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Interferon-gamma release assay as a diagnostic test for tuberculosis-associated uveitis.

Ang M, Wong W, Ngan CC, Chee SP - Eye (Lond) (2012)

Bottom Line: Those with T-SPOT.TB- or TST-positive results were referred to infectious diseases physician for evaluation.Patients with either a T-SPOT.TB (1.44; 95% confidence intervals (CI), 0.86-2.42) or TST (1.47; 95% CI, 1.12-1.94)-positive result are more likely to have TAU.Negative T-SPOT.TB or TST results do not exclude TAU (negative likelihood ratios <1.0).

View Article: PubMed Central - PubMed

Affiliation: Singapore National Eye Centre, National University of Singapore, Singapore, Singapore.

ABSTRACT

Background: To study the use of interferon-gamma release assay (IFN-γ) (IGRAs) as a diagnostic test for tuberculosis (TB)-associated uveitis (TAU).

Design: Prospective cohort study.

Participants: Consecutive new patients (n=162) with clinical ocular signs suggestive of TAU, seen >1 year period at a single tertiary center.

Methods: All subjects underwent investigations to rule out underlying disease, including T-SPOT.TB and tuberculin skin test (TST). Twenty-one subjects with underlying disease and three with interdeterminate T-SPOT.TB results were excluded. Those with T-SPOT.TB- or TST-positive results were referred to infectious diseases physician for evaluation. Anti-TB therapy (ATT) was prescribed if required. Patients' treatment response and recurrence were monitored for six months after completion of ATT, if given; or 1 year if no ATT was given.

Main outcome measure: Diagnosis of TAU.

Results: Mean age of study cohort (n=138) was 46.8 ± 15.3 years. Majority were Chinese (n=80, 58.0%) and female (n=75, 54.3%). TST was more sensitive than T-SPOT.TB (72.0% vs 36.0%); but T-SPOT.TB was more specific (75.0% vs 51.1%) for diagnosing TAU. Patients with either a T-SPOT.TB (1.44; 95% confidence intervals (CI), 0.86-2.42) or TST (1.47; 95% CI, 1.12-1.94)-positive result are more likely to have TAU. The accuracy of diagnosing TAU increases when both tests are used in combination (area under the receiver operator curve=0.665; 95% CI, 0.533-0.795). Patients with both tests positive are 2.16 (95% CI, 1.23-3.80) times more likely to have TAU. Negative T-SPOT.TB or TST results do not exclude TAU (negative likelihood ratios <1.0).

Conclusions: We recommend using a combination of clinical signs, IGRA, and TST to diagnose TAU.

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Related in: MedlinePlus

Final diagnoses of study cohort following T-SPOT.TB test (S), tuberculin skin test (T) and when used in combination (S+T). +, positive; −, negative.
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fig2: Final diagnoses of study cohort following T-SPOT.TB test (S), tuberculin skin test (T) and when used in combination (S+T). +, positive; −, negative.

Mentions: We studied the final diagnoses of all patients and compared their TST or T-SPOT.TB results after 6 months of completing therapy (Figure 2). We classified each patient's anatomical location, course, and laterality of ocular inflammation according to the International Uveitis Study Group clinical classification criteria.22 Statistical analysis included descriptive statistics, where the mean and SD with 95% CI was calculated for the continuous variables whereas frequency distribution and percentages were used for categorical variables. One-way ANOVA was used to compare means of outcome groups for each characteristic variable whereas Pearson's square χ2-tests (incorporating Yates' correction if necessary) were used to assess the independent association between characteristic variables and outcome groups. A P-value <0.05 was considered statistically significant. Performances of binary classification tests were evaluated using sensitivity, specificity, and area under the receiver operator curve (AUC). All analyses were performed using STATA version 11 (StataCorp LP, College Station, TX, USA).


Interferon-gamma release assay as a diagnostic test for tuberculosis-associated uveitis.

Ang M, Wong W, Ngan CC, Chee SP - Eye (Lond) (2012)

Final diagnoses of study cohort following T-SPOT.TB test (S), tuberculin skin test (T) and when used in combination (S+T). +, positive; −, negative.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3351054&req=5

fig2: Final diagnoses of study cohort following T-SPOT.TB test (S), tuberculin skin test (T) and when used in combination (S+T). +, positive; −, negative.
Mentions: We studied the final diagnoses of all patients and compared their TST or T-SPOT.TB results after 6 months of completing therapy (Figure 2). We classified each patient's anatomical location, course, and laterality of ocular inflammation according to the International Uveitis Study Group clinical classification criteria.22 Statistical analysis included descriptive statistics, where the mean and SD with 95% CI was calculated for the continuous variables whereas frequency distribution and percentages were used for categorical variables. One-way ANOVA was used to compare means of outcome groups for each characteristic variable whereas Pearson's square χ2-tests (incorporating Yates' correction if necessary) were used to assess the independent association between characteristic variables and outcome groups. A P-value <0.05 was considered statistically significant. Performances of binary classification tests were evaluated using sensitivity, specificity, and area under the receiver operator curve (AUC). All analyses were performed using STATA version 11 (StataCorp LP, College Station, TX, USA).

Bottom Line: Those with T-SPOT.TB- or TST-positive results were referred to infectious diseases physician for evaluation.Patients with either a T-SPOT.TB (1.44; 95% confidence intervals (CI), 0.86-2.42) or TST (1.47; 95% CI, 1.12-1.94)-positive result are more likely to have TAU.Negative T-SPOT.TB or TST results do not exclude TAU (negative likelihood ratios <1.0).

View Article: PubMed Central - PubMed

Affiliation: Singapore National Eye Centre, National University of Singapore, Singapore, Singapore.

ABSTRACT

Background: To study the use of interferon-gamma release assay (IFN-γ) (IGRAs) as a diagnostic test for tuberculosis (TB)-associated uveitis (TAU).

Design: Prospective cohort study.

Participants: Consecutive new patients (n=162) with clinical ocular signs suggestive of TAU, seen >1 year period at a single tertiary center.

Methods: All subjects underwent investigations to rule out underlying disease, including T-SPOT.TB and tuberculin skin test (TST). Twenty-one subjects with underlying disease and three with interdeterminate T-SPOT.TB results were excluded. Those with T-SPOT.TB- or TST-positive results were referred to infectious diseases physician for evaluation. Anti-TB therapy (ATT) was prescribed if required. Patients' treatment response and recurrence were monitored for six months after completion of ATT, if given; or 1 year if no ATT was given.

Main outcome measure: Diagnosis of TAU.

Results: Mean age of study cohort (n=138) was 46.8 ± 15.3 years. Majority were Chinese (n=80, 58.0%) and female (n=75, 54.3%). TST was more sensitive than T-SPOT.TB (72.0% vs 36.0%); but T-SPOT.TB was more specific (75.0% vs 51.1%) for diagnosing TAU. Patients with either a T-SPOT.TB (1.44; 95% confidence intervals (CI), 0.86-2.42) or TST (1.47; 95% CI, 1.12-1.94)-positive result are more likely to have TAU. The accuracy of diagnosing TAU increases when both tests are used in combination (area under the receiver operator curve=0.665; 95% CI, 0.533-0.795). Patients with both tests positive are 2.16 (95% CI, 1.23-3.80) times more likely to have TAU. Negative T-SPOT.TB or TST results do not exclude TAU (negative likelihood ratios <1.0).

Conclusions: We recommend using a combination of clinical signs, IGRA, and TST to diagnose TAU.

Show MeSH
Related in: MedlinePlus