Alarm Anti-protease Trappin-2 Negatively Correlates With Proinflammatory Cytokines in Patients With Periodontitis.

BACKGROUND: Trappin-2 is one of the potent biologically active serine protease inhibitor with anti-inflammatory properties that has also been characterized as an "alarm anti-protease". Despite the importance of Trappin-2 in several chronic infections has been demonstrated, its potential involvement in periodontitis remains undefined. This study aimed to investigate the salivary level of Trappin-2 and interleukin-1β (IL-1β) in periodontally healthy indivudals and patients with gingivitis or generalized chronic periodontitis (CP) or aggressive periodontitis (G-AgP).

METHODS: Whole unstimulated saliva samples were collected from 80 systemically healthy and non-smoking individuals prior to full-mouth periodontal examination. Trappin-2 and IL-1β was analyzed by enzyme-linked immunosorbent assay and reported as ng/mg after calibration for total protein levels.

RESULTS: The correlation analysis revealed a negative association between Trappin-2 and IL-1β levels. Trappin-2 also showed a strong negative correlation with clinical periodontal parameters, in contrast to IL-1β which showed positive correlation. Compared to health, Trappin-2 levels were significantly lower in CP and G-AgP, but not in gingivitis. Reduced salivary concentrations of Trappin-2 had high sensitivity and specificity to distinguish health from periodontitis.

CONCLUSIONS: Trappin-2 is abundant in saliva of individuals with healthy periodontium in line with its role as "anti-alarm" protease. The decreased salivary Trappin-2 and increased IL-1β levels in periodontitis, compared to health, may implicate a potential anti-protease/proinflammatory cytokine imbalance, resulting in impaired host protective capacity.