Successful A2 to O Simultaneous Liver and Kidney Transplantation in the Setting of Pre-operative Positive HLA Crossmatch: A Case Report

•The initial negative HLA antibody screening for the simultaneous liver and kidney transplantation (SLKT) recipient turned positive (calculated panel reactive antibodies [CPRAs] = 0% to 100%) within the short span of 6 days secondary to blood product transfusions in the interim and memory response from previous pregnancies.•Positive HLA crossmatch converted to negative, approximately 6 hours and 37 minutes after liver transplantation•Anti-A2 titer rapidly decreased from 512 pre-transplant to 256 at approximately 6 hours and 37 minutes after liver transplantation. The titers further decreased to 128 at approximately 4 months postoperatively. Simultaneous liver and kidney transplantation (SLKT) is possible for patients with high donor-specific HLA antibodies or with A2 donors to O recipients with high A2 titers. We report the first case of SLKT in a highly sensitized O recipient with organs from an A2 donor. The recipient is a 59-year-old woman with chronic kidney disease and liver failure due to autoimmune hepatitis and drug-induced liver injury. Immune work-up 8 days pre-transplant demonstrated a negative crossmatch and no HLA antibody (calculated panel reactive antibodies = 0%). Anti-A2 IgG levels were 512. The donor was a deceased 24-year-old man. One day before transplantation, serum from the recipient showed a significant increase in antibody reactivity (calculated panel reactive antibodies = 100%) attributable to blood product transfusion and memory response from previous pregnancies. Consequently, a crossmatch was positive for T and B cells with two newly detected HLA antibodies against the donor's antigens. On the day of surgery, the liver was transplanted first. Six hours and 37 minutes later, a repeat flow crossmatch was negative; donor-specific antibodies (DSAs) fell below the positive threshold, and anti-A2 IgG titer fell to 256. Thus, the kidney was transplanted after basiliximab induction therapy. Seven days post-transplant, non-donor-specific HLA antibodies were present but DSAs remain negative. The patient was discharged on postoperative day 57 with no signs of rejection at 4 months. This case illustrates a rapid and prolonged reduction in antibody titers (HLA and ABO) after SLKT. SLKT is feasible in patients with both DSA and high anti-A2 titer.