慢性甲状腺炎合併・C型慢性肝炎に関する臨床的検討

In recent years, the complication with chronic thyroiditis in patients of chronic hepatitis C were reported, and further, induction of thyroid dysfunction by administration of interferon has been shown. Therefore, we tested antithyroid antibody in 44 patients with chronic hepatitis C (24 females and 20 males; 61.1 years old in average), further HCV-RNA and anti-GOR antibody in 33, 24 subjects respectively. As a result, nine patients (20.2%; 6 females and 3 males) were antithyroid antibody positive, which is higher than the positive rate, 6.3% in normal subjects in Tokushima prefecture ( x2 test, p<0.01).
In the antithyroid antibody positive gyoup, the HCV-RNA level was higher than 0.5 Meq/ml in seven of nine subjects (77.8%), whereas in the antithyroid antibody negative group (35 subjects; 18 females and 17 males), six of 24 subjects (25.0%) tested showed higher level than 0.5 Meq/ml, i,e., significant change in the HCV-RNA level was found in antithyroid antobody positive group (Wilcoxon test, p<0.05). And there was not higher the anti-GOR antibody level of patients with antithyroid antibody positive group in comparison with negative group, however it was significant relationship between antimicrosomal antibody and anti-GOR antibody level in five patients with antithyroid antibody positive group (r=+0.891, p<0.05).
This study may be indicated that chronic hepatitis C probably complicate chronic thyroiditis by immunologicaly several cytokines to be related with anti-GOR antibody to be linked antimicrosomal antibody and self reactive T cell, to have been expressed class II antigen in thyroid tissue. Accordingly, these results suggest the induction of chronic thyroiditis by high HCVnemia.