Temporal dynamics of interferon gamma responses in children evaluated for tuberculosis.
BACKGROUND
Development of T-cells based-Interferon gamma (IFNgamma) assays has offered new possibilities for the diagnosis of latent tuberculosis infection (LTBI) and active disease in adults. Few studies have been performed in children, none in France. With reference to the published data on childhood TB epidemiology in the Paris and Ile de France Region, we considered it important to evaluate the performance of IGRA (QuantiFERON TB Gold In Tube(R), QF-TB-IT) in the diagnosis and the follow-up through treatment of LTBI and active TB in a cohort of French children.


RESULTS
131 children were recruited during a prospective and multicentre study (October 2005 and May 2007; Ethical Committee St Louis Hospital, Paris, study number 2005/32). Children were sampled at day 0, 10, 30, 60 (except Healthy Contacts, HC) and 90 for LTBI and HC, and a further day 120, and day 180 for active TB children. Median age was 7.4 years, with 91% of the children BCG vaccinated. LTBI and active TB children undergoing therapy produced significant higher IFNgamma values after 10 days of treatment (p = 0.035). In addition, IFNgamma values were significantly lower at the end of treatment compared to IFNgamma values at day 0, although the number of positive patients was not significantly different between day 0 and end of treatment.


CONCLUSIONS
By following quantitative IFNgamma values in each enrolled child with LTBI or active TB and receiving treatment, we were able to detect an increase in the IFNgamma response at day 10 of treatment which might allow the confirmation of a diagnosis. In addition, a decline in IFNgamma values during treatment makes it possible for clinicians to monitor the effect of preventive or curative therapy.
Herrmann
Jean-Louis
JL
Service de Microbiologie, Hôpital St Louis et Equipe d'Accueil (EA3510), Assistance Publique Hôpitaux de Paris et UFR Denis Diderot, Paris, France. jean-louis.herrmann@rpc.aphp.fr
Belloy
Marie
M
Porcher
Raphael
R
Simonney
Nancy
N
Aboutaam
Rola
R
Lebourgeois
Muriel
M
Gaudelus
Joel
J
De Losangeles
Laure
L
Chadelat
Katarina
K
Scheinmann
Pierre
P
Beydon
Nicole
N
Fauroux
Brigitte
B
Bingen
Martine
M
Terki
Mustapha
M
Barraud
Dominique
D
Cruaud
Philippe
P
Offredo
Catherine
C
Ferroni
Agnes
A
Berche
Patrick
P
Moissenet
Didier
D
Vuthien
Hoang
H
Doit
Catherine
C
Bingen
Edouard
E
Lagrange
Philippe Henri
PH
D000293:Adolescent; D000328:Adult; D001500:BCG Vaccine / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007371:Interferon-gamma / Q000276:immunology; D008297:Male; D011446:Prospective Studies; D012372:ROC Curve; D011933:Reagent Kits, Diagnostic; D013997:Time Factors; D014376:Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology* / Q000517:prevention & control
D001500:BCG Vaccine; D011933:Reagent Kits, Diagnostic; D007371:Interferon-gamma