QUANTA LITE H-TTG SCREEN

{0} 1 # 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY A. 510(k) Number: k073145 B. Purpose for Submission: New device C. Measurand: Anti-human tissue transglutaminase (htTG) IgG and IgA antibodies D. Type of Test: Semi-quantitative ELISA E. Applicant: INOVA Diagnostics, Inc. F. Proprietary and Established Names: QUANTA Lite™ h-tTG Screen G. Regulatory Information: 1. Regulation section: 21 CFR § 866.5660 Multiple autoantibodies immunological test systems 2. Classification: Class II 3. Product codes: MVM, Autoantibodies, Endomysial (Tissue Transglutaminase) 4. Panel: Immunology 82 H. Intended Use: 1. Intended use(s): The QUANTA Lite™ h-tTG Screen is an enzyme-linked immunosorbent assay (ELISA) for the semi-quantitative detection of IgA and IgG antibodies to human tissue transglutaminase (htTG) in human serum. The presence of these antibodies can be used in conjunction with clinical findings and other laboratory tests to aid in the diagnosis of both IgA sufficient and IgA deficient celiac disease as well as dermatitis herpetiformis 2. Indication(s) for use: Same as Intended use. 3. Special conditions for use statement(s): For prescription only. 4. Special instrument requirements: Microplate reader capable of measuring OD at 450 nm (or 650 for dual wavelength readings) I. Device Description: Each device contains the following: polystyrene microplate strips with breakaway (12 (1x8) microwells coated with human tissue transglutaminase antigen with holder; high positive, low positive and negative controls (human serum); HRP wash concentrate; HRP sample diluent; HRP IgG and IgA (goat) anti-human conjugate; TMB chromogen; and HRP stop solution (0.344M sulfuric acid). J. Substantial Equivalence Information: {1} 1. Predicate device name(s): QUANTA Lite™ h-tTG IgA QUANTA Lite™ h-tTG IgG 2. Predicate K number(s): k011566 (h-tTG IgA) k011570 (h-tTG IgG) 3. Comparison with predicate: | Similarities | | | | | --- | --- | --- | --- | | Item | New Device | Predicate Device | | | | QUANTA Lite™ h-tTG Screen | QUANTA Lite™ h-tTG IgA | QUANTA Lite™ h-tTG IgG | | Technology | ELISA | Same | Same | | Antigen | Purified h-tTG antigen | Same | Same | | Measurement | Semi-quantitative | Same | Same | | Assay Platform | 96 well microtiter plate | Same | Same | | Sample type and dilution | Serum at 1:101 | Same | Same | | Sample volume required | 5 μL | Same | Same | | Low Positive, High positive and Negative Control | Pre-diluted human serum. Ready to use. | Same | Same | | Diluent | HRP sample diluent | Same | Same | | HRP Wash concentrate | 40X | Same | Same | | Substrate | TMB Chromogen | Same | Same | | HRP Stop solution | 0.344M Sulfuric Acid | Same | Same | | Assay washing step | Two steps | Same | Same | | Incubation times | 30-30-30 minutes | Same | Same | | Spectrophotometric OD Reading | 450nm (or 620 for dual wavelength) | Same | Same | | Detection Method | Colorimetric | Same | Same | | Cut-off | 20.0 units | Same | Same | | Differences | | | | | --- | --- | --- | --- | | Item | Device | Predicate | | | | QUANTA Lite™ h-tTG Screen | QUANTA Lite™ h-tTG IgA | QUANTA Lite™ h-tTG IgG | | Intended use | For the semi-quantitative detection of IgA and IgG antibodies to human tissue transglutaminase | For the semi-quantitative detection of IgA antibodies to tissue transglutaminase | For the semi-quantitative detection IgG antibodies to tissue transglutaminase | {2} | Differences | | | | | --- | --- | --- | --- | | Item | Device | Predicate | | | | (htTG) in human serum. | (endomysium) in human serum. | (endomysium) in human serum. | | Indications for Use | Aid in the diagnosis of both IgA sufficient and IgA deficient celiac disease as well as dermatitis herpetiformis | Aid in the diagnosis of certain gluten sensitive enteropathies such as celiac disease and dermatitis herpetiformis | Aid in the diagnosis of certain gluten sensitive enteropathies such as celiac disease and dermatitis herpetiformis. This test is intended for providing added sensitivity when testing IgA deficient patients | | Enzyme Conjugate | Horseradish Peroxidase, Goat anti-human IgA and IgG | Horseradish Peroxidase, Goat anti-human IgA | Horseradish Peroxidase, Goat anti-human IgG | | Result Interpretation | Neg = <20 Units Pos = ≥20 Units | Neg = <20 Units Wk Pos = 20 -30 Mod to Strong Positive = >30 | Neg = <20 Units Wk Pos = 20 -30 Mod to Strong Positive = >30 | K. Standard/Guidance Document Referenced (if applicable): CLSI (NCCLS) H18-A3 Sample storage conditions and CLSI (NCCLS) C24-A3 Appropriate Quality Control Practices. L. Test Principle: Native human tissue transglutaminase is bound to the wells of a polystyrene microwell plate under conditions that will preserve the antigen in its native state. Pre-diluted controls and diluted patient sera are added to separate wells, allowing any h-tTG IgA or IgG antibodies present to bind to the immobilized antigen. Unbound sample is washed away and an enzyme labeled anti-human IgA and IgG conjugate is added to each well. A second incubation allows the enzyme labeled anti-human IgA and IgG to bind to any patient antibodies, which have become attached to the microwells. After washing away any unbound enzyme labeled anti-human IgA and IgG, the remaining enzyme activity is measured by adding a chromogenic substrate and measuring the intensity of the color that develops. The assay can be evaluated spectrophotometrically by measuring and comparing the color intensity that develops in the patient wells with the color in the control wells M. Performance Characteristics (if/when applicable): 1. Analytical performance: a. Precision/Reproducibility: {3} The intra-assay precision was determined by testing nine serum samples five times on one kit lot by one operator. Results showed that 4 samples with high anti-h-tTG concentrations (32.6-46.8 units) had $\% \mathrm{CV}$ of $1.2 - 7.7\%$ , 3 samples close to the cut-off (18.3-22.3 units) had $\% \mathrm{CV}$ of $2.1 - 5.8\%$ and 2 negative samples (7.7-13.5 units) had $\% \mathrm{CV}$ of $5.6 - 7.2\%$ (see table below). Intra-assay Performance of QUANTA Lite™ h-tTG Screen ELISA | Sample | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Mean units | 44.3 | 32.6 | 46.8 | 22.3 | 36.1 | 13.5 | 18.3 | 19.1 | 7.7 | | SD | 1.6 | 1.5 | 0.5 | 1.3 | 0.5 | 0.8 | 0.5 | 0.4 | 0.6 | | CV % | 3.5 | 4.7 | 1.2 | 5.8 | 1.5 | 5.6 | 2.6 | 2.1 | 7.2 | The inter-assay precision was determined by testing twelve serum samples in duplicate six times for five days on one kit lot by one operator. Results showed that 5 samples with high anti-h-tTG concentrations (31.3-49.3 units) had $\% \mathrm{CV}$ of $2.2 - 9.3\%$ , 3 samples close to the cut-off (16.0-23.0 units) had $\% \mathrm{CV}$ of $4.8 - 11.3\%$ and 4 negative samples (5.2-14.5 units) had $\% \mathrm{CV}$ of $6.1 - 18.4\%$ (see table below). Inter-assay Performance for QUANTA Lite™ h-tTG Screen ELISA | Sample | A | B | C | D | E | F | G | H | I | J | K | L | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Mean units | 46.4 | 31.3 | 48.7 | 23.0 | 35.0 | 14.5 | 16.0 | 6.0 | 10.3 | 49.3 | 17.8 | 5.2 | | SD | 1.4 | 1.6 | 1.1 | 1.1 | 3.3 | 0.9 | 1.8 | 1.1 | 1.9 | 1.3 | 1.8 | 0.8 | | CV % | 3.0 | 5.2 | 2.2 | 4.8 | 9.3 | 6.1 | 11.3 | 18.0 | 18.4 | 2.6 | 10.0 | 15.4 | b. Linearity/assay reportable range: Not applicable. c. Traceability, Stability, Expected values (controls, calibrators, or methods): There are no reference standards for htTG. The positive and negative controls are prepared in-house and arbitrary units are assigned during the development process. Stability: The expiration date claim is one year for the QUANTA Lite™ h-tTG Screen. d. Detection limit: Not applicable. e. Analytical specificity: Interference by endogenous substances: No data provided. The package insert states that grossly hemolyzed, lipemic, icteric, microbially contaminated, heat-treated samples or specimens containing visible particulate should be avoided in this assay. Crossreactivity with other autoantibodies: The QUANTA Lite™ h-tTG Screen was tested with 44 sera containing other autoantibodies specific for: Chromatin (4), Centromere (4), GBM (4), SS-B (4), RNP (5), SCL-70 (6), Jo1 (5), Sm (4), SS-A (4), and TPO (4). All samples were negative with the QUANTA Lite™ h-tTG Screen with a mean value of $4.6\mathrm{U / mL}$ which is below the 20 unit cut-off. {4} f. Assay cut-off: The assay cut-off of 20 units for the assay was established from 381 random asymptomatic healthy individuals residing in the United States. Age and gender were available for 269 samples and unavailable for the remaining 112 samples. The age ranges were 14-76 years and included 141 male subjects and 128 female subjects. The assay specificity was 97.9% (373/381). The mean value of 381 samples was 8.6 units. The standard deviation (SD) of the samples was 4.4 units. The mean value was 2.5SDs below the cut-off value of 20 units. Of the 8 positive samples, six were weak positive with values from 20.3 - 28.4 units; one moderate positive value was 32.4 units and one strong positive value was 54.9 units which was believed to be from a true celiac patient based on a positive IgA anti-h-tTG result of 72.4 units. 2. Comparison studies: a. Method comparison with predicate device: Testing was performed on 125 samples from four celiac disease reference labs and 81 normal samples. The Positive Percent Agreement was 100.0% (52/52); the Negative Percent Agreement was 97.1% (451/454) and the Overall Agreement was 97.4% (493/506). | | QUANTA Lite™ h-tTG IgA or IgG | | | | | --- | --- | --- | --- | --- | | | | Positive | Negative | Total | | QUANTA Lite™ h-tTG Screen | Positive | 52 | 13* | 65 | | | Negative | 0 | 441 | 441 | | | Total | 52 | 454 | 506 | * Of the 13 samples found to be h-tTG Screen positive, yet negative on both h-tTG IgA and h-tTG IgG kits, 3 from celiac patients on GFDs, two from 1st degree relatives, and eight from apparently healthy subjects. All 13 samples had values under 30 units. b. Matrix comparison: Serum is the only recommended matrix. 3. Clinical studies: a. Clinical Sensitivity and specificity: The clinical sensitivity and specificity study were evaluated on 517 clinically defined samples from patients with the following diagnosis: 23 Celiacs untreated, 5 Celiac IgA Deficient, 18 Celiac 1st degree relatives, 13 Dermatitis Herpetiformis, 44 Disease Controls, and 414 Healthy individuals. The QUANTA Lite™ h-tTG Screen assay sensitivity and specificity were 87.8% (36/41) and 97.1% (462/476) respectively (refer to table below). | | Diagnosis | | | | | --- | --- | --- | --- | --- | | | | Positives (Celiacs untreated and IgA deficient) | Negative (1st degree relatives, Disease Controls and Healthy Controls) | Totals | | QUANTA LITE™ h-tTG Screen | Positive | 36 | 14 | 50 | | | Negative | 5 | 462 | 467 | | | Total | 41 | 476 | 517 | {5} In addition, a summary of the results for the individual diagnosis is listed below: | | Diagnosis | n | Positive h-tTG Screen | % Sensitivity | | --- | --- | --- | --- | --- | | Patient Groups | Celiacs untreated | 23 | 23 | 100% | | | Celiac IgA Deficient | 5 | 4 | 80% | | | Celiacs on Gluten-Free Diet | 33* | 15 | 45% | | | 1stdegree relatives | 18 | 4 | 22% | | | Dermatitis Herpetiformis | 13 | 9 | 69% | | | Disease Controls | 44 | 0 | 0% | | Normals | | 414 | 10** | 2.4% | *33 GFD Celiacs were excluded from the previous sensitivity/ specificity table. **1 of the 10 positives was found to be positive on individual h-tTG ELISA assays and also positive for tTG by fluid phase RIA. 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.