RT Journal Article
SR Electronic
T1 Diagnostic performance of the interferon gamma release assay in elderly patients and clinical factors to support the diagnosis of active tuberculosis
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P415
VO 40
IS Suppl 56
A1 Hiroyuki Kamiya
A1 Soichiro Ikushima
A1 Keisuke Kondo
A1 Kota Satake
A1 Minoru Inomata
A1 Atsuko Moriya
A1 Tsunehiro Ando
YR 2012
UL http://erj.ersjournals.com/content/40/Suppl_56/P415.abstract
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.