46 The Chemistry of the Injured Cell 



in firm combination with a copper-binding globulin called caerulo- 

 plasmin. In hepatolenticular degeneration there is a deficiency of 

 this protein, and copper is transported instead in loose combination 

 with plasma albumin. As some tissues appear to have a greater affin- 

 ity for copper than does albumin, the metal becomes deposited in 

 excessive amounts in liver and brain with resultant fibrosis and de- 

 generation. There is also damage to renal tubules with glycosuria 

 and aminoaciduria. 



ABNORMALITIES OF PLASMA GLOBULINS 



A large portion of the plasma globulins is synthesised in the 

 cells of the reticuloendothelial system and disease of this system is 

 apt to be reflected in abnormalities in the globulin fraction of the 

 serum. Thus in agammaglobulinaemia, a disease characterised by 

 deficiency of circulating y globulin, there is a genetically-deter- 

 mined deficiency of plasma cells. These cells play a vital role in the 

 production of y globulin and therefore of antibodies. Because of 

 their inability to produce antibodies patients suffering from this 

 condition are abnormally susceptible to infection. 



In certain neoplastic diseases of the reticulo-endothelial system 

 there may be abnormal synthesis of globulin-like proteins. In 

 myelomatosis, in which the neoplastic cells resemble plasma cells, 

 there may be abnormal synthesis of a low molecular weight protein 

 (Bence-Jones protein) which is excreted freely in the urine. There 

 may also be abnormal globulins of large molecular size in the 

 circulation. In leukaemia (neoplasia of blood leucocytes) similar 

 defects may exist such as the synthesis of abnormally large globulin 

 molecules (macroglobulinaemia) . Similar dysproteinaemia may 

 develop in non-neoplastic diseases such as disseminated lupus ery- 

 thematosis. In a variety of conditions, some inflammatory, some de- 

 generative, a new protein appears in the circulation (C-reactive 

 protein) distinguished empirically by its ability to react with 

 pneumococcal antigens. Other reactive proteins, possibly with more 

 specific characteristics, have been observed in the circulation in 

 other diseases, notably rheumatoid arthritis. The significance of 

 many of these findings, however, has not yet been fully revealed. 



