← Product Code [MOB](/submissions/IM/subpart-f%E2%80%94immunological-test-systems/MOB) · K041040 # VARELISA MPO ANCA, MODEL 17648/17696 (K041040) _Sweden Diagnostics (Germany) GmbH · MOB · Jun 16, 2004 · Immunology · SESE_ **Canonical URL:** https://fda.innolitics.com/submissions/IM/subpart-f%E2%80%94immunological-test-systems/MOB/K041040 ## Device Facts - **Applicant:** Sweden Diagnostics (Germany) GmbH - **Product Code:** [MOB](/submissions/IM/subpart-f%E2%80%94immunological-test-systems/MOB.md) - **Decision Date:** Jun 16, 2004 - **Decision:** SESE - **Submission Type:** Traditional - **Regulation:** 21 CFR 866.5660 - **Device Class:** Class 2 - **Review Panel:** Immunology ## Indications for Use The Varelisa MPO ANCA EIA kit is designed for the semi-quantitative and qualitative determination of myeloperoxidase anti-neutrophil cytoplasmic antibodies (MPO ANCA) in human serum or plasma to aid in the diagnosis of certain autoimmune vasculitides such as microscopic polyangiitis, and crescentic glomerulonephritis. ## Device Story Varelisa MPO ANCA is an indirect noncompetitive enzyme immunoassay (EIA) for detecting MPO ANCA antibodies in human serum or plasma. The device uses microplate strips coated with human purified MPO antigen. Patient samples are added; MPO-specific antibodies bind to the antigen. An enzyme-labeled conjugate is added, binding to the antigen-antibody complex. A substrate is introduced, which the enzyme converts into a colored solution. The rate of color formation is proportional to the concentration of MPO ANCA in the sample. The assay is performed in a laboratory setting by trained personnel. Results are interpreted by healthcare providers to aid in the diagnosis of autoimmune vasculitides. The device provides a semi-quantitative and qualitative assessment, helping clinicians identify patients with specific autoimmune conditions. ## Clinical Evidence Clinical comparability supported by a data set including a comparison study of positive, equivocal, and negative sera, analysis of externally defined calibrators, clinically defined sera, and samples from healthy subjects. Data indicate the assay performs according to state-of-the-art expectations and medical literature. ## Technological Characteristics Indirect noncompetitive enzyme immunoassay (EIA). Components: microplate strips coated with human purified MPO antigen, calibrators, positive/negative controls, enzyme-labeled conjugate, substrate, stop solution, sample diluent, wash buffer. Analyte: MPO ANCA. Sample types: human serum or plasma. ## Regulatory Identification A multiple autoantibodies immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the autoantibodies (antibodies produced against the body's own tissues) in serum and other body fluids. Measurement of multiple autoantibodies aids in the diagnosis of autoimmune disorders (disease produced when the body's own tissues are injured by autoantibodies). ## Predicate Devices - INOVA Quanta Lite MPO (k955022) ## Submission Summary (Full Text) > This content was OCRed from public FDA records by [Innolitics](https://innolitics.com). If you use, quote, summarize, crawl, or train on this content, cite Innolitics at https://innolitics.com. > > Innolitics is a medical-device software consultancy. We help companies design, build, and clear FDA-regulated software and AI/ML devices, including [a 510(k)](https://innolitics.com/services/510ks/), [a De Novo](https://innolitics.com/services/regulatory/), [a SaMD](https://innolitics.com/services/end-to-end-samd/), [an AI/ML medical device](https://innolitics.com/services/medical-imaging-ai-development/), or [an FDA regulatory strategy](https://innolitics.com/services/regulatory/). {0} 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY DEVICE ONLY TEMPLATE A. 510(k) Number: k041040 B. Purpose for Submission: New device C. Analyte: Anti-neutrophil cytoplasmic antibody (ANCA) D. Type of Test: Semi-quantitative and qualitative ELISA E. Applicant: Sweden Diagnostics (Germany) GmbH F. Proprietary and Established Names: Varelisa® MPO ANCA G. Regulatory Information 1. Regulation section: 21 CFR § 866.5660, Multiple Autoantibodies Immunological Test System 2. Classification: Class II 3. Product Code: MOB, Anti-neutrophil cytoplasmic antibody (ANCA) 4. Panel: Immunology (82) H. Intended Use: 1. Intended use(s): The Varelisa MPO ANCA EIA kit is designed for the semi-quantitative and qualitative determination of myeloperoxidase anti-neutrophil cytoplasmic antibodies (MPO ANCA) in human serum or plasma to aid in the diagnosis of certain autoimmune vasculitides such as microscopic polyangiitis, and crescentic glomerulonephritis. 2. Indication(s) for use: This is used as an aid in the diagnosis of certain autoimmune vasculitides such as microscopic polyangiitis, and crescentic glomerulonephritis. {1} Page 2 of 7 3. Special condition for use statement(s): The device is for prescription use only. 4. Special instrument Requirements: A microplate reader capable of measuring OD at 450 nm is required. I. Device Description: The device is an enzyme-linked immunosorbent assay (ELISA) using microtiter plates as the solid phase. The plate wells are coated with MPO antigens, which allow anti-MPO antibodies to react with the immobilized antigen (sample). The conjugate is rabbit anti-human IgG horseradish peroxidase (HRP), which uses 3, 3'5, 5' tetramethylbenzidine dihydrochloride (TMB) as substrate. The kit contains a set of six calibrators, low positive, high positive and negative controls. The kit also contains sample diluent, wash buffer concentrate and stop solution. J. Substantial Equivalence Information: 1. Predicate device name(s): INOVA Quanta Lite MPO 2. Predicate K number(s): k955022 3. Comparison with predicate: | Similarities | | | | --- | --- | --- | | Item | Device | Predicate | | | Varelisa® MPO ANCA | Quanta Lite™ MPO | | Intended Use | To aid in the diagnosis of certain autoimmune vasculitides such as microscopic polyangiitis and crescentic glomerulonephritis | To aid in the assessment of certain autoimmune vasculitides such as microscopic polyarteritis and crescentic glomerulonephritis | | Antigen | Human purified MPO antigen | Same | | Conjugate | HRP conjugated anti-human IgG antibody | Same | | Assay principle | Indirect noncompetitive enzyme immunoassay | Same | | Sample dilution | 1:101 | Same | | Differences | | | | Item | Device | Predicate | | Specimen requirements | Serum and plasma | Serum specimen | | Calibrators | Set of six prediluted calibrators | None | | Controls | Low positive, high positive and negative controls | Prediluted low positive and high positive controls | {2} Page 3 of 7 | Result interpretation | Semiquantitative <6 U/mL = negative 6-9 U/mL = equivocal >9 U/mL = positive | Semiquantitative <20 U/mL = negative 21-30 U/mL = weak positive >30 U/mL = positive | | --- | --- | --- | | | Qualitative Ratio <1.0 = negative Ratio 1.0-1.4 = Equivocal Ratio >1.4 = Positive | | ## K. Standard/Guidance Document Referenced (if applicable): None referenced ## L. Test Principle: The assay is an indirect noncompetitive enzyme immunoassay. The wells of a microtiter plate are coated with human purified MPO antigen. Antibodies specific for MPO present in the patient samples bind to the antigen. In a second step, the enzyme labeled second antibody (conjugate) binds to the antigen-antibody complex which leads to the formation of an enzyme labeled conjugate-antibody-antigen complex. The enzyme labeled antigen-antibody complex converts the added substrate to form a colored solution. The rate of color formation from the chromogen is a function of the amount of conjugate complexed with the bound antibody and thus is proportional to the initial concentration of antibodies in the patient sample. ## M. Performance Characteristics (if/when applicable) ### 1. Analytical performance: #### a. Precision/Reproducibility: The purpose of the precision study was to investigate variation within and between runs. The samples (low, medium and high) were used in a standard 1:101 dilution except sample QC6 which was diluted 1:117. These diluted samples were analyzed in 5 runs with 16 replicates per run. Calibrators and controls were analyzed in duplicate. One operator carried out the analyses within one day. The following target values were set: Variance within <10% Variance between <15% The specifications were met and results are summarized below: | Sample ID | Mean U/mL | Within-Run %CV | Between-Run %CV | | --- | --- | --- | --- | | QC2 | 9.8 | 9.5 | 6.5 | | QC3 | 25.1 | 6.6 | 10.7 | | QC6 | 77.4 | 4.8 | 3.5 | Reproducibility study was expanded using two additional samples around the cut-off (1 negative and 1 equivocal sample). For {3} Page 4 of 7 equivocal or positive samples, the percents within and between variance were <10% and <15% respectively and the negative samples should not become positive. The data showed that the between and within assay variations were within stated specifications and the values for negative samples did not change into positive. | Sample | Run 1 | Run 2 | Run 3 | Run 4 | Run 5 | Mean U/mL | Variance Within %CV | Variance Between %CV | | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Negative | 5.5 | 6.3 | 6.2 | 5.9 | 5.8 | 5.9 | 15.7 | 3.9 | | Equivocal | 7.2 | 7.8 | 7.8 | 7.5 | 7.3 | 7.5 | 8.3 | 3.2 | b. Linearity/assay reportable range **Dilution Linearity** The reportable range of 1-100 U/mL was demonstrated by performing dilution study over the whole measuring range. Beginning with a standard dilution of 1:101, the samples were further diluted 2:3, 1:2, 1:4, 1:8, 1; 16, and 1:32 using sample diluent. Calibrator, controls and each dilution step were analyzed in triplicates. Specifications set for the study were the percents of observed/expected (O/E %) should be within ±20% for at least 3 successive dilution steps of each tested sample. Measured values ranged from 2.8 to 95.7 U/mL. Percent recovery for all six samples through the 1:32 dilution met the specifications. **Recovery** The purpose of this study was to demonstrate that the assay can detect known amounts of MPO specific IgG antibodies spiked into a sample. Two samples were diluted 1:101 and 1:201 respectively. Then the samples were spiked with 1/10 volume of calibrators S1-S6. The spiked samples, calibrators and controls were analyzed in duplicate. The Δ recovery (%) of (observed value/expected value) for the samples should be within ±20%. Recovery values ranged from 94.8% to 101.1% demonstrating that the assay detects added amounts of antigen specific IgG antibodies. c. Traceability (controls, calibrators, or method): An international reference material for anti-MPO antibodies is not available. The assay is calibrated in relative arbitrary units (U/mL). d. Detection limit: The purpose of the analytical sensitivity was to verify the detection limit of the assay and to prove the ability of the assay to differentiate between the background and the first calibrator point. The sample diluent was diluted 1:101 and measured 56 times on one plate. Calibrators and controls were analyzed in four replicates. The value {4} for the analytical sensitivity expressed in $\mathrm{U / mL}$ was calculated as the mean of the optical densities (OD) of the sample diluent plus 3 SD. The mean OD plus 3 SD of the sample diluent should be lower than the mean OD of calibrator S2. The detection limit of the device is $1.0\mathrm{U / mL}$ # e. Analytical specificity: # Interference: Interference study was performed by spiking three samples with different amounts of potentially interfering substances including, bilirubin (F and C), hemoglobin, chyle and rheumatoid factor or their respective blank solutions and analyzed in triplicates. Calibrators and controls were also analyzed in triplicate. The deviation of the value of the sample spiked with the interfering substance should be less than $\pm 20\%$ of the value of the sample spiked with a buffer blank. The spiking of high concentrations of Bilirubin C, Bilirubin F, Chyle, Hemoglobin and Rheumatoid Factor showed no significant effect on the test results. # Cross Reactivity: Quanta Check ANCA Panel from INOVA was used in this study. | Serum | Varelisa result (U/mL) | Target (according to INOVA) | Reactivity against MPO (Results according to INOVA) | | --- | --- | --- | --- | | Inova A | 5.7 | cANCA | negative | | Inova B | 0.2 | PR-3 | negative | | Inova C | 64.3 | pANCA | positive | | Inova D | >100 | MPO | positive | | Inova E | 6.7 | pANCA & aANCA* | negative | | Inova F | 0.5 | aANCA* | negative | | Inova G | 0.4 | ANA | negative | | Inova H | 0.4 | negative | negative | * Atypic ANCA, not positive for MPO or PR-3 The test results showed no crossreactivity to PR-3 or ANA antibodies. # f. Assay cut-off: A study was performed to confirm the defined cut-off by measuring 432 apparently healthy blood donor samples, equally distributed by gender and age. Specifications for the study were: $95\%$ of the normal population should be negative and the $95^{\text{th}}$ percentile should lie below the lower limit of the equivocal range. The cut-offs were set as <6 U/mL negative 6-9 U/mL equivocal >6 U/mL positive The $95^{\text{th}}$ percentile was $3.4 \, \text{U/mL}$ and thus below the negative cutoff so, the specifications were met. The results were independent of gender and age. {5} Page 6 of 7 2. Comparison studies: a. Method comparison with predicate device: The comparison was made by testing 270 clinically defined sera. (15 Churg-Strauss Syndrome, 50 microscopic polyangiitis, 20 non-ANCA associated vasculitides, 16 necrotizing crescentic glomerulonephritis, 40 rheumatoid arthritis, 102 Wegener's granulomatosis, 10 Morbus Crohn, 10 ulcerative colitis, 7 other diseases). Analyses and calculations were performed according to assay procedures. Correlations and Six Field Analysis were performed. | Varelisa MPO ANCA | N = 270 | INOVA QUANTA Lite | | | --- | --- | --- | --- | | | | Positive | Negative | | | positive | 34 | 13** | | | Equivocal | 1*** | 19*** | | | negative | 1* | 202 | *1 patient with microscopic polyangiitis (MPA) **12 ANCA associated vasculitides (AAV) and 1 disease control ***1 disease control ***19 AAV The equivocal results of the Varelisa™ MPO ANCA were regarded as negative in calculation of percent agreements. Positive agreement = 94.4% (95% CI 81.3% to 99.3%) Negative Agreement = 94.4% (95% CI: 90.7% to 97.0%) Total Agreement = 94.4% (95% CI 91.7% to 97.1%) b. Matrix comparison: The predicate device uses serum only. The new device recommends use of both serum and plasma. A study was performed to demonstrate that the new assay gives the same results for serum, heparin plasma, citrate plasma, and EDTA plasma collected from the same specimen. Ten MPO-antibody negative samples and 10 MPO-antibody positive samples, each available as serum, heparin plasma, citrate plasma and EDTA plasma variant were assayed. The 10 MPO-antibody negative samples were run in duplicate together with calibrators and controls. Then they were spiked with the 10 different MPO-antibody positive sera. All spiked samples were run in duplicate together with calibrators and controls. Specifications for this study were the percent deviation between serum and plasma results for positive samples should not be higher than ±20% and negative samples should be negative as serum or plasma. The data showed no difference greater than ±20% (deviations ranged from –16.4% to 13.6% for citrate, heparin or EDTA plasma and no negative sample changed from negative to positive). Thus the specifications were met. {6} Page 7 of 7 3. Clinical studies: a. Clinical sensitivity: Not provided b. Clinical specificity: Not provided c. Other clinical supportive data (when a and b are not applicable): Not applicable. 4. Clinical cut-off: See assay cut-off 5. Expected values/Reference range: The expected value in the normal population is negative. N. Conclusion: The submitted material in this premarket notification is complete and supports a substantial equivalence decision. --- **Source:** [https://fda.innolitics.com/submissions/IM/subpart-f%E2%80%94immunological-test-systems/MOB/K041040](https://fda.innolitics.com/submissions/IM/subpart-f%E2%80%94immunological-test-systems/MOB/K041040) **Published by [Innolitics](https://innolitics.com)** — a medical-device software consultancy. We help companies design, build, and clear FDA-regulated software and AI/ML devices. 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