ABSTRACT
BACKGROUND: The zonal differentiation of hepatic necrosis is important in the aspect of treatment, follow-up and prognosis of patients. The purpose of this study was evaluating the clinical usefulness of serum isocitrate dehydrogenase (ICDH) as a marker of centrilobular hepatic necrosis in patients with hyperthyroidism. METHODS: We determined the serum ICDH and alanine aminotransferase (ALT) activities in 56 patients with hyperthyroidism, 16 patients with chronic viral hepatitis, and 17 normal controls. RESULTS: The activities of serum ICDH were significantly higher in patients with hyperthyroidism than those of patients with chronic viral hepatitis or normal control (p< 0.01), even though those of serum ALT were higher in patients with chronic viral hepatitis (p< 0.01). The ratio of serum ICDH and ALT activities were markedly different between the patients with hyperthyroidism and chronic viral hepatitis (p< 0.001). There was a significant correlation between the serum ICDH and ALT activities in patients with hyperthyroidism as well as in those with chronic viral hepatitis (p< 0.05). In patients with hyperthyroidism, the serum ICDH levels were more significantly correlated with serum triiodothyronine (T3) than thyroxine (T4) levels. In a patients with hyperthyroidism and elevated ALT levels, the serum ICDH activity decreased progressively and was normalized ultimately, as serum ALT level and thyroid function were normalized with antithyroid medication. CONCLUSION: The serum ICDH or ratio of serum ICDH and ALT activities might be useful clinically in differentiating the centrilobular from periportal hepatic necrosis, and following up the degree of hepatic necrosis in patients with hyperthyroidism.