Screening panel-reactive antibody negative, single-antigen positive: a case report.

Area of Science:

• Nephrology
• Immunology
• Transplantation

Background:

• Kidney transplantation in sensitized patients presents challenges due to donor-specific antibodies.
• Virtual crossmatch, a method to detect these antibodies, is crucial for successful transplantation.
• Panel-reactive antibody (PRA) screening is standard, but limitations exist.

Observation:

• A kidney transplant recipient with negative PRA and a negative virtual crossmatch experienced delayed graft function and biopsy-proven antibody-mediated rejection.
• Post-rejection, single-antigen testing revealed a positive antibody against HLA-A*11:02, an allele not included in the standard PRA screen.
• The donor's HLA type was A*68:01 and A*11:01, indicating the detected antibody was not directed at the actual donor HLA.

Findings:

• The detected HLA-A*11:02 antibody, though present, was not implicated in the recipient's rejection episode.
• This case highlights a potential failure of virtual crossmatch to identify all relevant antibodies.
• The recipient's condition improved with plasmapheresis and intravenous immunoglobulin treatment.

Implications:

• Virtual crossmatch may not be sufficient for all patients, particularly those with specific HLA antibody profiles.
• Single-antigen testing for PRA is crucial, even in PRA-negative individuals, to prevent antibody-mediated rejection.
• Refined crossmatch strategies are needed to improve kidney transplant outcomes in sensitized populations.