Desensitization With Imlifidase: Overcoming Immunological Barriers in Kidney Transplantation

Abstract

Highly sensitized patients without compatible living donors face prolonged waiting times for a transplant. Prioritization and desensitization strategies often prove insufficient because of logistical challenges, extended treatments, and increased infection risk. The new drug imlifidase offers an opportunity for these patients by rapidly removing IgG antibodies, enabling desensitization when a donor is available. However, real-word experience remains limited. Here, we present the first case in Spain, outside of a clinical trial, in which imlifidase desensitization allowing a kidney transplant in a woman with a calculated panel reactive antibody >99.99%, requiring a second kidney transplant after 13 years on dialysis. After anti-human leukocyte antigen antibodies delisting (<20,000 mean fluorescence intensity [MFI], responders to dilution and noncomplement fixing), she received a deceased-donor kidney against whom she had 6 donor-specific antibodies (DSAs; ranging from 3,049 to 12,001 MFI; targeting human leukocyte antigen class I and II) and a positive flow cytometry crossmatch—all becoming negative after treatment with imlifidase. Early post-transplant DSA rebound was managed with conventional desensitization and anti-C5 blockade. Short-term outcomes were encouraging, with stable kidney function and significant DSA reduction at 9 months. This case highlights the potential of imlifidase in highly sensitized patients; however, long-term studies remain essential to optimize monitoring and concomitant desensitization protocols.