Erschienen in:
01.08.2013 | Brief Report
Contact investigation based on serial interferon-gamma release assays (IGRA) in children from the hematology-oncology ward after exposure to a patient with pulmonary tuberculosis
verfasst von:
A. C. C. Carvalho, R. F. Schumacher, S. Bigoni, E. Soncini, L. Notarangelo, A. Apostoli, C. Bonfanti, D. Cirillo, P. Mantegani, F. Porta, M. Comelli, A. Matteelli
Erschienen in:
Infection
|
Ausgabe 4/2013
Einloggen, um Zugang zu erhalten
Abstract
Background
Interferon-gamma release assays (IGRAs) have high specificity and sensitivity for the diagnosis of tuberculosis (TB) infection. However, their role as a screening tool in children with immunodeficiency disorders is still unclear. In the present study, we performed a contact investigation using serial IGRAs on children with immunodeficiency conditions exposed to a contagious TB patient.
Methods
Children who were exposed to a contagious TB case underwent serial QuantiFERON® TB Gold In-Tube (QFT-GIT) and T-SPOT®.TB (T-SPOT) testing.
Results
Eighteen children were tested. At the first testing, only two children (11 %) were positive to T-SPOT. Indeterminate results were more frequent with QFT-GIT (35 %) than with T-SPOT (12 %). In the multivariable analysis, a statistically significant association of lymphocyte count <500 cells/mm3 (p < 0.00005) and low age (p = 0.03) with indeterminate results for the QFT-GIT test but not for T-SPOT (p = 0.10 and p = 0.88, respectively) was found. At the end of October 2012, 15 of the 18 children were alive and none developed active TB disease.
Conclusion
T-SPOT provided more determinate results and was less influenced by low age and lymphocytopenia than QFT-GIT in this population of immunodeficient children. These findings suggest that T-SPOT is a more accurate test for the identification of TB infection in young children with lymphocytopenia and should be preferred to QFT-GIT under such specific conditions.