Fig. 1.

Functional assessment of adherent cell assay for TNF release from a single PPD skin test negative donor (DR). Purified adherent cells (1 × 10⁶ cells in 500 μl) were stimulated with either LPS (0.1 μg) or PPD (10 μg) in the presence and absence of polymyxin B (10 μg). Spontaneous release of TNF-α by adherent cells was also assessed without any added stimulant (spontaneous), and was <10 pg/ml for all plasma samples tested.