Comparative Expression of M1 And M2 Macrophage Markers in Radicular Cysts and Periapical Granulomas: A Study of Immune Polarization

Abstract

Background: Apical periodontitis (AP) characterized by inflammation and bone destruction in

the periapical tissues due to microbial infection in the dental pulp. This necessitates immunological responses to prevent the spread of infection. Macrophages are a group of heterogeneous cells that have many roles in the development of infections, destruction and reconstruction of bone tissues, and microbe–host interactions

Materials and Methods: Thirty paraffin embedded tissue blocks of radicular neck resected samples of 18 preapical granulomas and 12 radicular cysts were processed histopathological to detected CD68, CD11c and cd163 positive cells. Expression of macrophage was quantitatively assessed.

Results: The study found that M1 macrophage polarization, indicated by CD11c expression, was higher in radicular cysts compared to periapical granulomas (25.45 ± 4.11 vs. 14.66 ± 4.19). There was no significant difference between granulomas and radicular cysts concerning CD68 expression (46.27 ± 5.06 vs. 28.05 ± 5.06; p=0.054). Conversely, M2 macrophage polarization, indicated by CD163 expression, was significantly higher in periapical granulomas compared to radicular cysts (42.12 ± 6.59 vs. 21.03 ± 3.43; p=0.020).

Conclusions: Macrophages play a significant role in the inflammatory response of periapical lesions. The study found that M1 macrophages were more prevalent in radicular cysts, while M2 macrophage expression was significantly higher in periapical granulomas. This suggests distinct macrophage polarization patterns between radicular cysts and periapical granulomas.