1942: Prevalence and Screening Strategy for Latent Tuberculosis Infection in Patients with Rheumatic Immune-Mediated Diseases

Carmen Lasa¹, Joy Selene Osorio², David Martínez-Lopez³, Carmen Alvarez Reguera⁴, Virginia Portilla⁵, Jose Cifrian⁶, Ivan Ferraz Amaro⁷ and Ricardo Blanco², ¹Hospital Universitario Marqués de Valdecilla, IDIVAL., La Cavada, Spain, ²Hospital Universitario Marqués de Valdecilla, IDIVAL, Santander, Spain, ³Hospital Sierrallana, Torrelavega, Spain, ⁴Hospital Universitario Marqués de Valdecilla, Santander, Spain, ⁵Rheumatology Department, Immunopathology Group, Hospital Universitario Marqués de Valdecilla-IDIVAL, Santander, Spain, ⁶Immunopathology Group, Marqués de Valdecilla University Hospital-IDIVAL; Department of Pneumology, Marqués de Valdecilla University Hospital; School of Medicine, Cantabria University, Santander, Spain, ⁷Hospital Universitario de Canarias, Santa Cruz de Tenerife, Spain

Background/Purpose: Patients with rheumatic immune-mediated inflammatory diseases (rheumatic-IMID) with latent tuberculosis infection (LTBI) requiring biologic therapy (BT) are at anincreased risk of developing active tuberculosis (TB). Screening of LTBI with tuberculin skin test (TST) and/or interferon (IFN)-γ release assays (IGRA) is recommended before startingBT.

Methods: Cross-sectional single University hospital study including all patients diagnosedwith rheumatic-IMID who underwent a TST test and/or IGRA in a five-year period (2016-2020). TST was performed by a subcutaneous injection of 0.1 ml of purified proteinderivative (PPD) with a reading after 72 hours. TST was considered positive with aninduration of more than 5 mm of diameter. If the first TST was negative, a new TST (booster)was performed between 1 and 2 weeks after the first TST. The IGRA test used wasQuantiFERON®-TB Gold Plus (QFT-Plus). LTBI was diagnosed by a positive IGRA and/orTST and absence of active TB (normal chest X-ray). Concordance between IGRA and TSTwas studied using adjusted Cohen's kappa coefficient.

Results: Booster was positive in 66 patients (7.7%) out of 857 patients with a negative simple TST.TST (+ booster) was positive in 187 patients (22.9%) out of 817 with a negative orindeterminate IGRA test. IGRA test was positive in 30 (3.8%) out of 793 patients with anegative TST (+ booster), as is shown in Figure 1 and 2. Adjusted Cohen's Kappa coefficient between TST (+ booster) andIGRA (QFT-plus) was 0.62.

Conclusion: LTBI is frequent between patients with rheumatic-IMID. Booster after negativesimple TST may be useful, since it can detect LTBI. Furthermore, IGRA and TST (+ booster)show a moderate fair grade of agreement. In addition, some patients who had a negative orindeterminate result on IGRA or TST could have a positive result in the other examination.This highlights the importance of performing both tests in all patients. Accordingly,performing both tests in patients with rheumatic-IMID before BT may be highlyrecommended.






C. Lasa: None; J. Osorio: None; D. Martínez-Lopez: None; C. Alvarez Reguera: None; V. Portilla: None; J. Cifrian: None; I. Ferraz Amaro: AbbVie/Abbott, 5, 6, Amgen, 5, 6, Bristol-Myers Squibb(BMS), 6; R. Blanco: AbbVie, 5, 6, Amgen, 6, AstraZeneca, 2, BMS, 6, Eli Lilly, 6, Galapagos, 2, 6, Janssen, 2, 6, MSD, 6, Novartis, 2, 6, Pfizer, 2, 6, Roche, 5, 6, Sanofi, 6.