Humoral immunity in tuberculin skin test anergy and its role in high-risk persons exposed to active tuberculosis.
The most common test to identify latent tuberculosis is the tuberculin skin test that detects T cell responses of delayed type hypersensitivity type IV. Since it produces false negative reactions in active tuberculosis or in high-risk persons exposed to tuberculosis patients as shown in this report, we studied antibody profiles to explain the anergy of such responses in high-risk individuals without active infection. Our results showed that humoral immunity against tuberculin, regardless of the result of the tuberculin skin test is important for protection from active tuberculosis and that the presence of high antibody titers is a more reliable indicator of infection latency suggesting that latency can be based on the levels of antibodies together with in vitro proliferation of peripheral blood mononuclear cells in the presence of the purified protein derivative. Importantly, anti-tuberculin IgG antibody levels mediate the anergy described herein, which could also prevent reactivation of disease in high-risk individuals with high antibody titers. Such anti-tuberculin IgG antibodies were also found associated with blocking and/or stimulation of in vitro cultures of PBMC with tuberculin. In this regard, future studies need to establish if immune responses to Mycobacterium tuberculosis can generate a broad spectrum of reactions either toward Th1 responses favoring stimulation by cytokines or by antibodies and those toward diminished responses by Th2 cytokines or blocking by antibodies; possibly involving mechanisms of antibody dependent protection from Mtb by different subclasses of IgG.
Encinales
Liliana
L
Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115 6084, USA.
Zuñiga
Joaquin
J
Granados-Montiel
Julio
J
Yunis
Maria
M
Granados
Julio
J
Almeciga
Ingrid
I
Clavijo
Olga
O
Awad
Carlos
C
Collazos
Vilma
V
Vargas-Rojas
María Inés
MI
Bañales-Mendez
José Luis
JL
Vazquez-Castañeda
Lilia
L
Stern
Joel N
JN
Romero
Viviana
V
Fridkis-Hareli
Masha
M
Frindkis-Hareli
Masha
M
Terreros
Daniel
D
Fernandez-Viña
Marcelo
M
Yunis
Edmond J
EJ
D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D017635:Clonal Anergy / Q000276:immunology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D056724:Immunity, Humoral / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D016273:Occupational Exposure / Q000009:adverse effects*; D010564:Personnel, Hospital; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014374:Tuberculin Test; D014376:Tuberculosis / Q000097:blood / Q000276:immunology*
D000907:Antibodies, Bacterial