POLYMORPHONUCLEAR LEUKOCYTE-MEDIATED BONE DEGRADATION AND INFLUENCE OF BLOOD MONONUCLEAR-CELLS ON THE MOUSE CALVARIAL MODEL

Objective. To investigate the relationships between degradation of bon e and activated blood polymorphonuclear leukocytes (PMNL) and mononucl ear leukocytes (ML) as well as their soluble products in vitro. Materi als and Methods. A neonatal mouse calvarial bone model was used to ass ess the activity of degradation (by measuring the amount of Ca-45 rele ase) by normal human blood leukocytes, separated PMNL and ML following 24-hour incubation. The effects of conditioned culture medium obtaine d from Staphylococcus aureus-stimulated ML on PMNL-mediated calvarial bone loss were also studied. Results. It was demonstrated that isolate d human PMNL rapidly degraded bone in a dose and time dependent manner . The PMNL-mediated bone degradation was enhanced by conditioned mediu m obtained from Staphylococcus aureus-stimulated ML. Conclusion. These findings implicate PMNL as major contributors to early bone loss in i nfectious diseases such as acute haematogenous osteomyelitis.