Background: Neutrophils destroy pathogens via phagocytosis. Neutrophils are effective innate and acquired immunity phagocytes. Low-density neutrophils are distinct neutrophil phenotypes linked to several systemic and infectious diseases. To our knowledge, low-density neutrophil phagocytosis in periodontitis has not been examined. Opsonized and non-opsonized fluorescent beads mixed with low-density neutrophils were gated and analyzed by flow cytometry to count cells that consumed at least one bead.

Aims of the Study: To estimate the potential impact of antibody (Ab)-labeled and non-labeled phagocytosis capacity of low-density neutrophils in the 60 patients with periodontitis compared to 40 patients with healthy periodontium.

Methods: Blood samples were collected from 100 subjects with no systemic diseases and allocated into a periodontitis group of sixty unstable periodontitis patients compared to a control group of forty subjects with healthy periodontium. Flow cytometry was used to estimate both groups’ Ab-labeled and non-labeled phagocytosis assays of low-density neutrophil groups.

Results: Ab-labeled and non-labeled low-density neutrophil phagocytic assays showed no significant difference (p-value > 0.05) between research groups. In both study groups, low-density neutrophils had higher Ab-labeled phagocytosis than non-labeled. A significant positive correlation was observed between Ab-labeled and non-labeled phagocytosis in the control group.

Conclusion: Low-density neutrophils express the same labeled and non-labeled phagocytic index in both groups (periodontitis and control). However, the intra-group comparison revealed enhanced Ab-labeled phagocytosis compared to non-labeled phagocytosis in both groups (periodontitis and control).