Morphological changes in periodontal tissues under the influence of clinical methods of reprogramming macrophages

Objective of the study – to study morphological changes in periodontal tissues under the influence of a novel clinical technique of macrophages reprogramming using autologous blood serum and to assess the method effectiveness at the cellular level.
Material and methods. Using histomorphology and morphometry, we studied gingival tissue sections of 20 volunteers from 35 to 44 years old – patients with moderate chronic generalized periodontitis – obtained at the beginning and after one month of conservative preoperative preparation. There were 4 men and 6 women in each of the main group and comparison group. The preparation included individual and professional oral hygiene meausers, selective grinding and temporary splinting of movable teeth where indicated, as well as local conservative anti-microbial and anti-inflammatory treatment. In addition, a novel in vivo method of clinical macrophage reprogramming was implemented in the main group, but not in the comparison group. Based on the experimental studies, we developed a clinical technology for reprogramming macrophages in periodontal tissues from the inflammation-supporting phenotype M1 to the anti-inflammatory phenotype M2. The method consists in obtaining autologous venous blood serum depleted of cellular elements but containing many factors of macrophage reprogramming. Such serum was obtained directly beside the patient by double centrifugation of the whole blood with “soft start” at 10 000 rpm and injected immediately submucosally in the mucogingival fold in the areas of inflammation. Under the influence of the autologous serum, there is a gradual reprogramming of macrophages into the M2 phenotype.
Results. Histomorphological assessment showed the absence of inflammatory infiltration in the main group after the end of treatment. The composition of the infiltrate changed during this period: the mean decrease in the number of neutrophilic leukocytes reached 31,0%, lymphocytes – 11,2%, plasma cells – 6,2%, macrophages – 4,8%. The number of fibroblasts increased. Macrophages of M2 phenotype became predominant (82,3%) over the M1 phenotype (17,7%). The morphological index of macrophages in the main group decreased from 2,9 at the beginning to 0.2 at the end of the observation period, i.e. by 14,5 times. In the comparison group, where the technique was not used, the morphological index was 0.6 at the end of observation, which also confirms an increase in the proportion of M2 phenotype of macrophages, but to a lesser extent than in the main group – only by 4,8 times.
Conclusion. Histomorphological and morphometric comparative study of gingival biopsy specimens revealed high efficiency of the new clinical technique of periodontal tissue macrophage reprogramming into anti-inflammatory M2 phenotype. The method can be used in addition to traditional complex treatment of inflammatory periodontal disease. Keywords: periodontium, chronic generalized periodontitis, inflammation, autologous serum, macrophage reprogramming, histomorphological study.

Conflicts of interest. The authors have no conflicts of interest to declare.
Funding. There was no funding for this study
For citation: Rumyantsev V.A., Denis A.G., Shimansky Sh.L., Shestakova V.G., Donskov S.A., Blinova A.V. Morphological changes in periodontal tissues under the influence of clinical methods of reprogramming macrophages. Head and neck. Russian Journal. 2022;10(4):8–15
The authors are responsible for the originality of the data presented and the possibility of publishing illustrative material – tables, drawings, photographs of patients.