Peripheral blood mononuclear phagocytes from patients with chronic periodontitis are primed for osteoclast formation.

BACKGROUND: During inflammatory periodontal disease, peripheral blood mononuclear cells (PBMCs) are attracted to bone and differentiate into active bone-resorbing osteoclasts (OCs), thus providing evidence that the impact of chronic periodontitis (CP) on the activity of circulating mononuclear cells is of central importance. The authors test the hypothesis that peripheral blood mononuclear phagocytes (PBMPs) from patients with CP are activated and more susceptible to differentiation into OCs, which in turn would lead to more intense bone resorption. METHODS: In vitro cytokine production by both unstimulated and lipopolysaccharide-stimulated PBMCs from individuals with (n = 10) or without (n = 12) periodontitis was determined by cytokine array. OC differentiation from CD14(+) PBMCs was induced by receptor activator of nuclear factor-kappa B ligand (RANKL), either alone or in the presence of macrophage colony-stimulating factor (M-CSF). PBMC differentiation to OCs was confirmed by tartrate-resistant acid phosphatase staining; bone resorbing activity was assessed by using an osteologic plate assay (bone resorption pit formation). RESULTS: PBMCs from patients with CP produced tumor necrosis factor-α and higher amounts of interferon-γ, interleukin (IL)-1α, IL-1ß, IL-1rα, CXC motif chemokine 10, macrophage migration inhibitory factor, macrophage inflammatory protein (MIP)-1α, and MIP-1ß than the control cells. OC differentiation was induced by RANKL alone in PBMCs from patients with CP, but not in PBMCs from the healthy controls, which required the addition of M-CSF. In addition, PBMC-derived OCs from patients with CP showed significantly higher resorption activity than that observed in the healthy controls. Also, the circulating concentrations of M-CSF were significantly higher in patients with CP than in the control participants. CONCLUSIONS: These data indicate that in patients with CP, circulating PBMCs are primed for increased proinflammatory activity and that M-CSF plays a central role in this process by increasing OC formation and the consequent bone resorption activity.

Leukocyte numbers correlate with plasma levels of granulocyte-macrophage colony-stimulating factor in sickle cell disease.

Despite a clear role for leukocytes in modulating the pathophysiology of sickle cell disease (SCD), the mechanism by which leukocyte numbers are increased in this disorder remains unclear. Hypothesizing that the chronic inflammatory state, elicited by adhesive interactions involving various cell types, might underlie leukocytosis, we measured plasma levels of proinflammatory or myeloid cytokines that play a role in leukocytosis and examined their correlations with leukocyte numbers in patients with SCD. Our studies found that, although plasma levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin 3, and macrophage colony-stimulating factor are elevated in steady-state patients with SCD, only plasma GM-CSF levels are positively correlated with the numbers of total leukocytes, neutrophils, monocytes, and eosinophils, regardless of whether they received hydroxyurea. GM-CSF levels were significantly decreased in patients on hydroxyurea therapy. These data suggest a role of GM-CSF in leukocytosis of SCD. In contrast, plasma levels of granulocyte colony-stimulating factor, a major cytokine that induces leukocytosis due to bacterial infection, were lower than those of control subjects. These results indicate that elevated GM-CSF levels may contribute, at least in part, to high leukocyte numbers in SCD. As plasma GM-CSF levels were decreased in patients on hydroxyurea therapy, hydroxyurea may decrease leukocyte numbers by reducing circulating GM-CSF levels.

Serum levels of macrophage colony-stimulating factor-1 in cervical human papillomavirus infection and intraepithelial neoplasia.

OBJECTIVE: Our goal was determine the correlation between serum colony stimulating factor-1 levels, cervical human papillomavirus infection, and dysplasia. STUDY DESIGN: Serum samples were obtained from control subjects from the United States and from a group of Panamanian women. Members of the latter group fell into 3 categories: those who serve as Panamanian control subjects and who test negative for human papillomavirus (n = 10); those who are high risk by history and test positive for human papillomavirus types 16/18 and 30s (n = 10); and those with the same high-risk history with biopsy-proven cervical intraepithelial neoplasia (n = 8). Serum colony-stimulating factor-1 levels were determined using enzyme-linked immunosorbent assay. Data were analyzed with the Student-Newman-Keuls and t tests. RESULTS: Mean serum colony-stimulating factor-1 levels of patients with a positive test result for human papillomavirus (1166 +/- 949 pg/mL) and cervical intraepithelial neoplasia (1295 +/- 314 pg/mL) were higher than those of control subjects from the United States (584 +/- 237 pg/mL) and those of Panamanian control subjects (520 +/- 229 pg/mL). Statistical analysis revealed the concentration of colony-stimulating factor in patients with positive test results for human papillomavirus or cervical intraepithelial neoplasia were significantly higher than in control groups. In addition, combining patients with human papillomavirus with those who have cervical intraepithelial neoplasia results in a group that has significantly higher colony-stimulating factor levels compared with control subjects. CONCLUSIONS: Both high-grade cervical dysplasia and high-risk human papillomavirus infection are associated with higher mean serum colony-stimulating factor levels, suggesting a possible role for colony-stimulating factor-1 in cervical neoplasia. Further studies are needed to understand the mechanism of colony- stimulating factor activation in human papillomavirus infection. This may assist in designing therapeutic approaches for the management of this disease.

Effects of milk-borne colony stimulating factor-1 on circulating growth factor levels in the newborn infant.

Colony stimulating factor-1 (CSF-1) concentrations in colostrum were 20 to 25 times higher than in serum at birth and declined with lactation. No difference in concentrations of circulating CSF-1, however, were noted between breast-fed and formula-fed infants, suggesting that milk-borne CSF-1 may feed back negatively on endogenous growth factor levels, may act locally in the gastrointestinal tract, or may be locally degraded.