Immune complexes in tissues of obese strain (OS) chickens.

Obese strain (OS) chickens develop spontaneous autoimmune thyroiditis (SAT) comparable in many aspects to human Hashimoto's thyroiditis. In a chronologic study on chickens of the Obese strain with B1B1 and B4B4 genotypes, immune and electron dense deposits suggesting immune complexes (IC) were found in the basal lamina of thyroid follicles (BLTF) as early as the time of hatching. The incidence of IC deposition in BLTF increased with age. In some of the chickens studied, thyroglobulin could also be demonstrated in the immune deposits. In addition, IC were also detected in the glomerular basement membrane of kidneys and in basement membranes of cecal tonsils. The early occurrence of IC in tissues of OS chickens suggests a possible primary role of these immune reactants in the pathogenesis of SAT.