The ratio of cytokine responses in spouses and TB patients.

<p>The ratio of cytokine responses to ESAT-6 (A) and PPD (B) were analysed in the spouses who showed negative IFN-γ responses to ESAT-6 (<62.5 pg/mL, n = 102; indicated as S1), the spouses with positive IFN-γ responses (>62.5 pg/mL, n = 48; indicated as S2) and TB patients (n = 15; indicated as T). The ratio of IFN-γ/IL-10, CXCL10/IL-10, TNF-α/IL-17, IFN-γ/IL-17 and IL-17/IL-10 differentiated the S2 and TB groups from S1 in responses to both ESAT-6 and PPD. None of the ratios differentiated between the S2 and T groups upon ESAT-6 stimulation while IFN-γ/IL-10 and IFN-γ/IL-17 in response to PPD distinguished S2 from TB patients. Median ratio of cytokine responses is marked with horizontal bars. (* P<0.05, ** P<0.01, *** P<0.001)