(881 days)
The LCx Neisseria gonorrhoeae Assay uses LCR™ (Ligase Chain Reaction) amplification technology in the LCx Probe System for the direct, qualitative detection of a specific target nucleic acid sequence in the Opa gene of Neisseria gonorrhoeae in female endocervical and male urethral swab specimens or in male and female ur ne specimens from symptomatic and asymptomatic males and females.
The LCx Neisseria gonorrhoeae Assay uses LCR™ (Ligase Chain Reaction) amplification technology in the LCx Probe System for the direct, qualitative detection of a specific target nucleic acid sequence in the Opa gene of Neisseria gonorrhoeae.
Here's an analysis of the provided text, outlining the acceptance criteria and study details for the LCx® Neisseria gonorrhoeae Assay:
Acceptance Criteria and Reported Device Performance
The acceptance criteria for this device are implicitly tied to demonstrating substantial equivalence to the culture method for Neisseria gonorrhoeae detection. The performance metrics presented (Sensitivity and Specificity) serve as the criteria by which this equivalence is assessed. While explicit sensitivity and specificity targets are not stated as "acceptance criteria" in the document, the presented ranges with 95% Confidence Intervals imply that the performance observed met the internal/regulatory expectations for substantial equivalence.
Table of Acceptance Criteria and Reported Device Performance (Based on provided data)
| Metric | Sample Type | Symptomatology | Acceptance Criteria (Implicit) | Reported Performance (Fresh Specimens) | Reported Performance (Frozen Specimens) |
|---|---|---|---|---|---|
| Sensitivity | Female Endocervical | Asymptomatic | High | 100.0% (69.2-100.0) | 88.9% (70.8-97.6) |
| Female Endocervical | Symptomatic | High | 100.0% (83.2-100.0) | 100.0% (92.5-100.0) | |
| Female Urine | Asymptomatic | High | 100.0% (66.4-100.0) | 92.0% (74.0-99.0) | |
| Female Urine | Symptomatic | High | 85.0% (62.1-96.8) | 95.6% (84.5-99.5) | |
| Male Urethra | Asymptomatic | High | 100.0% (2.5-100.0) | 85.7% (42.1-99.6) | |
| Male Urethra | Symptomatic | High | 100.0% (92.5-100.0) | 98.7% (95.5-99.2) | |
| Male Urine | Asymptomatic | High | 100.0% (2.5-100.0) | 85.7% (42.1-99.6) | |
| Male Urine | Symptomatic | High | 97.9% (88.9-99.9) | 99.4% (96.8-100.0) | |
| Total | Asymptomatic | High | 100.0% | 89.4% | |
| Total | Symptomatic | High | 97.0% | 98.8% | |
| Specificity | Female Endocervical | Asymptomatic | High | 95.6% (87.6-99.1) | 98.2% (96.7-99.1) |
| Female Endocervical | Symptomatic | High | 99.1% (95.1-100.0) | 97.2% (94.5-98.8) | |
| Female Urine | Asymptomatic | High | 98.5% (91.7-100.0) | 99.1% (95.3-100.0) | |
| Female Urine | Symptomatic | High | 99.1% (95.0-100.0) | 100.0% (98.1-100.0) | |
| Male Urethra | Asymptomatic | High | 100.0% (95.1-100.0) | 98.8% (95.7-99.9) | |
| Male Urethra | Symptomatic | High | 97.8% (88.2-99.9) | 97.6% (94.9-99.1) | |
| Male Urine | Asymptomatic | High | 100.0% (95.1-100.0) | 99.6% (97.5-100.0) | |
| Male Urine | Symptomatic | High | 97.8% (86.2-99.9) | 96.6% (93.5-98.4) | |
| Total | Asymptomatic | High | 98.6% | 98.6% | |
| Total | Symptomatic | High | 98.7% | 97.7% |
Study Information:
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Sample Size Used for the Test Set and Data Provenance:
- Fresh Specimens:
- Asymptomatic Total: 300
- Symptomatic Total: 446
- Overall Fresh Total: 746
- Frozen Specimens:
- Asymptomatic Total: 1169
- Symptomatic Total: 1447
- Overall Frozen Total: 2616
- Data Provenance: The study was conducted in four U.S. sites. The data is prospective, as it compares the LCx assay results to culture results from specimens collected in real-world clinical settings.
- Fresh Specimens:
-
Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications:
- The document does not explicitly state the number of experts used or their qualifications for establishing the ground truth (culture results). However, it is a standard assumption in such studies that clinical microbiology laboratories, staffed by qualified microbiologists and technicians, performed the culture method and interpreted its results.
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Adjudication Method for the Test Set:
- The document does not specify an adjudication method beyond "comparing assay results to results of culture." For discordant results (LCx positive, culture negative; or LCx negative, culture positive), it is common practice to perform further testing (e.g., re-culture, additional molecular tests, or follow-up clinical data) to resolve the discrepancy, but this is not mentioned.
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Multi Reader Multi Case (MRMC) Comparative Effectiveness Study:
- No, an MRMC comparative effectiveness study was not performed as described in this summary. This study compares a new diagnostic device (LCx) to a comparator diagnostic method (culture), not the performance of human readers with and without AI assistance.
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Standalone Performance Study (Algorithm Only Without Human-in-the-Loop):
- Yes, this study represents a standalone performance study of the LCx Neisseria gonorrhoeae Assay. The reported sensitivity and specificity values are for the device (algorithm) itself compared to the ground truth (culture), without human interpretation of the LCx results directly impacting the reported performance metrics. The results of the LCx are quantitative or qualitative outputs that are then interpreted.
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Type of Ground Truth Used:
- The ground truth used was culture for Neisseria gonorrhoeae. This is a direct method for detecting the viable organism, making it a widely accepted "gold standard" for N. gonorrhoeae diagnosis.
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Sample Size for the Training Set:
- The document does not mention a separate training set or its sample size for the LCx assay. This device likely relies on established molecular biology principles and was developed and optimized in laboratory settings, possibly using internal validation data not detailed here. For a diagnostic assay like this, the "training" would be more akin to assay development and optimization rather than machine learning model training on a distinct dataset.
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How the Ground Truth for the Training Set Was Established:
- As no explicit training set is mentioned in the context of a machine learning model, the concept of establishing ground truth for a training set in that sense is not applicable here. The assay development would have involved using well-characterized Neisseria gonorrhoeae strains and other microorganisms, likely with their identities confirmed by established microbiological methods (e.g., culture, biochemical tests, sequencing) to ensure the assay's ability to detect the target and avoid cross-reactivity.
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510 (k) SUMMARY
MAY -6 1996
LCx® Neisseria gonorrhorae Assay
SUMMARY OF SAFETY AND EFFECTIVENESS INFORMATION SUPPORTING A SUBSTANTIAL EQUIVALENCE DETERMINATION
The following information as presented in the Premarket Notification (510(k) for LCx Neisseria gonorrhoeae Assay) constitutes data supporting a substantially equivalent determination.
The LCx Neisseria gonorrhoeae Assay uses LCR™ (Ligase Chain Reaction) amplification technology in the LCx Probe System for the direct, qualitative detection of a specific target nucleic acid sequence in the Opa gene of Neisseria gonorrhoeae in female endocervical and male urethral swab specimens or in male and female ur ne specimens from symptomatic and asymptomatic males and females.
The LCx Neisseria gonorrhoeae Assay is substantially iquivalent to the culture method.
The two methods are similar in that:
-Both assays detect the presence of N. gonorrhoeae.
-Both assays are in vitro tests.
The two methods differ in that:
-The LCx Neisseria gonorrhoeae Assay detects the DNA of N. gonorrhoeae
organisms, while the culture method detects the whole organism.
-The LCx Neisseria gonorrhoeae Assay detects the DNA of N. gonorrhoeae in male and female urine.
In four U.S. sites, the performance characteristics of the LCx Neisseria gonorrhoeae Assay were determined by comparing assay results to results of culture for Neisseria gonorrhoeae. The overall results presented by specimen type and storage condition are shown in the table below.
| Sample Type | Symptomatology | Total | LCxCulture | PosPos | PosNeg | NegPos | NegNeg | Sensitivity(95% C.I.) | Specificity(95% C. I.) |
|---|---|---|---|---|---|---|---|---|---|
| Female Endocervical | Asymptomatic | 623 | 24 | 11 | 3 | 585 | 88.9% (24/27)(70.8-97.6) | 98.2% (505/596)(96.7-99.1) | |
| Symptomatic | 332 | 47 | 8 | 0 | 277 | 100.0% (47/47)(92.5-100.0) | 97.2% (277/285)(94.5-98.8) | ||
| Female Urine | Asymptomatic | 140 | 23 | 1 | 2 | 114 | 92.0% (23/25)(74.0-99.0) | 99.1% (114/115)(95.3-100.0) | |
| Symptomatic | 237 | 43 | 0 | 2 | 192 | 95.6% (43/45)(84.5-99.5) | 100.0% (192/192)(98.1-100.0) | ||
| Male Urethra | Asymptomatic | 172 | 6 | 2 | 1 | 163 | 85.7% (6/7)(42.1-99.6) | 98.8% (163/165)(95.7-99.9) | |
| Symptomatic | 412 | 155 | 6 | 2 | 249 | 98.7% (155/157)(95.5-99.2) | 97.6% (249/255)(94.9-99.1) | ||
| Male Urine | Asymptomatic | 234 | 6 | 1 | 1 | 226 | 85.7% (6/7)(42.1-99.6) | 99.6% (226/227)(97.5-100.0) | |
| Symptomatic | 466 | 170 | 10 | 1 | 265 | 99.4% (170/171)(96.8-100.0) | 96.6% (285/295)(93.5-98.4) | ||
| Total | Asymptomatic | 1169 | 59 | 15 | 7 | 1088 | 89.4% (59/66) | 98.6% (1088/1103) | |
| Symptomatic | 1447 | 415 | 24 | 5 | 1003 | 98.8% (415/420) | 97.7% (1003/1027) |
Performance Summary Compared to Culture: Frozen Specimens
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| Sample Type | Symptomatology | Total | LCxCulture | PosPos | PosNeg | NegNeg | Sensitivity(95% C.I.) | Specificity(95% C.I.) |
|---|---|---|---|---|---|---|---|---|
| Female Endocervical | Asymptomatic | 78 | 10 | 3 | 0 | 55 | 100.0% (10/10)(69.2-100.0) | 95.6% (65/68)(87.6-99.1) |
| Symptomatic | 112 | 20 | 1 | 0 | 111 | 100.0% (20/20)(83.2-100.0) | 99.1% (111/112)(95.1-100.0) | |
| Female Urine | Asymptomatic | 74 | 9 | 1 | 0 | 64 | 100.0% (9/9)(66.4-100.0) | 98.5% (64/65)(91.7-100.0) |
| Symptomatic | 129 | 17 | 1 | 3 | 108 | 85.0% (17/20)(62.1-96.8) | 99.1% (108/109)(95.0-100.0) | |
| Male Urethra | Asymptomatic | 74 | 1 | 0 | 0 | 73 | 100.0% (1/1)(2.5-100.0) | 100.0% (73/73)(95.1-100.0) |
| Symptomatic | 92 | 47 | 1 | 0 | 44 | 100.0% (47/47)(92.5-100.0) | 97.8% (44/45)(88.2-99.9) | |
| Male Urine | Asymptomatic | 74 | 1 | 0 | 0 | 73 | 100.0% (1/1)(2.5-100.0) | 100.0% (73/73)(95.1-100.0) |
| Symptomatic | 93 | 47 | 1 | 1 | 44 | 97.9% (47/48)(88.9-99.9) | 97.8% (44/45)(86.2-99.9) | |
| Total | Asymptomatic | 300 | 21 | 4 | 0 | 275 | 100.0% (21/21) | 98.6% (275/279) |
| Symptomatic | 446 | 131 | 4 | 4 | 307 | 97.0% (131/135) | 98.7% (307/311) |
Performance Summary Compared to Culture: Fresh Specimens
The analytical sensitivity of this assay (limit of detection) is 10 Colony Forming Units (CFU) of any of the 6 auxotrophs of Neisseria gonorrhoeae. The analytical sensitivity of this assay was determined by a serial dilution study on all 6 auxotrophs (auxotype 1, 5, 9, 12, 16, and 23) of Neisseria gonorrhoeae. Each auxotroph was diluted to less than 10 CFU per reaction and tested in the LCx Neisseria gonorrhoeae Assay. In all cases, each replicate of a dilution giving 10 CFU per test (100 ul specimen volume) was positive by the LCx Neisseria gonorrhoeae Assay.
91 bacteria, parasites, viruses, veast and fungi, including organisms that are commonly found in the urogenital tract and 12 non-gonococcal Neisseria species were tested by the LCx Neisseria gonorrhoeae Assay. All gave negative results indicating the specificity of the test.
In conclusion the LCx Neisseria gonorrhoeae Assay is substantially equivalent to culture for detection of Neisseria gonorrhoeae in endocervical, male urethral, female and male urine specimens.
Prepared and submitted April 1, 1996 Mary Spiewak 847-937-5376 Abbott Laboratories 200 Abbott Park Road Abbott Park, IL 60064-3537
§ 866.3390
Neisseria spp. direct serological test reagents.(a)
Identification. Neisseria spp. direct serological test reagents are devices that consist of antigens and antisera used in serological tests to identifyNeisseria spp. from cultured isolates. Additionally, some of these reagents consist ofNeisseria spp. antisera conjugated with a fluorescent dye (immunofluorescent reagents) which may be used to detect the presence ofNeisseria spp. directly from clinical specimens. The identification aids in the diagnosis of disease caused by bacteria belonging to the genusNeisseria, such as epidemic cerebrospinal meningitis, meningococcal disease, and gonorrhea, and also provides epidemiological information on diseases caused by these microorganisms. The device does not include products for the detection of gonorrhea in humans by indirect methods, such as detection of antibodies or of oxidase produced by gonococcal organisms.(b)
Classification. Class II (performance standards).