Supplementation With L-ornithine But Not L-arginine Increases Density of CD68+ and CD163+ Macrophages in Periodontitis

The aim of the study was to investigate whether oral administration of L-arginine or L-ornithine could modulate local representation density and ratio of macrophages in periodontitis-affected gingiva by using immunohistochemical detection of CD68+ and CD163+ macrophages in biopsies of the gingiva. The null hypothesis tested was that L-arginine and L-ornithine have no influences on CD68+ and CD163+ macrophages densities when supplementing the treatment of periodontitis. Materials and methods. 75 individuals with a diagnosis of generalized periodontitis at stages II-III and grade B (38 women and 37 men, 51% and 49%, respectively) were included in the study. Periodontitis was diagnosed by using the criteria of the Classification of Periodontal and Peri-Implant Diseases and Conditions 2017. 25 patients received scaling and root planing only; 25 patients additionally received L-arginine, and 25 - L-ornithine, according to instructions available in Ukraine. For the immunohistochemical study of paraffin-embedded sections, the gingival biopsy was taken from 5 selected patients per group before treatment and after 1 month. CD68+ (cluster of differentiation 68 positive) and CD163+ cells served as a morphological equivalent of M1, M2 macrophages subpopulations, and their densities were calculated per 10000 μm2. Statistical analysis was performed by adequate power methods.