title: Serial interferon-γ release assays for screening and monitoring of tuberculosis infection during treatment with biologic agents.
abstract: 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.
authors.affiliation: Dipartimento di Medicina Interna e Specialità Mediche, Reumatologia, Sapienza Università di Roma, viale del Policlinico 155, 00161 Rome, Italy. rossana.scrivo@uniroma1.it
authors.forename: Rossana
authors.initials: R
authors.lastname: Scrivo
authors.forename: Ilaria
authors.initials: I
authors.lastname: Sauzullo
authors.forename: Fabio
authors.initials: F
authors.lastname: Mengoni
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Iaiani
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Vestri
authors.forename: Roberta
authors.initials: R
authors.lastname: Priori
authors.forename: Elisa
authors.initials: E
authors.lastname: Di Filippo
authors.forename: Manuela
authors.initials: M
authors.lastname: Di Franco
authors.forename: Francesca Romana
authors.initials: FR
authors.lastname: Spinelli
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Vullo
authors.forename: Claudio Maria
authors.initials: CM
authors.lastname: Mastroianni
authors.forename: Guido
authors.initials: G
authors.lastname: Valesini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001688:Biological Products / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000628:therapy; D007371:Interferon-gamma / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012216:Rheumatic Diseases / Q000628:therapy; D012307:Risk Factors; D014374:Tuberculin Test; D014376:Tuberculosis / Q000097:blood* / Q000628:therapy*
chemical_list: D001688:Biological Products; D007371:Interferon-gamma