solution at a concentration of 100 U /ml. In addition, the catheter will only need to remain open 
for several days at most. The Broviac can be studied at 24-48 hours after cell reinfusion to 
provide information about the rate of early thrombosis of the portal venous system. Such data 
will have to be collected to ultimately answer questions about the efficacy of this approach. Our 
experience with the baboon indicates this may not be a problem. 
Infection of the catheter may also occur. In any patient who may require a liver 
transplant, the threat of infection is serious. The development of infection may cause the 
transplant to be deferred for a period of time with an obvious negative impact on patient well 
being. These patients will not be given prophylactic antibiotics to minimize the risk of an 
adverse drug reaction. The operation will be performed in an operating room with standard 
sterile technique. The catheter will only need to be in place for 3-4 days, and will be inspected 
several times daily to watch for early signs of infection. If cellulitis or purulent drainage 
develop, appropriate cultures will be taken and empiric intravenous antibiotics will be started. 
If necessary, the catheter can be removed prior to the cell infusion. The ability to institute 
prompt treatment and completely remove the prosthetic device will minimize any adverse 
impact on the patient. 
Portal vein thrombosis is the most morbid potential complication of the intraportal 
administration of autologous hepatocytes. There are no data on the incidence of portal vein 
thrombosis after the intraportal administration of autologous hepatocytes, but when pancreatic 
islet preps are used, the incidence is about 4% (109). The relevance of this experience to the 
infusion of autologous hepatocytes is discussed above. Complete thrombosis with organized clot 
adherent to the endothelium of the portal vein may preclude subsequent liver transplantation. 
In addition, portal hypertension with the development of ascites or variceal hemorrhage may 
cause clinical deterioration in these patients with diminished cardiovascular reserves. This 
form of treatment in the face of even a single case of post-infusion portal vein thrombosis would 
require a re-evaluation of the route of delivery. Treatment of the complications of portal 
hypertension are relatively standard and are used frequently in the care of patients seen at the 
University of Michigan. 
G. Evaluation and Consequences of Engraftment 
The efficacy of the treatment will be assessed through a careful analysis of associated 
changes in lipoprotein metabolism. In addition, liver tissue will be obtained by percutaneous 
biopsy 3 months after the treatment and will be subjected to various molecular studies to 
characterize the presence and abundance of recombinant derived RNA and DNA. 
1. Metabolic Consequences of Gene Transfer 
A variety of animal and human studies indicate that steady state levels of lipoproteins 
such as LDL are affected rather dramatically by modest changes in residual LDL receptor 
function of FH homozygotes. We will, therefore, assess the functional consequences of gene 
therapy by comparing baseline metabolic parameters prior to and following the therapy. We 
have carefully considered the usefulness of measuring the effects of gene therapy on lipoprotein 
kinetics in the patient. We have decided not to pursue these more complicated measurements in 
the initial studies for several reasons. Fractional catabolic rates of lipoproteins such as LDL 
would likely be a less sensitive indication of LDL receptor expression in vivo than steady state 
lipoprotein levels. Furthermore, kinetic studies pre- and post-treatment would represent a 
major inconvenience to the patient because it would involve the injection of radioactivity and 
would protract the inpatient evaluations, leading to substantially more phlebotomies. 
Recombinant DNA Research, Volume 15 
[187] 
