PATHOLOGY OF THE IMMUNE RESPONSE 



the appearance of forbidden patterns. If, for local 

 or general reasons, the normal elimination of such 

 clones fails to take place, immune disease may 

 result. 

 G. Like all other body cells, mesenchymal cells may 

 undergo mutation to a form approaching or reaching 

 malignancy. 

 The main groups of diseases involving a distortion of the 

 immune response — immunopathies or dysautasic diseases — 

 may now be considered. It will be convenient to consider 

 them in a different order from that given on p. 121. 



2. Hashimoto's disease 



In this disease, also called lymphadenoid goitre, there is 

 a diffuse swelling of the thyroid with histological evidence 

 of sub-acute inflammation, the tissue being infiltrated with 

 lymphocytes and plasma cells. There are frequently symp- 

 toms of hypothyroidism. 



The serum in most typical cases shows an increase in 

 gamma globulin content and antibody reacting by comple- 

 ment fixation and precipitation with thyroid extract or 

 thyroglobulin. It is immaterial whether the antigen is pre- 

 pared from normal or thyrotoxic glands (Roitt, Doniach and 

 Campbell, 1956). 



An almost completely analogous condition has been pro- 

 duced experimentally in rabbits by Witebsky and Rose 

 (1956) by immunizing the animals with thyroid extract and 

 Freund adjuvant. In a number of instances the condition 

 was induced in hemithyroidectomized rabbits by immuniza- 

 tion with their own tissues. 



This is the only condition in human pathology that has 

 been clearly shown to be an auto-immune condition in the 

 sense of being a result of the production of antibody by 

 normal body cells against a definable antigen. In this case 

 the antigen is human thyroglobulin which we must assume 

 does not normally find opportunity to make contact with 



124 



