Hepatocyte growth factor in saliva is a potential marker of symptomatic periodontal disease

Evidence has been emerging that hepatocyte growth factor (HGF) - a pluripotential regenerative cytokine - is a key factor in the pathogenesis and progression of periodontal disease, mostly through its over-stimulation of gingival epithelial cell growth and impairment of the regeneration of collagenous structures. We measured the levels of immunoreactive HGF in unstimulated whole mixed saliva from 26 patients referred for treatment of periodontal disease, and from 20 healthy subjects. HGF was detected in all saliva samples from the patients, the concentration ranging from 0.06 to 5.38 ng/ml, with a mean concentration of 1.87 +/- 1.32 ng/ml. In healthy individuals, the median salivary HGF level was 0.68 ng/ml (range: 0 - 7.33 ng/ml), being almost 3-fold lower (P < 0.0001) than that in the patients. Periodontal parameters in the patients were: gingival index (GI) 2.0 (0 - 2.8), papillary bleeding index (PBI) 2.2 (0 - 3.2), plaque index (PI) 2.0 (0 - 3.0), probing depth (PD) 3.0 (1.8 - 5.9) mm, and loss of clinical attachment level (CAL) 4.7 (1.1 - 10.6) mm. We found that the salivary HGF level was positively correlated with GI (P = 0.004), PBI (P = 0.046) and PI (P = 0.001), but not with PD (P = 0.351), CAL loss (P = 0.172), number of teeth (P = 0.279) or patient age (P = 0.362). Our findings suggest that salivary HGF concentration may be a novel marker of symptomatic periodontal disease, and that it warrants further validation.