146 Annual AACHT Meeting, 1985

donors including four family members were typed for DR antigens by both conventional and IL-2 expansion techniques. In every case DR detection was identical by both methods. No false positive or negative reactions were observed. Next, we applied this technique to the three situations previously noted that had been difficult or impossible to DR type using conventional methods. Three renal dialysis patients who had been untypable on several occasions were successfully DR typed using the IL-2 technique. Six blood specimens received in poor con- dition and up to 4 days old were DR typed after IL-2 expansion when normal methods did not show DR expression. Eleven of 12 potential bone marrow recipients who were untypable were activated and typed on expanded cells. It! summary, we consider this IL-2 expansion technique to be an effective supple- mentary method for patients who are difficult to DR type by conventional methods,

A BONE MARROW TRANSPLANT WITH AN ACQUIRED LYMPHOCYTOTOXIC ANTb Lea: A CASE STUDY. T. Myser, M. Steedman, K. Hunt, P. Strohm, M. Williams, and M. Kennedy: The Ohio State University Hospitals. Columbus. OH

A patient with aplastic anemia received an ABO incompatible bone marrou transplant (BMT) from an HLA identical sibling. Weekly HLA antibody screens were performed as part of the BMT protocol. At the time of transplant a hemolytic anti-Le '* was detected in the Le ( a - b - ) donor. The Le ( a - b + ) recipient had no red cell or LCT antibody. A hemolytic anti-L¢ ' was detected in the recipient on day 8, but no LCT reactivity was noted at this time. On day 15, the LCT panel demonstrated reactivity with nine of 50 panel cells without apparent HLA specificity. Graft vs. host disease (GVHD) was present on the skin at this timt-. The dose of cyclosporine was increased, but by day 20 the G V H D worsened and the LCT titers increased to 8. This strong reactivity was noted only in the Le ( a+) panel members (12/50) and was neutralized with commercial Lewis substance. On day 34 there was no evidence of G V H D , but the lymphocytotoxi( anti-Le a continued to be present. The patient began experiencing renal and gas trointestinal difficulties by day 48, and expired on day 60. In renal transplants the kidneys retain their Lewis type and secrete Lewis substance in the urine, hi our experience BMT patients retain their Lewis type regardless of the type of the donor. The Lewis system has been linked to renal allograft rejection, and Lewis antigens may function as transplantation antigens in BMT patients as well. In addition, lymphocytotoxic Lewis antibodies can mask other significant HLA antibodies and must be identified when screening patients in need of platelet pheresis products.

EVALUATION OF B-CELL IMMUNITY IN PATIENTS WITH PRE-TRANSPLANT SENSI~ TIZATION. Dimitri S. Monos, Michael B. Prystowsky, and Chester M. Zmijewski; Hospital ofth~ University of Pennsylvania, Philadelphia, PA

it has been hypothesized that a substantial decrease (>40%) in panel-reactive ~ antibody (PRA) prior to transplantation does not necessarily indicate a decrease in potential donor aUoreactivity and in first-graft recipients may reflect an in- creased susceptibility to life threatening infections following transplantation. We have examined this hypothesis by studying two groups of patients. Those in group 1 initially had a PRA -- 100% but experienced a large decrease in PRA (> 70%1 in 0 .5-2 .8 yr, while those in group 2 maintained a high PRA ( t00%) for the same period of time. Three blood samples from each patient representing a maximum time span of 2.8 yr were analyzed. The sera were examined for indi- cators of B cell function including levels of IgG and IgM, presence of isohe-