Expression of Metallothionein I/II and Ki-67 Antigen in Graves' Disease

BACKGROUND/AIM: The expression of metallothionein I/II (MT-I/II) was examined in thyroids of Graves' disease (GD) and nodular goiter (NG) patients to determine its role as a potential marker of proliferation and autoimmune inflammation in the thyroid. PATIENTS AND METHODS: MT-I/II and Ki-67 antigen expression was studied using immunohistochemistry in 72 GD and 24 NG patients. RESULTS: MT-I/II expression was noted in the cytoplasm and nuclei of thyrocytes of GD and NG patients. Cytoplasmic and nuclear MT-I/II expression correlated strongly with GD (r=0.51; p<0.0001) and NG (r=0.50; p=0.0137). Cytoplasmic MT-I/II expression was significantly higher in GD (mean IRS 9.24±2.36) than in NG (mean IRS 7.13±2.51; p=0.0006) and correlated positively with Ki-67 antigen expression (r=0.28; p=0.0165). Nuclear MT-I/II expression was elevated in GD (mean 3.53±0.65) in comparison to NG (mean 2.96±0.86; p=0.028). CONCLUSION: MT-I/II may be a potential marker of GD in the thyroid and may be potentially involved in thyrocytes' proliferation.