Myeloperoxidase activity in peripheral blood, neutrophil crevicular fluid and whole saliva of patients with periodontal disease.

Mean levels of myeloperoxidase (MPO) activity were determined in samples of gingival crevicular fluid (GCF), whole saliva and peripheral blood neutrophils from patients with rapidly progressive periodontitis (RPP) and adult periodontitis (AP) using a spectrophotometric method. The mean neutrophil MPO activity in the RPP group was 563.1 +/- 137.05 U/l x 10(6)/ml, that in the AP group was 483.3 +/- 88.81 U/l x 10(6)/ml, and that in the control group was 220.6 +/- 26.7 U/l x 10(6)/ml. The mean GCF MPO activity in the RPP group was 15.13 +/- 2.34 U/mg, which was significantly higher than in the other two groups. The mean whole saliva MPO activity in the RPP group was 0.14 +/- 0.04 U/ml, that in the AP group was 0.11 +/- 0.02 U/ml, and that in the control group was 0.05 +/- 0.06 U/ml. MPO activity detected in the samples was significantly increased in the patient groups when compared to the healthy subjects. The highest MPO activity was found in the RPP group. The present findings suggest a relationship between MPO activity and the pattern and severity of periodontal breakdown. Also the increased MPO activity in periodontally diseased patients can be attributed to the increased number of neutrophils, the degranulation of these cells and also their hyperactive state in the presence of chronic antigenic stimulation.