K Number
K191184
Date Cleared
2020-03-05

(307 days)

Product Code
Regulation Number
866.3300
Reference & Predicate Devices
Predicate For
N/A
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

The ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test is an in vitro, rapid, lateral flow test, also known as a lateral flow immunochromatographic assay, intended for the qualitative detection of Streptococus pneumoniae and Legionella pneumophila antigens in urine specimens with symptoms of pneumonia. The assay is intended to aid in diagnosis of S. pneumoniae and L. pneumophila serogroup 1 infections. The assay is further intended to aid in the diagnosis of S. pneumoniae infection of S. pneumoniae antigen in cerebrospinal fluid (CSF). Results from the ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test should be interpreted in conjunction with the patient's clinical evaluation and other diagnostic methods.

Device Description

ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test is a rapid lateral flow test for qualitative detection of S. pneumoniae in human urine and CSF samples and L. pneumophila (primarily serogroup 1) antigens in human urine samples. The test is effective in presumptive diagnosis of pneumococcal pneumonia caused by S. pneumoniae or Legionella pneumonia (Legionnaires' disease) caused by L. pneumophila, in conjunction with culture and other methods. Correct and early treatment is vital for the prognosis of both diseases and therefore quick methods to confirm both diseases in the initial phase are very important in order to initiate the proper antibiotic treatment as soon as possible.

AI/ML Overview

This document describes the validation of the ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test, an in vitro lateral flow immunochromatographic assay.


1. Acceptance Criteria and Reported Device Performance

The acceptance criteria for the device are implicitly demonstrated by the reported sensitivities and specificities, and positive/negative percent agreements achieving certain levels across various studies (retrospective, prospective, analytical). While explicit numerical acceptance criteria are not stated in a dedicated table, the consistently high performance metrics across both S. pneumoniae and L. pneumophila detection in urine and CSF demonstrate the device's acceptable performance.

Here's a summary of the reported device performance, which serves as evidence of meeting implicit acceptance criteria:

Table 1: Summary of ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test Performance

ParameterTarget AnalyteSample TypeStudy TypePerformance (ImmuView)95% Confidence IntervalComparator Performance (if applicable)
Sensitivity (vs. Culture)S. pneumoniae (Urine)UrineRetrospective78% (78/100)(69.0-85.0%) / (67-85%)80% (76/95)
L. pneumophila (Urine)UrineRetrospective87.8% (86/98)(79.8-92.9%)
L. pneumophila Sg 1 (U.S.)UrineRetrospective97.7% (42/43)(88-100%)100% (43/43)
L. pneumophila Sg 1 (Europe)UrineRetrospective80.0% (44/55)(68-88%)66.7% (36/54)
Specificity (vs. Culture)S. pneumoniae (Urine)UrineRetrospective98.1% (217/221)(95.4-99.3%) / (95-99%)97.8% (218/223)
L. pneumophila (Urine)UrineRetrospective99.6% (239/240)(97.4-100.0%)
L. pneumophila (U.S.)UrineRetrospective100% (19/19)(83-100%)100% (19/19)
L. pneumophila (Europe)UrineRetrospective99.5% (220/221)(97-100%)99.6% (223/224)
Positive Percent AgreementS. pneumoniae (Urine)UrineProspective96.0% (72/75)(88.9%-98.6%)-
Negative Percent AgreementS. pneumoniae (Urine)UrineProspective97.4% (225/231)(94.5%-98.8%)-
Positive Percent AgreementL. pneumophila SG1 (Urine)UrineProspective100.0% (3/3)(43.9%-100%)-
Negative Percent AgreementL. pneumophila SG1 (Urine)UrineProspective100.0% (303/303)(98.8%-100%)-
Sensitivity (vs. Culture)S. pneumoniae (CSF)CSFClinical Study92.9% (13/14)(68.5%-98.7%)-
Specificity (vs. Culture)S. pneumoniae (CSF)CSFClinical Study96.0% (162/169)(91.7%-98.0%)-
Positive Percent AgreementS. pneumoniae (Spiked CSF)CSFSpiked Study100% (50/50)(92.9%-100%)100% (50/50) (Comparator)
Negative Percent AgreementS. pneumoniae (Negative CSF)CSFSpiked Study100% (10/10)(72.2%-100%)100% (10/10) (Comparator)
ReproducibilityVarious positive/negative samplesUrine/CSFReproducibility99.6% (1068/1072 correct results)--
Limit of Detection (LOD)S. pneumoniae antigenUrineAnalytical62.5 pg/mL--
L. pneumophila SG1 (Philadelphia) antigenUrineAnalytical25 ng/mL (0.025 µg/mL)--
S. pneumoniae (whole cell)UrineAnalytical10^5^ CFU/mL--
L. pneumophila SG1 (whole cell)UrineAnalytical10^4^ CFU/mL--
S. pneumoniae (whole cell)CSFAnalytical10^3^ CFU/mL--

2. Sample Sizes and Data Provenance

  • Retrospective Study (Urine Samples):

    • S. pneumoniae: 100 culture-positive urine samples (48 from Sweden, 52 from Denmark, all from blood culture positive patients). 221 known negative urine samples.
    • L. pneumophila: 98 culture-confirmed urine samples (55 from Europe, 43 from the United States (US), these 43 were previously determined positive in a urinary antigen test). 240 known negative urine samples.
    • Data Provenance: Retrospective, samples from Europe (Sweden, Denmark) and the United States.
  • Prospective Study (Urine Samples):

    • Total Samples: 306 freshly collected urine samples (with 92 having to be frozen before testing due to practicalities).
    • Data Provenance: Prospective, collected from two sites in Spain and Denmark. These were from "all comers" at risk of community-acquired pneumonia.
  • Clinical Study (CSF Samples):

    • S. pneumoniae: 14 culture-positive CSF specimens (9 from US labs, 5 from European labs). 169 known negative CSF samples (113 from US labs, 56 from European labs).
    • Data Provenance: Retrospective/Clinical, samples from US and Europe.
  • Spiked CSF Testing:

    • S. pneumoniae: 50 human CSF samples spiked at the LOD. 10 additional unspiked negative CSF samples.
  • Analytical Studies (Cross-Reactivity, LOD, Interfering Substances, Strain Reactivity): Sample sizes vary by test and are described in the relevant sections (e.g., 143 samples for cross-reactivity with spiked bacteria/viruses in urine, 47 interfering agents tested).


3. Number of Experts and Qualifications for Ground Truth

The document does not explicitly state the number of experts or their specific qualifications (e.g., "radiologist with 10 years of experience") used to establish the ground truth. However, the ground truth for clinical studies (both retrospective and prospective) is defined as culture-confirmed results for S. pneumoniae and L. pneumophila infections, and "known negative" samples based on culture.

For the CSF study, patients were "suspected of meningitis," and the ground truth was also culture-confirmed S. pneumoniae.

Given that these are in vitro diagnostic tests, the "experts" in establishing ground truth would primarily be laboratory personnel performing culture confirmation, which is the gold standard for defining infection status.


4. Adjudication Method

The document does not describe any specific adjudication method (e.g., 2+1, 3+1 concensus) for establishing the ground truth for the test sets. The ground truth appears to be based on culture results, which typically do not require adjudication by multiple human interpreters in the same way imaging studies might.

For the reproducibility study, the reading and interpretation of the panels were performed visually by operators. Errors in reading (e.g., operator interpreted S. pneumoniae Band result as negative even though band was present) are mentioned, indicating potential for individual variability, but a formal adjudication process for disagreements is not explicitly stated beyond what happens when "invalid" results occur.


5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No multi-reader, multi-case (MRMC) comparative effectiveness study was performed or described. This device is an in vitro diagnostic (IVD) lateral flow assay, which is primarily a standalone test designed to provide a direct result, not an AI-assisted diagnostic tool for human readers. Therefore, there is no discussion of how human readers' performance might improve with AI assistance.


6. Standalone Performance

Yes, extensive standalone performance testing was done. The entire study described focuses on the "algorithm only" (i.e., the ImmuView test's intrinsic performance) without human-in-the-loop assistance for interpretation. The results in the tables for sensitivity, specificity, and agreement are all measures of the device's standalone performance against established ground truth (culture or comparator tests).


7. Type of Ground Truth Used

The primary type of ground truth used was culture confirmation for S. pneumoniae and L. pneumophila from urine and CSF samples.

  • Urine Retrospective Study: Culture-positive urine samples (blood culture positive for S. pneumoniae, culture confirmed for L. pneumophila) and known negative (culture confirmed negative) urine samples.
  • CSF Clinical Study: Culture-positive CSF specimens.
  • Prospective Study: Comparison with other lateral flow urine antigen tests (Comparator) was used, implying the Comparator's results served as an indirect ground truth or reference in this specific study, although the retrospective studies relied on culture.
  • Analytical Studies: Ground truth was based on known concentrations of purified antigens (pg/mL, ng/mL) or specific colony-forming units (CFU/mL) for LOD and strain reactivity, and known substances/organisms for cross-reactivity and interfering substances.

8. Sample Size for Training Set

The document does not explicitly mention a "training set" in the context of an algorithm or AI development. This product is a lateral flow immunoassay, a biochemical test, not a machine learning algorithm that undergoes a training phase. Therefore, the concept of a "training set" as it pertains to AI/ML models is not applicable here. The samples described were used for validation and performance evaluation.


9. How Ground Truth for Training Set Was Established

As explained under point 8, the product is a lateral flow immunoassay, not an AI/ML model. Therefore, there is no "training set" in the computational sense, and thus no ground truth establishment specific to a training set for an algorithm. All samples were used for validation and performance assessment, with ground truth established primarily by culture confirmation as described in point 7.

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March 5, 2020

SSI Diagnostica A/S % Christopher Bentsen Regulatory and Clinicals Consultant Bentsen Regulatory and Clinicals Consulting LLC 25803 NE 9th Street Redmond, Washington 98074

Re: K191184

Trade/Device Name: ImmuView S pneumoniae and L pneumophila Urinary Antigen Test Regulation Number: 21 CFR 866.3300 Regulation Name: Haemophilus Spp. Serological Reagents Regulatory Class: Class II Product Code: MJH, GTZ Dated: June 3, 2019 Received: June 10, 2019

Dear Christopher Bentsen:

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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

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

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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 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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 https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

Kristian Roth, Ph.D. Chief Bacterial Multiplex and Medical Counter Measures Branch Division of Microbiology Devices OHT7: Office of In Vitro Diagnostics and Radiological Health Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K191184

Device Name

ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test

Indications for Use (Describe)

Intended use

The ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test is an in vitro, rapid, lateral flow test, also known as a lateral flow immunochromatographic assay, intended for the qualitative detection of Streptococus pneumoniae and Legionella pneumophila antigens in urine specimens with symptoms of pneumonia. The assay is intended to aid in diagnosis of S. pneumoniae and L. pneumophila serogroup 1 infections. The assay is further intended to aid in the diagnosis of S. pneumoniae infection of S. pneumoniae antigen in cerebrospinal fluid (CSF). Results from the ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test should be interpreted in conjunction with the patient's clinical evaluation and other diagnostic methods.

X Prescription Use (Part 21 CFR 801 Subpart D)

Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) #K191184510(k) SUMMARYDate of Preparation: March 4, 2020
Submitter:Christopher Bentsen, M.S., RAC, FRAPS; Bentsen Regulatory and Clinicals Consulting LLC.
Submitters Address:Gig Harbor, Washington 98332
Submitters Number:(206) 910-1974
Sponsor:SSI Diagnostica A/S (SSID)
Contact:Dr. Pernille Landsbo Elverdal, VP R&D
Contact Number:0045 4111 2731
Device Name:ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test
Common Name:Urinary Antigen Test, Streptococcus pneumoniae and Legionella pneumophila serogroup 1
Classification:Streptococcus spp and Legionella spp serological reagents21 CFR 866.3740 and 866.3300
Product Codes:GTZ and MJH
Predicate Devices:BinaxNOW® Streptococcus pneumoniae (K012521) and BinaxNOW® Legionella (K982238)

Panel:

Microbiology

Intended Use:

The ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test is an in vitro, rapid, lateral flow test, also known as a lateral flow immunochromatographic assay, intended for the qualitative detection of Streptocccus pneumoniae and Legionella pneumophila antigens in urine specimens from patients with symptoms of pneumonia. The assay is intended to aid in diagnosis of S. pneumoniae and L. pneumophila serogroup 1 infections. The assay is further intended to aid in the diagnosis of S. pneumoniae infection of S. pneumoniae antigen in cerebrospinal fluid (CSF). Results from the ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test should be interpreted in conjunction with the patient's clinical evaluation and other diagnostic methods.

Indication(s) for use:

Same as Intended Use

Special conditions for use statement(s):

This device is for in vitro diagnostic use only. It is for prescription use only and to be used only by clinical laboratory professionals.

Special instrument requirements:

N/A

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Device Description:

ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test is a rapid lateral flow test for qualitative detection of S. pneumoniae in human urine and CSF samples and L. pneumophila (primarily serogroup 1) antigens in human urine samples. The test is effective in presumptive diagnosis of pneumococcal pneumonia caused by S. pneumoniae or Legionella pneumonia (Legionnaires' disease) caused by L. pneumophila, in conjunction with culture and other methods. Correct and early treatment is vital for the prognosis of both diseases and therefore quick methods to confirm both diseases in the initial phase are very important in order to initiate the proper antibiotic treatment as soon as possible.

Substantial Equivalence Information:

    1. Predicate device names(s): BinaxNOW" Streptococcus pneumoniae Card and BinaxNOW" Legionella pneumophila Card
    1. Predicate 510(k) number(s): K991726 and K012521 and K982238 and K070522

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Table 1 Comparison with predicate:

DescriptionImmuView S. pneumoniae andL. pneumophila UrinaryAntigen TestBinaxNOW® Streptococcuspneumoniae and BinaxNOW®Legionella Antigen Cards
Test FormatRapidimmunochromatographiclateral flow testRapid immunochromatographiccard tests
Quantitative/QuantitativeQualitativeQualitative
Test AntigenStreptococcus pneumoniaeand Legionella pneumophilaserogroup 1Streptococcus pneumoniae orLegionella pneumophilaserogroup 1
Specimen TypesHuman CSF and human urineHuman CSF and human urine
Reagents/ComponentsTest StripsTest TubesSample Running BufferNegative ControlPositive ControlPlastic transfer pipettesTweezerCardboard test tube holderTest CardsReagent APositive Control SwabNegative Control SwabSwabs
Antibody Sources
Test CardRabbit Polyclonal antibodiesRabbit Polyclonal antibodies
ConjugateRabbit Polyclonal antibodiesRabbit Polyclonal antibodies
Sample Preparation
Unpreserved andpreserved urineAdd 3 (120 ul) drops of urineor add 10 ul of CSF to a testtubeAdd 2 (90 ul) drops of samplerunning diluentMix wellAdd test strip with arrowdown1. Dip swab into the urine sampleand then insert swab into thebottom hole of the Test Card.2. Add 2 drops of Reagent A tothe bottom hole for LegionellaCard and 3 drops for S.pneumoniae Card.
Testing TimeApproximately 15 minutesApproximately 15 minutes
Equipment
General LaboratoryEquipmentUrine collection containerTimerVortex or mix by swirlingDisposable glovesUrine collection containerTimerSwab packDisposable gloves
Reading MethodVisualVisual
Results Interpretation
Visual ReadNegative: A single purple/grayControl line in the top of thestrip.Positive: For both S. pn. and L.pn. S-1 will show a pink/redline and a blue line.For S. pn. will show a pink/redline.For L. pn. S-1 will show a bluelineNegative: Single pink to purplecolored Control line visible in tophalf of the windowPositive: Two pink to purple lines
Invalid: No line at the Control line position and if there is adot instead of a test line.Also, if gray lines appear.Follow IFU instructionsInvalid: No line at the Control line position or no lines at the Control and Sample line positions.Test

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Principle:

ImmuView® S. pneumoniae and L. pneumophila Urinary Antigen Test is a rapid lateral flow test for detection of S. pneumoniae and L. pneumophila using the same test.

Clinical Sensitivity and Specificity for Urine Samples (Retrospective study)

To determine the sensitivity of the ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test, 100 frozen urine samples from patients originally determined to be infected with S. pneumoniae were tested. All 100 urine samples came from Europe, and all were from blood culture positive patients; Fortyeight (48) samples were from Sweden3 and fifty-two (52) samples were from Denmark.

To determine the sensitivity of the ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test, 98 stored frozen urine samples from patients with a culture confirmed Legionella infection were tested. A total of 55 urine samples came from Europe. The remaining 43 urine samples came from the United States (U.S.), and these were also determined to be previously positive in a urinary antigen test.

The clinical specificity of the ImmuView S. pneumoniae and L. pneumophila test lines was obtained by testing known negative (culture confirmed negative) urine samples collected from 3 sites, one in the U.S. and two in Europe.

S. pneumoniae culture verified vs. ImmuView
Culture positiveCulture negative
ImmuView pos784
ImmuView neg22217
Total100221
ImmuView Sensitivity78%95%CI (69.0-85.0%)
ImmuView Specificity98.1%95%CI (95.4-99.3%)
L. pneumophila culture verified vs. ImmuView
Culture positiveCulture negative
ImmuView pos861
ImmuView neg12239
Total98240
ImmuView Sensitivity87.8%95%CI (79.8-92.9%)

Table 1

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Table 3

ImmuViewComparator
Sensitivity (Urine) Based on culture vs comparator
S. pneumoniae(Blood culture only)78% (78/100)(CI 67-85%)80% (76/95a)(CI 71-87%)
L. pneumophila Sg 1(U.S.)97.7% (42/43)(CI 88-100%)100% (43/43)(CI 92-100%)
L. pneumophila Sg 1(Europe)80.0% (44/55)(CI 68-88%)66.7% (36/54b)(CI 53-78%)
Specificity (Urine) Based on culture vs comparator
S. pneumoniae(Europe)98.2% (217/221c)(CI 95-99%)97.8% (218/223)(CI 95-99%)
L. pneumophila(U.S.)100% (19/19)(CI 83-100%)100% (19/19)(CI 83-100%)
L. pneumophila(Europe)99.5% (220/221d)(CI 97-100%)99.6% (223/224)(CI 98-100%)

ª 5 samples were QNS for testing, º 1 sample was QNS for testing, º 3 samples were QNS for testing, º 3 samples were QNS for testing

S. pneumoniae sensitivity (Europe) increased to 81/100 or 81% for ImmuView S. pneumoniae and L. pneumophila urinary antigen test compared with comparator that after boiling had 76/95 or 80%. L. pneumophila sensitivity (Europe) changed to 41/55 or 74.6% for ImmuView and remained 36/54 or 66.7% for the comparator. The specificity (Europe) increased to 98.6% (218/221) and 100% (221/221) for S. pneumoniae and L. pneumophila respectively after boiling when using ImmuView. The comparator did not change after boiling. L. pneumophila sensitivity (U.S.) increased to 43/43 or 100% (95%Cl 91.8-100%) in the ImmuView Test for L. pneumophila after boiling2-2. L. pneumophila specificity (U.S.) did not change after boiling for either test.

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Positive and Negative Percent Agreement for urine samples

(Prospective study)

In a prospective study three-hundred-six (306) prospective collected urine samples from two different sites (Spain and Denmark) were tested with both the ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test and the Comparator tests. Fresh* urine samples were from patients (all comers) at risk of having community acquired pneumonia. The results were compared with other lateral flow urine antigen tests (Comparator).

ableT4
----------------
Prospective samples positive agreement S. pneumoniae
ImmuViewComparator positiveComparator negativeTotal
Positive72678
Negative3225228
Total75231306
Positive percent agreement96.0%95% CI (88.9%-98.6%)
Negative percent agreement97.4%95% CI (94.5%-98.8%)
Prospective samples positive agreement L. pneumophila SG1
ImmuViewComparator positiveComparator negativeTotal
Positive303
Negative0303303
Total3303306
Positive percent agreement100.0%95% CI (43.9%-100%)
Negative percent agreement100.0%95% CI (98.8%-100%)
  • Of the 306 samples, a total of 92 had to be frozen before testing could be performed.

The positive agreement for S. pneumoniae was 72/75 or 96% (88.9-98.6%). The negative agreement for S. pneumoniae was 226/232 or 97.4% (94.5-98.8). The positive agreement for L. pneumophila was 3/3 or 100% (43.9-100%). Negative agreement for L. pneumophila was 304/304 or 100% (98.8-100%).

After boiling22 the positive and negative agreement for S. pneumoniae and L. pneumophila remained the same.

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Analytical Studies - Urine

Specificity (Cross-Reactivity)

To determine the analytical specificity of the ImmuView S. pneumoniae and L. pneumophila Urinary Antigen test for cross-reactivity with urines spiked with whole cell bacteria and different inactivated viruses (N=143). The whole cell bacterial panel was tested in a 107 CFU/mL diluted from a stock solution. The Viral panel had a concentration of 105 TCID50/mL. The panel was also tested in negative urine.

Organisms tested for interference
Acinetobacter ssp.(4)Lactobacillus sp.
Bacillus subtilisListeria monocytogenes
Bordetella pertussisMorganella morganii
Moraxella catarrhalisMoraxella osloensis
Candida albicans (4)Mycoplasma genitalium
Citrobacter freundiiNeisseria gonorrhoeae (3)
Cornyebacterium sp.Neisseria lactamica
Cornyebacterium uralyticumNeisseria meningitidis
Enterobacter cloacae (3)Neisseria polysaccharea
Escherichia coli (10)Proteus mirabilis (2)
Enterococcus faecalis (7)Proteus vulgaris
Enterococcus faeciumPseudomonas aeruginosa (4)
Enterococcus duransPseudomonas stutzeri
Gardnerella vaginalisPseudomonas spp. (2)
Haemophilus Influenzae type a-f and non-caps (11)Salmonella bredeney
Haemophilus paraInfluenzaeSalmonella Thompson
Adenovirus 2,Salmonella typhimurium
Chlamydophila pneumoniae (2)Serratia marcescens
Chlamydia trachomatisStaphylococcus epidermidis
CytomegalovirusSalmonella glostrup
Enterovirus D68Streptococcus mutans (2)
Herpes Simplex 1,2Streptococcus parasanguis
Influenzae A (H1N1 and H3N2) virusStreptococcus sanguinis
Influenzae B VirusStreptococcus aureus (6)
ParaInfluenzae virus 1,2,3 (3)Streptococcus epidermidis (5)
Respiratory Syncytial Virus AStreptococcus saprophyticus (3)
Klebsiella oxytoca (2)Stenotrophomonas maltophilia
Klebsiella pneumoniae (3)Streptococcus gr. A, B, C, F, L and G (16)
Lactobacillus catenaformeStreptococcus mitis
Lactobacillus rhamnosus

Table 5

All of the above bacterial isolates were negative when using ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test. The only potential cross-reactivity was 1 of 3 isolates of E. cloaced which was positive for L. pneumophila. This was confirmed on re-testing of that one isolate.

A total of 19 Urinary tract infection from patients were tested. Previously culture results had shown that eight (8) of them were infected with Escherichia coli, five (5) with Staphylococcus, aureus, five (5) with Streptococcus agalactiae gr. B and one (1) with Candida albicans. None showed any cross reactions with the ImmuView test.

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Sensitivity (Limit of detection (LOD))

The limit of detection (LOD) for the ImmuView S. pneumoniae and L. pneumophila urinary antigen test is 62.5 pg/mL for purified S. pneumoniae CWPS antigen (native). For LPS specific for L. pneumophila SG1 (Philadelphia) the LOD is 25 ng/mL. Whole cell S. pneumoniae bacteria can be detected at an LOD at 105 CFU/mL and L. pneumophila SG1 (Philadelphia) has a LOD at 104 CFU/mL. Boiling or urine preservatives did not change these results.

Table 6

Stock solutionLOD
S. pneumoniae antigen62.5 pg/mL
L. pneumophila SG 1 (Philadelphia) antigen0.025 µg/mL
L. pneumophila SG 1 (Bellingham) antigen0.5 µg/mL
S. pneumoniae (serotype 1)105 CFU/mL
L. pneumophila SG1 (Philadelphia)104 CFU/mL
L. pneumophila SG 1 (Bellingham)105 CFU/mL

Strain Reactivity

lsolates from different S. pneumoniae serotypes were also positive tested with the ImmuView assay including serotype three (3), five (5), and thirty-seven (37). Different species of L. pneumophila were also found to be positive using the assay. Within serogroup one (1) these includes Philadelphia, Knoxville, OLDA/Oxford, Allentown/France, and Benidorm-Strain Lens. In additional studies have found other Legionella serogroups to be positive such as serogroup 3, 6, 8, 10 and 12.

Streptococcus pneumoniae in urine
SubgroupAntigen Concentration(µg/mL)Whole Organism Concentration(CFU/mL)
type 1ND*104
type 30.001104
type 50.010105
type 370.0001ND*
Legionella pneumophila in urine
SubgroupPontiac/Non-PontiacSpeciesConcentration(µg/mL)Concentration(CFU/mL)
SG1PontiacKnoxville0.100105
SG1PontiacAllentown/France0.005ND*
SG1PontiacBenidormND104
SG1PontiacPhiladelphia0.010104
SG1Non-PontiacOLDA/Oxford0.001ND
SG1Non-PontiacCamperdown0.315ND
SG1Non-PontiacHeysham1.250ND

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SG3250ND
SG6250ND
SG8250ND
SG10250ND
SG127.8ND

*ND=Not done

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Interfering Substances

ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test were tested with forty-seven (47) interfering agents at different concentrations in urine samples.

Table 8

AgentConcentrationAgentConcentration
Acetaminophen0.1mg/mLLeucocytes>250 cells/µL
Acetylsalicylic acid0.1mg/mLMiconazole5%
Amantadine0.03mg/mLMix (pH, whole blood, protein and glucose) (H)
Amoxicillin0.075mg/mLMix (pH, whole blood, protein and glucose) (M)
Amphotericin B0.22mg/mLMix (pH, whole blood, protein and glucose) (L)
Antihistamine0.22mg/mLMucin0.086mg/mL
Ascorbic acid (C-Vitamin)1mg/mLOseltamivir (Tamiflu)0.03mg/mL
Augmentin (Amoxicillin Clavulanate)0.22mg/mLOxalic acid0.01%
Azithromycin0.012mg/mLpH (acidic)4
Beet root20%pH (neutral)7
Beet root1.17%pH (basic)9
Beet root0.01%Plasma90%
Bilirubin0.2mg/mLPlasma50%
Bromhexin/cough drops/couch syrup0.22mg/mLPlasma10%
Caffeine15mg/mLPrednisone0.22mg/mL
Chlorophyll0.11mg/mLProtein (albumin) (H)10mg/mL
Chlorophyll0.04mg/mLProtein (albumin) (M)5mg/mL
Chlorophyll0.01mg/mLProtein (albumin) (L)0.6mg/mL
Ciprofloxacin0.22mg/mLPyridium1mg/mL
Decongestant0.22mg/mLRifampicin0.09mg/mL
Corticosterone (Corticosteroids)0.015mg/mLSpinach1%
Erythromycin0.067mg/mLTobacco purified0.4mg/mL
Glucose (H)20mg/mLTriglycerides4mg/mL
Glucose (M)10mg/mLUrea20mg/mL
Glucose (L)3mg/mLVaginal contraceptive gel5%
Hemoglobin5mg/mLVancomycin0.1mg/mL
Human albumin35mg/mLWater-based personal lubricant5%
Human red blood cells 10%10%White blood cells10%
Washed pooled cells
Ibuprofen0.1mg/mLWhole blood10%
Itraconazole0.22mg/mLWhole blood15%

High concentration of plasma in urine may result in gray test lines. Additionally, basic (pH≥9) conditions in urine can give false positive S. pneumoniae lines. Water-based personal lubricant might result in false positive or gray L. pneumophila lines, however, this outcome seems dose-related.

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Clinical sensitivity and specificity - CSF

The sensitivity of the S. pneumoniae test line was obtained by testing leftover CSF specimens from patients suspected of meningitis, as well as spiked CSF and negative CSF table 10 below.

Table 9

ImmuViewS.pn. Culture positiveS.pn. Culture negative
S.pn. Positive137
S.pn. Negative1162
Total14169
sensitivity92.9% (13/14)95% CI (68.5%-98.7%)
specificity96.0% (162/169)95% CI (91.7%-98.0%)

U.S.A Laboratory testing

Of the samples tested at the two U.S. labs, 9 were known positive for S. pneumoniae meningitis. Onehundred-thirteen (113) were negative human CSF samples were blinded, and the testing of the ImmuView Test was performed by three operators on different days to prevent test bias.

European Laboratory testing

Of the samples tested within Europe, 5 were known to be positive for S. pneumoniae. Of the total samples, 56 were negative CSF samples were blinded and the testing with the ImmuView Test was performed by one operator on different

days to prevent test bias.

The sensitivity of ImmuView L. pneumophila test line was not validated in this study, Legionella do not usually cause meningitis.

Spiked CSF testing

Additional human CSF samples were spiked at the LOD with S. pneumoniae (N=50) and an additional unspiked negative CSF samples (N=10) were tested with the Immuview test and the comparator test. The sensitivity for the both the ImmuView test and the comparator test was 50/50 (100%) and the additional negative CSF samples used for blinding of the testing were negative 10/10 (100%) in both the ImmuView test and the comparator test.

60 real human CSF samples 50 spiked with S. pneumoniae
ImmuViewComparator
S.pn. PositiveS.pn. NegativeTotal
S.pn. Positive50050
S. pn. Negative01010
Positive percentagreement100%95% CI (92.9%-100%)
Negative percentagreement100%95% CI (72.2%-100%)

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Analytical Studies - CSF

Specificity (Cross-Reactivity)

ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test were tested with a panel of 24 potential cross-reacting agents. No cross-reactions were detected for the S. pneumoniae or the L. pneumophila test lines.

Table 11

Organisms not affecting test performance in CSF
E. coli (5)Neisseria meningitidis Gr. B, D and W135 (3)
Haemophilus influenza type a-f and non-caps (7)Staphylococcus aureus
Listeria monocytogenesStreptococcus Gr A
MeaslesStreptococcus agalactiae (GBS) sg la, Ib, II, III (4)
Streptococcus mitis

Sensitivity (Limit of detection (LOD)) in CSF

ImmuView S. pneumoniae and L. pneumophila analytical sensitivity was determined by limit of detection. Two different operators performed the dilutions and the testing. The dilutions were made with whole cell bacteria spiked in human CSF.

CSFLoD
S. pneumoniae103 CFU/mL

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Interference agents

ImmuView S. pneumoniae and L. pneumophila Urinary Antigen Test were tested with forty-seven (47) interfering agents at different concentrations in artificial CSF either negative or spiked with either CWPS or S. pneumoniae 107 CFU/mL.

Table 13

Agent in CSFConcentrationAgentConcentration
Whole S. pneumoniae (Type 1)Negative Artificial CSF
Glucose (H)1mg/mLGlucose (H)1mg/mL
Glucose (M)0.5mg/mLGlucose (M)0.5mg/mL
Glucose (L)0.1mg/mLGlucose (L)0.1mg/mL
Red blood cells (H)15%Red blood cells (H)15%
Red blood cells(M)10%Red blood cells(M)10%
Red blood cells (L)5%Red blood cells (L)5%
Protein (H)60mg/mLProtein (H)60mg/mL
Protein (M)30mg/mLProtein (M)30mg/mL
Protein (L)10mg/mLProtein (L)10mg/mL
White blood cells10.6x106/mLWhite blood cells10.6x106/mL
White blood cells5.3x106/mLWhite blood cells5.3x106/mL
White blood cells2.7x106/mLWhite blood cells2.7x106/mL
White blood cells1.8x106/mLWhite blood cells1.8x106/mL
White blood cells0.9x106/mLWhite blood cells0.9x106/mL
Bilirubin
AntigenBilirubin
Bilirubin15%Bilirubin
Bilirubin10%Plasma
Bilirubin5%Plasma
Plasma15%Plasma
Plasma10%
Plasma5%

Red blood cells may give false positive shadows on the S. pneumoniae line due to excessive red color. The other agents in the panel did not interfere with the test.

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Reproducibility study

The ImmuView S. pneumoniae and L. pneumophila Urinary Antigen test demonstrated excellent overall reproducibility with 1,068 correct results out of 1,072 test results (99.6%), when tested with 10 members of real positive S. pneumoniae or L. pneumophila urine samples and negative urine samples; and artificial CSF positive spiked with S. pneumoniae isolates as well as negative artificial CSF samples. The ImmuView Positive Control and Negative Control were also tested as blinded/masked panel members. The testing was performed for 5 days with a different kit lot at each site, two in the U.S. and one in Europe.

DescriptionCorrect resultsAgreement
S. pneumoniae , moderate positive urine90/90 Positive100.0%
S. pneumoniae , moderate positive CSF89/892 Positive100.0%
S. pneumoniae , low positive spiked in artificial CSF89/903 Positive98.9%
S. pneumoniae , low positive urine90/90 Positive100.0%
L. pneumophila , moderate positive urine 2A90/90 Positive100.0%
L. pneumophila , moderate positive urine 2B88/894 Positive98.9%
L. pneumophila , low positive urine 1A89/895 Positive100.0%
L. pneumophila , low positive urine 1B89/906 Positive98.9%
Negative pooled urine90/90 Negative100.0%
Negative artificial CSF90/90 Negative100.0%
ImmuView Pos Control89/907 Positive98.9%
ImmuView Neg Control85/858 Negative100.0%
Summary1068/1072 Correct99.6%

Table 14

A total of 3 different lots were tested. Each site, using two operators (A and B) performed a total of 360 reproducibility tests and a grand total of 1,072 reproducibility results out of 1,080 tests in the study using 6 operators. A total of 8 test results (0.7%) were determined to be invalid and were excluded and not re-tested. The panel members were blinded by changing of the panel members and identity daily. The reading and interpretation of the reproducibility panels was performed visually. There were no statistical differences in reproducibility by lot, by time or by operator.

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  1. The protocol was run five different days, each day each sample had a different code number.

  2. Operator did not see a positive control band, so one sample was invalid as the package insert states that this is necessary before interpreting the result. The sample was not re-tested.

  3. A visual L. pneumophila band was seen.

  4. Operator interpreted band as S. pneumoniae positive instead of L. pneumophila positive. One sample was invalid due to dot (incomplete band) on the strip per the package insert and was not re-tested.

  5. One sample was invalid due to an incomplete band in S. pneumoniae according to the pack insert.

  6. No L. pneumophila band present.

  7. Operator interpreted S. pneumoniae Band result as negative even though band was present.

  8. Five samples excluded due to the presence of dots and incomplete bands. The samples were not retested.

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References

  • Rota MC, Fontana S, Montaño-Remacha C, et al. Legionnaires? disease pseudoepidemic due to 1. falsely positive urine antigen test results. J Clin Microbiol. 2014;52(6):2279-2280. doi:10.1128/JCM.00493-14
    1. Briones ML, Blanquer J, Ferrando D, Blasco ML, Gimeno C, Marín J. Assessment of analysis of urinary pneumococcal antigen by immunochromatography for etiologic diagnosis of community-acquired pneumonia in adults. Clin Vaccine Immunol. 2006;13(10):1092-1097. doi:10.1128/CVI.00090-06
    1. Athlin S, Iversen A, Özenci V. Comparison of the ImmuView and the BinaxNOW antigen tests in detection of Streptococcus pneumoniae and Legionella pneumophila in urine. Eur J Clin Microbiol Infect Dis. 2017;36(10):1933-1938. doi:10.1007/s10096-017-3016-6

§ 866.3300

Haemophilus spp. serological reagents.(a)
Identification. Haemophilus spp. serological reagents are devices that consist of antigens and antisera, including antisera conjugated with a fluorescent dye, that are used in serological tests to identifyHaemophilus spp. directly from clinical specimens or tissue culture isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by bacteria belonging to the genusHaemophilus and provides epidemiological information on diseases cause by these microorganisms. Diseases most often caused byHaemophilus spp. include pneumonia, pharyngitis, sinusitis, vaginitis, chancroid venereal disease, and a contagious form of conjunctivitis (inflammation of eyelid membranes).(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.