Alloimmunization to red cell antigens in liver and multivisceral transplant patients

Alloimmunization to red blood cell (RBC) antigens can significantly impact transfusion support of patients undergoing solid-organ transplantation. This study evaluated the incidence of clinically significant RBC alloantibodies (abs) in 2000 consecutive adults receiving liver (OLTX), intestinal (ITX) or multivisceral (MVT) transplants.

From January 1991 to May 2006, 2000 patients underwent OLTX (n=1892), MVT (n=74), or ITX (n=34). Blood sample for serologic investigation was submitted to the transfusion service no later than 4 hr before surgery. The presence of clinically significant RBC abs before transplant with subsequent transfusion requirements, the incidence of delayed transfusion reactions, and de novo abs after transplant were evaluated.

One hundred fifteen patients (5.75%) had clinically significant RBC abs before transplant, with 56.7% directed against Rh system antigens. Forty-six (40%) had multiple abs. A mean of 18 packed RBC units (U) were transfused per patient. Patients requiring >20 U (n=34) or those with multiple abs received antigen-negative units for the first 5-10 U when antibody was still present, switched to antigen-unscreened units during massive blood loss and returned to antigen-negative units for the last 5-10 U transfused. Twelve patients (0.6%) developed de novo abs posttransplant. Twenty-two (1.1%) had delayed serologic transfusion reaction. All patients were successfully managed without delay in initiation of surgery or hemolytic complications.

RBC alloimmunization can present a special challenge to solid-organ transplantation. Early serologic testing of the recipient pretransplant and prompt communication between the transfusion service and transplant team facilitates successful transfusion management of these patients.