Soluble urokinase plasminogen activator receptor (suPAR) is a potential biomarker of stage III-IV, grade C periodontitis through the impact of post-radiotherapy on head and neck cancer patients

Background: The urokinase-type plasminogen activator receptor (uPAR) plays an essential function in leukocytes and endothelial homeostasis and, therefore, in the development of chronic periodontitis.

Methods: The study enrolled 150 participants, 50 chronic periodontitis with head and neck cancer post radiotherapy (CP + HNC post-RT) patients, 50 chronic periodontitis (CP) without HNC patients, and 50 healthy controls. Clinical Attachment Loss (CAL), Probing Pocket Depth (PPD), Plaque Index (PI), and Gingival Bleeding Index (GBI) were recorded. An enzyme-linked immunosorbent assay (ELISA) was constructed to quantify serum (suPAR) levels.

Results: Stage and grade of periodontitis were stage III-IV, grade C in patients (CP + HNC post-RT), stage I-III, grade A/B in patients (CP without HNC), and absent in (healthy). Chronic periodontitis with HNC post-RT patients presented a significantly higher proportion of suPAR levels (506.7 pg/ml) compared to chronic periodontitis without HNC and healthy controls (423.08 pg/ml and 255.9 pg/ml), respectively. A significant positive correlation was found between serum suPAR levels and CAL, PPD, PI, and GBI in the periodontal disease groups. ROC results of suPAR (AUC = 0.976 for CP + HNC post-RT, AUC = 0.872 for CP without HNC). Hyposalivation appeared in patients (CP + HNC post-RT; 0.15 [0.11-0.23] ml/min, P = 0.001) and (CP without HNC; 0.30 [0.25-0.41] ml/min, P = 0.001), compared to healthy controls; 0.35 [0.28-0.54] ml/min, P = 0.001).

Conclusion: The study showed a significant elevation in serum suPAR levels in CP + HNC post-RT patients compared to the CP without HNC and control groups.

Clinical trial registration: The study was registered retrospectively; clinicaltrials.gov identifier: NCT06529588. Date of registration: July 31, 2024 https://clinicaltrials.gov/study/NCT06529588 .