Clinical significance of antimonocyte antibody in kidney transplant recipients.

Monocytes appear to contain an antigen system very similar to the "cell-specific" antigen system previously identified on the vascular endothelial cell (VEC). By using a crossmatch technique with monocytes as the target cell, we tested for the presence of antibody to donor vascular endothelial cell antigens in kidney transplantation recipients, as well as performed mixed lymphocyte cultures, and T and B cytotoxicity testing. This technique detected clinically significant sensitization in some (living related) donor-recipient combinations not detected with standard T and B lymphocyte techniques. Patients with positive monocyte crossmatches but negative T or B lymphocyte crossmatches have a very high incidence of severe rejection and graft failure.