurately and reproducibly measure cystatin C levels in serum and plasma. Latex particles coated with anti-human cystatin C antibody agglutinate when mixed with sample containing human cystatin C. The change in absorbance due to agglutination of the reaction mixture is proportional to the quantity of human cystatin C in the sample.

**Assay standardization**

The Cystatin C assay on Alinity c system is aligned to the certified reference material ERM-DA471/IFCC.

The Cystatin C Calibrators are manufactured gravimetrically and are referenced to European Reference Material ERM-DA471/IFCC at each concentration level.

### B. Reagent

The various configurations of the Cystatin C for Alinity c Reagent Kit are described below.

| | List Number | |
| --- | --- | --- |
| | 06T3220 | 06T3230 |
| Tests per cartridge | 100 | 250 |
| Number of cartridges per kit | 2 | 2 |
| Tests per kit | 200 | 500 |
| Reagent (R1) | 20.8 mL | 46.5 mL |
| Reagent (R2) | 7.5 mL | 13.7 mL |

Administrative Documentation – 510(k) Summary

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

Volumes (mL) listed in the table above indicate the volume per cartridge.

Each Cystatin C cartridge contains 2 ready to use liquid reagents (R1 and R2).

| Active Ingredients | Concentration |
| --- | --- |
| Reagent 2: latex particles coated with rabbit IgG against human cystatin C | 0.09% |

Inactive ingredients:
Reagent 1: buffer and stabilizers. Preservative: sodium azide (&lt; 0.1%)
Reagent 2: buffer and stabilizers. Preservative: sodium azide (&lt; 0.1%)

## VI. Indications for Use/Intended Use of the Device

The Cystatin C assay is an in vitro diagnostic test used in the quantitative immunoturbidimetric determination of cystatin C in human serum and plasma on the Alinity c system.

Measurement of cystatin C aids in the diagnosis and treatment of renal diseases.

For laboratory professional use only.

## VII. Comparison of Technological Characteristics

The similarities and differences between the subject device (Cystatin C, 06T32) and the predicate device (Roche Tina-quant Cystatin C Gen.2) are presented in the table below.

| | Subject Device: Cystatin C | Predicate Device: Roche Tina-quant Cystatin C Gen.2 |
| --- | --- | --- |
| General Device Characteristic Similarities | | |
| Intended Use/Indications for Use | The Cystatin C assay is an in vitro diagnostic test used in the quantitative immunoturbidimetric determination of cystatin C in human serum and plasma on the Alinity c system. Measurement of cystatin C aids in the diagnosis and treatment of renal diseases. For laboratory professional use only. | In vitro test for the quantitative determination of cystatin C in human serum and plasma on Roche/Hitachi cobas c systems. Cystatin C measurements are used as an aid in the diagnosis and treatment of renal diseases. |
| Methodology | Immunoturbidimetric | Same |
| Principal of Operation | Particle-enhanced turbidimetric immunoassay | Same |
| Specimen Type | Human serum and plasma | Same |

Administrative Documentation – 510(k) Summary

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

| | Subject Device: Cystatin C | Predicate Device: Roche Tina-quant Cystatin C Gen.2 |
| --- | --- | --- |
| Measurement Type | Quantitative | Same |
| Tube Type | Serum, Li-heparin, Na-heparin, K2-, and K3- EDTA plasma | Serum, Li-heparin, K2-, and K3- EDTA plasma |
| Standardization | This method has been standardized against ERM-DA471/IFCC. | Same |
| General Device Differences | | |
| Measuring Interval | Analytical Measuring Interval (AMI): 0.30–10.00 mg/L
Extended Measuring Interval (EMI): 10.00–40.00 mg/L
Reportable Range (RI): 0.30–40.00 mg/L | Measuring Range: 0.40–6.80 mg/L
Extended Measuring Range: 6.80–10.20 mg/L |
| Hook Effect | No prozone effect was observed up to 40.00 mg/L. | No false result occurs up to a cystatin C concentration of 12 mg/L. |
| Lower Limits of Measurement | Limit of Blank: 0.03 mg/L
Limit of Detection: 0.05 mg/L
Limit of Quantitation: 0.30 mg/L | Limit of Blank: 0.30 mg/L
Limit of Detection: 0.40 mg/L
Limit of Quantitation: 0.40 mg/L |
| Platform | Alinity c system | Roche/Hitachi cobas c 501 |

Administrative Documentation – 510(k) Summary
Page 4 of 12

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

# VIII. Summary of Nonclinical Performance

## A. Reportable Interval

Based on representative data for the limit of quantitation (LoQ), the ranges over which results can be reported are provided below in accordance with Clinical and Laboratory Standards Institute (CLSI) EP34, 1st ed.*

| | mg/L |
| --- | --- |
| Analytical Measuring Interval (AMI)a | 0.30–10.00 |
| Extended Measuring Interval (EMI)b | 10.00–40.00 |
| Reportable Intervalc | 0.30–40.00 |

a AMI: The AMI extends from the LoQ to the upper limit of quantitation (ULoQ). This is determined by the range of values in mg/L that demonstrated acceptable performance for linearity, imprecision, and bias.
b EMI: The EMI extends from the ULoQ to the ULoQ × sample dilution.
c The reportable interval extends from the LoQ to the upper limit of the EMI.

Administrative Documentation – 510(k) Summary

Page 5 of 12

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

# B. Within-Laboratory Precision (20-Day)

A study was performed based on guidance from the CLSI document EP05-A3.* Testing was conducted using 1 lot of Cystatin C reagents, 1 lot of Cystatin C Calibrators, 1 lot of Cystatin C Controls, and 1 instrument. Two controls and 4 human serum panels were tested in a minimum of 2 replicates, twice per day on 20 days.

| Sample | n | Mean (mg/L) | Within-Run (Repeatability) | | Within-Laboratory1 | |
| --- | --- | --- | --- | --- | --- | --- |
| | | | SD | %CV | SD | %CV |
| Control Level 1 | 80 | 0.81 | 0.01 | 1.0 | 0.01 | 1.7 |
| Control Level 2 | 80 | 4.11 | 0.03 | 0.6 | 0.04 | 1.0 |
| Panel A (native) | 80 | 0.49 | 0.01 | 1.7 | 0.01 | 1.8 |
| Panel B (native) | 80 | 0.92 | 0.01 | 0.8 | 0.01 | 0.9 |
| Panel C (native) | 80 | 5.89 | 0.03 | 0.5 | 0.03 | 0.6 |
| Panel D (supplemented) | 80 | 8.95 | 0.07 | 0.8 | 0.09 | 1.0 |
<a>1</a> Within-Laboratory variability contains within-run, between-run, and between-day variance components.

Administrative Documentation – 510(k) Summary

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

# C. Reproducibility

A study was performed based on guidance from the CLSI document EP05--A3.* Testing was conducted at each of 3 testing sites using 2 lots of the Cystatin C reagents, 1 lot of the Cystatin C Calibrators, 1 lot of the Cystatin C Controls, and 1 instrument. Two controls and 3 human serum panels were tested in a minimum of 4 replicates at 2 separate times per day on 5 different days.

| Sample | n | Mean (mg/L) | Repeatability | | Within-Laboratory1 | | Between-Site | | Between-Lot | | Overall Reproducibility | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | | | SD | %CV | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| Control Level 1 | 240 | 0.81 | 0.01 | 1.5 | 0.02 | 2.0 | 0.00 | 0.3 | 0.00 | 0.0 | 0.02 | 2.0 |
| Control Level 2 | 240 | 4.08 | 0.02 | 0.6 | 0.04 | 0.9 | 0.02 | 0.5 | 0.02 | 0.4 | 0.04 | 1.1 |
| Panel 1 | 240 | 0.49 | 0.02 | 5.0 | 0.03 | 5.4 | 0.00 | 0.3 | 0.00 | 0.0 | 0.03 | 5.4 |
| Panel 2 | 240 | 0.93 | 0.01 | 1.3 | 0.01 | 1.6 | 0.00 | 0.0 | 0.00 | 0.5 | 0.02 | 1.6 |
| Panel 3 | 240 | 8.80 | 0.09 | 1.0 | 0.13 | 1.5 | 0.00 | 0.0 | 0.06 | 0.6 | 0.14 | 1.6 |
<a>1</a> Includes repeatability (within-run), between-run, and between-day variability.
<a>b</a> Includes repeatability (within-run), between-run, between-day, between-site, and between-lot variability.

Administrative Documentation – 510(k) Summary

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

# D. Accuracy

A study was performed to estimate the bias of the Cystatin C assay relative to standard reference material (ERM-DA471/IFCC). Testing was conducted using 2 lots of the Cystatin C reagents, 2 lots of the Cystatin C calibrators, and 1 instrument. The bias ranged from 1.3% to 1.8% across all reagent and calibrator lots.

# E. Linearity

A study was performed based on guidance from the CLSI document EP06, 2nd ed.* This assay is linear across the AMI of 0.30 to 10.00 mg/L.

# F. Lower Limits of Measurement

A study was performed based on guidance from the CLSI document EP17-A2.† Testing was conducted using 3 lots of the Cystatin C reagents on each of 2 instruments over a minimum of 3 days. The maximum observed limit of blank (LoB), limit of detection (LoD), and limit of quantitation (LoQ) values are summarized below.

| | mg/L |
| --- | --- |
| LoBa | 0.03 |
| LoDb | 0.05 |
| LoQc | 0.30 |

a The LoB represents the 95th percentile from n ≥ 60 replicates of zero-analyte samples.
b The LoD represents the lowest concentration at which the analyte can be detected with 95% probability based on n ≥ 60 replicates of low-analyte level samples.
c The LoQ is defined as the lowest concentration at which a total allowable error of 25% was met and was determined from n ≥ 60 replicates of low-analyte level samples.

Administrative Documentation – 510(k) Summary

Page 8 of 12

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

# G. Analytical Specificity

## 1. Potentially Interfering Endogenous Substances

A study was performed based on guidance from the CLSI document EP07, 3rd ed.* Each substance was tested at 2 levels of the analyte (approximately 0.79 and 3.95 mg/L).

No significant interference (interference within ± 0.08 mg/L for samples &lt; 0.79 mg/L) was observed at the following concentrations.

| Potentially Interfering Substance | Interferent Level |
| --- | --- |
| Bilirubin (conjugated) | 60 mg/dL |
| Bilirubin (unconjugated) | 60 mg/dL |
| Hemoglobin | 1000 mg/dL |
| Rheumatoid factor | 550 IU/mL |
| Total protein | 10.2 g/dL |
| Triglycerides | 1500 mg/dL |

No significant interference (interference within ± 10.0% for samples ≥ 0.79 mg/L) was observed at the following concentrations.

| Potentially Interfering Substance | Interferent Level |
| --- | --- |
| Bilirubin (conjugated) | 60 mg/dL |
| Bilirubin (unconjugated) | 60 mg/dL |
| Hemoglobin | 1000 mg/dL |
| Rheumatoid factor | 1200 IU/mL |
| Total protein | 11.8 g/dL |
| Triglycerides | 1500 mg/dL |

* Clinical and Laboratory Standards Institute (CLSI). Interference Testing in Clinical Chemistry. 3rd ed. CLSI Guideline EP07. Wayne, PA: CLSI; 2018.

Administrative Documentation – 510(k) Summary

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

Interference beyond ± 0.08 mg/L for samples &lt; 0.79 mg/L and beyond ± 10.0% for samples ≥ 0.79 mg/L (based on 95% Confidence Interval [CI]) was observed at the concentrations shown below for the following substances.

| Potentially Interfering Substance | Interferent Level | Analyte Level | % Interference (95% CI) |
| --- | --- | --- | --- |
| Rheumatoid factor | 1200 IU/mL | 0.79 mg/L | 0.19 (0.16, 0.22) |
| Total protein | 15 g/dL | 0.79 mg/L | 0.27 (0.26, 0.28) |
| Total protein | 15 g/dL | 3.95 mg/L | 18.5% (18.0%, 18.9%) |

## 2. Potentially Interfering Exogenous Substances

A study was performed based on guidance from the CLSI document EP07, 3rd ed.* Each substance was tested at 2 levels of the analyte (approximately 0.79 and 3.95 mg/L).

No significant interference (interference within ± 0.08 mg/L for samples &lt; 0.79 mg/L and within ± 10.0% for samples ≥ 0.79 mg/L) was observed at the following concentrations.

| Potentially Interfering Drug | Interferent Level | Potentially Interfering Drug | Interferent Level |
| --- | --- | --- | --- |
| Acetaminophen | 250 mg/L | Doxycycline | 50 mg/L |
| Acetylcysteine | 150 mg/L | Ibuprofen | 500 mg/L |
| Acetylsalicylic acid | 1000 mg/L | Levodopa | 20 mg/L |
| Ampicillin-Na | 1000 mg/L | Methyldopa | 22.5 mg/L |
| Ascorbic acid | 300 mg/L | Metronidazole | 200 mg/L |
| Biotin | 3510 ng/mL | Phenylbutazone | 400 mg/L |
| Ca-dobesilate | 200 mg/L | Rifampicin | 60 mg/L |
| Cefoxitin | 6600 mg/L | Sodium heparin | 10 U/mL |
| Cyclosporin | 5 mg/L | Theophylline (1,3-dimethylxanthine) | 100 mg/L |

* Clinical and Laboratory Standards Institute (CLSI). Interference Testing in Clinical Chemistry. 3rd ed. CLSI Guideline EP07. Wayne, PA: CLSI; 2018.

Administrative Documentation – 510(k) Summary

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

# H. Method Comparison

A study was performed based on guidance from the CLSI document EP09c, 3rd ed.* using the Passing-Bablok regression method.

| Cystatin C on Alinity c vs a Comparator Cystatin C assay | | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| | n | Units | Correlation Coefficient | Intercept | Slope | Concentration Range |
| Serum | 161 | mg/L | 1.00 | -0.07 | 1.03 | 0.60–8.20 |

# I. Matrix Comparison (Tube Type Equivalence)

A study was performed to evaluate the suitability of specific blood collection tube types for use with the Cystatin C assay. The following blood collection tube types were determined to be acceptable for use with the Cystatin C assay:

## Serum

- Serum
- Serum separator

## Plasma

- Dipotassium EDTA
- Lithium heparin
- Lithium heparin separator
- Sodium heparin
- Tripotassium EDTA

# J. High Dose Hook

There is no prozone interference for undiluted samples containing up to $40.00\mathrm{mg / L}$ of cystatin C.

Administrative Documentation – 510(k) Summary

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SENTINEL CH. SpA

Assay Name: Cystatin C

Traditional 510(k)

## K. Expected Values (Reference Interval)

A study was performed based on guidance from CLSI EP28-A3c.* Testing was conducted on apparently healthy individuals, including 105 females and 145 males, with an estimated glomerular filtration rate (eGFR) &gt; 80 (mL/min/1.73 m²). The age of the study population ranged from 18 to 69 years.

The reference range using the 2.5th and 97.5th percentile is summarized below.

| | Range (mg/L) |
| --- | --- |
| Adult | 0.59–1.28 |

## IX. Summary of Clinical Performance

This section does not apply.

## X. Conclusion

The information presented in this 510(k) premarket notification demonstrate that the performance of the subject device, Cystatin C for use with Alinity c system (List Number 06T32), is substantially equivalent to the predicate device, Tina-quant Cystatin C Gen.2 (K161817).

The minor differences between predicated device and candidate device raise no new issues of safety and effectiveness and do not impact the indications for use or technological characteristics.

Administrative Documentation – 510(k) Summary