Performance%20of%20Bio-Rad%20Genetic%20Systems%20HIV-1/HIV-2%20Plus%20O%20EIA%20Followed%20by%20Multispot%20or%20OraQuick%20Advance%20in%20a%20Dual%20Immunoassay%20HIV%20Testing%20Strategy - PowerPoint PPT Presentation

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Performance%20of%20Bio-Rad%20Genetic%20Systems%20HIV-1/HIV-2%20Plus%20O%20EIA%20Followed%20by%20Multispot%20or%20OraQuick%20Advance%20in%20a%20Dual%20Immunoassay%20HIV%20Testing%20Strategy

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Performance of Bio-Rad Genetic Systems HIV-1/HIV-2 Plus O EIA Followed by Multispot or OraQuick Advance in a Dual Immunoassay HIV Testing Strategy – PowerPoint PPT presentation

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Title: Performance%20of%20Bio-Rad%20Genetic%20Systems%20HIV-1/HIV-2%20Plus%20O%20EIA%20Followed%20by%20Multispot%20or%20OraQuick%20Advance%20in%20a%20Dual%20Immunoassay%20HIV%20Testing%20Strategy


1
Performance of Bio-Rad Genetic Systems
HIV-1/HIV-2 Plus O EIA Followed by Multispot or
OraQuick Advance in a Dual Immunoassay HIV
Testing Strategy
  • Laura Wesolowski, PhD
  • S. Michele Owen, PhD
  • Debra Candal, BS
  • Susan Phillips, BS
  • Steve Ethridge, BS, MT (ASCP)
  • Duncan MacKellar (MA, MPH)

Diagnostic Applications Team, Behavioral and
Clinical Surveillance Branch, Centers for Disease
Control and Prevention
2
Objectives
  • To assess the sensitivity and specificity of a
    dual immunoassay testing strategy using Bio-Rad
    HIV-1/HIV-2 Plus O EIA (A1) followed by Multispot
    HIV-1/HIV-2 rapid test (A2) for HIV-1 diagnosis
  • To describe the concordance of A2 test
    (Multispot) when run in duplicate
  • To assess the sensitivity of a dual immunoassay
    testing strategy using Bio-Rad EIA (A1) and
    OraQuick Advance (A2) rapid test for HIV-1
    diagnosis

3
Background
  • Lack of performance data for EIA followed by
    rapid test
  • Concern about similarity of antigens in EIAs and
    rapid tests on market
  • may contribute to dual false positives
  • Bio-Rad EIA
  • 3rd generation EIA (detects IgG and IgM)
  • Serum or plasma
  • Sensitivity 100 (99.84-100)
  • Specificity 99.89 (99.83-99.96)

4
Background Multispot
  • Serum or plasma
  • Sensitivity
  • Serum and plasma
  • 100 (99.94-100)
  • Specificity
  • Serum
  • 99.93 (99.79-100)
  • Plasma
  • 99.91 (99.77-100)

5
Background OraQuick Advance
  • Whole blood or plasma
  • Sensitivity
  • Whole blood
  • 99.6 (98.5 - 99.9)
  • Plasma
  • 99.6 (98.9-99.9)
  • Specificity
  • Whole blood
  • 100 (99.7-100)
  • Plasma
  • 99.9 (99.6-99.9)

6
Methods HIV-1 uninfected specimens
  • HIV-uninfected specimens plasma samples from
    uninfected blood donors
  • EIA negative (Abbott HIV AB HIV-1/HIV-2 (rDNA))
  • Pooled HIV-1 PCR-negative (Roche Ampliscreen)
  • Uninfected specimens tested with Bio-Rad EIA and
    Multispot (in duplicate) at CDC. Not tested with
    OraQuick yet.

7
Methods HIV-1 infected specimens
  • HIV-1 infected specimens Serum Western blot
    positive specimens from CDCs Validating
    Supplemental Testing to Confirm Preliminary
    Positive Rapid HIV Tests
  • CDC IRB Approved Feb. 2006
  • Enrollment began March to June 2006
  • Enrollees from 6 study sites
  • AIDS Research Consortium of Atlanta, GA
  • Denver Metro Health (STD) clinic
  • Philadelphia FIGHT, Jonathan Lax HIV Clinic
  • Howard Brown Health Center, Chicago, Gay
    Lesbian Health Clinic
  • Louisville Hospital, Louisville, KY, WINGS STD
    Clinic
  • University of MD Baltimore, Evelyn Jordan Center
    (HIV Clinic)
  • Reference laboratory University of MD

8
Methods HIV-1 infected specimens
  • Inclusion criteria
  • Previously diagnosed with HIV infection
  • No antiretrovirals within 3 months
  • Not pregnant
  • 18 - 55 years
  • Understand English
  • Infected specimens tested at UMD (Bio-Rad EIA)
    and CDC (Multispot in duplicate)
  • OraQuick Advance conducted at study site using
    whole blood (not in duplicate)

9
Methods Outcomes
  • Specificity and sensitivity for Bio-Rad EIA (A1)
    followed by Multispot (A2) individually and
    together in dual test strategy
  • Concordance of Multispot results run in duplicate
  • Sensitivity for Bio-Rad EIA (A1) followed by
    OraQuick Advance (A2) individually and together
    in dual test strategy

SpecificityTrue negative/(true negative false
positive) SensitivityTrue positive/(true
positive false negative)
10
Results Specificity Bio-Rad EIA and Multispot
  • Among 302 HIV-uninfected persons
  • 4 false positive on Bio-Rad EIA
    (specificity298/30298.7)
  • 7 false positive on Multispot (specificity295/302
    97.7)
  • 0 false positive on both Bio-Rad EIA and
    Multispot

11
Strategy 3. HIV-1/2 dual immunoassay for 4
initially false positive on Bio-Rad EIA (truly
uninfected)



A1 BioRad EIA

A1 ()
A1 (-)
Negative for HIV-1 and HIV-2 antibodies

A1 (- -)
Repeat A1 in duplicate
A2 Multispot in duplicate
A2 (- -)
A1 ( or -)
A2 ( or -)

Inconclusive for HIV antibodies request plasma
redraw for NAAT Requires medical follow-up for
further evaluation and testing
Presumptive positive for HIV-1 or HIV-2
antibodies requires medical follow-up for
further evaluation and testing


HIV-2 Testing Strategy 5, if applicable
Must be a different EIA, CIA, or non-waived
rapid test depending on laboratory setting (for
A2 only) If window period infection is
suspected based on risk assessment or discordant
testing, refer to Acute HIV Infection Testing,
Strategy 4

12
Results Specificity Bio-Rad EIA and Multispot
  • Strategy specificity excluding those with
    inconclusive results300/300100
  • 2 uninfected persons eventually get correct
    results, but in the interim will be told that
    their results are inconclusive and have to wait
    for correct results after NAAT testing

13
Results Sensitivity Bio-Rad EIA and Multispot
  • Among 1065 HIV-infected persons
  • 0 false negative on Bio-Rad EIA
    (sensitivity1065/1065100)
  • 1 false negative on Multispot (sensitivity1064/10
    6599.9)
  • 0 false negative on both Bio-Rad EIA and
    Multispot

14
Strategy 3. HIV-1/2 dual immunoassay for 1
person false negative on Multispot (truly
infected)


A1 BioRad EIA

A1 ()
A1 (-)
Negative for HIV-1 and HIV-2 antibodies

A1 (- -)
Repeat A1 in duplicate
A2 Multispot in duplicate
A2 (- -)
A1 ( or -)
A2 ( or -)

Inconclusive for HIV antibodies request plasma
redraw for NAAT Requires medical follow-up for
further evaluation and testing
Presumptive positive for HIV-1 or HIV-2
antibodies requires medical follow-up for
further evaluation and testing


HIV-2 Testing Strategy 5, if applicable
Must be a different EIA, CIA, or non-waived
rapid test depending on laboratory setting (for
A2 only) If window period infection is
suspected based on risk assessment or discordant
testing, refer to Acute HIV Infection Testing,
Strategy 4

15
Results Sensitivity Bio-Rad EIA and Multispot
  • Strategy sensitivity excluding those with
    inconclusive results1064/1064100
  • 1 HIV-infected person likely have inconclusive
    results and would have to await NAAT results

16
Results Multispot duplicates
  • All Multispots same result on duplicate as when
    initially run (i.e. non-reactive on both test
    runs or reactive on both test runs)
  • Testing in duplicate did not provide any
    additional information on infection status for
    those with false positive or false negative
    results

17
Results Sensitivity Bio-Rad EIA and OraQuick
  • Among 1065 HIV-infected persons
  • 0 false negative on Bio-Rad EIA
    (sensitivity1065/1065100)
  • 0 false negative on OraQuick (whole blood)
    (sensitivity1065/1065100)
  • 0 false negative on both Bio-Rad EIA and OraQuick
  • Strategy sensitivity1065/1065100

18
Conclusions
  • Dual test strategy using Bio-Rad EIA and
    Multispot has high sensitivity and specificity.
    However, some persons would receive inconclusive
    results and require additional testing to get
    correct result.
  • Conducting the secondary screening test in
    duplicate does not appear to be beneficial.
  • Dual test strategy using Bio-Rad EIA and OraQuick
    has high sensitivity, though specificity should
    be evaluated.

19
Next steps
  • Continue testing samples with Bio-Rad EIA,
    Multispot and OraQuick
  • Obtain challenge specimens (false EIA positive,
    NAAT negative) to challenge dual immunoassay
    strategy

20
Acknowledgements
  • PIs staff from 6 study sites
  • University of MD Laboratory of Viral Diagnostics
  • MDC Associates, Joanne Lebrun
  • CDC
  • Bernard Branson
  • Maxia Dong
  • Tim Granade
  • Dollene Hemmerlein
  • Sheryl Lyss
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