Figure 1
From: Negative effect of smoking on the performance of the QuantiFERON TB gold in tube test
Influence of smoking on crude IFN-γ responses in Danish and Tanzanian TB patients. In non-smokers (NS) and smokers (S), levels of Interferon-γ were measured in supernatants from QuantiFERON-TB Gold In tube blood collection tubes after incubation with saline (Nil), M. tuberculosis-specific antigens (Antigen) or phytohaemagglutinin (Mitogen). Nil levels of antigen and mitogen values have NOT been subtracted. Medians and p-values for comparison of nil, antigen and mitogen levels between non-smokers (14 Danish patients and 149 Tanzanian patients) and smokers (20 Danish patients and 23 Tanzanian patients) are shown (Wilcoxon signed rank test).