MPO and systemic lupus erythematosus: Hence, we tried the combination of anti-MPO (Abcam) and -CitH3 (Abcam) antibodies in 5% NRS blocking buffer and detected a significant and striking increase in NET detection from SLE patient and IRF5 risk plasma samples (Figures 2B, C), but not from PMA-induced NETs, when comparing anti-CitH3 alone and combined anti-MPO + anti-CitH3 antibody detection (Figure 2D) (32).