PT  - JOURNAL ARTICLE
AU  - Hiroyuki Kamiya
AU  - Soichiro Ikushima
AU  - Keisuke Kondo
AU  - Kota Satake
AU  - Minoru Inomata
AU  - Atsuko Moriya
AU  - Tsunehiro Ando
TI  - Diagnostic performance of the interferon gamma release assay in elderly patients and clinical factors to support the diagnosis of active tuberculosis
DP  - 2012 Sep 01
TA  - European Respiratory Journal
PG  - P415
VI  - 40
IP  - Suppl 56
4099  - http://erj.ersjournals.com/content/40/Suppl_56/P415.short
4100  - http://erj.ersjournals.com/content/40/Suppl_56/P415.full
SO  - Eur Respir J2012 Sep 01; 40
AB  - Background and objectiveThe understanding of the diagnostic performance of the interferon gamma release assay in elderly patients is crucial in a country like Japan, where the higher rate of a prior history of tuberculosis can affect the test result.MethodsFrom a total of four hundred twenty five patients screened, who were suspected of having active tuberculosis and received the QuantiFERON-TB Gold In-Tube test (QFT-GIT), 65 patients in younger age group with the age less than 70 years, and 52 patients in elderly age group were eligible for the analysis. The diagnostic performance of the test was compared between two age groups, and the possible clinical factors to discriminate active tuberculosis cases from elderly patients with positive results of the test were also evaluated.ResultsAlthough the number of patients diagnosed to have active tuberculosis was similar among both age groups, the number of false positive results was significantly higher in elderly patients (4.6% compared to 23.1%). The specificity, positive predictive value and positive likelihood ratio were significantly lower in elderly patients, at 72.7% compared to 93.8%, 36.8% to 83.8%, and 3.21 to 14.12, respectively although other values were almost similar. Radiological findings, such as small nodules and infiltrates, were noted in more cases with active tuberculosis in elderly patients with positive results of the test than with other diseases.ConclusionsThe QFT-GIT test may be less accurate in elderly patients in the diagnosis of active tuberculosis, and radiological findings can be helpful in the clinical evaluation of positive results of the test.