HOMOGRAFT SENSITIVITY IN HUMAN BEINGS 275 



Results of local and systemic transfer of homograft 



sensitivity 



Two techniques of transfer were employed : 

 (i) Local transfer whereby a test and a control graft are placed on 

 each forearm of a non-sensitive subject. On the third day of graft 

 residence, when assurance of vascularization of the grafts is 

 evident, leucocyte extracts obtained from a donor sensitized to 

 the test graft are injected halo fashion lo mm. away from and 

 around both test and control graft on one forearm, and serum 

 (i/o ml.) from the same sensitized donor is injected around both 

 test and control graft on the other forearm. 



This manoeuvre resulted in accelerated rejection of the test 

 graft (4-5 days) within 24 to 48 hours following transfer although 

 the control graft exhibited no evidence of sickness or death until 

 the eighth day when it was accorded a first-set reaction of rejec- 

 tion. The grafts on the opposite arm of the same recipient treated 

 with serum were both accorded a first-set reaction (test graft 

 survival 10 days, control graft survival 8 days). 



Three other recipients bearing only one test and one control 

 graft responded similarly following local transfer (recipient No. 6 : 

 test graft survival 4 days, control graft survival 10 days; recipient 

 No. 8 : test graft survival 5-6 days, control graft survival 10 days; 

 recipient No. 9 : test graft survival 5-6 days, control graft survival 

 10 days). To control these results further, two additional reci- 

 pients had two test grafts — one on each forearm. Repeating the 

 above experiment and injecting /io/i-sensitized leucocyte extract 

 or sensitized serum around each test graft had no effect on their 

 survival times — each test graft being accorded a first-set reaction 

 (e.g. recipient No. 7 : test graft + sensitized serum, survival time 

 10 days; test graft + non-sensitized WBC extract, survival time 

 10 days.) 



From the group of experiments it was concluded that although 

 a first-set and second-set skin homograft were insufficient to 



