Modulation of neutrophil apoptosis in plasma of patients after orthognathic surgery.
BACKGROUND
Human neutrophils undergo rapid apoptosis during in vitro culture. The aim of this study was to investigate the role of interleukin-8 (IL-8) on neutrophil apoptosis in surgery-induced inflammation.


METHODS
Blood samples were drawn from 21 patients with mandibular prognathism 2 days before, and 1 and 5 days after orthognathic surgery. The IL-8 levels in the separated plasma were measured using an ELISA kit. The expression of two receptors for IL-8, CXCR1, and CXCR2, and their role in neutrophil apoptosis was evaluated using a flow cytometer.


RESULTS
The IL-8 levels in the plasma were correlated with acute inflammatory markers, such as peripheral blood neutrophil counts and C-reactive protein levels. Both IL-8 receptors were markedly raised in patient-derived neutrophils 1 day post-operatively. Recombinant IL-8 (0-100 ng/ml) suppressed apoptosis in fresh-isolated neutrophils from healthy donors dose-dependently. Neutrophil apoptosis 1 day post-operatively was slightly accelerated in the presence of fetal bovine serum compared to the value 2 days pre-operatively and 5 days post-operatively. In contrast, in the presence of autogenous plasma, neutrophil apoptosis was significantly suppressed 1 day post-operatively compared to the value 2 days pre-operatively and 5 days post-operatively. Moreover, the anti-apoptotic effect of plasma on neutrophil apoptosis was partially decreased by the addition of anti-IL-8 neutralizing antibody.


CONCLUSIONS
These results suggest that circulating neutrophils are susceptible to augmentation by IL-8 through the reinforcement of IL-8 receptors in acute inflammatory conditions. Furthermore, IL-8 may, in part, contribute to the regulation of neutrophil survival during the inflammatory response.
Suzuki
Rikako
R
Department of Oral and Maxillofacial Surgery, Showa University School of Dentistry, Tokyo, Japan.
Iwase
Masayasu
M
Miyaoka
Ken-ichi
K
Kondo
Gen
G
Watanabe
Hitoshi
H
Ohashi
Masaru
M
Nagumo
Masao
M
D000328:Adult; D000906:Antibodies / Q000276:immunology; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D002097:C-Reactive Protein / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D016209:Interleukin-8 / Q000097:blood / Q000276:immunology* / Q000494:pharmacology; D007958:Leukocyte Count; D009504:Neutrophils / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D019647:Oral Surgical Procedures; D011184:Postoperative Period; D023062:Receptors, Interleukin-8A / Q000378:metabolism; D023063:Receptors, Interleukin-8B / Q000378:metabolism; D013312:Stress, Physiological / Q000276:immunology
D000906:Antibodies; D016209:Interleukin-8; D023062:Receptors, Interleukin-8A; D023063:Receptors, Interleukin-8B; D002097:C-Reactive Protein