RECIPIENT CONSENT 
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After you and your twin have had screening blood tests, a tetanus booster 
injection, and a complete history and physical examination performed at the NIH, your 
twin will be scheduled to have a fraction of his/her lymphocytes removed from the 
blood by a procedure called “lymphapheresis." This will be performed in the 
Apheresis Unit of the NIH Blood Bank. These lymphocytes will then be separated into 
CD4 (T4) and CD8 (T8) cells and grown separately in the lab. After 1 to 4 days, a new 
gene will be introduced into the cells. The process involved in introducing the new 
gene is accomplished by first inserting the gene into a vector (i.e., an organism that 
carries material from one cell to another). This vector is prepared from a disabled 
mouse retrovirus. The vector is mixed with the cells in the laboratory, enters the cells, 
and inserts the new gene into the cells’ genetic material (chromosomes). Once 
inserted, the new gene will survive as long as the cell survives. The new gene that will 
be used is derived from bacteria and wiil enable the cells that contain it to resist the . 
cell-killing effects of the antibiotic neomycin (neoR gene). This gene is being selected 
for use in this study because it has been used safely and successfully in a number of 
other human and animal studies. By inserting the neoR gene into the lymphocytes, we 
will be able to distinguish these modified lymphocytes from those your body normally 
produces once the cells have been infused into your bloodstream. We plan to use two 
different neoR genes, which both make cells resistant to neomycin but which differ 
from each other in terms of their molecular structure, to mark your cells. One neoR 
gene will be used to mark CD4 cells, while the other neoR gene will be used to fnark 
CD8 cells. In this way, we will be able to monitor the survival of CD4 cells and CD8 
cells separately once they have been infused into your bloodstream. 
After the lymphocytes are marked with the new genes, they will be expanded in 
cell cultures up to 1 ,000 times the original number of cells obtained. The time required 
to achieve these numbers of cells is approximately 10 days to 2 weeks from the time 
your twin undergoes lymphapheresis. Once the desired numbers of cells have been 
attained, you will come to the NIH Clinical Center to receive these cells by intravenous 
infusion. We plan to repeat this process approximately every 6 weeks for a total of 3 
cell infusions. 
For the first cell infusion, you will be admitted to the inpatient wards of the NIH 
Warren G. Magnuson Clinical Center. An intravenous catheter will be inserted into an 
arm vein. However, if a suitable vein cannot be found, you may need to have a special 
intravenous catheter placed into a large vein in the neck or chest. This procedure 
would require local anesthesia (lidocaine or novacaine®) and would be performed by 
a physician in the intensive care unit. Once an intravenous catheter is established, the 
gene marked cells obtained from your twin will be infused over 60 minutes. During the 
infusion and for the next 24 hours your vital signs (temperature, pulse, blood pressure, 
respirations), blood oxygen concentration, and urine output will be monitored 
regularly, as outlined in the protocol. Blood samples will be obtained from you at 1 , 2, 
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