The bactericidal/permeability-increasing protein (BPI) in antibacterial host defense

The bactericidal/permeability‐increasing protein (BPI) is a 456‐residue cationic protein produced only by precursors of polymorphonuclear leukocytes (PMN) and is stored in the primary granules of these cells. The potent (nM) cytotoxicity of BPI is limited to gram‐negative bacteria (GNB), reflecting the high affinity (900 normal and severely ill individuals have issues of safety or immunogenicity been encountered. Preliminary evidence points to overall benefit in BPI‐treated patients. These results suggest that BPI may have a place in the treatment of life‐threatening infections and conditions associated with bacteremia and endotoxemia. J. Leukoc. Biol. 64: 14–18; 1998.