Abstract
Screening for latent tuberculosis infection (LTBI) in patients with inflammatory bowel disease (IBD) is mandatory prior to the start of anti-tumor necrosis factor-α (anti-TNFα). The aims of the study are to assess concordance between two IGRA with TST and the diagnostic performance of all them.
Methods: We aimed to evaluate the results of TST (retesting if the first one was negative) and two IGRA (T-SPOT.TB and QuantiFERON-TB GOLD In Tube) in 164 IBD patients from our hospital. Concordance between IGRA and TST was evaluated using kappa test.
Results: 164 patients were enrolled. TST was positive in 47 (28.7%) of 164 patients. The concordance between TST and T-SPOT.TB was low (kappa: 0.215, p: 0.004) (Table 1), the same as TST and QuantiFERON (Kappa 0.230, p: 0.001) (Table 2), and between T-SPOT.TB and QuantiFERON was moderate (Kappa 0.413, p<0,001).
Overall, 57 patients (34.8%) were diagnosed as LTBI (47 for positive TST and 10 more were detected by positive IGRA with TST negative result); the joint performance of two IGRA increased the percentage of patients diagnosed of LTBI (21.3% [95% CI, 8.5%-34.0%]); 8 out 10 positive-IGRA and negative-TST patients were receiving steroids therapy.
Conclusions: In IBD patients, concordance between TST and the two IGRA studied (T-SPOT.TB and QuantiFERON) was in general low. Performance of two IGRA altogether increases the number of IBD patients diagnosed of LTBI.
- © 2011 ERS
