OBJECTIVE: We evaluated the T-SPOT.TB assay to identify latent tuberculosis infection (LTBI) in patients with rheumatic disease receiving immunosuppressive medication including tumor necrosis factor (TNF) antagonists. METHODS: A total of 200 patients seen in the Arthritis Center at Brigham and Women's Hospital were enrolled for study. Most patients were US-born women with rheumatoid arthritis. A medical history was obtained using a questionnaire, whole blood was drawn for the T-SPOT.TB assay, and tuberculin skin testing (TST) was performed. RESULTS: Both tests were performed on 179 subjects, who had no history of a positive TST. All subjects had a strong response to the T-SPOT.TB test positive control, and there were no indeterminate results. Among these 179 subjects, 2 had a positive TST and 10 had a positive T-SPOT.TB test. No subject was positive for both tests. Patients with a positive T-SPOT.TB test did not have typical risk factors for LTBI based on clinical evaluation. CONCLUSION: The lack of concordance between the TST and the T-SPOT.TB assay may indicate that the immunoassay is more sensitive, particularly in a patient population taking immunosuppressive medications. It is equally likely that the low prevalence of LTBI in this low-risk population led to an increase in the false-positive rate despite the high sensitivity and specificity of the T-SPOT.TB assay. In the context of our patient population, the T-SPOT.TB assay is likely to be most useful in evaluation of patients with a positive TST, since these patients have a higher pretest probability of having LTBI.
OBJECTIVE: We evaluated the T-SPOT.TB assay to identify latent tuberculosis infection (LTBI) in patients with rheumatic disease receiving immunosuppressive medication including tumor necrosis factor (TNF) antagonists. METHODS: A total of 200 patients seen in the Arthritis Center at Brigham and Women's Hospital were enrolled for study. Most patients were US-born women with rheumatoid arthritis. A medical history was obtained using a questionnaire, whole blood was drawn for the T-SPOT.TB assay, and tuberculin skin testing (TST) was performed. RESULTS: Both tests were performed on 179 subjects, who had no history of a positive TST. All subjects had a strong response to the T-SPOT.TB test positive control, and there were no indeterminate results. Among these 179 subjects, 2 had a positive TST and 10 had a positive T-SPOT.TB test. No subject was positive for both tests. Patients with a positive T-SPOT.TB test did not have typical risk factors for LTBI based on clinical evaluation. CONCLUSION: The lack of concordance between the TST and the T-SPOT.TB assay may indicate that the immunoassay is more sensitive, particularly in a patient population taking immunosuppressive medications. It is equally likely that the low prevalence of LTBI in this low-risk population led to an increase in the false-positive rate despite the high sensitivity and specificity of the T-SPOT.TB assay. In the context of our patient population, the T-SPOT.TB assay is likely to be most useful in evaluation of patients with a positive TST, since these patients have a higher pretest probability of having LTBI.
Authors: Patricio Escalante; Kirstin J Kooda; Rizwana Khan; San San Aye; Stratos Christianakis; Daniel G Arkfeld; Glenn R Ehresmann; Jens J Kort; Brenda E Jones Journal: Lung Date: 2014-10-16 Impact factor: 2.584
Authors: Aran Singanayagam; Kavina Manalan; Saranya Sridhar; Philip L Molyneaux; David W Connell; Peter M George; Anne Kindelerer; Suranjith Seneviratne; Ajit Lalvani; Melissa Wickremasinghe; Onn Min Kon Journal: Thorax Date: 2013-08-23 Impact factor: 9.139
Authors: Maria Del Mar Arenas Miras; Carmen Hidalgo-Tenorio; Pilar Jimenez-Gamiz; Juan Jiménez-Alonso Journal: Biomed Res Int Date: 2014-05-28 Impact factor: 3.411