Diazyme Human Kappa Free Light Chain Assay, Diazyme Human Lambda Free Light Chain Assay, Diazyme Human Kappa/Lamda Free Light Chain Calibrator, Diazyme Human Kappa/Lamda Free Light Chain Calibrator

{0} 1 # 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY A. 510(k) Number: K153394 B. Purpose for Submission: New device C. Measurand: Kappa (κ) free light chains Lambda (λ) free light chains D. Type of Test: Turbidimetry, quantitative E. Applicant: Diazyme Laboratories F. Proprietary and Established Names: Diazyme Human Kappa (κ) Free Light Chain Assay Diazyme Human Lambda (λ) Free Light Chain Assay Diazyme Human Kappa/Lambda FLC Calibrator Set Diazyme Human Kappa/Lambda FLC Control Set G. Regulatory Information: 1. Regulation section: 21 CFR §866.5550 – Immunoglobulin (light chain specific) immunological test system 2. Classification: Class II {1} 3. Product code: DFH, Kappa, antigen, antiserum, control DEH, Lambda, antigen, antiserum, control 4. Panel: Immunology (82) H. Intended Use: 1. Intended uses: The Diazyme Human Kappa (κ) Free Light Chain Assay is intended as a latex particle enhanced immunoturbidimetric assay for the quantitative determination of Kappa Free Light Chain (FLC) concentration in serum on Hitachi 917 analyzers. The measurement of Kappa FLC in conjunction with Lambda FLC aids in the diagnosis of multiple myeloma in conjunction with other laboratory findings. For in-vitro diagnostic use only. The Diazyme Human Lambda (λ) Free Light Chain Assay is intended as a latex particle enhanced immunoturbidimetric assay for the quantitative determination of Lambda Free Light Chain (FLC) concentration in serum on Hitachi 917 analyzers. The measurement of Kappa FLC in conjunction with Lambda FLC aids in the diagnosis of multiple myeloma in conjunction with other laboratory findings. For in-vitro diagnostic use only. Diazyme Human Kappa/Lambda FLC Calibrator (DZ169A-CAL) is intended for use in establishing the calibration curve for the Diazyme Human Kappa/Lambda Free Light Chain Assay. For in-vitro diagnostic use only. Diazyme Human Kappa/Lambda FLC Control (DZ169A-CON) is intended for use in monitoring the quality control of results obtained with the Diazyme Human Kappa/Lambda Free Light Chain Assay. For in-vitro diagnostic use only. 2. Indications for use: Same as intended use 3. Special conditions for use statement: For prescription use only. 4. Special instrument requirements: Roche Hitachi 917 Analyzer (K023009) {2} I. Device Description: The Diazyme Human Kappa (κ) Free Light Chain and Lambda (λ) Free Light Chain Assays are comprised of the following reagents: - Reagent R1 is a Tris buffer solution - Reagent 2 contains anti-human Kappa Free Light Chain Ig fraction coated on polystyrene beads - Reagent 2 contains anti-human Lambda Free Light Chain Ig fraction coated on polystyrene beads - Calibrator Set: A five-level set that is supplied in liquid form (5 x 1 mL) intended for use in establishing the calibration curve for the Diazyme Human Kappa (κ)/Lambda (λ) Free Light Chain Assays. The Calibrator levels are manufactured from human serum. The concentration of the calibrators is lot-specific and the Kappa/Lambda FLC concentrations are expressed in mg/L. - Control Set: 2 levels, serum based, liquid stable format, intended for use in monitoring the quality control of results obtained with the Diazyme Human Kappa (κ)/Lambda (λ) Free Light Chain Assays. J. Substantial Equivalence Information: 1. Predicate device names and 510(k) numbers: Freelite® Human Kappa Free Kit for use on the Hitachi 911/912/917/Modular P analyzers (K023009 and K040009) Freelite® Human Lambda Free Kit for use on the Hitachi 911/912/917/Modular P analyzers (K023009 and K023131) {3} # 2. Comparison with predicate: | Similarities | | | | --- | --- | --- | | Item | Candidate Diazyme Human Kappa (κ) /Lambda (λ) Free Light Chain Assays | Predicate Freelite® Human Kappa Free Kit for use on the Hitachi 911/912/917/Modular P (K023009, K040009) Freelite® Human Lambda Free Kit for use on the Hitachi 911/912/917/Modular P (K023131, K040009) | | Intended use | Kappa: The Diazyme Human Kappa (κ) Free Light Chain Assay is intended as a latex particle enhanced immunoturbidimetric assay for the quantitative determination of Kappa Free Light Chain (FLC) concentration in serum on Hitachi 917 analyzers. The measurement of Kappa FLC in conjunction with Lambda FLC aids in the diagnosis of multiple myeloma in conjunction with other laboratory findings. For in-vitro diagnostic use only. Lambda: The Diazyme Human Lambda (λ) Free Light Chain Assay is in-tended as a latex particle enhanced immunoturbidimetric assay for the quantitative determination of Lambda Free Light Chain (FLC) concentration in serum on Hitachi 917 analyzers. The measurement of Kappa FLC in conjunction with Lambda FLC aids in the diagnosis of multiple myeloma in conjunction with other laboratory findings. For in-vitro diagnostic use only. | Kappa: This kit is intended for the quantitation of kappa free light chains in serum and urine on the Roche Hitachi 911 and Hitachi 912. Measurement of the various amounts of the different types of light chains aids in the diagnosis and monitoring of multiple myelomas, lymphocytic neoplasms, Waldenstrom's macroglobulinemia and connective tissue diseases, such as systemic lupus erythematosus. Lambda: This kit is intended for the quantitation of lambda free light chains in serum and urine on the Roche Hitachi 911 and Hitachi 912. Measurement of the various amounts of the different types of light chains aids in the diagnosis and monitoring of multiple myelomas, lymphocytic neoplasms, Waldenstrom's macroglobulinemia and connective tissue diseases, such as systemic lupus erythematosus. | | Indication for use | Same as Intended Use | Same | | Analyte | Kappa: Kappa FLC Lambda: Lambda FLC | Same | {4} | Similarities | | | | --- | --- | --- | | Item | Candidate Diazyme Human Kappa (κ) /Lambda (λ) Free Light Chain Assays | Predicate Freelite® Human Kappa Free Kit for use on the Hitachi 911/912/917/Modular P (K023009, K040009) Freelite® Human Lambda Free Kit for use on the Hitachi 911/912/917/Modular P (K023131, K040009) | | Measurement | Quantitative | Same | | Detection Method | Turbidimetric | Same | | Open Vial Stability | Seven Weeks | Three months | | Reference Interval | Kappa: 3.3–19.4 mg/L Lambda: 5.7–26.3 mg/L | Same | | Differences | | | | Item | Candidate Diazyme Human Kappa (κ) /Lambda (λ) Free Light Chain Assays | Predicate Freelite Human Kappa Free Kit and Freelite Human Lambda Free Kit | | Instrument | Hitachi 917 | Hitachi 911/ 912/ 917/ Modular P | | Detection Antibody | Rabbit anti-Human Kappa Free light chain Ig fraction coated on polystyrene latex microparticles. | Polystyrene beads coated with monospecific antibody | | Sample type | Serum | Serum or Urine | | Kappa Measuring Range | 4.5–150 mg/L 90–3000 mg/L (extended) | 6 –180 mg/L 150–4,500 mg/L (extended) | | Lambda Measuring Range | 6.1–200 mg/L 122–4000 mg/L (extended) | 8–270 mg/L 200–6,750 mg/L (extended) | # K. Standard/Guidance Document Referenced (if applicable): Clinical and Laboratory Standards Institute CLSI EP05-A2 "Evaluation of Precision Performance of Quantitative Measurement Methods; Approved Guideline-Second Edition". Clinical and Laboratory Standards Institute CLSI EP06-A "Evaluation of the Linearity of Quantitative Measurement Procedures: A Statistical Approach; Approved Guideline". Clinical and Laboratory Standards Institute CLSI EP07-A2 "Interference Testing in Clinical {5} Chemistry, Approved Guideline - Second Edition". Clinical and Laboratory Standards Institute CLSI EP09-A2 - Method Comparison and Bias Estimation Using Patient Samples: Approved Guideline-Second Edition (2002) Clinical and Laboratory Standards Institute CLSI EP17-A “Protocols for Determination of Limits of Detection and Limits of Quantitation; Approved Guideline”. Clinical and Laboratory Standards Institute CLSI C28-A3 “Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory”. L. Test Principle: Human Kappa $(\kappa)/\text{Lambda} (\lambda)$ Free Light Chain Assays are latex enhanced immunoturbidimetric assays. Kappa FLC and Lambda FLC in the sample bind to specific anti-Kappa FLC and anti-Lambda antibodies (respectively) that are coated on latex particles and cause agglutination. The degree of the turbidity caused by agglutination can be measured optically and is proportional to the amount of Kappa FLC in the sample. The instrument calculates the Kappa FLC concentration by interpolation of obtained signal of a 6-point calibration curve prepared from calibrators of known concentrations. M. Performance Characteristics: 1. Analytical performance: a. Precision/Reproducibility: The precision of the Diazyme Kappa and Lambda FLC Assays were evaluated according to Clinical and Laboratory Standards Institute EP5-A2 guideline. Serum samples were obtained from IRB-approved commercial sources and samples with values close to normal, abnormal and very abnormal analyte levels were pooled to achieve target concentrations spanning the linear range of each FLC assay. In the study, eight levels of serum specimens were tested. These specimens included two samples within $25\%$ of the cutoff/upper limit of normal and two levels of serum based controls for Kappa FLC and Lambda FLC. Testing was performed on three Hitachi 917 instruments with two replicates per run, two runs per day and over 20 working days using one lot of the assay-specific reagents. 6 {6} Diazyme Human Kappa (κ) FLC Assay - One lot of the reagent on three analyzers | | Mean mg/L | Within-Run | Between-Run | Between-Day | Between-Instrument | Total | | --- | --- | --- | --- | --- | --- | --- | | ID | | % CV | % CV | % CV | % CV | % CV | | S1 | 9.4 | 7.6% | 4.9% | 3.5% | 5.1% | 11.0% | | S2 | 6.0 | 7.5% | 3.0% | 8.5% | N/A | 11.7% | | S3 | 15.8 | 2.9% | 1.6% | 2.1% | 0.2% | 3.9% | | S4 | 25.9 | 1.7% | 1.3% | 0.5% | 0.4% | 2.2% | | S5 | 35.30 | 2.1% | 1.5% | 1.3% | 2.0% | 3.5% | | S6 | 122.37 | 2.4% | 0.9% | 1.8% | 0.8% | 3.2% | | S7 | 139.2 | 1.5% | 1.5% | 0.7% | 1.1% | 2.5% | | S8 | 2588.6 | 1.4% | 0.6% | 2.6% | 1.5% | 3.3% | | Con1 | 16.7 | 3.2% | 2.6% | 2.4% | 0.9% | 4.9% | | Con2 | 29.1 | 2.1% | 1.2% | 2.1% | 5.9% | 6.7% | Diazyme Human Lambda (λ) FLC Assay - One lot of the reagent on three analyzers | | Mean mg/L | Within-Run | Between-Run | Between-Day | Between-Instrument | Total | | --- | --- | --- | --- | --- | --- | --- | | ID | | % CV | % CV | % CV | % CV | % CV | | S1 | 8.31 | 6.5% | 0.4% | 3.1% | 0.8% | 7.3% | | S2 | 11.89 | 6.3% | 4.5% | 6.1% | N/A | 9.9% | | S3 | 22.27 | 3.0% | 1.4% | 2.6% | 1.1% | 4.3% | | S4 | 35.09 | 2.1% | 1.2% | 1.4% | 1.0% | 2.9% | | S5 | 48.65 | 2.1% | 0.7% | 1.3% | 0.8% | 2.7% | | S6 | 144.55 | 1.6% | 1.0% | 1.3% | 0.6% | 2.4% | | S7 | 181.13 | 0.8% | 0.7% | 1.3% | 1.1% | 2.0% | | S8 | 3472.59 | 3.6% | N/A | 2.1% | 0.6% | 4.2% | | Con1 | 27.62 | 3.9% | N/A | 0.9% | 0.1% | 4.0% | | Con2 | 62.58 | 1.3% | 0.7% | N/A | 2.9% | 3.2% | The lot-to-lot reproducibility of the Diazyme Kappa and Lambda FLC Assay was evaluated according to CLSI guideline EP5-A2. The serum samples with values close to normal, abnormal and very abnormal antigen levels were pooled to achieve the target concentrations spanning the linear range of each FLC assay. In the study, eight levels of serum specimens were tested. These specimens included two samples within 25% of the cutoff/upper limit of normal and two levels of serum based controls for Kappa FLC and Lambda FLC. Testing was performed on three Hitachi 917 instruments with two replicates per run, two runs per day and over 20 working days using one lot of the assay-specific reagents {7} Diazyme Human Kappa (κ) FLC Assay - Three lots of the reagents on one analyzer | | Mean mg/L | Within-Run | Between-Run | Between-Day | Between-Lots | Total | | --- | --- | --- | --- | --- | --- | --- | | ID | | % CV | % CV | % CV | % CV | % CV | | S1 | 5.8 | 6.3% | 2.6% | 2.7% | 0.7% | 7.4% | | S2 | 9.5 | 7.9% | 5.7% | 5.7% | 2.6% | 11.6% | | S3 | 15.4 | 2.4% | 0.9% | 0.6% | 2.2% | 3.5% | | S4 | 25.7 | 1.1% | 0.3% | 0.6% | 1.0% | 1.7% | | S5 | 35.1 | 2.9% | 0.8% | 1.5% | 0.8% | 3.5% | | S6 | 121.5 | 2.6% | 1.5% | 2.3% | N/A | 3.8% | | S7 | 138.2 | 1.1% | N/A | 1.0% | 1.0% | 1.8% | | S8 | 2588.5 | 1.3% | 1.0% | 2.5% | 1.5% | 3.3% | | Con1 | 16.6 | 4.2% | 1.4% | 3.0% | 1.6% | 5.6% | | Con2 | 27.8 | 3.2% | N/A | 2.7% | 1.8% | 4.6% | Diazyme Human Lambda (λ) FLC Assay - Three lots of the reagents on one analyzer | | Mean mg/L | Within-Run | Between-Run | Between-Day | Between-Lots | Total | | --- | --- | --- | --- | --- | --- | --- | | ID | | % CV | % CV | % CV | % CV | % CV | | S1 | 8.16 | 6.3% | 2.3% | N/A | 3.1% | 7.4% | | S2 | 11.78 | 5.9% | 4.0% | 7.4% | 4.9% | 11.4% | | S3 | 21.90 | 2.9% | 1.3% | N/A | 0.6% | 3.2% | | S4 | 34.79 | 2.0% | 0.4% | 0.3% | N/A | 2.1% | | S5 | 48.95 | 1.3% | N/A | 1.7% | 0.3% | 2.2% | | S6 | 142.63 | 1.1% | 0.8% | 0.5% | 0.8% | 1.6% | | S7 | 183.02 | 0.6% | 0.3% | 0.8% | 0.3% | 1.1% | | S8 | 3442.60 | 3.2% | N/A | 2.0% | N/A | 3.8% | | Con1 | 28.13 | 4.5% | N/A | 0.2% | 3.8% | 5.9% | | Con2 | 65.31 | 1.9% | 0.6% | N/A | 1.2% | 2.3% | All results met the manufacturer's predetermined acceptance criteria. b. Linearity/assay measuring range: A linearity study was performed with three lots of reagents. The linearity set was created by spiking pooled serum samples with Kappa or Lambda FLC Bence Jones proteins to a final concentration of $\sim 160\mathrm{mg / L}$ for Kappa FLC and $\sim 210\mathrm{mg / L}$ for Lambda FLC and creating a series of 10 concentrations down to $15\mathrm{mg / L}$ Kappa FLC and $20\mathrm{mg / L}$ Lambda FLC by diluting with saline. Samples were run in triplicate. Linearity for Diazyme Human Kappa (κ) FLC Assay The linearity of the Assay was evaluated utilizing three sera, according to CLSI EP6- {8} A guideline. The Assay is linear up to $150\mathrm{mg / L}$ . Based on the linearity data and limit of quantitation $(\mathrm{LOQ} = 4.5\mathrm{mg / L})$ , the AMR is claimed to be $4.5 - 150\mathrm{mg / L}$ . The regression statistics are presented in the following table: | | Slope | Slope 95% CI | Intercept | Intercept 95% CI | R² | | --- | --- | --- | --- | --- | --- | | Sample 1 | 0.978 | 0.973–0.983 | 0.000 | -0.009–0.008 | 0.999 | | Sample 2 | 1.014 | 1.002–1.025 | -1.666 | -2.760– -0.552 | 0.999 | | Sample 3 | 0.990 | 0.980–1.000 | 0.000 | -0.011–0.011 | 0.999 | Linearity for Diazyme Human Lambda (λ) FLC Assay The linearity of the Assay was evaluated according to CLSI EP6-A guideline. The Assay is linear up to $200\mathrm{mg / L}$ . Based on the linearity data and limit of quantitation $(\mathrm{LOQ} = 6.10\mathrm{mg / L})$ , the AMR is claimed to be $6.1 - 200\mathrm{mg / L}$ . The regression statistics are presented in the following table: | | Slope | Slope 95% CI | Intercept | Intercept 95% CI | R² | | --- | --- | --- | --- | --- | --- | | Sample 1 | 1.014 | 1.005–1.024 | -0.001 | -0.032–0.029 | 0.999 | | Sample 2 | 0.972 | 0.961–0.982 | -0.112 | -0.472–0.247 | 0.999 | | Sample 3 | 0.991 | 0.982–0.999 | -0.001 | -0.025–0.023 | 0.999 | Extended range linearity studies were performed on the Hitachi 917 in extended range mode with one lot of reagents. Extended range mode on the Hitachi 917 automatically dilutes the sample on board with a 1:20 sample dilution and calculates the extended range value. The linearity set was created as follows: a pooled serum sample was spiked with Kappa or Lambda FLC Bence Jones proteins to a final concentration of $3,000\mathrm{mg / L}$ for Kappa and $4,000\mathrm{mg / L}$ for Lambda FLC. The results of the study on the Hitachi 917 analyzer demonstrated linearity up to $3,000\mathrm{mg / L}$ for Kappa and $4,000\mathrm{mg / L}$ for Lambda FLC in extended range mode. | Kit | Assay reportable range Standard Dilution | Assay reportable range Extended Range | | --- | --- | --- | | Kappa FLC | 4.5–150 mg/L | 4.5–3000 mg/L | | Lambda FLC | 6.1–200 mg/L | 6.1–4000 mg/L | The regression statistics are presented in the following table: | | Slope | Slope 95% CI | Intercept | Intercept 95% CI | R² | | --- | --- | --- | --- | --- | --- | | Kappa FLC | 0.991 | 0.982–0.999 | -0.001 | -0.025–0.023 | 0.999 | | Lambda FLC | 1.003 | 0.998–1.009 | 0.000 | -0.010–0.010 | 0.999 | # Antigen Excess: When samples containing analyte concentrations greater than the upper limit of the measuring range in standard mode are diluted and re-tested in extended mode, a hook effect was not seen up to concentrations of $105,939\mathrm{mg / L}$ Kappa FLC or 109,532 {9} mg/L Lambda FLC. c. Traceability, Stability, Expected values (controls, calibrators, or methods): Traceability: There is no international reference standard for FLC. The calibrators for the Diazyme Kappa and Lambda FLC Assay are traceable to an internally assigned master calibrator. Kit Stability: Reagent Real-time stability: The manufacturer has claimed stability up to 12 months when kept at $2 - 8^{\circ}\mathrm{C}$ . Data provided demonstrated that the real time stability at $2 - 8^{\circ}\mathrm{C}$ is for 14 months for three lots of Kappa FLC and 13 months for three lots of Lambda FLC. Reagent On-board stability: On board, real-time reagent stability for Kappa and Lambda FLC on Hitachi 917 is seven weeks. Control stability: The opened calibrators are stable for four weeks when stored at $2-8^{\circ}\mathrm{C}$ and capped tightly to minimize exposure to air and evaporation. Calibrator Stability: The opened calibrators are stable for at least four weeks when stored at $2 - 8^{\circ}\mathrm{C}$ and capped tightly to minimize exposure to air and evaporation. d. Detection limit: Detection limit for Diazyme Human Kappa $(\kappa)$ and Lambda $(\lambda)$ FLC Assays The LoB, LoD, LoQ of the Assays were determined according to CLSI guideline EP17-A2 and listed in the table below. | Detection Limits (mg/L) | LoB | LoD | LoQ | | --- | --- | --- | --- | | Kappa FLC | 1.2 | 2.0 | 4.5 | | Lambda FLC | 1.7 | 2.9 | 6.1 | e. Analytical specificity: To determine the level of interference from substances that may be present in serum, the Diazyme Human Kappa $(\kappa)$ and Lambda $(\lambda)$ assays were used to test three serum pools that contained low, medium and high Kappa/Lambda concentrations (approximately 10, 60 and $120~\mathrm{mg / L}$ ) spiked with various amounts of substances following CLSI guideline EP07-A2. Each serum sample spiked with interference substances was tested in triplicate on the {10} Hitachi 917. The following substances were tested and shown not to interfere at levels equal to the concentrations listed below. | Category | Interferent | Diazyme Human Kappa FLC | Diazyme Human Lambda FLC | | --- | --- | --- | --- | | | | Concentration tested | Concentration tested | | Interferent | Bilirubin | 40 mg/dL | 40 mg/dL | | | Conjugated Bilirubin | 40 mg/dL | 40 mg/dL | | | Hemoglobin | 1000 mg/dL | 1000 mg/dL | | | Triglyceride | 1000 mg/dL | 1000 mg/dL | | | Rheumatoid Factor | 100 IU/mL | 100 IU/mL | | | Ascorbic Acid | 10 mM | 10 mM | All results met the manufacturer's predetermined acceptance criteria. f. Assay cut-off: See expected values/reference range. 2. Comparison studies: a. Method comparison with predicate device: The Diazyme Human Kappa (k) and Lambda $(\lambda)$ FLC assays were evaluated and compared to the results obtained with the predicate device following CLSI guideline EP09-A2. A total of 126 serum samples ranging from $4.63 - 2975.80~\mathrm{mg / L}$ were tested in comparison with predicate assay. Among the 126 samples, 39 were Multiple Myeloma (MM), 12 were Monoclonal Gammopathy of Undetermined Significance (MGUS), 34 were Abnormal (due to other disease states) and 41 were Normal (no disease). The results are summarized in the following table: | Kit | N | Sample Range (mg/L) | Slope (Deming) | 95% CI (Slope) | Y-Intercept (Deming) | 95% CI (Y-Intercept) | R² | | --- | --- | --- | --- | --- | --- | --- | --- | | Kappa FLC | 126 | 4.6–2,976 | 0.969 | 0.943–0.966 | -4.8 | -17.014–7.388 | 0.977 | | Lambda FLC | 126 | 6.9–3,918 | 1.07 | 1.038–1.102 | -3.16 | -24.63–18.31 | 0.977 | All results met the manufacturer's predetermined acceptance criteria. {11} b. Matrix comparison: Not applicable 3. Clinical studies: a. Clinical Sensitivity: Not applicable. b. Clinical specificity: Not applicable. c. Other clinical supportive data: Not applicable. 4. Clinical cut-off: Not applicable. 5. Expected values/Reference range: To establish the reference interval for the Diazyme Kappa and Lambda FLC assays, serum samples from 120 apparently healthy individuals (60 females and 60 males) with age ranges from 18–70 were tested with one replicate per sample on the Hitachi 917 with the Diazyme Kappa and Lambda FLC assays according to CLSI guideline C28-A3. The central 95% reference interval was established to be from 2.37 mg/L to 20.73 mg/L for Kappa FLC and from 4.23 mg/L to 27.69 mg/L for Lambda FLC. The manufacturer recommends that each user of the kit should establish a range of normal values for the population in their region. N. Proposed Labeling: The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10. O. Conclusion: The submitted information in this premarket notification is complete and supports a substantial equivalence decision. 12