FIG. 2.

Cytokine protein concentrations in pleural fluid. TGF-β1 (A) and total bioactive IFN (B) protein levels in pleural fluid of guinea pigs during 9 days of tuberculous pleurisy were measured. TGF-β1 protein levels were analyzed by ELISA and are expressed in nanograms per milliliter. Total IFN protein levels were analyzed by bioassay as described in Materials and Methods and are expressed in units per milliliter. Data and error bars represent the mean ± the standard error of the mean for three or four animals per day. An asterisk indicates a significant increase in TGF-β1 levels above that on all days except day 5.