Ex vivo evaluation of PPD-specific IFN-gamma or IL-5 secreting cells in the peripheral blood and lungs of patients with tuberculosis.
OBJECTIVE
To evaluate ex vivo purified protein derivative (PPD) specific Th1- and Th2-type functional responses in human tuberculosis (TB).


METHODS
IFN-gamma and IL-5 secreting cells were measured by a computer-assisted ELISPOT assay in the peripheral blood of patients with pulmonary TB, in patients with other respiratory diseases (control patients) and in tuberculin skin test negative or positive healthy controls. Moreover, the number of IFN-gamma or IL-5 spots was assessed in the bronchoalveolar lavage (BAL) cells of five patients with advanced TB and lung inflammation.


RESULTS
The frequency of PPD-specific IFN-gamma secreting cells in TB patients was higher than in control patients and healthy subjects. Although the number of PPD-specific IL-5 spots was low, a trend towards a higher frequency was observed in the peripheral blood of TB patients. Patients with advanced TB and lung inflammation had an increased number of both PPD-specific IFN-gamma and IL-5 spots in BAL as compared to that in peripheral blood, but the IFN-gamma/IL-5 ratio was about two-fold lower.


CONCLUSIONS
In human TB, the host response in the periphery is driven by a specific Th1-type cytokine response, whereas in the lungs of patients with advanced disease and lung inflammation, polarisation towards a Th2-like bias is observed.
Morosini
M
M
Pneumology Section, Department of Haematological, Pneumological and Cardiovascular Sciences, University of Pavia and IRCCS Policlinico San Matteo, Pavia, Italy.
Meloni
F
F
Uccelli
M
M
Marone Bianco
A
A
Solari
N
N
Fietta
A M
AM
D000328:Adult; D000368:Aged; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis*; D015848:Interleukin-5 / Q000032:analysis*; D008168:Lung / Q000276:immunology; D008297:Male; D008875:Middle Aged; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*; D014373:Tuberculin / Q000276:immunology; D014397:Tuberculosis, Pulmonary / Q000097:blood* / Q000276:immunology
D015848:Interleukin-5; D014373:Tuberculin; D007371:Interferon-gamma