Neutrophil cells constitute the first barrier against the oral bacterial. Our previous work implicates the apoptosis of neutrophils in the pathogenesis of periodontitis. We now demonstrate that granulocyte monocyte-colony stimulated factor (GM-CSF) present in the gingival crevicular fluid and secreted during the immune response reduce the apoptosis of neutrophils. The presence of GM-CSF and TNFα were detected in the majority of sites from periodontal patients. GM-CSF reduces the neutrophil apoptosis and Bax expression. These findings suggest a novel mechanism by which neutrophils specifically accumulate in adult patients with periodontitis.

Detection and quantification of periodontopathogenic bacteria in subgingival plaque samples. Culture techniques have been the classic diagnostic method to detect the bacterial species residing in the subgingival microflora. However, these techniques have serious limitations. The recent advent of RT-PCR with species-specific primers provides a very specific and sensitive method for an accurate detection of target microorganisms. Our group has recently developed and tested a RT-PCR assay for the quantitation of bacteria in subgingival plaque samples. This assay has shown a high degree of specificity and a very reproducible and consistent methodology to quantitate these pathogenic species. However, this test has only been evaluated on reference strains and therefore, its diagnostic utility on subjects with different periodontal conditions is unknown.