ABSTRACT
Objective To express human thyroid peroxidase (hTPO) epitopes gene and apply its products in clinical assay. Methods hTPO epitopes gene was cloned into expression vector pGEX 4T 3 then transformed into E. coli BL21. Expression of hTPO gene was induced by isopropyl ? D thiogalactoside, expressed product (GST hTPO) was purified by affinity chromatography and their immunoactivity was demonstrated. ELISA technique using GST hTPO as antigen was established for determining TPOAb. Serum TPOAb level was determined, and HLA DR antigen, dendritic cells and lymphocytes in the thyroid gland tissue were observed in these same AITD patients.Results GST hTPO acquired from procaryotic expression had high purity and good immunoactivity. The CVs of the ELISA technique established with GST hTPO were between 5.93%～7.59%. A significantly positive correlation was found between the TPOAb levels determined respectively by ELISA and RIA method. Serum TPOAb level and distribution of HLA DR antigen and dendritic cells showed the same ascending tendency following the aggravation of lymphocyte infiltration. Conclusion Product of genetic engineering, GSH hTPO, can be used to establish a clinical assay for TPOAb. The correlation between the level of serum TPOAb and the detriment of thyroid tissue is demonstrated.