Ask the Experts - Monocyte Cross-matching Prior to Kidney...
What is the importance of monocyte cross-matching in kidney transplantation in terms of hyperacute rejection and long-term graft survival?

Nelson Roberto Toledo Lumillo, MD

To the best of my knowledge, there are few (if any) transplant centers that perform monocyte cross-matching prior to transplantation, at least routinely. The idea that monocyte antigens may cause graft rejection was discussed nearly 2 decades ago in a news article in JAMA. Two more recent publications have reported on monocyte cross-matching in renal transplantation. O'Connell and colleagues studied the sera of 164 patients to determine the incidence of antimonocyte antibodies and to assess the appropriateness of prospective screening for these antibodies. They found the overall incidence of monocyte reactivity to be 3.6% (and when expressed as a percentage of consecutive cross-matches, the calculated incidence was 0.45%). This incidence was much lower than previously reported, and the investigators concluded that prospective cross-matching for antimonocyte antibodies was not warranted.

Leichter and colleagues prospectively evaluated the significance of antibodies to the vascular-endothelial (VEM) antigen system in early renal transplant rejection. Lymphocyte and monocyte complement-dependent cytotoxic cross-matches were performed in 16 previously transfused patients using pre- and posttransplant recipients' sera and donor lymphocytes and monocytes. Only 1 patient had a positive pre- and posttransplant monocyte cross-match. The investigators concluded that anti-VEM antibody occurs rarely pretransplant and is an unusual cause of immediate rejection in the living-related transplant situation. However, when anti-VEM antibody is identified, transplantation should be avoided because of the likelihood of immediate early rejection.