Use of Quantiferon-TB-Gold in Tube(®) test for detecting latent tuberculosis in patients considered as candidates for anti-TNF therapy in routine clinical practice.
METHODS
Quantiferon-TB-Gold in Tube(®) test (QFT-G-IT) may have advantages if combined with TST when screening for Latent Tuberculosis Infection (LTBI) prior to initiating anti-TNF therapy in an area of intermediate tuberculosis incidence such as Spain. In a small-scale prospective study, we evaluate the use of QFT-G-IT in combination with the screening recommended in Spain (Tuberculin-Skin Test, TST retest, clinical data, and Chest X-Ray (CXR)) for LTBI in patients considered as candidates for anti-TNFα treatment.


RESULTS
From June 2008 to October 2010, 123 patients from a 300-bed hospital in Palma de Mallorca (Spain) were included in the study. The majority of patients were under immunosuppressive therapy. A positive TST and TST booster were found in 22 and 17 patients, respectively. Thus 39 (31.7%) of the 123 patients had a positive TST. QFT-G-IT was positive in 16 patients (13.6%), indeterminate in 4 (3.2%), and negative in 103 (83.7%). One of the two tests was positive and LTBI was diagnosed in 34.1% of patients. The agreement between TST and QFT-G-IT among vaccinated patients was low and not statistically significant (Kappa=0.15) and was almost perfect among non-BCG vaccinated patients (K=0.81). TST positive responses were significantly related to BCG-vaccination (p<0.05) and QFT-G-IT positive response rates were related to older age (p<0.05).


CONCLUSIONS
QFT-G-IT may have advantages when combined with TST in immunosuppressed patients especially in older patients with a negative TST; in BCG vaccinated patients with a positive TST, QFT-G-IT could avoid unnecessary treatments and toxicities related to a false-positive TST result.
Internal Medicine Department/Tuberculosis Unit, Hospital Son Llàtzer, Crtra de Manacor km 4, 07189 Palma de Mallorca, Islas Baleares, Spain. mercedesggasalla@yahoo.es
Mercedes
M
García-Gasalla
Victoria
V
Fernández-Baca
Antonio
A
Juan-Mas
Antoni
A
Payeras-Cifre
Carmen
C
Cifuentes-Luna
Rosa
R
Taberner-Ferrer
Joan
J
Riera-Oliver
Immaculada
I
Ros-Villamajó
Verónica
V
Navarro-Fernández
Catalina
C
Morey Torrandell
Carmen
C
Gallegos-Alvarez
Isabel
I
Mir-Villadrich
D000293:Adolescent; D000328:Adult; D000368:Aged; D001431:Bacteriological Techniques / Q000379:methods; D005260:Female; D006801:Humans; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011446:Prospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*; D055815:Young Adult
D014409:Tumor Necrosis Factor-alpha