Table 3. The percentage of granulomas positive for specific cytokines in HIV negative and HIV positive pleural tuberculosis patients.

	Cytokine expression grade HIV negative granulomas				Cytokine expression grade HIV positive granulomas				Chi-square test
	0	1	2	3	0	1	2	3
IL-12	0	31%	46%	23%	0	20%	49%	31%	p = 0.03
IFNγ	0	50%	30%	20%	0	26%	37%	37%	p = 0.02
TNFα	0	31%	42%	27%	0	24%	15%	61%	p<0.01
IL-4	2%	46%	26%	26%	7%	24%	46%	23%	p = 0.02

IL-12, IFN-γ, TNF-α and IL-4 mRNA expression was examined by in situ hybridisation on granulomas from pleural biopsies. Positivity was graded according to the total number of cells staining positive in a specific granuloma (<25%, grade 1; 25–75%, grade 2 and >75%, grade 3).