(263 days)
The ALPHA Cryptococcal Antigen enzyme immunoassay (CrAg EIA) is a qualitative or semi-quantitative (titration) test system for the detection of capsular polysaccharide antigens of Cryptococcus species complex (Cryptococcus neoformans and Cryptococcus gattii) in serum and cerebrospinal fluid (CSF). The ALPHA Cryptococcal Antigen Enzyme Immunoassay is an assay which can be used as an aid in the diagnosis of cryptococcosis. Test results are to be used in conjunction with information available from the patient clinical evaluation and other diagnostic procedures.
The ALPHA Cryptococcal Antigen Enzyme Immunoassay (EIA) is a direct immunoenzymatic sandwich microplate assay which detects Cryptococcus antigens in serum and CSF. Anti-Cryptococcus antibodies bound to microwell plates are used as capture antibodies, and horseradish peroxidase (HRP)-conjugated anti-Cryptococcus antibodies are used as detect antibodies. The positive control and standard curve material are composed of cryptococcal capsular polysaccharide antigen in a buffered protein solution with a preservative. In the qualitative procedure, specimens are analyzed undiluted. In the titration procedure, specimens are analyzed after serial dilution in specimen diluent. Either serum or CSF is added to the microwells coated with the capture antibodies and incubated. If the patient specimen contains cryptococcal antigens that are recognized by the capture antibodies, those antigens will become bound to the microwells. The microwells are washed to remove unbound patient material, and HRP-conjugated detect antibody is added to the wells. If Cryptococcus antigens are bound to the microwells by the capture antibodies, the detect antibody will also become bound to the microwells. The wells are then washed to remove any unbound detect antibody. Next, tetramethylbenzidine (TMB) substrate is added to the microwells, and in the presence of HRP, a blue color will develop. The reaction is stopped by the addition of a stop solution. The optical density (OD) is determined with a microplate reader at 450 nm with reference at 630 nm (reference is optional).
Here's an analysis of the ALPHA Cryptococcal Antigen EIA based on the provided 510(k) summary, structured to address your specific points:
Acceptance Criteria and Device Performance Study
The document describes several analytical performance studies rather than clinical studies with patient outcomes or a specific "acceptance criteria" table for diagnostic accuracy. The primary criteria for device approval appear to be substantial equivalence to the predicate device (Meridian's Premier™ Cryptococcal Antigen EIA, K904393) and meeting internal laboratory performance benchmarks for precision, sensitivity, specificity, and non-interference.
However, based on the ROC analysis and method comparison studies, we can infer some performance expectations for sensitivity and specificity.
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Inferred from Predicate Equivalence and ROC analysis) | Reported Device Performance (ALPHA Cryptococcal Antigen EIA) |
|---|---|---|
| Qualitative Agreement vs. Commercial EIA (Serum) | High agreement (similar to predicate) | % Positive Agreement: 98.5% (95% CI: 94.7% - 99.6%) |
| % Negative Agreement: 97.7% (95% CI: 96.7% - 98.4%) | ||
| Qualitative Agreement vs. Commercial EIA (CSF) | High agreement (similar to predicate) | % Positive Agreement: 93.5% (95% CI: 79.3% - 98.2%) |
| % Negative Agreement: 99.2% (95% CI: 97.8% - 99.7%) | ||
| Qualitative Agreement vs. IMMY CrAg LFA (Serum) | High agreement (similar to companion LFA) | % Positive Agreement: 96.9% |
| % Negative Agreement: 99.8% | ||
| Qualitative Agreement vs. IMMY CrAg LFA (CSF) | High agreement (similar to companion LFA) | % Positive Agreement: 93.8% |
| % Negative Agreement: 99.5% | ||
| Analytical Sensitivity (LoD) - Serum | Not explicitly stated as acceptance criteria, but demonstrates detection capability. | 5.3 ng/ml |
| Analytical Sensitivity (LoD) - CSF | Not explicitly stated as acceptance criteria, but demonstrates detection capability. | 1.7 ng/ml |
| Analytical Specificity (Cross-Reactivity) | Total positive for fungal pathologies < 10% (excluding specific known cross-reactants) | Total fungal pathologies: 3.9% (excluding Paracoccidioides brasiliensis, which was 67%) |
| Interference | No interference from icteric, hemolyzed, or lipemic samples | All spiked samples were positive, all unspiked negative. |
| High Dose Hook Effect | Positive result still recorded at high concentrations; semi-quantitative titration able to differentiate. | Signal reduced, but still positive. Titration can differentiate. |
| Freeze-Thaw Stability | Acceptance implied to be defined by observed OD reductions. Avoid multiple freeze-thaws for very low-positive samples. | Reductions in OD values after one week at ≤ -20°C and after multiple freeze-thaws observed. |
| ROC Cutoff Sensitivity (vs. IMMY CrAg LFA) | Not explicitly stated, but target was to match LFA. | 97.4% (for blanked OD > 0.265) |
| ROC Cutoff Specificity (vs. IMMY CrAg LFA) | Not explicitly stated, but target was to match LFA. | 99.9% (for blanked OD > 0.265) |
2. Sample Size Used for the Test Set and Data Provenance
The "test set" for performance evaluation consists of several cohorts:
- Precision Studies: Spiked serum and mock CSF samples. The number of unique samples is not given, but they were tested twice per day over five days across three sites. Each panel consisted of negative, high negative, low positive, and moderate positive samples for both serum and CSF.
- Analytical Sensitivity (LoD): 80 replicates of normal human serum, 80 replicates of artificial CSF for LoB. For LoD, initially 20 replicates of 4 concentrations, then 24 replicates of serum and CSF spiked with antigen near initial LoD.
- Analytical Specificity (Cross-Reactivity): 118 serum specimens and 15 fungal culture filtrates.
- Interference Studies: Five icteric, five hemolyzed, and five lipemic serum specimens.
- High Dose Hook Effect: One negative serum specimen pool spiked with antigen.
- Freeze-Thaw Study: Three CrAg-Negative human CSF specimens and four CrAg-Negative human serum specimens, spiked.
- ROC Analysis (for Cutoff Determination): 995 combined serum and CSF specimens.
- Method Comparison (vs. Commercial EIA and IMMY LFA): 1782 specimens (CSF n=426; serum n=1356).
- Data Provenance: The studies were conducted at Immuno-Mycologics, Inc. (IMMY) and two national reference laboratories, as well as a clinical lab for precision. The specimens for the method comparison were "submitted for cryptococcal antigen EIA testing," implying they were clinical samples, likely retrospective or leftover clinical samples. The country of origin is not explicitly stated, but the locations (Norman, OK; national reference labs) suggest United States origin. The nature of the samples (spiked or "submitted for testing") suggests retrospective use of clinical samples or artificially prepared samples.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The ground truth for the test sets was primarily established through:
- Spiking: For precision, LoD, interference, high dose hook, and freeze-thaw studies, samples were spiked with known concentrations of cryptococcal antigen, establishing a de facto ground truth.
- Reference Methods:
- For ROC analysis and comparison to LFA, the IMMY CrAg Lateral Flow Assay (LFA) was used as the reference method to classify specimens as true positive or negative. The expertise behind the LFA's accuracy would pertain to its own validation.
- For comparison to another manufacturer's device, the commercial Cryptococcal antigen EIA (the predicate device, Meridian's Premier™ Cryptococcal Antigen EIA) was used as the comparator.
- For analytical specificity, known positive/negative states for cross-reactants (e.g., Aspergillus galactomannan positive confirmed by Bio-Rad's Platelia™ Aspergillus EIA) were used.
The document does not mention the use of human experts (e.g., radiologists, pathologists) to establish ground truth for the test sets in the traditional sense of medical image analysis or complex diagnostic interpretation. The focus is on analytical performance and agreement with established laboratory tests.
4. Adjudication Method for the Test Set
No explicit adjudication method (e.g., 2+1, 3+1) is mentioned for the test sets. The ground truth was primarily defined by:
- Known concentrations (for spiked samples).
- Results from a single reference laboratory test (IMMY CrAg LFA or the commercial predicate EIA).
- Known status for cross-reactivity samples (e.g., confirmed Aspergillus positive).
There is no indication of multiple human readers or a consensus process for determining the ground truth for any of these studies.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
No, an MRMC comparative effectiveness study was not done. This device is an in vitro diagnostic (IVD) immunoassay that provides a quantitative or qualitative result. It is not an AI-powered diagnostic tool designed to assist human readers in interpreting images or complex data, nor does it involve "human readers" in the sense of medical specialists interpreting results that the device then supports or enhances.
6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done
This device is a standalone diagnostic test. It functions as an "algorithm only" in the sense that the assay procedure and subsequent optical density (OD) readings lead to a quantitative value or a positive/negative determination based on a defined cutoff. The performance studies described (precision, LoD, cross-reactivity, method comparison) are reflections of its standalone performance. There isn't a "human-in-the-loop" component in interpreting the EIA's direct output beyond standard laboratory practice of running the assay and reporting the result.
7. The Type of Ground Truth Used
The ground truth used for these studies can be categorized as:
- Known Spiking Concentrations: For analytical sensitivity, precision, interference, high-dose hook, and freeze-thaw studies.
- Reference Laboratory Assay Results:
- IMMY CrAg Lateral Flow Assay (LFA): Used as the reference for ROC analysis and comparison studies against the LFA.
- Commercial Cryptococcal Antigen EIA (Predicate Device): Used as the reference for method comparison studies to demonstrate substantial equivalence.
- External reference assays: For confirming known states of potentially cross-reacting substances (e.g., Bio-Rad's Platelia™ Aspergillus EIA).
8. The Sample Size for the Training Set
No explicit "training set" for an AI algorithm is mentioned as this is a traditional immunoassay.
However, if we interpret "training set" in the context of establishing assay parameters or a cutoff:
- The ROC analysis to determine the cutoff (0.265 blanked OD) was performed on a dataset of 995 combined serum and CSF specimens. This dataset could be considered analogous to a "training set" for defining the assay's threshold for positivity.
9. How the Ground Truth for the Training Set was Established
For the 995 specimens used in the ROC analysis to establish the cutoff:
- The ground truth was established by comparing the ALPHA Cryptococcal Antigen EIA results to the IMMY CrAg Lateral Flow Assay (LFA). The LFA was used to classify a specimen as a "true positive or negative" for the purpose of matching the sensitivity and specificity of the new EIA to the LFA. This means the LFA's results were accepted as the ground truth for this particular analysis aiming for concordance.
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K1209Y6
Immuno-Mycologics, Inc. Norman, OK
510(k) Premarket Notification ALPHA Cryptococcal Antigen EIA
510(k) Summary ALPHA Cryptococcal Antigen EIA
This 510(k) summary is submitted in accordance with 21 CFR §807.92
DEC 1 7 2012
- Owner: Immuno-Mycologics, Inc. 2700 Technology Place Norman, OK 73071 Tel: 405-360-4669 Fax: 405-364-1058 Contact: Dr. Sean K. Bauman, President & CEO
February 27th, 2012 Prepared:
ALPHA Cryptococcal Antigen EIA Trade Name:
- Common Name: Cryptococcus Antigen EIA
Classification Name: Antigen, Elisa, Cryptococcus
Regulation: 866.3165
Predicate Device: Meridian's Premier™ Cryptococcal Antigen EIA, K904393
The ALPHA Cryptococcal Antigen enzyme immunoassay (CrAg EIA) is a Intended Use: qualitative or semi-quantitative (titration) test system for the detection of capsular polysaccharide antigens of Cryptococcus species complex (Cryptococcus neoformans and Cryptococcus gattii) in serum and cerebrospinal fluid (CSF). The ALPHA Cryptococcal Antigen Enzyme Immunoassay is an assay which can be used as an aid in the diagnosis of cryptococcosis. Test results are to be used in conjunction with information available from the patient clinical evaluation and other diagnostic procedures.
Device Description:
The ALPHA Cryptococcal Antigen Enzyme Immunoassay (EIA) is a direct immunoenzymatic sandwich microplate assay which detects Cryptococcus antigens in serum and CSF. Anti-Cryptococcus antibodies bound to microwell plates are used as capture antibodies, and horseradish peroxidase (HRP)-conjugated anti-Cryptococcus antibodies are used as detect antibodies. The positive control and standard curve material are composed of cryptococcal capsular polysaccharide antigen in a buffered protein solution with a preservative. In the qualitative procedure, specimens are analyzed undiluted. In the titration procedure, specimens are analyzed after serial dilution in specimen diluent. Either serum or CSF is added to the microwells coated with the capture antibodies and incubated. If the patient specimen contains cryptococcal antigens that are recognized by the capture antibodies, those antigens will
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Immuno-Mycologics, Inc. Norman, OK
become bound to the microwells. The microwells are washed to remove unbound patient material, and HRP-conjugated detect antibody is added to the wells. If Cryptococcus antigens are bound to the microwells by the capture antibodies, the detect antibody will also become bound to the microwells. The wells are then washed to remove any unbound detect antibody. Next, tetramethylbenzidine (TMB) substrate is added to the microwells, and in the presence of HRP, a blue color will develop. The reaction is stopped by the addition of a stop solution. The optical density (OD) is determined with a microplate reader at 450 nm with reference at 630 nm (reference is optional).
Comparison with Predicate:
A comparison of the similarities and differences between the ALPHA Cryptococcal Antigen EIA and the predicate device is presented in the tables below (Table 1).
| AssayFeature | SIMILARITIESALPHA Cryptococcal Antigen EIANew Device | Premier Cryptococcal Antigen EIAK904393 |
|---|---|---|
| Intended Use | ||
| Intended Use | Detection of capsular polysaccharide antigens | Detection of capsular polysaccharide antigens |
| Indication For Use | Aid in the diagnosis of cryptococcosis | Aid in the diagnosis of cryptococcosis |
| Device Description | ||
| Assay Principle | EIA | EIA |
| Sample Matrix | Serum & CSF | Serum & CSF |
| Assay components | Antibody coated 96-well microplate, wash buffer,positive control, enzyme conjugate, TMB substrate,stop solution, sample diluent | Antibody coated 96-well microplate, wash buffer,positive control, enzyme conjugate, TMB substrate,stop solution, sample diluent |
| Detection Chemistry | HRP + TMB | HRP + TMB |
| Specimen pre-treatment? | none | none |
| Controls/Standard | Cryptococcal Antigen | Cryptococcal Antigen |
| Microplate | 96-well microplate coated with antigen | 96-well microplate coated with antigen |
Table 1. Similarities and Differences between ALPHA Cryptococcal Antigen EIA and Premier Cryptococcal Antigen EIA
| AssayFeature | DIFFERENCESALPHA Cryptococcal Antigen EIANew Device | Premier Cryptococcal Antigen EIAK904393 |
|---|---|---|
| Device Description | ||
| Output | Positive or Negative Only | Positive, Negative, and Indeterminate |
| Reagent Application | Pipette or equivalent | Reagent Droppers |
| Optional Visual Read | No | Yes |
Analytical Performance Summary
- A. Precision Studies
Precision Test Methods:
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The ALPHA Cryptococcal Antigen ElA was evaluated for reproducibility and precision by spiking serum and mock CSF with cryptococcal antigen to produce a panel consisting of a negative sample, a high negative (Cs) sample, a low positive sample and a moderate positive sample. This panel was tested twice per day at three sites [Immuno-Mycologics, Inc., a national reference lab, and a clinical lab] with a total of five operators over a five-day period in order to determine both the inter-lab and the intra-lab reproducibility and precision of the assay. The results of this study are shown in the table below.
| IMMY | National Reference Lab | Clinical Lab | Combined Data (3 Sites) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Description | Type | AveO.D. | StdDev | %CV | AveO.D. | StdDev | %CV | AveO.D. | StdDev | %CV | ਕਿਪਦ0.0. | Std.Dev. | %CV |
| Blank | Control | 0.066 | 0.012 | 17.8 | 0.000 | 0.0027 | 3585.2 | 0.075 | 0.005 | 7.0 | 0.046 | 0.034 | 74.67 |
| CRYPC1 | Control | 1.814 | 0.078 | 4.3 | 1.973 | 0.1083 | ર્ટ રે | 2.473 | 0.158 | 6.4 | 2.059 | 0.295 | 14.34 |
| Negative | Serum | 0.022 | 0.011 | 48.7 | 0.012 | 0.0058 | 48.8 | 0.019 | 0.005 | 25.4 | 0.018 | 0.009 | 50.25 |
| High Negative | Serum | 0.040 | 0.008 | 19.2 | 0.028 | 0.0077 | 27.7 | 0.035 | 0.007 | 20.0 | 0.034 | 0.009 | 26.51 |
| Low Positive | Serum | 0.420 | 0.041 | 9.7 | Q.338 | 0.0436 | 12.9 | 0.372 | 0.038 | 10.3 | 0.377 | 0.053 | 14.16 |
| Moderate Positive | Serum | 1.683 | 0.229 | 13.6 | 1.666 | 0.1281 | 7.7 | 1.959 | 0.205 | 10.5 | 1.756 | 0.229 | 13.05 |
| Negative | CSF | 0.065 | 0.018 | 27.8 | 0.028 | 0.0087 | 15.1 | 0.099 | 0.010 | 10.0 | 0.072 | 0.022 | 29.85 |
| High Negative | CSF | 0.179 | 0.020 | 11.1 | 0.174 | 0.0190 | 10.9 | 0.298 | 0.027 | 9.2 | 0.211 | 0.059 | 28.09 |
| Low Positive | CSF | 0.346 | 0.028 | 8.0 | 0.339 | 0.0319 | ਰੇ ਕੇ | 0.533 | 0.039 | 7.3 | 0.397 | 0.092 | 23.27 |
| Moderate Positive | CRF | 0.629 | 0.039 | 6.2 | 0.606 | 0.0443 | 7.3 | 0.929 | 0.056 | 6.0 | 0.707 | 0.149 | 21.13 |
Below is the data from the reproducibility study presented by percent positive for each specimen type.
| Serum | Site 1 % | Site 2 % | Site 3 % | Overall % |
|---|---|---|---|---|
| Positive | Positive | Positive | Positive | |
| Negative | 0% | 0% | 0% | 0% |
| High Negative | 0% | 0% | 0% | 0% |
| Low Positive | 100% | 100% | 100% | 100% |
| Moderate Positive | 100% | 100% | 100% | 100% |
| CSF | Site 1 %Positive | Site 2 %Positive | Site 3 %Positive | Overall %Positive |
| Negative | 0% | 0% | 0% | 0% |
| High Negative | 0% | 0% | 83% | 24% |
| Low Positive | 100% | 100% | 100% | 100% |
| Moderate Positive | 100% | 100% | 100% | 100% |
- B. Analytical Sensitivity (Lower limits of the assay)
LoB and LoD Testing Methods
Analytical sensitivity was estimated at IMMY according to Clinical and Laboratory Standards Institute (CLSI) EP-17A. The limit of the blank (LoB) was estimated by running 80 replicates of normal human serum and 80 replicates of artificial CSF. The initial limit of detection (LoD) was estimated by running 20 replicates of 4 concentrations near the LoB in both serum and CSF.
The LoD was established by testing 24 replicates of both serum and CSF spiked with Cryptococcal antigen at a range of concentrations near the initial LoD. Results were considered positive if they yielded a blanked OD that was greater than the cut-off.
Analysis shows that for serum the LoD was 5.3 ng/ml. For CSF, the LoD was 1.7 ng/ml.
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C. Analytical Specificity (Cross-Reactivity)
Analytical specificity for the ALPHA Cryptococcal Antigen EIA was determined by running potentially cross-reacting medical conditions unrelated to cryptococcosis. The following specimens were run on one lot of the ALPHA Cryptococcal Antigen EIA. A total of 118 serum specimen and 15 fungal culture filtrates were tested. Culture filtrates were tested at three different dilutions: undiluted, 1:10, and 1:100. Dilutes were made in 1X Specimen Diluent. Percent positive was determined for each condition.
As expected, some fungal cross-reactivity was observed. One Aspergillus galactomannan positive specimen (positive by Bio-Rad's Platelia™ Aspergillus EIA) was positive in the ALPHA Cryptococcal Antigen EIA and Paracoccidioides brasiliensis culture filtrates undiluted and 1:10 were positive as well. The total percent positive for fungal pathologies was 3.9%, well below the acceptance criteria of 10%. However, Paracoccidioides brasiliensis Culture Filtrate had a total percent positive of 67%.
Rheumatoid factor is known to cause false-positive results in the Cryptococcal latex agglutination method. Rheumatoid factor did not cause false positives in the ALPHA Cryptococcal Antigen EIA between the range of 112 IU/ml and 6479 IU/ml. The normal reference range for rheumatoid factor is 0-14 IU/ml.
D. Interference Studies
In addition to the cross-reactivity study, interference testing was also performed on five icteric, five hemolyzed, and five lipemic serum specimens. Each specimen was spiked with cryptococcal antigen at three times the C95 concentration. All specimens were then tested at IMMY, on one lot of the ALPHA Cryptococcal Antigen EIA in triplicate: spiked and unspiked.
All of the unspiked specimens had negative results on the ALPHA Cryptococcal Antigen EIA. All spiked specimens were positive, thus, these types of serum specimens do not interfere with the ALPHA Cryptococcal Antigen EIA.
- E. High Dose Hook Effect
The effects of high doses were determined by spiking a serum specimen pool that was negative by the IMMY Latex-Cryptococcus Antigen Detection System and ALPHA Cryptococcal Antigen EIA, with cryptococcal antigen at 1 mg/ml and testing it in triplicate at IMMY on one lot of ALPHA Cryptococcal Antigen EIA, according to the package insert.
It was observed that at extremely high concentrations, the signal can be reduced due to the high dose hook effect. Although the signal is reduced leading to lower than expected EIA values, the result is still positive. The semi-quantitative titration procedure can differentiate between a low EIA score due to the high dose hook effect and a low EIA score due to low concentrations of Cryptococcal Antigen.
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F. Specimen Acceptance Criteria - Freeze-Thaw Study
Three CrAg-Negative human CSF specimens and four CrAg-Negative human serum specimens were spiked with concentrations of Cryptococcal Antigen near and slightly above the cutoff of the assay. The specimens were tested on the ALPHA CrAg EIA immediately after spiking and then they were frozen at < - 20 C for the Day 0 time point. The specimens were then divided into three aliquots and tested as follows:
- . Aliquot 1 - Tested daily in triplicate, subjected to a freeze-thaw cycle each day
- . Aliquot 2 - Frozen for 1 week, thawed and tested in triplicate
- Aliquot 3 Frozen for 2 weeks, thawed and tested in triplicate .
Image /page/4/Figure/7 description: The image is a graph titled "Freeze-Thaw Study - ALPHA CrAg EIA". The x-axis represents freeze-thaw cycles, including Day 0, F/T Cycle 1-4, Frozen 1wk, and Frozen 2wk. The y-axis represents Blanked OD (Ave of 3 Replicates) ranging from 0.0 to 0.5. There are three lines on the graph representing CSF 1, CSF 2, and CSF 3.
Specimens may be stored for up to one week at <- 20 ℃. Reductions in OD values after one week of specimen storage at ≤ - 20 ℃ and after multiple freeze thaws may occur. Since a reduction in OD values was observed, it is possible that a fresh, very low-positive specimen (near 0.300 Blanked OD) could become negative if it is stored for one week. If possible, multiple freeze-thaw cycles should be avoided to minimize any effects due to specimen storage.
G. Linearity
N/A
- H. Assay cut-off
The assay cutoff was determined through ROC analysis using the IMMY CrAg Lateral Flow Assay (LFA) as the means of classifying a specimen as a true positive or negative. The
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intent of this classification system was to match the sensitivity and specificity of this assay to the sensitivity and specificity of the LFA.
ROC Analysis was performed on a dataset consisting of 995 combined serum and CSF specimens.
ROC Analysis suggested a blanked OD cutoff value of greater than 0.265 which vielded a sensitivity of 97.4% and a specificity of 99.9% when compared to the IMMY CrAg LFA as the reference method.
This cutoff was confirmed through the method comparison comparing the results from the IMMY Cryptococcal Antigen EIA to the predicate device.
Cut-Off Conclusions:
In summary our cut-offs are defined based on the blanked OD from the ROC analysis:
| $x \le 0.265$ | Negative |
|---|---|
| $x > 0.265$ | Positive |
F. Method Comparison
Comparison to Another Manufacturer's Device
A three-site (IMMY and two national reference laboratories) split-specimen comparison study was performed on both serum and CSF specimens that had been submitted for cryptococcal antigen ElA testing. A total of 1782 specimens (CSF n=426; serum n=1356) were tested in both the ALPHA Cryptococcal Antigen EIA and a commercial Cryptococcal antigen EIA according to their respective package inserts.
The resulting data from the split sample comparison is shown in the tables below.
Serum 2x2 Contingency Table
| Commercial EIA (+) | Commercial EIA (-) | |
|---|---|---|
| IMMY EIA (+) | 131 | 28 |
| IMMY EIA (-) | 2 | 1195 |
CSF 2x2 Contingency Table
| Commercial EIA (+) | Commercial EIA (-) | |
|---|---|---|
| IMMY EIA (+) | 29 | 3 |
| IMMY EIA (-) | 2 | 392 |
The combined results, excluding indeterminates, were analyzed for percent agreement positive, percent agreement negative and overall percent according to Clinical and Laboratory Standards Institute (CLSI) EP12-A2. The results of this analysis are shown in the table below.
| Dataset | Point Estimate | 95% Confidence Interval | |
|---|---|---|---|
| % Agreement Positive | Serum Only | 98.5% | 94.7% - 99.6% |
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| % Agreement Negative | Serum Only | 97.7% | 96.7% - 98.4% |
|---|---|---|---|
| % Agreement Positive | CSF Only | 93.5% | 79.3% - 98.2% |
| % Agreement Negative | CSF Only | 99.2% | 97.8% - 99.7% |
Comparison to IMMY CrAg Lateral Flow Assay
A three-site (IMMY and two national reference laboratories) split-specimen comparison study was performed on both serum and CSF specimens that had been submitted for cryptococcal antigen EIA testing. A total of 1782 specimens (CSF n=426; serum n=1356) were tested in both the ALPHA Cryptococcal Antigen EIA and the IMMY Cryptococcal Antigen Lateral Flow Assay (LFA) according to their respective package inserts.
The ALPHA Cryptococcal Antigen EIA performs similarly to the IMMY Cryptococcal Antigen Lateral Flow Assay (LFA) with 96.9% and 93.8% Agreement Positive, and 99.8% and 99.5% Agreement Negative to the LFA in serum and CSF, respectively.
Conclusion
The information submitted in this premarket notification is complete and supports a substantial equivalence decision.
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DEPARTMENT OF HEALTH & HUMAN SERVICES
Public Health Service
Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
Immuno-Mycologics, Inc. c/o Sean K. Bauman, Ph.D. 2700 Technology Place Norman, OK 73071
DEC 1 7 2012
Re: K120946
Trade/Device Name: ALPHA Cryptococcal Antigen EIA Regulation Number: 21 CFR $866.3165 Regulation Name: Cryptococcus neoformans serological reagents Regulatory Class: Class II Product Code: MDU Dated: October 25, 2012 Received: October 26, 2012
Dear Dr. Bauman:
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 (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. 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.
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.
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); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set
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Page 2 - Sean K. Bauman
forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic form and quinn control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
If you desire specific advice for your device on our labeling regulation (21 CFR Parts 801 and 809), please contact the Office of In Vitro Diagnostics and Radiological Health at (301) 796-5450. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Tou may of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.
Sincerely yours,
Uwe Scherf for
Sally A. Hojvat, M.Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostics And Radiological Health Center for Devices and Radiological Health
Enclosure
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Immuno-Mycologics, Inc. Norman, OK
Indications for Use Statement
510(k) Number (if known): K120946
Device Name: ALPHA Cryptococcal Antigen Enzyme Immunoassay
Indications for Use: The ALPHA Cryptococcal Antigen enzyme immunoassay (CrAg EIA) is a qualitative or semi-quantitative (titration) test system for the detection of capsular polysaccharide antigens of Cryptococcus species complex (Cryptococcus neoformans and Cryptococcus gattii) in serum and cerebrospinal fluid (CSF). The ALPHA Cryptococcal Antigen Enzyme Immunoassay is an assay which can be used as an aid in the diagnosis of cryptococcosis. Test results are to be used in conjunction with information available from the patient clinical evaluation and other diagnostic procedures.
Prescription Use ਮ (Part 21 CFR 801 Subpart D) AND/OR Over-The-Counter Use (21 CFR 801 Subpart C)
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ence of CDRH, Office of In Vitro Diagnostic Devices (OIVD) Concul
Division Sign-Off Office of In Vitro Diagnostic Device Evaluation and Safety
C
510(k) k 120 946
§ 866.3165
Cryptococcus neoformans serological reagents.(a)
Identification. Cryptococcus neoformans serological reagents are devices that consist of antigens used in serological tests to identify antibodies toCryptococcus neoformans in serum. Additionally, some of these reagents consist of antisera conjugated with a fluorescent dye (immunofluorescent reagents) and are used to identifyCryptococcus neoformans directly from clinical specimens or from cultured isolates derived from clinical specimens. The identification aids in the diagnosis of cryptococcosis and provides epidemiological information on this type of disease. Cryptococcosis infections are found most often as chronic meningitis (inflammation of brain membranes) and, if not treated, are usually fatal.(b)
Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 866.9.