Clinical Importance of Neuregulin-4 and Its Receptor ErbB4 in Periodontal Disease Pathogenesis.

The aim of this clinical trial is to evaluate the levels of Neuregulin-4 (Nrg4), Erb-b2 receptor tyrosine kinase 4 (ErbB4), interleukin (IL)-6, IL-10, nitric oxide synthase (NOS)-2 and arginase (Arg)-1 in periodontal health and disease.This study includes systemically healthy 20 periodontally healthy (H), 20 gingivitis (G), 20 stage II periodontitis (P1), and 20 stage III periodontitis (P2) subjects. Periodontal clinical measurements and samples of gingival crevicular fluid (GCF) and serum were obtained at baseline and 4 weeks after nonsurgical periodontal treatment (NSPT). Enzyme-linked immunosorbent assay (ELISA) was used to determine ErbB4, Nrg4, IL-6, IL-10, NOS2 and Arg1 levels in all samples.GCF ErbB4 and Nrg4 total amounts and IL-6/IL-10 ratio were significantly higher in G, P1 and P2 groups than H group. Serum NOS2 levels were significantly lower, whereas serum Arg1 levels were higher in H group than the others. The GCF levels of ErbB4 and Nrg4 were significantly decreased after NSPT in G, P1 and P2 groups. Additionally, the GCF levels of ErbB4 and Nrg4 were positively correlated with all clinical parameters and IL-6/IL-10 ratio.Nrg4 and its receptor ErbB4 might have crucial roles in the pathogenesis of periodontal disease. These results should be verified with future prospective studies to further clarify the exact role of those biomarkers.