Mixed leucocyte culture blocking factor activity in allograft recipients and its role in the clinical outcome of human cadaveric renal allografts

Abstract

Seventeen renal allograft recipients were followed serially both pre- and post-transplantation for the presence of mixed leucocyte culture blocking factor activity (MLC-BFA) in their plasma. Patients could be divided into three distinct groups on the basis of MLC-BFA and lymphocytotoxin (LT) determinations. Fifteen out of seventeen patients possessed MLC-BFA at one time or another while four out of seventeen were positive for LT. Four patients of group 1 with pre-transplant LT and MLC-BFA rejected their grafts within 1 year. Two LT negative patients of group 2 developed no detectable MLC-BFA during a follow-up period of over 1 year. One other patient developed MLC-BFA 8 months following transplantation. All three patients had an excellent clinical course. Ten patients belonging to group 3 possessed no LT or MLC-BFA prior to transplantation but developed MLC-BFA alone after receiving an allograft. Only one patient rejected his allograft within 2 months. The remaining nine patients experienced mild rejection crises during the first 3 months after transplantation but had excellent renal function at 1 year or beyond that time. Our results indicate that MLC-BFA in the presence of LT may not prevent rejection. MLC-BFA is associated with a good clinical course in LT negative patients. However, certain patients who fail to develop LT or MLC-BFA in spite of repeated blood transfusions prior to transplantation may also do extremely well in the absence of detectible MLC-BFA.