expression levels of th-2 and th-17 characteristic genes in healthy tissue versus periodontitis.

the t helper 17 (th17) cells have been suggested to have osteoclast activating effects while t helper 2 (th2) cells are considered to have an osteoprotective role in periodontitis. this study was to compare the markers of th17 cells (rorc2 and il-17 genes) with that of th2 cells (il-4 and gata-3 genes) between healthy and periodontitis tissues.the samples were obtained from patients with periodontitis and healthy tissues. the mrna expression levels of il-17, rorc2, il-4 and gata-3 were measured in both groups using quantitative rt-pcr. the results were compared using spss 11.0. correlation coefficient was analyzed by spearman's rho test. mann-whitney was used to measure the difference between il-17 and il-4 as well as rorc2 and gata-3.in periodontal lesions, the expression levels of all markers were significantly higher than the healthy tissue (p≤ 0.001). the results showed a significant increase in the number of markers of th17 (rorc2 and il-17 genes) compared to markers of th2 (gata-3, il-4) in patients with periodontitis compared to controls (p≤0.002). a positive correlation between il-17 and rorc2 (p≤0.05) and between il-4 and gata-3 (p≤0.001) was found.the results show that expression levels of il-4, gata-3, il-17 and rorc2 increase significantly in periodontal lesions compared with the controls. in periodontal lesions, il-17 levels are significantly greater than il-4, which plays a protective role against alveolar bone loss.