Plasmapheresis and lymphapheresis: Patients will have to fulfill the criteria of the NIH Department of Transfusion Medicine regarding lymphapheresis donors. These include age (less that 65 years), weight (greater than 120 pounds), hematocrit (greater than 30 percent), blood pressure (less than 120 diastolic and greater than 90 systolic), and temperature (less than 37.5 degrees C). Because this is a research procedure to obtain reagents and assay materials, only patients who are active and relatively fit (i.e. not disabled from their liver disease) will be asked to undergo this procedure.