Fig. 5

Soluble CD40 ligand (sCD40L) plasma levels are increased in patients with Behçet’s disease (BD) and stimulate neutrophil extracellular trap (NET) release and oxidative burst. a Screening with the addressable laser bead immunoassay (see Additional file 2: Table S2 for more details) showed strikingly higher sCD40L plasma levels in patients with inactive Behçet’s disease (iBD; n = 31) and patients with active Behçet’s disease (aBD; n = 30) than in healthy control subjects (HC; n = 30). b sCD40L plasma levels measured by enzyme-linked immunosorbent assay in HCs, patients with iBD, patients with aBD, and patients with active systemic lupus erythematosus (aSLE; n = 27) or patients with inactive systemic lupus erythematosus (iSLE; n = 27). c Effect of sCD40L or plasma from HCs, patients with iBD, and patients with aBD blocked with recombinant human CD40 (rhCD40-muIg) upon NET release by neutrophils from HCs and patients with BD. d–g Superoxide (d and f) and hydrogen peroxide (e and g) production by neutrophils (d and e) and peripheral blood mononuclear cells (PBMCs) (f and g) after stimulation with sCD40L, CD40L-poor plasma from hyper immunoglobulin M (hyper-IgM) patients, or aBD plasma containing sCD40L-blocking rhCD40-muIg, calculated by the AUC. Bars are defined as follows: a Median; b–g mean ± SE. Statistical analysis was performed using the Kruskal-Wallis test with the Mann-Whitney posttest (a) or one-way analysis of variance with the Bonferroni posttest (b–g)