Studies on the pathogenesis of subacute thyroiditis

Despite the fact that subacute thyroiditis (SAT) is a common disease, its pathogenesis is still uncertain. At present, viral infection is simply thought to be a possible pathogenic factor. In Caucasians and Chinese, however, a strong association has recently been found between HLA-Bw35 and SAT. Therefore, genetic factors are also thought to participate in the onset of SAT. In this study we have further attempted to clarify the pathogenesis of this disease in this regard. Protocol: HLA typing for A, B and C loci (class I antigens) was performed on 89 patients with SAT (males: 7, females: 82) aged from 23 to 66 years, and DR and MT loci (class II antigens) were investigated in 55 patients. In 12 patients, viral antibody titers were measured as soon as possible after onset and two weeks later. The viral antibodies evaluated were those of Influenza A and B, Coxsackie A9, B1, B2, B3, B4, B5 and B6, Echo 3, 7, 11 and 12, Parainfluenza 1, 2, 3 and 4, and Adeno 8 virus. The following results were obtained: In class I HLA typing, the frequency of HLA-Bw35 in SAT was 67.4%, which was significantly (p less than 0.0001) higher than that in the control (14.1%). On the other hand, the frequency of Cw1 in SAT (14.6%) was significantly (p less than 0.01) lower than that of the control (32.1%), and that of Cw3 (65.2%) was significantly (p less than 0.01) higher than that of the control (46.5%). In class II HLA typing, the frequency of DRw8 in SAT was 38.2%, which was significantly (p less than 0.05) higher than that of the control (21.9%). Other antigens showed no significant changes.(ABSTRACT TRUNCATED AT 250 WORDS)