IL-32 Levels in Patients With Chronic Periodontitis

Overview

Interleukin-32 (IL-32) is a recently described cytokine that is a strong inducer of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α. A previous report have reported that Porphyromonas gingivalis-derived LPS significantly up-regulated IL-32 expression compared with the unstimulated cells in monocytes (THP-1 cells). They suggested that IL-32 may contribute to the pathogenesis of periodontal disease. In the present study the investigators hypothesized that IL-32 levels may increase in the gingival crevicular fluid (GCF) and saliva of patients with chronic periodontitis compared with healthy controls and these levels may decrease together with treatment.

The purpose of this study was to investigate IL-32 levels in the GCF and saliva of patients with chronic periodontitis and to evaluate changes after nonsurgical periodontal therapy. Twenty-seven CP and 27 periodontally healthy controls were enrolled in this study. Periodontitis patients received nonsurgical periodontal treatment. GCF and saliva sampling and clinical periodontal parameters were assessed before and a month after treatment. IL-32, IL-10 and TNF-α levels in GCF and saliva were measured by enzyme-linked immunosorbent assay. Unstimulated salivary samples were collected using standard techniques. About 2 mL whole saliva was collected in disposable tubes and centrifuged immediately to remove cell debris (10,000 g x 10 minutes). The supernatants (50µL each) were stored at -40C until analyzed. GCF samples were collected from a mesio-buccal and disto-palatal site on each tooth. In the CP group, the samples were obtained from patients at areas with ≥5 mm CAL, ≥6 mm PD and ≥30% bone loss. In the healthy group, GCF samples were collected from teeth exhibiting PD\<3 mm without CAL and BOP. The area was isolated with cotton rolls, saliva contamination elimination was ensured, and it was slightly air dried. GCF was sampled with paper strips. Paper strips were placed into the crevice until mild resistance was felt (intracrevicular method) and left in the position for 30 seconds. Strips contaminated with blood or saliva were discarded. Each sampled strip was placed into a 400µl eppendorf centrifuge tube and stored at -40C until analyzed.