Neopterin is a biomarker of the activation of cellular immunity. The purpose of this review is to summarise neopterin metabolism, methods of its detection, and its role in inflammation, focusing on periodontal inflammatory diseases. This derivative of guanosine is a non-enzymatic product of 7,8-dihydroneopterin oxidation caused by free radicals which protect activated macrophages from oxidative stress. Various methods, usually based on enzyme-linked immunosorbent essay, high-performance liquid chromatography, or radioimmunoassay were developed for the isolation of neopterin. A wide spectrum of diseases and conditions are known to affect neopterin levels, including cardiovascular, bacterial, viral, and degenerative diseases, as well as malignant tumours. Neopterin levels were found to increase in subjects with periodontitis, especially when the oral fluid and gingival crevicular fluid were evaluated. These findings confirm the role of activated macrophages and cellular immunity in periodontal inflammatory diseases. The gingival crevicular fluid and the oral fluid appear to be the most valuable biologic fluids for the evaluation of neopterin levels in periodontitis. For gingival crevicular fluid, neopterin can be determined as the concentration or the so-called total amount. Nonsurgical periodontal treatment was associated with a decrease in neopterin levels, but an increase was also reported, suggesting the possible role of macrophages in the resolution of the periodontal lesion.

Introduction: Oral lichen planus (OLP) is a chronic inflammatory disease with an unknown etiology rating among oral potentially malignant disorder. The aim of the study was to determine the epidemiological and clinical characteristics of the patients with OLP and rate of malignant transformation. Patients and methods: Data were obtained from the medical records of 271 patients referred to the Oral Medicine Unit at the University Hospital in Hradec Králové diagnosed with oral lichen planus in the period of 2003–2020. The records were retrospectively analyzed. The following clinical data were retrieved from the medical charts: gender, age, systemic diseases, alcohol and tobacco consumption, localization/clinical appearance of lesions, distribution of the lesions, presence of the symptoms, treatment provided and malignant transformation. Results: A total of 271 charts of patients with confirmed diagnosis of OLP were retrospectively analyzed, of whom, 66.4% (180/271) were women and 33.6% (91/271) were men. The mean age of the patients was 56.0 (18.2–85.0) years. The median follow-up of all patients was 15.2 months. Overall, 2 patients (2/271, 0.74%) meeting the above-mentioned criteria for malignant transformation were identified during the follow-up period. Both patients suffered from erosive type OLP and developed squamous cell carcinoma of the tongue. Conclusions: This retrospective study is in concordance with other studies showing the similar profile and clinical features of the patients with OLP. Malignant transformation rate was 0.74%.

Background: Hematopoietic stem cell transplantation (HSCT) can induce serious oral complications, including oral mucositis (OM). The presence of periodontal inflammation before HSCT is believed to be associated with OM. The aim of our study was to determine the prevalence and severity of OM in patients undergoing HSCT and its relation to periodontal status. Patients and methods: This is a retrospective study of patients who underwent HSCT and a detailed dental examination between 2007 and 2015. The dental and periodontal status of all patients was evaluated by clinical and radiographic examination prior to HSCT. Oral health was assessed with the gingival index, the the community periodontal index, presence of plaque-related gingivitis, and marginal periodontitis. During the HSCT period, patients were examined daily for the presence of OM, which was graded according to World Health Organization (WHO) classification if present. The patients were assigned to the groups according to type of transplantation: autologous HSCT, myeloablative allogeneic HSCT, and non-myeloablative allogeneic HSCT. Results: A total of 496 patients were included in the study. OM was present in 314 of 496 patients (63.3%): 184/251 (73.3%) in the autologous group, 100/151 (66.2%) in the myeloablative allogeneic group, and 30/94 (31.9%) in the nonmyeloablative allogeneic group. Significantly more patients suffered from OM in the autologous and myeloablative groups versus the nonmyeloablative conditioning group (p < 0.001). The presence of periodontal inflammation did not significantly differ among the groups. There was only a borderline trend for the higher prevalence of OM in the non-myeloablative allogeneic nonmyeloablative group when periodontal inflammation was present (0.073939). Conclusions: Oral mucositis prevalence and severity after stem cell transplantation is not widely affected by the oral hygiene and periodontal disease presence before HSCT. We confirmed the wide-known connection of the conditioning regimen intensity to the prevalence of OM.

Periodontitis is a chronic inflammatory disease that leads to the destruction of the tooth-supporting tissues with complex immune response. Neopterin (Np), secreted via activated macrophages, is considered a biomarker of cellular immunity. The aim of this study was to evaluate the impact of periodontitis and nonsurgical periodontal therapy. Np gingival crevicular fluid (GCF), oral fluid, serum and urine levels were compared in subjects with periodontitis before periodontal treatment, three months after and in a healthy control. Np GCF concentrations in the study group after treatment were significantly higher than the control group (p = 0.038). The GCF total amount (amount of substance) was significantly higher in the study group before periodontal treatment than in the control group (p = 0.001) and higher than the levels taken after treatment collection (p = 0.024). The oral fluid Np concentrations in the study group after treatment were significantly increased compared to the before treatment concentrations (p = 0.020). The same trend was observed in the urine samples. Significant correlation was found between the serum and oral fluid Np concentrations (p = 0.001, ρ = 0.40). Our results confirm the impact of cellular immunity and macrophages on periodontitis and on the resolution of periodontal inflammation. The presence of neopterin in oral fluid most likely originates in the serum.