Abstract
Background: Biologic and non-biologic immunosuppressants carry the risk of re-activation of latent TB infection. Local guidance advises screening before starting particular high-risk agents with a focused history, chest x-ray and Interferon Gamma Release Assay (IGRA).
We identified patients on biologics who subsequently developed TB to explore common themes in this important subgroup.
Methods: Patients on therapy conferring the highest risk of TB infection (i.e. targeting TNFα, IL-1, Janus kinases, CD52 and T-cell modulation) were identified from 6 years of pharmacy records. We searched the London TB Register (LTBR) for entries matching these patients. IGRA data were obtained for tests performed from at least three months prior to these infections. Screening was considered the occurrence of IGRA testing.
Results: 2975 prescriptions for 2885 patients were identified, of which 10 appeared on the LTBR during the period studied. In 7 there was convincing evidence of TB infection whilst taking biologic therapy (a rate of 23.5 per 10,000 biologic prescriptions). Of these, 4 had culture proven diagnoses.
Infliximab was implicated in 3 cases, and adalimumab and etanercept in 2 each. 3 patients were treated each under rheumatology and gastroenterology and 1 by dermatology. All underwent IGRA testing at some point and failure to screen at treatment initiation was identified in only one patient.
ConclusionLocally, TB infection associated with biologics is uncommon and occurs despite negative screening IGRA results. Explanations include false negatives or new exposures. IGRA tests are critical, if fallible, before starting anti-TNF drugs. Interventions to reduce these infections must be more than just good adherence to screening protocols.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 487.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020