INTRODUCTION: Immunosuppressive therapy with anti-tumour necrosis factor-α (TNF-α) agents in rheumatic patients modulates the immune system and may increase the risk of reactivating infections that are normally maintained in a latent state, such as tuberculosis. The purpose of this study was to analyse the value of QuantiFERON TB Gold In-Tube (QFT IT) and tuberculin skin test (TST) in BCG vaccinated patients with rheumatoid arthritis and ankylosing spondylitis who were qualified to receive TNF-α blockers.
MATERIAL AND METHODS: Ninety patients with rheumatoid arthritis and ankylosing spondylitis were included in the study. The control group consisted of 20 healthy participants. Chest X-ray, TST and QFT IT were carried out in all persons.
RESULTS: In rheumatic patients positive results of QFT IT and TST tests were identified in 15 cases (16.7%) whereas negative results of both tests were detected in 56 cases (62.2%). In the group of examined patients, 11 (12.2%) had QFT IT-/TST+ test results. In patients with QFT IT+/TST- status one active tuberculosis case was detected. In the control group QFT IT positive results were found in 4 cases (20%) and TST positive in 11 cases (55%). Treatment with TNF-α blockers was introduced in 26 rheumatology patients with the following test status: 3 with QFT IT+/TST+; 20 with QFT IT-/TST-; 3 with QFT IT-/TST+.
CONCLUSIONS: In the BCG vaccinated population the QFT IT assay may potentially improve the identification and selection for therapy for latent TB infection before treatment with anti-TNF agents.
OBJECTIVES: The risk of activation of latent tuberculosis infection (LTBI) is increased in patients treated with anti-TNF-α drugs. Tuberculin skin test (TST) and Quantiferon-TB Gold test (QFT) are used to detect LTBI before and during anti-TNF-α treatment. We describe here a relation of these tests at various timepoints and also longitudinal QFT data.
METHODS: Study group consisted of 305 patients with several rheumatic inflammatory diseases treated and/or scheduled for anti-TNF-α drugs. The QFT was performed in 303 patients during therapy and in 177 patients also during screening. The TST was used in 284 patients. Both tests simultaneously were utilised in 360 instances.
RESULTS: Twenty-two patients were QFT positive; 3.9% before and 5.9% during anti-TNF-α treatment. Two patients who became QFT positive developed active tuberculosis. The TST was positive in 42% and 38% of patients before and during treatment, respectively. There was poor agreement between the two tests. Patients on glucocorticoids had a negative TST more frequently. The IFN-γ response to mycobacterial antigens significantly increased after application of tuberculin, but never reached the positive threshold. There was a significant increase in mitogen-induced IFN-γ production after initiation of anti-TNF-α therapy.
CONCLUSIONS: Poor correlation between the QFT and TST renders the TST non-specific for LTBI. QFT is more specific to detect LTBI and conversion to a positive result may predict active TB. An increase in IFN-γ production in response to mycobacterial antigens is seen when the TST is performed before the QFT. Mitogen-induced IFN-γ production increases after initiation of anti-TNF-α therapy.
OBJECTIVES: To estimate the positivity and agreement between QuantiFERON-tuberculosis (TB) gold in tube test (QFT-GIT) and tuberculin skin test (TST) according to underlying rheumatic diseases and to identify the influencing factors on discrepancies between the 2 tests.
METHODS: Among the 757 patients who underwent both QFT-GIT and TST simultaneously from September 2008 to November 2010, patients with indeterminate QFT-GIT results (n = 21), with active (n = 11) or suspicious (n = 1) findings for tuberculosis on a chest radiograph, were excluded. Finally, 724 patients were recruited for this study: 497 patients with rheumatoid arthritis (RA), 198 with ankylosing spondylitis (AS), and 29 with juvenile rheumatoid arthritis (JRA). The agreement between the 2 tests was estimated by Cohen's κ and factors influencing discrepancies were identified using multivariate analysis.
RESULTS: The positivity of QFT-GIT was higher in RA than AS or JRA (30.2%, 16.2%, and 3.4%, respectively). In contrast, TST positivity was highest in AS compared to RA and JRA (45.5%, 28.2%, and 17.2%, respectively). The agreement between the 2 tests was low in all patients (κ = 0.285). The only predictor of a discrepancy between the 2 tests was older age. Factors associated with discordant QFT-GIT-negative/TST-positive results were female [odds ratio (OR) = 2.33, confidence interval (CI) 1.11 to 4.89] and AS (OR = 3.12, CI 1.44 to 6.79), whereas a discordant QFT-GIT-positive/TST-negative result was associated with glucocorticoid use (OR = 2.44, CI 1.24 to 4.81).
CONCLUSIONS: The agreement between the 2 tests is low; therefore, it would be better to perform both tests than to use any 1 test alone for the detection of LTBI in TB-endemic regions. Female and underlying AS are related to being QFT-GIT-negative/TST-positive, and the use of glucocorticoid is associated with being QFT-GIT-positive/TST-negative.
Screening for latent tuberculosis infection (LTBI) prior to the prescribing of anti-TNF agents and monitoring for infection during treatment are recommended. The feasibility of novel screening tools, including QuantiFERON-TB Gold In-Tube (QFT-GIT), remains unclear in the setting of immunosuppression. The aim of this study was to evaluate the usefulness of serial QFT-GIT during biologic therapy to assess whether dynamic changes in IFN-γ levels may be helpful in identifying reactivation of LTBI or newly acquired TB. We conducted a prospective study on patient candidates to TNF inhibitors. QFT-GIT was performed at baseline and after 3 and 6 months since biologic onset. A further follow-up period of 6 months was observed. Among patients enrolled (n = 119; F = 69 %; median age = 47 years, range 18-80), 24 had at least 1 risk factor for LTBI. Ninety-six were taking immunosuppressants at the time of TB testing. At baseline, 5 patients displayed positive, 93 negative, and 21 indeterminate QFT-GIT results. We observed QFT-GIT conversions and reversions in 12 patients with LTBI and in 73 without LTBI. QFT-GIT results changed of 28 % at month 3 and of 21 % at month 6; the greatest change was observed in patients with indeterminate results that became negative (15 %; p < 0.02). No TB cases were detected. In conclusion, the routine use of both QFT-GIT and TST at screening seems not to give any advantage in the setting of patients awaiting biologics. In addition, the feasibility of serial QFT-GIT during biologic therapy needs definition since changes in IFN-γ levels may occur without a pathologic connotation.
INTRODUCTION: The usefulness of interferon-gamma (IFN-γ) release assays for tuberculosis screening before tumor necrosis factor-alpha (TNF-α) antagonists and for monitoring during treatment is a contraversial issue. The aims of this study were to determine whether TNF-α antagonists affect the results of the Quantiferon-TB Gold in-tube assay (QTF); to assess how QTF performs in comparison with the tuberculin skin test (TST) in rheumatoid arthritis (RA) patients who are about to start treatment with TNF-α antagonists, RA patients who are not candidates for treatment with TNF-α antagonists, rheumatology patients with confirmed current or past tuberculosis infection, and healthy controls, and to determine the specificity of the QTF test to differentiate leprosy patients, another group of patients infected with mycobacteria.
METHODS: The 38 RA patients who were prescribed TNF-α antagonists, 40 RA patients who were not considered for TNF-α antagonist use, 30 rheumatology patients with a history or new diagnosis of tuberculosis, 23 leprosy patients, and 41 healthy controls were studied. QTF and TST were done on the same day, and both were repeated after a mean of 3.6 ± 0.2 months in patients who used TNF-α antagonists.
RESULTS: Treatment with TNF-α antagonists did not cause a significant change in the QTF or TST positivity rate (34% versus 42%; P = 0.64; and 24% versus 37%; P = 0.22). Patients with leprosy had a trend for a higher mean IFN-γ level (7.3 ± 8.0) and QTF positivity (61%) than did the other groups; however, the difference was not significant (P = 0.09 and P = 0.43).
CONCLUSIONS: Treatment with TNF-α antagonists does not seem to affect the QTF test to an appreciable degree. The higher IFN-γ levels in leprosy patients deserves further attention.
Objective To evaluate the performance of an interferon-γ release assay (IGRA) versus the standard tuberculin skin test (TST) as a screening tool for latent tuberculosis (TB) infection prior to the initiation of anti-tumor necrosis factor therapy in patients with autoimmune inflammatory diseases. Methods This integrated analysis involved screening of patients with rheumatoid arthritis, those with psoriatic arthritis, and those with ankylosing spondylitis from phase III trials of golimumab. The IGRA used to screen for latent TB was the QuantiFERON-TB Gold In-Tube test. Results In this pooled analysis, 2,282 patients underwent both IGRA and TST screening prior to golimumab treatment. Among these patients, 13.8% had at least one test yielding positive findings for latent TB, including 9.4% with positive results by TST, 7.0% with positive results by IGRA, and 2.6% with positive results on both tests. The rate of indeterminate results for TB on IGRA was 1.8%. Agreement between the TST and IGRA results, measured by the kappa coefficient, was 0.22 (95% confidence interval 0.157-0.279; P = 0.021). Among the patients with positive IGRA findings, 36.9% had positive TST findings. Among the patients with positive TST findings, 27.4% had positive IGRA findings. Overall, 781 (34.2%) of the 2,282 patients had previously received the bacillus Calmette-Guérin (BCG) vaccine; among this vaccinated group, the rate of positivity for latent TB by TST was 15.2% (119 of 781), compared to a rate of positivity of 9.1% (71 of 781) by IGRA ( P = 0.0002). Among patients who had not received the BCG vaccine, the rate of positivity by TST was 5.0% (62 of 1,248) and the rate of positivity by IGRA was 5.8% (72 of 1,248) ( P = 0.3745). When the IGRA was repeated in patients whose results were initially indeterminate, the rate of indeterminate IGRA findings for latent TB was much lower than has been previously reported. Conclusion In the absence of a true gold standard test for latent TB infection, results of this comparison of IGRA and TST in a large cohort of patients with rheumatic diseases suggest that the IGRA provides greater specificity and possibly greater sensitivity than the TST.
BACKGROUND: The recommendations for detecting latent tuberculosis infection (LTBI) before antitumour necrosis factor (anti-TNF) therapy are based on the tuberculin skin test (TST), which lacks both specificity and sensitivity and can lead to unnecessary treatment with antibiotics. A study was undertaken to investigate the effect of replacing TST with interferon γ (IFNγ) release assays (IGRA) in screening for LTBI and deciding to begin prophylactic antituberculosis (TB) antibiotics before anti-TNF therapy in immune-mediated inflammatory diseases.
METHODS: In 15 tertiary care hospitals, consecutive patients with rheumatoid arthritis, spondylarthropathies or Crohn's disease were screened for LTBI before anti-TNF therapy with TST, QuantiFERON TB Gold in tube (QTF-Gold IT) and T-SPOT.TB at the same time. The potential diagnosis of LTBI and the effect on the decision to begin antibiotic prophylaxis were assessed.
RESULTS: Among 429 patients, 392 had results for the three tests. The results for TST, T-SPOT.TB and QTF Gold IT were positive for 35.2%, 15.1% and 9.9% of patients, respectively (p<0.0001). Antibiotics were required for 177 patients (45.2%) if positive TST results were included in the LTBI definition, 107 patients (27.3%) if TST results were replaced with results from one of the IGRA tests and 84 patients (21.4%) if TST results were replaced with QTF-Gold IT results (p<0.0001). The decision on the use of antibiotic prophylaxis was changed for 113 patients (28.8%, 95% CI 24.4% to 33.6%) if TST results were replaced with QTF-Gold IT results.
CONCLUSIONS: Replacing TST with IGRA for determining LTBI allowed the proportion of patients with immune-mediated inflammatory diseases needing prophylactic anti-TB antibiotics before beginning anti-TNF agents to be reduced by half.
Revista»The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease
BACKGROUND: Screening for latent tuberculosis infection (LTBI) using a protocol comprising chest X-ray and tuberculin skin test (TST) interpreted with medical history, Sc1, reduces LTBI reactivation on treatment with anti-tumour necrosis factor-alpha (anti-TNF-α). In the district of Seine-Saint-Denis, France, where tuberculosis (TB) incidence ranges from 30 to >100/100 000 person-years, however, Sc1 might be insensitive as a screening tool. We adopted another protocol, Sc2, comprising Sc1 plus two additional tests: the QuantiFERON(®)-TB Gold In-Tube (QFT-GIT) and chest computed tomography (CT).
METHODS: We screened 123 consecutive patients with inflammatory rheumatic diseases (IRDs), candidates for anti-TNF-α treatment, and evaluated the impact of Sc2 vs. Sc1 on the prescription of prophylactic anti-tuberculosis treatment.
RESULTS: Sc2 led to a diagnosis of LTBI in 69 patients vs. 59 when using Sc1: eight were QFT-GIT-positive. Diagnosis was based on CT findings in two patients. QFT-GIT had higher diagnostic accuracy than TST, but no single diagnostic test could detect all patients at high risk for LTBI reactivation (respectively 30.2% and 37.5% of patients positive with only TST or QFT-GIT). CT detected TB sequelae in 3/46 rheumatoid arthritis patients who were negative to all tests.
CONCLUSIONS: Testing with both TST and QFT-GIT seems the safest strategy for detecting LTBI in patients with IRD from populations with high incidence of TB. Systematic screening with CT warrants further evaluation.
Biological agents, particularly anti-Tumour Necrosis Factor (TNF)-α agents, have emerged as an effective treatment in patients with chronic inflammatory diseases. An association between anti-TNF-α antibodies and reactivation of latent tuberculosis infection (LTBI) has been established. Appropriate screening for TB infection has become mandatory before starting a treatment based on TNF-α inhibition. The objective was to determine the usefulness of IFN-γ release assays in diagnosing LTBI in patients with inflammatory rheumatic diseases scheduled for anti-TNF-α treatment. The study included 53 individuals with inflammatory rheumatism. All patients had a TST, a chest radiograph, QuantiFERON Gold In-Tube (QFN-G-IT) and T-SPOT.TB. To investigate the influence of non-tuberculous mycobacteria (NTM) infections on non-BCG-vaccinated patients, with a positive TST result and both negative IFN-γ assays, we performed an ex vivo ELISPOT, stimulating the cells separately with NTM sensitins. TST was positive in 7 cases, T-SPOT.TB in 11 and QFN-G-IT in 9 cases. Agreement between TST and T-SPOT.TB and QFN-G-IT was 77.35% (κ = 0.33 and κ = 0.40, respectively), and between both in vitro tests, it was 83.01% (κ = 0.57). Of the three patients with positive TST and negative T-SPOT.TB and QFN-G-IT, one positive ELISPOT result was obtained after stimulation with NTM sensitins. Positive TST, T-SPOT.TB and QFN-G-IT results were not affected by the immunosuppressive therapies. IFN-γ release assays are useful methods for avoiding TST false-positive results, but in those patients with a high risk of developing active TB and in the absence of predictive value studies in this specific kind of population for knowing how safe is the use of IGRAs alone, the combined use of TST and IFN-γ tests should be recommended in order to increase the overall number of LTBI diagnoses.
OBJECTIVES: The risk of active tuberculosis increases in rheumatoid arthritis (RA) patients receiving antitumour necrosis factor alpha (TNFα) therapy. Longitudinal data concerning serial interferon γ (IFNγ) assays for detecting tuberculosis have been limited. This study investigated the time course of the development of active tuberculosis, and evaluated the utility of serial QuantiFERON-TB Gold (QFT-G) assays for detecting its emergence in RA patients undergoing long-term anti-TNFα therapy.
METHODS: 242 RA patients who received anti-TNFα therapy and serial QFT-G assays were prospectively evaluated. QFT-G was performed by measuring IFNγ levels in whole blood treated with tuberculosis-specific antigens.
RESULTS: Among 242 RA patients, 75 (31.0%) had a positive tuberculin skin test (TST) and 45 (18.6%) had positive QFT-G results, with another nine (3.7%) showing indeterminate QFT-G assay. Isoniazid prophylaxis was given to 37 patients with TST+/QFT-G+ results and 24 TST+/QFT-G- patients with TST induration diameter ≧10 mm. Four patients (three with baseline QFT-G+ results) developed tuberculosis within the first 3 months of anti-TNFα therapy, whereas five patients with baseline TST-/QFT-G- results developed active tuberculosis after 20-24 months' anti-TNFα therapy. Progressively rising levels of released IFNγ (2.17 ± 0.98 vs 5.93 ± 2.92 IU/ml in early secretory antigenic target-6-stimulated well; 1.12 ± 0.84 vs 2.96 ± 1.02 IU/ml in culture filtrate protein-10-stimulated well) were observed in those who developed tuberculosis early in anti-TNFα therapy. QFT-G conversion was found in baseline QFT-G-negative patients who developed tuberculosis late in treatment.
CONCLUSION: The emergence of active tuberculosis follows a biphasic pattern. Persistently high levels of released IFNγ or QFT-G conversion strongly indicate the development of active tuberculosis in patients undergoing long-term anti-TNFα therapy.
Immunosuppressive therapy with anti-tumour necrosis factor-α (TNF-α) agents in rheumatic patients modulates the immune system and may increase the risk of reactivating infections that are normally maintained in a latent state, such as tuberculosis. The purpose of this study was to analyse the value of QuantiFERON TB Gold In-Tube (QFT IT) and tuberculin skin test (TST) in BCG vaccinated patients with rheumatoid arthritis and ankylosing spondylitis who were qualified to receive TNF-α blockers.
MATERIAL AND METHODS:
Ninety patients with rheumatoid arthritis and ankylosing spondylitis were included in the study. The control group consisted of 20 healthy participants. Chest X-ray, TST and QFT IT were carried out in all persons.
RESULTS:
In rheumatic patients positive results of QFT IT and TST tests were identified in 15 cases (16.7%) whereas negative results of both tests were detected in 56 cases (62.2%). In the group of examined patients, 11 (12.2%) had QFT IT-/TST+ test results. In patients with QFT IT+/TST- status one active tuberculosis case was detected. In the control group QFT IT positive results were found in 4 cases (20%) and TST positive in 11 cases (55%). Treatment with TNF-α blockers was introduced in 26 rheumatology patients with the following test status: 3 with QFT IT+/TST+; 20 with QFT IT-/TST-; 3 with QFT IT-/TST+.
CONCLUSIONS:
In the BCG vaccinated population the QFT IT assay may potentially improve the identification and selection for therapy for latent TB infection before treatment with anti-TNF agents.
