RT Journal Article
SR Electronic
T1 Interferon-γ release assay screening in biologics: safe and reliable, but not perfect
JF ERJ Open Research
JO erjor
FD European Respiratory Society
SP 00193-2022
DO 10.1183/23120541.00193-2022
VO 8
IS 4
A1 Cafferkey, John
A1 Padayachee, Yorissa
A1 Kostich, Sophia
A1 Kumar, Kartik
A1 Jewell, Paul
A1 Patel, Mikin
A1 Chavda, Aneeka
A1 Cox, Alison
A1 Park, Mirae
A1 Russell, Georgina
A1 Coleman, Meg
A1 Martin, Laura
A1 Kon, Onn Min
YR 2022
UL http://openres.ersjournals.com/content/8/4/00193-2022.abstract
AB Background Systemic biologic agents can increase the risk of re-activation of latent tuberculosis (TB). Prior to initiation, screening for latent TB using an interferon-γ release assay (IGRA) is recommended. There is concern that false-negative IGRAs may be more likely in this context.Methods This retrospective analysis of IGRAs, specifically T-SPOT.TB, results and outcomes of patients already on or due to start biologics identifies the rate of TB re-activation in a low TB incidence setting. Additionally, we estimate the negative predictive value (NPV) of IGRAs in this population.Results Patients on biologics were more likely to have a negative IGRA result than patients not on biologics. There was no statistically significant change in conversion or reversion rates between groups. Of 9263 patients on biologics, 19 developed active TB after starting biologics at an incidence rate of 55.1 per 100 000 patient-years. This occurred despite screening in half of the 16 patients for whom we were able to review medical records. Most drugs implicated were known to be high risk, although rituximab and natalizumab were being taken by five patients and one patient, respectively. The T-SPOT.TB NPV was 99.20% and dropped only slightly to 99.17% when we simulated an approach where all borderline IGRA results were regarded as being negative.Conclusions Negative IGRA results confer a low risk of subsequent active TB in patients on biologics in a low TB incidence setting. However, continued awareness is needed given that a number of active TB cases will have had a prior negative result.This retrospective analysis examines TB outcomes and IGRA performance in a large cohort of patients on biologics. It signals that negative and even borderline IGRA results confer a low risk of subsequent active TB in patients on biologics. https://bit.ly/3T9rlQ7