The conundrum of indeterminate QuantiFERON-TB Gold results before anti-tumor necrosis factor initiation

• Published in: Biologics 2018-01, Vol.12, p.61-67
• Main Authors: Hakimian, Shahrad, Popov, Yevgeniy, Rupawala, Abbas H, Salomon-Escoto, Karen, Hatch, Steven, Pellish, Randall
• Format: Article
• Language: English
• Subjects: Antigens; Corticosteroids; Cytokines; Endoscopy; Indeterminate Quantiferon Gold; Infections; Inflammation; Inflammatory Bowel Disease; Latent TB infection; Medical imaging; Original Research; Patients; Proteins; Rheumatoid Arthritis; Rheumatology; Tuberculosis; Tumor necrosis factor-TNF
• ISSN: 1177-5475; 1177-5491; 1177-5491
• DOI: 10.2147/BTT.S150958

Tumor necrosis factor alpha (TNFα) is a key cytokine in both the pathogenesis of inflammatory bowel disease (IBD) and rheumatoid arthritis (RA) and the host defense against tuberculosis (TB). Consequently, anti-TNFα medications result in an increased risk of latent TB infection (LTBI) reactivation. Here, we sought to evaluate the factors affecting the results of QuantiFERON-TB Gold In-Tube (QFT-GIT) assay as a screening tool for LTBI. We conducted an observational, retrospective study in patients with IBD and RA who underwent LTBI screening using QFT-GIT at UMass Memorial Medical Center between 2008 and 2016 prior to initiation of anti-TNF medications. We included 107 and 89 patients with IBD and RA, respectively. We found that a higher proportion of IBD patients had indeterminate QFT-GIT result compared to RA patients. Furthermore, we found that the majority of patients with indeterminate results were tested during an acute flare of IBD (88%) and while taking corticosteroids. Of all patients receiving ≥20 mg equivalent prednisone dose (n=32), 63% resulted in indeterminate QFT-GIT, compared to only 6% indeterminate testing in patients receiving