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Diagnostic Utility of QuantiFERON-TB Gold (QFT-G) in Active Pulmonary Tuberculosis.

Anwar A, Hamdan AJ, Salim B, Yosra A, Hani M, Abdullah AH - J Glob Infect Dis (2015 Jul-Sep)

Bottom Line: We included only patients with an available result of the QFT-G test.Of the 226 pneumonia cases, the QFT-G tested positive in only 20.4%, while a majority of 66.4% tested negative, with 30 cases (13.3%) being indeterminate.It certainly cannot be used solely and indiscriminately, separate from other clinical and radiological information, in the diagnosis of active tuberculosis cases.

View Article: PubMed Central - PubMed

Affiliation: King Abdullah International Medical Research Center/College of Public Health and Health Informatics, Riyadh, Kingdom of Saudi Arabia.

ABSTRACT

Background: The utility of QuantiFERON-TB Gold In-Tube (QFT-G) test in the diagnosis of tuberculosis disease has been validated in high and low tuberculosis-prevalent (TB) countries.

Aim: The aim of this study is to assess the performance of the QFT-G test in the diagnosis of tuberculosis disease among tuberculosis patients in an intermediate prevalent country.

Setting and design: A retrospective study at the King Abdulaziz Medical City-Riyadh (KAMC-R).

Materials and methods: We retrospectively reviewed all the patients with a diagnosis of pneumonia, including tuberculosis, admitted to KAMC-R between 1 January 2009 and 31 December 2013. We included only patients with an available result of the QFT-G test. A total of 142 tuberculosis cases and 226 pneumonia cases were studied, to assess the utility of the QFT-G test in diagnosing tuberculosis cases.

Results: Among the tuberculosis (n = 142) cases, the QFT-G tested positive in 68.3%, negative in 23.2%, and indeterminate in 12 cases (8.5%). Of the 226 pneumonia cases, the QFT-G tested positive in only 20.4%, while a majority of 66.4% tested negative, with 30 cases (13.3%) being indeterminate. When we excluded 42 patients with indeterminate results, the QFT-G test achieved a sensitivity of 74.6% [95% CI: 66.09 to 81.65%] and specificity of 76.53 % [95% CI: 69.85 to 82.15%] in the diagnosis of tuberculosis cases.

Conclusions: This study concludes that the QFT-G test is a useful tool for detecting tuberculosis disease when used as an adjunct tool for the diagnosis of active TB cases. It certainly cannot be used solely and indiscriminately, separate from other clinical and radiological information, in the diagnosis of active tuberculosis cases.

No MeSH data available.


Related in: MedlinePlus

Diagnostic accuracy of the QuantiFERON Test among cases with pneumonia or tuberculosis
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Figure 1: Diagnostic accuracy of the QuantiFERON Test among cases with pneumonia or tuberculosis

Mentions: Over the study period, 6907 patients were admitted with diagnoses of pneumonia, and 639 (9%) of them were diagnosed with tuberculosis. The results of QFT-G test were available in 368 patients: 142 (38.6%) patients with active TB and 226 (61.4%) patients with pneumonia. Table 1 demonstrates the patients’ demographic and clinical characteristics in relation to the disease status. Out of 368 patients, 188 (51.1%) were female and 180 (48.9%) were male. Most of the 368 patients were Saudis: 363 (98.6%). In both groups (tuberculosis and pneumonia), the results of the QFT-G tests were observed to be negative in 183 cases (49.7%), positive in 143 cases (38.9%), and indeterminate in 42 cases (11.4%). When the 368 patients were classified by the disease status, the QFT-G test appeared to have a higher positivity rate among the tuberculosis cases (68.3%) than the pneumonia cases (20.4%), P-value = 0.001. The result of the QFT-G test was observed to be negative in 33 cases (23.2%) and indeterminate in 12 cases (8.5%) in the tuberculosis group, whereas, the QFT-G test was observed to be negative in 150 cases (66.4%) and indeterminate in 30 cases (13.3%) in the pneumonia group [Table 1 and Figure 1]. The patients’ ages were significantly higher among the pneumonia group (64.4 ± 17.4, range 19–107 years) than the tuberculosis group (54.9 ± 19.4, range 18–92), P-value = 0.001. There were no differences between males and females across the two groups (P-value = 0.755).


Diagnostic Utility of QuantiFERON-TB Gold (QFT-G) in Active Pulmonary Tuberculosis.

Anwar A, Hamdan AJ, Salim B, Yosra A, Hani M, Abdullah AH - J Glob Infect Dis (2015 Jul-Sep)

Diagnostic accuracy of the QuantiFERON Test among cases with pneumonia or tuberculosis
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4557139&req=5

Figure 1: Diagnostic accuracy of the QuantiFERON Test among cases with pneumonia or tuberculosis
Mentions: Over the study period, 6907 patients were admitted with diagnoses of pneumonia, and 639 (9%) of them were diagnosed with tuberculosis. The results of QFT-G test were available in 368 patients: 142 (38.6%) patients with active TB and 226 (61.4%) patients with pneumonia. Table 1 demonstrates the patients’ demographic and clinical characteristics in relation to the disease status. Out of 368 patients, 188 (51.1%) were female and 180 (48.9%) were male. Most of the 368 patients were Saudis: 363 (98.6%). In both groups (tuberculosis and pneumonia), the results of the QFT-G tests were observed to be negative in 183 cases (49.7%), positive in 143 cases (38.9%), and indeterminate in 42 cases (11.4%). When the 368 patients were classified by the disease status, the QFT-G test appeared to have a higher positivity rate among the tuberculosis cases (68.3%) than the pneumonia cases (20.4%), P-value = 0.001. The result of the QFT-G test was observed to be negative in 33 cases (23.2%) and indeterminate in 12 cases (8.5%) in the tuberculosis group, whereas, the QFT-G test was observed to be negative in 150 cases (66.4%) and indeterminate in 30 cases (13.3%) in the pneumonia group [Table 1 and Figure 1]. The patients’ ages were significantly higher among the pneumonia group (64.4 ± 17.4, range 19–107 years) than the tuberculosis group (54.9 ± 19.4, range 18–92), P-value = 0.001. There were no differences between males and females across the two groups (P-value = 0.755).

Bottom Line: We included only patients with an available result of the QFT-G test.Of the 226 pneumonia cases, the QFT-G tested positive in only 20.4%, while a majority of 66.4% tested negative, with 30 cases (13.3%) being indeterminate.It certainly cannot be used solely and indiscriminately, separate from other clinical and radiological information, in the diagnosis of active tuberculosis cases.

View Article: PubMed Central - PubMed

Affiliation: King Abdullah International Medical Research Center/College of Public Health and Health Informatics, Riyadh, Kingdom of Saudi Arabia.

ABSTRACT

Background: The utility of QuantiFERON-TB Gold In-Tube (QFT-G) test in the diagnosis of tuberculosis disease has been validated in high and low tuberculosis-prevalent (TB) countries.

Aim: The aim of this study is to assess the performance of the QFT-G test in the diagnosis of tuberculosis disease among tuberculosis patients in an intermediate prevalent country.

Setting and design: A retrospective study at the King Abdulaziz Medical City-Riyadh (KAMC-R).

Materials and methods: We retrospectively reviewed all the patients with a diagnosis of pneumonia, including tuberculosis, admitted to KAMC-R between 1 January 2009 and 31 December 2013. We included only patients with an available result of the QFT-G test. A total of 142 tuberculosis cases and 226 pneumonia cases were studied, to assess the utility of the QFT-G test in diagnosing tuberculosis cases.

Results: Among the tuberculosis (n = 142) cases, the QFT-G tested positive in 68.3%, negative in 23.2%, and indeterminate in 12 cases (8.5%). Of the 226 pneumonia cases, the QFT-G tested positive in only 20.4%, while a majority of 66.4% tested negative, with 30 cases (13.3%) being indeterminate. When we excluded 42 patients with indeterminate results, the QFT-G test achieved a sensitivity of 74.6% [95% CI: 66.09 to 81.65%] and specificity of 76.53 % [95% CI: 69.85 to 82.15%] in the diagnosis of tuberculosis cases.

Conclusions: This study concludes that the QFT-G test is a useful tool for detecting tuberculosis disease when used as an adjunct tool for the diagnosis of active TB cases. It certainly cannot be used solely and indiscriminately, separate from other clinical and radiological information, in the diagnosis of active tuberculosis cases.

No MeSH data available.


Related in: MedlinePlus