Gingipain-Mediated Matrix Metalloproteinase-8 and -9 Activation in Oral Rinse Samples from Patients with Cancer: A Cross-Sectional Study

Objectives: To investigate whether Porphyromonas gingivalis gingipains contribute to the activation of MMP-8 and MMP-9 in patients with cancer and to evaluate the potential of aMMP-8 chair-side test for early detection of active periodontal inflammation in cancer care. Methods: This cross-sectional study enrolled 89 of 119 initially assessed patients with cancer at Dr. Sardjito Hospital, Yogyakarta, Indonesia (2023–2024). Active MMP-8 was quantified using a chair-side test on oral rinse samples. Total MMP-8 was measured by ELISA, MMP-9 activation by gelatin zymography, and gingipain presence by Western immunoblotting. Associations with periodontal parameters (PPD, GI, OHI-S, and VPI) were analyzed using linear regression. Results: aMMP-8 chair-side test demonstrated 91% positive results in 89 patients with cancer. Western blotting revealed the co-localization of gingipains with fragmented MMP-8. aMMP-8 levels were significantly associated with MMP-9 activation (p = 0.003, R2 = 0.097), suggesting proteolytic cascade activation. Oral hygiene indices showed stronger associations (OHI-S: p = 0.003, R2 = 0.100; VPI: p = 0.014, R2 = 0.067) than deeper periodontal parameters (PPD: p = 0.094; GI: p = 0.358), suggesting early-stage inflammation detection. Conclusions: Gingipain presence may be associated with the activation of MMP-8 and MMP-9 in patients with cancer, which links bacterial virulence to amplified tissue destruction. aMMP-8 chair-side test enables rapid identification of active inflammation, facilitating timely periodontal intervention during cancer care.