traditional and novel diagnostic tests of tb infection toru mori, md, phd research institute of...
TRANSCRIPT
Traditional and Novel Diagnostic Tests of TB Infection
Toru Mori, MD, PhD
Research Institute of Tuberculosis/JATANational Institute of Infectious Diseases, Japan
1st Asia Pacific Region Conference of IUATLDKuala Lumpur, Aug 2-5, 2007
Roles of TB Infection Roles of TB Infection DiagnosisDiagnosis
• Indication for treatment of LTBI• Adjunct to diagnosis of TB Disease• Decision making for contact actions• Monitoring of infection control• Epidemiological surveillance and
research
0%
5%
10%
15%
20%
25%
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Induration diamter (mm)
Tuberculin Reaction in TB PatientsTuberculin Reaction in TB Patients( Bacteriologically Confirmed Patients, PPD 0.05mcg )
No. 602Mean 16.1mmS.D. 4.6mm
(Mori et al, 1975)
Tuberculin Reactions of Uninfected InfantsTuberculin Reactions of Uninfected Infants(Infants 0 to 3 Years(Infants 0 to 3 Years ))
86.4
0.10.10.20.20.5
0.71.0
1.51.6
3.0
4.6
0
2
4
6
8
10
0 4 8 12 16 20 24 28 32 36 40
Erythema (mm)
(%)
Total 10,71010mm+ 2.9%20mm+ 0.29%30mm+ 0.02%
0.00.0 0.0
(Okinawa Pref, 1982)
Tuberculin Reaction after 6 Months of BCTuberculin Reaction after 6 Months of BCG VaccinationG Vaccination
(Infants, Erythema, N=103)
0%
5%
10%
15%
20%
25%
30%
35%
0-4 10-14 20-24 30-34 40-44
Erythema (mm)
Mean 21.3mm>=10mm 91.3%>=30mm 13.6%
(Mori, 1980)
Problems of TST in Infection DxProblems of TST in Infection Dx
• Confounded by BCG history
• Confounded by environmental mycobacteria
• Booster phenomenon
• Variability in administering and reading
• Needs two visits
Specific Antigens ESAT-6/CFP-10Specific Antigens ESAT-6/CFP-10
Tuberculosis complexTuberculosis complexM. tuberculosisM. tuberculosis M. africanumM. africanumM. bovis M. bovis (Other than BCG)(Other than BCG) M. lepraeM. leprae
Environmental strainsEnvironmental strainsM. kansasiiM. kansasii M. marinumM. marinum M. szulgaiM. szulgaiM. flavescensM. flavescensM. gastriiM. gastrii
M. bovis BCG All substrains
Environmental strainsM. intracellulare M. avium
Present in Absent from
Interferon-gamma Release Assays (IGRAs)Interferon-gamma Release Assays (IGRAs)
Enzyme-linked Enzyme-linked Immunosorbent assayImmunosorbent assay
QuantiFERON-TB Gold T-SPOT.TB
Enzyme-linked Enzyme-linked immunospotimmunospot
PBMC separated
Whole bloodWhole blood
Plasma separated
Stimulation with Antigens
ESAT-6 CFP-10 ESAT-6 or CFP-10* ESAT-6 CFP-10 ESAT-6 or CFP-10*
0.0
0.5
1.0
1.5
2.0
10
20
30
2
TB Disease Low Risk for TB
n = 118
n = 220
n = 217 n = 217
n = 118 n = 118
IFN
-gam
ma
(IU
/mL
)Responses to CFP-10 & ESAT-6 for each study groupResponses to CFP-10 & ESAT-6 for each study group
Nursing students
Cut-off
(Mori et al, 2004)
0%
5%
10%
15%
20%
25%
30%
0 10 20 30 40 50 60 70 80
Induration diameter (mm)
TST Distribution and QuantiTST Distribution and QuantiFERON FERON (+)(+)
(BCG-vaccinated Healthy Subjects, N=220,
*QTF(+))
** **
(Mori et al, 2004)
63%
86%82%
86%
100%92%
82%
0%
20%
40%
60%
80%
100%
0-4 5-9 10-14 15-19 20-24 25+ Total
Induration size (mm)
QTF Positivity according to Mantoux test SizeQTF Positivity according to Mantoux test Size(TB Patients, Over-all QFT-Positivity = 82%, p for Linear trend
=0.002)
(Mori et al, 2004)
Sensitivity, TB PatientsSensitivity, TB Patients QFT-G, ESAT-6+CFP-10QFT-G, ESAT-6+CFP-10
Pooled 0.81 (0.76-0.84)Chi-sq=17.1, df=8, p=0.03I2 = 53%
Sensitivity, TB PatientsSensitivity, TB Patients TSTTST
Pooled 0.73 (0.67- 0.78)Chi-sq=15.2, df=7, p=0.03I2 = 54%
1.00 (0.54 - 1.00)0.83 (0.63 - 0.95)0.83 (0.61 - 0.95)0.78 (0.64 - 0.88)0.74 (0.63 - 0.82)0.70 (0.46 - 0.88)0.66 (0.54 - 0.76)0.33 (0.07 - 0.70)
QFT-G & QFT-GIT ComparedQFT-G & QFT-GIT ComparedUntreated TB PatientsUntreated TB Patients
QFT-GIT
Positive Negative Total
QFTG
Positive77
(81.9%)
1
(1.1%)
78
(83.0%)
Negative10
(10.6%)
6
(6.4%)
16
(17.0%)
Total87
(92.6%)
7
(7.4%)
94
(100%)
Sensitivity QFT-G=83.0% QFT-GIT=92.6% (p=0.006) kappa=0.466(Harada et al, submitted)
Sensitivity, TB PatientsSensitivity, TB Patients QFT-G-IT, ESAT-6+CFP-10+TB7.7QFT-G-IT, ESAT-6+CFP-10+TB7.7
Pooled 0.78 (0.71- 0.83)Chi-sq=27.5, df=4, p=0.000I2 = 89%
Specificity, BCG-vaccinatedSpecificity, BCG-vaccinated Low-riskLow-risk QFT-G, ESAT-6+CFP-10 (+TB7.7)QFT-G, ESAT-6+CFP-10 (+TB7.7)
Pooled 0.97 (0.95- 0.98)Chi-sq=13.5, df=5, p=0.019I2 = 63%
1.00 (0.82-1.00)0.99 (0.96-1.00)0.98 (0.95-0.99)0.97 (0.87-1.00)0.96 (0.90-0.99)0.92 (0.85-0.96)
0
2
4
6
8
10
12
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 1100
2
4
6
8
10
12
14
16
18
20
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110
Index Case : A Student, aged 22 yearsIll for 2 mos, Heavily Smear Positive, Secondary cases: 12Close contacts: 220 QFT(+) 32.7 % (+-) 15.9 % (-) 52.3 %
Other contacts: 135 QFT(+) 0.7 % (+-) 0.7 % (-) 98.5 %
( Funayama et al, 2005)
A TB Outbreak in a University
QFT-Negative N=148 QFT-Positive N=72
Results Age in mosTotal (N=195)
QFT TST <36 mos (N=113) >36mos (N=82)
+ + 14 14 28
+ - 4 1 5
- + 7 12 19
- - 88 55 143
QFT(+)% 15.9 (9.2 – 22.7) 18.3 (9.9 – 26.7) 16.9 (11.7 – 22.2)
TST(+)% 18.6 (11.4 – 25.8) 31.7 (21.6 – 41.8) 24.1 (18.1 – 30.1)Agreement 0.903 0.841 0.877
κ 0.660 0.587 0.626
( Submitted)
QFT/TST on TB Contact ChildrenQFT/TST on TB Contact Children( Cambodia, 0 ~ 5 yo , N=195 , Okada et al, 2006)
Indian TB Suspects Study(1-12 yrs, N=106, In-Tube QFT-G, Dogra, 2006)
QFT+ QFT- Total Agreement κ-coeff.
Cut-off:>=5mm
TST+ 8 8 16
0.8950.53
(0.34-0.71)TST- 3 86 89
Total 11 94 105
Cut-off:>=10mm
TST+ 8 2 4
0.9520.73
(0.53-0.92)TST- 3 92 95
Total 11 94 99
Cut-off:>=15mm
TST+ 4 0 4
0.9330.50
(0.33-0.66)TST- 7 94 101
Total 11 94 105
Indian TB Suspects Study (cont’d)(1-12 yrs, N=106, In-Tube QFT-G, Dogra, 2006)
TST(>=10mm) QFT (0.35IU/mL)
No.Pos
/Tested (%)OR, adjusted
No.Pos
/Tested (%)OR, adjusted
Age
1-4 yrs 2/42 (5) 1 2/42 (5) 1
5-9 yrs 2/33 (6) 1.16 (0.14,9.49) 3/33 (9) 2.02 (0.30,13.5)
9-12 yrs 6/30 (20) 5.69 (0.95,33.8) 6/30 (20) 5.92(1.02,34.5)
Contact
No 7/89 (8) 1 8/89 (9) 1
Yes 3/16 (19) 2.48 (0.51,11.9) 3/16 (19) 2.00 (0.42,9.35)
QFT Level at TB Detection among Contacts( Comparison with LTBI, Harada et al, 2007, submitted)
Active TB LTBI0.1
1
10
100
IFN
-ga
mm
a p
rod
uc
tio
n (
IU/m
l)
Adj.O
R95%CI p
Sex 0.8450.31
72.25
20.73
6
Age group
1.6331.05
42.53
0.028
TST 0.7170.44
61.15
20.16
9
QFT (CFP/ESAT)
1.8491.20
92.82
90.00
5
N=35 N=76
Factors contributing to TB Onset(Multivariate analysis)
TB Risk according to Parameter Value( Induration size for TST, Quartile grade for QFT)
11.14
1
2.48
1
1.40.950.780.951
4.04
1.35
2.481.58
1.131.59
0.1
1
10
1 2 3 4 1 2 3 4 1 2 3 4 Od
ds
rati
o
-14 -19 -24 25+
TST ESAT-6 CFP-10 ESAT/CFP*
*Chi2 for trends p=0.028 ( Harada et al, submitted)
QFT in Healthy General QFT in Healthy General PopulationPopulation
(Japan, Rural Community, N=1,559)(Japan, Rural Community, N=1,559)
7%
10%
6%
3%
0%
5%
10%
15%
40-49 (291) 50-59 (607) 60-69 (661) Total
Age (years)
%
(Mori et al, 2007)
Age- group 1950 2005
0- 8 0.1
5- 25 0.3
10- 38 0.6
15- 50 0.9
20- 59 1.3
25- 66 1.8
30- 72 2.7
35- 77 4.2
40- 81 6.8
45- 85 11
50- 88 18
55- 90 29
60- 92 42
65- 93 53
70- 94 61
75- 95 68
80- 96 74
Age-specific Prevalence of TB InfectionAge-specific Prevalence of TB Infection( Japan, Estimated, Years 1950 & 2005)
0
20
40
60
80
100
0 10 20 30 40 50 60 70 80
Age (years)
19502005
(Mori, 2005)
QFT in Healthy General QFT in Healthy General PopulationPopulation
(Comparison with Estimated Prevalence of TB Infection)
8%
22%
47%
30%
7%10%
6%3%
0%
10%
20%
30%
40%
50%
40-49 50-59 60-69 Total
Age (years)
%
QFT(+) Estimated
(Mori et al, 2007)
QFT according to Types of X-ray TB QFT according to Types of X-ray TB FindingsFindings
(Predicted: Expected from Rate of those with No TB Finding, Age (Predicted: Expected from Rate of those with No TB Finding, Age adjustedadjusted ))
11.1%
19.4%
6.9% 7.6%
13.7%
6.5% 7.1%
0%
10%
20%
30%
No TB Finding Possible Probable Certain
ObservedPredicted
( 1,359) ( 51) ( 45) ( 31)
[ Example ] Certain : Fibrotic lesion Probable: Calcification ・ Pleural adhesion . Possible : Apical cap
1 1.93 1.60 2.54
(Mori et al, 2007)
Change in QFT after Treatment of LTBI (1)Change in QFT after Treatment of LTBI (1)
ESAT-6 CFP-10
0.999 >> 0.272 IU/ml (p=<0.001) 0.346 >> 0.124 IU/ml (p=004)GeometricMean
0.01
0.1
1
10
100
1 2
Before After
IFN
-g p
rodu
ctio
n (I
U/m
l)
0.001
0.01
0.1
1
10
100
1 2
Before After
IFN
-g p
rodu
ctio
n (I
U/m
l)
(Higuchi et al, 2007)
Change in QFT after Treatment of LTBI (2)Change in QFT after Treatment of LTBI (2)(TB Outbreak in a mental hospital, with >15 secondary cases)(TB Outbreak in a mental hospital, with >15 secondary cases)
6 mos treatment completed ( 7(25%) reverted )
N=28 ESAT-6 0.999 0.272
CFP-10 0.346 0.124
Interrupted (< 3 mos) ( No reversion )
N=5 ESAT-6 0.743 0.729
CFP-10 0.595 0.572
1.5 Years after Treatment ( No net reversion )
N=17 ESAT-6 0.381 0.442
CFP-10 0.087 0.192(Higuchi et al, 2007)
89.6 90.9
75.6
46.2
0
20
40
60
80
100
0 1 6 15
Treatment month
Pos
itiv
e ra
te %
QFT Profile in TB Patients during and after ChemotherapyQFT Profile in TB Patients during and after Chemotherapy(N=50, Aoki et al, 2006)(N=50, Aoki et al, 2006)
IGRAs in Special SettingsIGRAs in Special Settings1. Children1. Children
• QFT(+) in 30 clinically diagnosed TB patients aged 0-14 years in Japan (Takamatsu et al, 2007); 77% (62 – 92%)
• For 41 patients aged 0-5 years in Italy (Russo, 2007); 88.0-95.6%
• In India (Dogra et al, 2006) and Cambodia (Okada et al, 2007), QFT-G gave results comparable with TST in family contact children.
• In Nigeria QFT-GIT detected more LTBIs than TST, regardless of age (0-4/5-9/10/14) (Nakaoka et al, 2007)
• IFN-G response to mitogen is lower in young infants, causing more “Indeterminate” results. (Harada et al, 2007)
IFN-G Release to Mitogen according to Age(Age: 0-95 years, N=12,856)
0
2
4
6
8
10
12
14
16
18
0 5 10 15 20 30 50 70 90
Age in years
IU/m
L
4.8%
1.7%
1.1%
0.5% 0.6%
2.0%
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
0-4 5-9 10-14 15-19 20-59 60+
Age group (years)
Mean value Frequency of “Indeterminate”
(Harada et al, unpublished)
IGRAs in Special SettingsIGRAs in Special Settings2. Aged subjects2. Aged subjects
34.5%
23.8%
9.1%
26.2%
0%
10%
20%
30%
40%
-79(29) 80-89(21) 90+(11) Total(61)
Age in yrs (Number tested)
(Nursing home residents, N=61, Mean age =79.9 yrs, Chi-square for linear trend=2.68, p=0.101)
(Suzuki, Harada et al)
In other sample, the “indeterminate” results are commoner in the aged
subjects; 2.0% for 60+years vs 0.6 for 20-59 years. (p=0.00)
QFT-G vs TST by Age in TB PatientsQFT-G vs TST by Age in TB Patients
90100 94 100
90 92
80
93100
58
75
50
75
55
17
64
0
20
40
60
80
100
-30,n=19
31-40,n=14
41-50,n=16
51-60,n=19
61-70,n=19
71-80,n=13
>80,n=10
Total,n=110
Age, Number of subjects
Pos
itiv
e ra
te, %
QTF
Mx
IGRAs in Special SettingsIGRAs in Special Settings3. Immunocompromized hosts3. Immunocompromized hosts
• In rheumatic patietns receiving immuno-suppressive therapy IFN-gamma assay was superior compared to the TST for detection of LTBI. (Matulis et al, 2007)
• In HIV+ patients, those with a CD4 count ≤ 200 were more likely to have an indeterminate test 200 were more likely to have an indeterminate test result. Further studies are needed to assess utility of IGRAs. (Talati et al, 2007)
• In hematological malignancy patients, IGRA produced more positives than TST. (Losi et al, 2007)
QTF-TB2G as Compared with QTF-TB2G as Compared with TSTTST
• Strengths– Specific– Sensitive – Reliable– Needs one visit
only– No booster effect
• Weaknesses– Cost– Needs whole blood– Labor intensive– Stimulation <12hrs– Technical/
Instrument
Uses of QFTTB Control of Healthcare Workers
On Employment: Replace Two-Step TSTWhen exposed to TB: without TST
Contact InvestigationWith / without TST
Clinical DiagnosisDifferentiate TB / NTM / Tumor . . . . Prescribe Rx of LTBI in High Risk Subjects
(Jap Soc TB, 2006)
Further Research NeedsFurther Research Needs
PerformancesTime from Infection to Positive ConversionRelationship with Risk of Clinical BreakdownInfluence of TB Treatment, Response in “Old” InfectionsDifference in Response between different antigensDifference from TST: Effect of prolonged incubation (effect
or vs memory cells?)Children & Infants
ProceduresTest with Smaller amount of Blood ( for Children )Time until Stimulation→QFT-3G
Costs
Acknowledgment
• Collaborators– Dr. Harada N (RIT/JATA), – Dr. Higuchi K (RIT/JATA), – Dr. Takamatsu (Osaka Municipal Respiratory &
Allergy Center)
• Funded partly by the Emerging and Reemerging Diseases Study Grant, Ministry of Health, Labor & Welfare, Japan.