In the absence of clinico-radiographic findings for LTBI, blood assays could replace TST for antibiotherapy
Comparison of in vitro-specific blood tests with tuberculin skin test for diagnosis of latent tuberculosis before anti-TNF therapy
Jérémie Sellam 1,*, Haifa Hamdi 2,*, Carine Roy 3, Gabriel Baron 3, Marc Lemann 4, Xavier Puéchal 5, Maxime Breban 6, Francis Berenbaum 7, Marc Humbert 8, Karin Weldingh 9, Dominique Salmon 10, Philippe Ravaud 3, Dominique Emilie 2, Xavier Mariette 1 for the RATIO (Research Axed on Tolerance of Biotherapies) Study Group
1 Rhumatologie, Hôpital de Bicêtre, Assistance Publique-Hôpitaux de Paris, Université Paris-Sud, Le Kremlin Bicêtre, France
2 INSERM UMR-S764, Service de Microbiologie-Immunologie Biologique, Hôpital Antoine Béclère, Assistance Publique-Hôpitaux de Paris, Institut Paris-Sud sur les Cytokines, Université Paris-Sud, Clamart, France
3 Département d’Epidémiologie, Biostatistique et Recherche Clinique, Groupe Hospitalier Bichat Claude-Bernard, Assistance Publique-Hôpitaux de Paris, Université Paris VII, Paris, France
4 Service de Gastro-entérologie, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France
5 Service de Rhumatologie, Centre hospitalier du Mans, Le Mans, France
6 Service de Rhumatologie, Hôpital Ambroise Paré, Assistance Publique-Hôpitaux de Paris, Boulogne, France
7 Service de Rhumatologie, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, Paris, France
8 Service de Pneumologie, Hôpital Antoine Béclère, Assistance Publique-Hôpitaux de Paris, Université Paris-Sud, Clamart, France
9 Department of Infectious Disease and Immunology, Statens Serum Institut, Copenhagen, Denmark
10 Service de Médecine interne et maladies infectieuses, Hôpital Cochin, Assistance Publique-Hôpitaux de Paris, Paris, France
Correspondence to:
Pr Xavier Mariette, Service de Rhumatologie, Hôpital de Bicêtre, 78 rue du Général Leclerc, 94275 Le Kremlin Bicêtre, France; xavier.mariette@bct.ap-hop-paris.fr
Introduction: Latent tuberculosis infection (LTBI) is detected with the tuberculin skin test (TST) before anti-TNF therapy. We aimed to investigate in vitro blood assays with TB-specific antigens (CFP-10, ESAT-6), in immune-mediated inflammatory diseases (IMID) for LTBI screening.
Patients and methods: Sixty-eight IMID patients with (n = 35) or without (n = 33) LTBI according to clinico-radiographic findings or TST results (10 mm cutoff value) underwent cell proliferation assessed by thymidine incorporation and PKH-26 dilution assays, and IFN{gamma}-release enzyme-linked immunosorbent spot (ELISPOT) assays with TB-specific antigens.
Results: In vitro blood assays gave higher positive results in patients with LTBI than without (p<0.05),>0.3) and lower results than those with LTBI (p<0.05) on CFP-10+ESAT-6 ELISPOT and CFP-10 proliferation assays.
Conclusion: Anti-TB blood assays are beneficial for LTBI diagnosis in IMID. Compared with TST, they show a better sensitivity, as seen by positive results in 5 patients with certain LTBI and negative TST, and better specificity, as seen by negative results in most patients with intermediate TST as the only criteria of LTBI. In the absence of clinico-radiographic findings for LTBI, blood assays could replace TST for antibiotherapy
