Expression of intracellular elastase activity in peripheral neutrophils from patients with adult periodontitis

This study aimed to investigate whether circulating neutrophils from patients with periodontitis contain more catalytically active elastase than neutrophils from healthy controls. The amount of IL-1beta in these cells was also analyzed and the correlation with elastase activity was tested. The periodontitis group consisted of 15 subjects with marked periodontal destruction. The healthy control group consisted of 15 subjects with no clinical signs of periodontal destruction. The elastase activity and the IL-1beta content in the cells were measured with flow cytometry using a specific substrate and antibodies, respectively. The plasma concentration of IL-1beta and the total content of antigenic elastase in the crushed cells were measured with an ELISA. The elastase activity per neutrophil was significantly higher in the patients than in the controls, while the total antigenic elastase content did not differ. The % of cells positively stained for IL- 1beta was somewhat higher in the patient group. Significantly higher amounts of IL-1beta per sample, estimated by multiplying the % of stained cell with the amount of staining per cell, were found in the patient group. A significant correlation between IL-Ibeta and elastase activity was noted in the patient group (R=0.6, p=0.001), but not in the control group. In conclusion, peripheral neutrophils from patients with adult periodontitis express more active elastase and total amounts of IL-1. The similar amounts of antigenic elastase suggests that this higher activity is possibly due to some kind of priming/activation already in the circulation.