Isoelectric focusing spectrotypes of anti-thyroglobulin autoantibodies in autoimmune thyroiditis: a PVG rat model

We have studied the isoelectric focusing (IEF) spectrotypes of autoantibodies against thyroglobulin in two rat models of Hashimoto's thyroiditis: (1) AUG strain rats immunized with autologous thyroglobulin in Freund's complete adjuvant; (2) PVG/c strain rats which have been thymectomized and sublethally irradiated. The IEF spectrotypes revealed differences between the two models. The anti-thyroglobulin response in immunized AUG rats is mainly oligoclonal or polyclonal, often with dominant clones in the spectrotype, similar to about 90% of Hashimoto's patients, whereas the response in the PVG/c rat is highly restricted. There were pronounced changes in spectrotype with time in the PVG/c, but not AUG, rats with considerable variation in the lifespan of individual clones. The maximum lifespan of an anti-self secreting B-cell clone in the PVG/c rat, determined by persistence of its clonotype, was at least 16 weeks