Area Editoriale
Prednisolone treatment affects the performance of the QuantiFERON gold in-tube test and the tuberculin skin test in patients with autoimmune disorders screened for latent tuberculosis infection.Bélard E, Semb S, Ruhwald M, Werlinrud AM, Soborg B, Jensen FK, Thomsen H, Brylov
A, Hetland ML, Nordgaard-Lassen I, Ravn P. Inflamm Bowel Dis. 2011;17:2340-9.
BACKGROUND: During screening for latent tuberculosis infection (LTBI), before anti-tumor-necrosis-factor-α treatment, most patients are already receiving immunosuppressive therapy. The objective was to evaluate the performance of the QuantiFERON Gold In-Tube (QFT-IT) and the Tuberculin Skin Test (TST). METHODS: A prospective multicenter study included 248 patients with ulcerative colitis (39), Crohn's disease (54), rheumatoid arthritis (111), and spondylo-arthropathy (44). RESULTS: QFT-IT was positive in 7/248 (3%), negative in 229 (92%), and indeterminate in 12 (5%). TST was positive in 54/238 (23%) patients. Chest x-ray was suspect for tuberculosis in 5/236 (2%), and 35/167 (21%) had ≥1 risk-factors for infection with Mycobacterium tuberculosis. The main finding was a pronounced negative effect on QFT-IT and TST performance associated with prednisolone treatment. During prednisolone treatment interferon gamma (IFN-γ) response to mitogen stimulation was impaired (median IFN-γ response 4.9 IU/mL; interquartile range [IQR] 0.8 to ≥10.0) compared to patients 1) not receiving corticosteroids (median ≥10.0; IQR 5.0 to ≥10.0; P = 0.0015) or 2) receiving long-acting corticosteroids (median >10.0; IQR 9.7 to >10.0; P = 0.0058). Prednisolone treatment was strongly associated with negative TST, adjusted odds ratio (AOR) 0.22 (0.1-0.8; P = 0.018), and with an increased risk of indeterminate QFT-IT
results AOR 16.1 (4.1-63.2; P < 0.001), whereas no negative effect was found for long-acting corticosteroids. Doses of ≥10 mg prednisolone were associated with a 27% risk of indeterminate results. Single use of azathioprine, methotrexate, or 5-aminosalicylate (5-ASA) did not affect the test results.