WIESLAB CAP MPO-ANCA

{0} 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY A. 510(k) Number: k051455 B. Purpose for Submission: New Device C. Measurand: Anti- MPO antibodies D. Type of Test: Qualitative and Semi-quantitative ELISA E. Applicant: Eurodiagnostica F. Proprietary and Established Names: Wieslab™ Cap MPO ANCA G. Regulatory Information: 1. Regulation section: 21 CFR 866.5660, Multiple autoantibodies immunological test system 2. Classification: II 3. Product codes: MOB, Test system, antineutrophil cytoplasmic antibodies (ANCA) 4. Panel: Immunology 82 H. Intended Use: 1. Intended use(s): The Wieslab™ Cap MPO ANCA test kit is an enzyme-linked immunosorbent assay (ELISA) for detection and semi-quantitation of IgG antibodies to myeloperoxidase (MPO) in human serum. The assay is used to detect antibodies in a single serum specimen. The results of the assay are to be used as an aid to the diagnosis of Microscopic polyangiitis. The analysis should be performed by trained laboratory professionals. For In Vitro Diagnostic Use. 2. Indication(s) for use: The Wieslab™ Cap MPO ANCA test kit is an enzyme-linked immunosorbent assay (ELISA) for detection and semi-quantitation of IgG antibodies to myeloperoxidase (MPO) in human serum. The assay is used to detect antibodies in a single serum specimen. The results of the assay are to be used as an aid to the diagnosis of Microscopic polyangiitis. The assay is intended for use in patients with signs and symptoms consistent with MP. It is not intended for screening a healthy population. The analysis should be performed by trained laboratory professionals. 3. Special conditions for use statement(s): The device is for prescription use only. 4. Special instrument requirements: Microplate reader capable of measuring OD at 405 nm. 1 {1} Microplate washer (300μL volume). I. Device Description: Each device contains the following: microplate strips (green colored) coated with monoclonal anti-myeloperoxidase/myeloperoxidase antigen; five levels calibrators (10, 40, 80, 160, 320 U/mL); positive and negative controls (human serum in diluent); wash solution concentrate; sample diluent; goat anti-human IgG alkaline phosphatase conjugate; p-Nitro phenyl Phosphate (pNPP) substrate. J. Substantial Equivalence Information: 1. Predicate device name(s): Wieslisa® MPO ANCA Kit 2. Predicate 510(k) number(s): k974166 3. Comparison with predicate: | Similarities | | | | --- | --- | --- | | Item | New Device | Predicate Device | | Intended use | To aid in the diagnosis of Microscopic polyangiitis (MP) | Same | | Assay Format | Qualitative and semi-quantitative | Same | | Enzyme-Conjugate | Alkaline Phosphatase | Same | | Positive and Negative controls | Ready to use | Same | | Calibrators: Five Levels | Ready to use | Same | | Sample volume required | 5 μL | Same | | Sample type and dilution | Serum at 1:80 | Same | | Sample diluent | PBS | Same | | Wash solution | 30x Concentrate | Same | | Substrate | pNPP | Same | | Incubation times | 30-30-60 minutes | Same | | OD reading | 405 nm | Same | | Platform | 96 well microtiter plates | Same | | Differences | | | | --- | --- | --- | | Item | Device | Predicate | | Technology | Capture ELISA | Direct ELISA | | Antigen | Purified anti-MPO monoclonal antibody and MPO capture complex | Purified MPO | | OD measurement | Within ± 5 minutes | None specified | | Anti-MPO Antibody Results Interpretation | Negative: < 16 U/mL Equivocal: 16-20 U/mL Positive: > 20 U/mL | Negative: < 21 Units Equivocal: 21-25 Units Positive: > 25 Units | K. Standard/Guidance Document Referenced (if applicable): None provided. L. Test Principle: {2} The Wieslab™ Cap MPO ANCA test kit is an enzyme-linked immunosorbent assay (ELISA) for detection and semi-quantitation of IgG antibodies to myeloperoxidase (MPO) in human serum. The wells of the microtiter plate strips are coated with a capture complex of monoclonal antibody to myeloperoxidase and purified MPO antigen. Antibodies specific to MPO in diluted serum bind to the capture antigen during the first incubation. The wells are then washed to remove unbound antibodies. An enzyme labeled anti-human IgG conjugate is added to bind the capture antigen- antibody complex in the well during the second incubation step. After a further washing step, detection of the specific antibodies is obtained by incubation with substrate solution. The amount of bound antibodies correlated to the color intensity and is measured in terms of absorbance (optical density, OD). The absorbance is then calculated against the calibrator curve and the results are given in arbitrary Units/mL. ## M. Performance Characteristics (if/when applicable): ### 1. Analytical performance: a. **Precision/Reproducibility:** The intra-assay reproducibility was determined by testing one sample 36 times and six samples 24 times. Four samples with high anti-MPO concentrations (89-125 U/mL) had a CV of 2.6-8.0% and three samples close to the assay cut-off (29-44 U/mL) had a CV of 11-15%. The inter-assay reproducibility was determined by testing seven samples in duplicate for four times. Four samples with high anti-MPO concentrations (51-89 U/mL) had a CV of 4-15%. Three samples close to the assay cut-off (18-35 U/mL) had a CV of 5-15%. b. **Linearity/assay reportable range:** Three positive sera were diluted serially from neat, 1:2, 1:4, 1:8, 1:16 and 1:32 dilutions. The values were compared to log 2 of dilution by standard regression. The values indicate that the assay has a linear relationship with serum dilutions. The assay reportable range is from 10-320 U/mL. c. **Traceability, Stability, Expected values (controls, calibrators, or methods):** There is no reference standard for anti-MPO. The calibrators and controls (positive and negative) are prepared in-house and arbitrary units are assigned during the development process. d. **Detection limit:** Not applicable. e. **Analytical specificity:** **Interference** by endogenous substances: No data provided. The package insert states to avoid sera which are icteric, lipemic, and hemolyzed; and heat-inactivated sera should not be used. **Crossreactivity with heterophile antibodies:** Since one of the capture antigen component is a monoclonal antibody, some in-house interference studies (~12000 samples) were performed. The effect was determined to be very low (0.025%). The package insert states that ‘individuals receiving mouse anti-human antibodies for treatment or diagnosis, or those patients who have otherwise exposed to mouse immunoglobulin, may produce Human Anti-Mouse Antibodies (HAMA). These antibodies can interfere with assays using mouse monoclonal antibodies and may cause falsely elevated levels’. {3} f. Assay cut-off: The cut-off value of $&gt;20\mathrm{U / mL}$ was based on testing 120 normal blood donor sera, and 61 non-vasculitis disease samples (17 rheumatoid arthritis (RA) samples; 29 systemic lupus erythematosus (SLE); 8 Ulcerative colitis; 3 Celiac disease; and 4 Crohn's disease). All of the normal donors and non-vasculitis disease samples were negative. 2. Comparison studies: a. Method comparison with predicate device: Testing was performed on 102 samples. The positive percent agreement was $97.0\%$ (32/33); the negative percent agreement was $97.0\%$ (64/66) and the Overall Agreement was $97.0\%$ (96/99). | | Wieslisa MPO-ANCA ELISA Kit | | | | | | --- | --- | --- | --- | --- | --- | | | | Positive | Equivocal* | Negative | Total | | WiesLab™ Cap MPO-ANCA | Positive | 32 | 0 | 2 | 34 | | | Equivocal | 0 | 0 | (3)* | (3)* | | | Negative | 1 | 0 | 64 | 65 | | | Total | 33 | 0 | 66 | 99 | *Equivocal results were excluded in the calculation. b. Matrix comparison: Not applicable. 3. Clinical studies: a. Clinical sensitivity and specificity: The clinical sensitivity and specificity study were evaluated on 337 clinically characterized sera from patients with the following diagnosis: 53 Microscopic polyangiitis (MP); 52 WG (Wegener's granulomatosis); 29 SLE; 17 RA; 51 Glomerular basement membrane (GBM); 8 Ulcerative colitis; 3 Celiac disease; 4 Crohn's disease; and 120 healthy blood donors. Sensitivity for MP was $98.1\%$ , which was higher than the predicate device sensitivity of $66.6\%$ . The overall specificity of the new device (healthy and disease controls) was $91.8\%$ . | N=337 | | ELISA | | | | --- | --- | --- | --- | --- | | Patient Group | n= | positive | Equivocal* | negative | | MP | 53 | 52 | 0 | 1 | | WG | 52 | 2 | 0 | 50 | | Healthy controls | 120 | 0 | 0 | 120 | | Disease controls | | | | | | SLE | 29 | 0 | 0 | 29 | | RA | 17 | 0 | 0 | 17 | | GBM | 51 | 7 | 12 | 32 | | Ulcerative colitis | 8 | 0 | 0 | 8 | | Celiac disease | 3 | 0 | 0 | 3 | | Crohn's disease | 4 | 0 | 0 | 4 | *Equivocal results were excluded from the calculation. {4} 5 Sensitivity: MP: 98.1% (52/53) 95% CI: 89.9% to 100% WG: 3.9% (2/52) 95% CI: 0.47% to 13.2% Specificity: Healthy controls: 100% (120/120) (95% CI: 95.5% to 100%) SLE: 100% (29/29) (95% CI: 88.1% to 100%) RA: 100% (17/17) (95% CI: 80.5% to 100%) GBM: 82.1% (32/39) (95% CI: 66.5% to 92.5%) Ulcerative colitis 100% (8/8) (95% CI: 63.1% to 100%) Celiac disease 100% (3/3) (95% CI: 29.2% to 100%) Crohn's disease 100% (4/4) (95% CI: 39.8% to 100%) b. Other clinical supportive data (when a. is not applicable): Not Applicable. 4. Clinical cut-off: Same as assay cut-off. 5. Expected values/Reference range: Expected values in the normal population should be negative. 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.