FIGURE 2.

Cytokine production of blood leukocytes from patients with community-acquired pneumonia stratified according to TNF-α production capacity. Patients were stratified into those with the lowest 25% blood leukocyte TNF-α production (low TNF-α producers, n = 20) and those with the highest 25% blood leukocyte TNF-α production (high TNF-α producers, n = 20) following LPS stimulation. Cytokines were measured in supernatants of whole blood leukocytes stimulated for 24 h with lipopolysaccharide (LPS; 100 ng/mL) or heat-killed Klebsiella pneumoniae (equivalent of 12.5 × 10⁶ CFU/mL). Individual data points are displayed with the horizontal line depicting the median. Dotted lines indicate median concentrations in medium control samples (i.e., blood leukocytes incubated without stimulus), which were all significantly altered compared to LPS and K. pneumoniae stimulation. Asterisks indicate differences between patients with the lowest and the highest TNF-production following LPS stimulation (**P < 0.01, ***P < 0.001). IL, interleukin; TNF, tumor necrosis factor; RA, receptor antagonist.