IFN-gamma, but not IP-10, MCP-2 or IL-2 response to RD1 selected peptides associates to active tuberculosis.
OBJECTIVE
To evaluate whether in vitro response to Mycobacterium tuberculosis RD1 peptides selected by computational analysis, measured by IFN-gamma, IP-10, MCP-2 or IL-2 production, is associated with active tuberculosis (TB) in a country with a high incidence of TB.


METHODS
129 individuals were prospectively enrolled, 41 with active-pulmonary TB and 88 without (household contacts and community controls). A whole blood assay based on RD1 selected peptides was performed. Soluble factors were evaluated by ELISA in plasma harvested at day1-post-culture. Enrolled individuals were also tested by QuantiFERON TB-Gold In tube (QFT-IT) and tuberculin skin tests (TST).


RESULTS
IFN-gamma response to RD1 selected peptides was significantly higher in active TB patients than in household contacts and community controls. IP-10 and MCP-2 response did not differ between active TB patients and household contacts, although it was higher in these groups compared to community controls; conversely IL-2 response did not differ among the three groups. When IFN-gamma response to RD1 selected peptides was scored based on receiver-operator-characteristic analysis, active TB was predicted with 68% sensitivity and 86% specificity. QFT-IT and TST showed a sensitivity for active TB of 90% and 68% and a specificity of 58% and 59%, respectively.


CONCLUSIONS
IFN-gamma (but not IP-10, MCP-2 and IL-2) response to RD1 selected peptides is associated with active TB with a higher specificity than QFT-IT and TST.
Goletti
Delia
D
Translational Research Unit, Department of Epidemiology and Preclinical Research, L. Spallanzani National Institute for Infectious Diseases (INMI), Via Portuense 292, Rome, Italy. delia.goletti@inmi.it
Raja
Alamelu
A
Ahamed Kabeer
Basirudeen Syed
BS
Rodrigues
Camilla
C
Sodha
Archana
A
Butera
Ornella
O
Carrara
Stefania
S
Vernet
Guy
G
Longuet
Christophe
C
Ippolito
Giuseppe
G
Thangaraj
Satheesh
S
Leportier
Marc
M
Girardi
Enrico
E
Lagrange
Philippe Henri
PH
D000328:Adult; D000942:Antigens, Bacterial / Q000276:immunology; D054412:Chemokine CCL8 / Q000276:immunology*; D054357:Chemokine CXCL10 / Q000276:immunology*; D005260:Female; D006801:Humans; D007118:Immunoassay; D007371:Interferon-gamma / Q000276:immunology*; D007376:Interleukin-2 / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis* / Q000276:immunology*
D000942:Antigens, Bacterial; C515453:CCL8 protein, human; C114753:CXCL10 protein, human; D054412:Chemokine CCL8; D054357:Chemokine CXCL10; D007376:Interleukin-2; D007371:Interferon-gamma