Title: Guidelines for Using the QuantiFERONTB Gold Test for Detecting M' tuberculosis Infection, United Sta
1Guidelines for Using the QuantiFERON-TB Gold
Test for Detecting M. tuberculosis Infection,
United States
- May 11, 2006
- Gerald Mazurek, M.D.
2Headlines
3Talk Objectives
- Summarize guidelines
- Describe the guideline development process
- Encourage further evaluation
4Guideline Summary
- QFT-G may be used in all circumstances in which
the TST is currently used - Further research is needed regarding use of
QFT-G
5Guideline Development Process
- Establish guideline objectives
- Identify representative experts
- Review evidence on testing
- Develop consensus
- Publish guidelines
6Guideline Objectives
- Make recommendations from public health
perspective - Address knowledge gaps
- Encourage further evaluation
- Provide reference for other guidelines
7Representatives
- Academic Institutions
- Local Health Departments
- Neil Schluger
- Hank Blumberg
- John Bernardo
- Gail Woods
- David Lewinsohn
- Randall Reves
- Jessie Wing
- Esmaeil Porsa
- Other Associations
- Rachel Stricof (APIC)l
- Ray Chinn (HICPAC)
- Edward Ellis (Can. MOH)
- Stephen Kralovic (VA)
- Tanya Oemig (NTCA)
- Nancy Warren (APHL)
- (ACET)
- Masae Kawamura
- Mike Iseman
- Chuck Daley
- Dick Menzies
- Frank Wilson
- Ed Nardell
- Madhu Pai
- CDC
- Ken Castro
- Andy Vernon
- Michael Iademarco
- John Jereb
- Elsa Villarino
- Rachael Albalak
- Beverly Metchock
- Jerry Mazurek
- Phillip LoBue
- David Weissman
- Cellestis
- Jim Rothel
- Tony Catanzaro
- Tony Radford
8Review of Evidence
- Literature search
- Meeting at ATS (May 2005)
- Unpublished studies
- Consultation meeting at CDC (July 2005)
9QFT-G vs. TST
- in vitro
- Specific TB antigens
- Boosting not likely
- 1 patient visit
- Results in gt 1 day
- Stimulate w/i 12 hrs
- Unknown risk if
- Includes Control
- Minimal inter-reader variability
- in vivo
- Less specific PPD
- Boosting
- 2 patient visits
- Results in 2 - 3 days
- Read in 48 - 72 hrs
- Increased TB risk if
- No Control
- Inter-reader variability
10Limitations
- Inadequate diagnostic standards
- Unable to confirm clinical TB
- Unable to confirm LTBI
- Few reports using QFT-G or similar tests
- Variations in antigens used
- Variations in methods
11Addressing Limitations
- Sensitivity in people with culture TB
- Sen positives / tested
- Specificity in people at low risk for TB
infection - Spec negative / tested
- Test agreement in various populations
- Agreement concordant / tested
- Review both published unpublished data
12Sensitivity Estimates
- ? Subset of 118 tested by TST using Nippon PPD
1 of 5
13Sensitivity Estimates
2 of 5
14Sensitivity Estimates
3 of 5
15Sensitivity Estimates
4 of 5
16Sensitivity Estimates
- 81 to 89 IFN excluding indeterminates
5 of 6
17Sensitivity Estimates
- 81 to 89 IFN excluding indeterminates
- 71 to 88 IFN including indeterminates
6 of 6
18Specificity Estimates
- ? Subset of 213 tested by TST using Nippon PPD
- Specificity 98
4 of 4
19Specificity Estimates
4 of 4
20Specificity Estimates
4 of 4
21Specificity Estimates
- 96 to 99.8 specificity w/o indeterminates
- 96 to 98.9 specificity including indeterminates
4 of 4
22Assessments of TST QFT-GAgreement
23Test Agreement in Korea
- Increase agreement with increased chance of
infection
(n 273)
Percent positive
Kang 2005
24Test Agreement in US
- Good agreement for low-risk and TB patients
- Less agreement with risk for LTBI for contacts
(n 1,500)
Percent positive
CDC Unpublished
25Test Agreement in US Navy Recruits
- Greater association of TST with risk than QFT-G
(n 810)
Percent positive
TB cases/100K in the recruits country of birth
CDC Unpublished
26Test Agreement in Contacts US
- Greater TST association with exposure than QFT-G
(n 446 exposed to AFB Respiratory TB)
Percent positive
CDC Unpublished
27Test Agreement in Inmate US
- 474 Harris Co. Jail inmates
- Factors associated with TST / QFT-G negative
discord - African-American race
- Foreign birth
- Prior incarceration
Porsa 2006
28Test Agreement in Contacts Denmark
- Good agreement between TST QFT-RD1
No BCG
BCG
Percent positive
Brock, 2004
29Other Unpublished Studies
- QFT-GIT in a Dutch investigation - S. Arend
- QFT-G in Australian HCWs - P. Vinton
- QFT-G in Japanese HCWs - N. Harada
- QFT-G in hospitalized persons in Italy - L.
Richeldi - Other studies - J. Rothel
30Develop Consensus
- Available evidence
- Expert opinion
- Guidelines
31Guideline Summary
- QFT-G may be used in all circumstances in which
the TST is currently used - Further research is needed regarding use of
QFT-G
32Examples of Research Need
- Risk of future TB if QFT-G
- Reproducibility (conversions, reversions)
- Effect of treatment on QFT-G
- Performance in special populations
- Threshold for IFN-? response
- Timing of QFT-G conversion after infection
- Programmatic use - PPV NPV - costs
- Implementation - Rx completion rates
33Published Guidelines