#18
APHERESIS: A RENEWABLE LYMPHOCYTE SOURCE FOR ANTIBODY SCREENING.
Marilyn P. Downs, BS,CHS, Sandra L. Smith, BS, Wanda Eckrich, BS, Paula Hightower, RN, Jerry L. Morrisey, PhD and Daniel Ladd, MD. Temple TX, USA, Scott
White Memorial Hospital, 76508, Clinical Pathology.
A consistent source is needed for lymphocytes used in HLA antibody screens. HLA matched platelets are often requested for refractory patients. A simple method for a renewable HLA antibody cell panel, and expansion of the number of HLA typed platelet donors was sought.
Platelet apheresis is done on a Cobe LRS whose channel tubing is routinely discarded after each use. We thought that viable cells could be isolated from the 50 to100 ml of diluted anticoagulated blood remaining in this sterile channel tubing after apheresis.
The lymphocytes are separated from the diluted buffy coat over ficoll-hypaque. The cells are suitable for typing, antibody screening, and freezing. The lymphocyte yield averages 10 X 106 cells, with viability > 80%. Optimum viability is from cells isolated within 24 hours of collection. They can be used fresh, or aliquoted and frozen in 10%DMSO /RPMI (20% FCS) for several years. The cell component yields enough cells for a year when stored in a liquid nitrogen freezer.
This local donor pool is more representative of the potential organ donor population.
The isolated lymphocytes are a cost-effective source for assembling a panel of repeat donors for HLA panel antibody screens. The total cost is about 40% of the cost of commercial frozen cell trays.
The platelet component is also usable for platelet absorption, and platelet crossmatching. The platelet component aliquots can be kept frozen for several years.
This protocol has enabled the Blood Center to expand their list of HLA typed platelet donors. The HLA lab benefits by reducing HLA reagent costs and stablizing the pool of HLA panel cells for antibody screening and identification.