Potential role for IL-2 ELISpot in differentiating recent and remote infection in tuberculosis contact tracing.
Interferon (IFN)-gamma release assays (IGRA) have improved tuberculosis contact tracing, but discrimination of recent from remote Mycobacterium tuberculosis contacts is not possible by IGRA alone. We present results of a tuberculosis contact investigation with a new early-secretory-antigenic-target (ESAT)-6 and culture-filtrate-protein (CFP)-10 specific interleukin (IL)-2 ELISpot in addition to ESAT-6 and CFP-10 specific IFN-gamma ELISpot and tuberculin skin testing (TST). Results of the TST, IFN-gamma ELISpot and IL-2 ELISpot were positive in 6/172 (3.4%), 7/167 (4.2%) and 6/196 (3.1%) of contacts, respectively. Close contact (> or =100 hours) to the index case increased the risk of positive results in the IFN-gamma ELISpot, TST, and IL-2 ELISpot by 40.8, 19.3, and 2.5 times, respectively. Individuals with a positive IFN-gamma ELISpot/negative IL-2 ELISpot result had a median (IQR) duration of index case exposure of 568 hours (133_1000) compared to individuals with a positive IFN-gamma ELISpot/positive IL-2 ELISpot result (median = 24 hours; 20_130; p-value = 0.047). Combination of a M. tuberculosis specific IFN-gamma ELISpot with a M. tuberculosis specific IL-2 ELISpot significantly improved the identification of individuals with the highest risk of recent M. tuberculosis infection and is a promising method that should be explored to target tuberculosis preventive chemotherapy.
Krummel
Benjamin
B
Division of Clinical Infectious Diseases, Research Center Borstel, Borstel, Germany.
Strassburg
Alan
A
Ernst
Martin
M
Reiling
Norbert
N
Eker
Barbara
B
Rath
Heidrun
H
Hoerster
Robert
R
Wappler
Waltraud
W
Glaewe
Andrea
A
Schoellhorn
Volker
V
Sotgiu
Giovanni
G
Lange
Christoph
C
D000293:Adolescent; D000328:Adult; D002460:Cell Line; D002648:Child; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007371:Interferon-gamma / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism*; D016015:Logistic Models; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology* / Q000378:metabolism; D012882:Skin Tests; D014373:Tuberculin / Q000378:metabolism; D014376:Tuberculosis / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D055815:Young Adult
D007376:Interleukin-2; D014373:Tuberculin; D007371:Interferon-gamma