Effects of heparin-binding protein (CAP37/azurocidin) in a porcine model of Actinobacillus pleuropneumoniae-induced pneumonia

Abstract Heparin-binding protein (HBP; CAP37/azurocidin) is secreted from neutrophil leukocytes early during inflammation and plays a central role in early capillary leakage and extravasation of neutrophils. Furthermore, HBP is chemotactic towards monocytes and lymphocytes and protects against stress-induced apoptosis, e.g. induced by oxygen radicals released during inflammation. Thus, administration of HBP as an adjunct to antibiotics increased survival of mice with peritonitis. In the present study, the effects of recombinant HBP as an adjunct to standard antibiotics were examined in a porcine model of Actinobacillus pleuropneumoniae -induced pneumonia. Beneficial and possible adverse effects of HBP were evaluated clinically and pathologically as well as by measurement of clinical chemical variables and markers of inflammation (interleukin-6 and C-reactive protein) and oxidative stress (ascorbic acid and α-tocopherol). Pigs receiving HBP (0.55 mg kg −1 , n  = 11) as a 6-hourly subcutaneous infusion starting 1-h post-infection had a faster decrease in rectal temperature compared to control animals receiving a carrier-infusion ( n  = 11), with a significant lower temperature at 32 h post-infection ( p