Table 2.

Comparisons between the PhagoBurst and the DCFH-DA assay

	Relative reactive oxygen species formation in SLE patients as% of formation in healthy controls
Stimuli	PhagoBurst	DCFH-DA	P -value
PMA	68 ± 7.7	76 ± 6.2	0.6783
E. coli	84 ± 13	103 ± 13	0.1775
S. aureus	92 ± 8.7	102 ± 6.3	0.2716
P. aeruginosa	88 ± 12	97 ± 14	0.5897

Comparisons of the PhagoBurst assay with the dichlorodihydrofluorescein-diacetate (DCFH-DA) assay according to Perazzio et al. [23]. No significant differences between the methods were observed. Polymorphonuclear leukocytes (PMN) from systemic lupus erythematosus (SLE) patients (n = 15) and healthy controls (n = 15) were analysed in parallel with both methods using phorbol 12-myristate 13-acetate (PMA), E. coli, S. aureus or P. aeruginosa as stimuli. ROS formation was defined as geometric mean fluorescence intensity. Samples from each individual patient were divided by the mean value of the controls to gain the relative ROS formation in SLE-PMN as% of ROS produced in healthy controls. Values represent mean ± standard error of the mean. The two-sided Mann-Whitney test was used to calculate the level of significance.