Overcoming the ABO incompatibility barrier in pediatric renal transplantation

Pediatric ABO-incompatible kidney transplantation: Evolving with the advancing apheresis technology: A single-center experience

Recent literature has endorsed favorable outcomes following ABOi kidney transplantation in pediatric population. Nevertheless, reluctance to pursue an ABOi still remains pervasive. This could be ascribed to various legitimate reasons, namely less extensive pediatric ABOi data, technical difficulties encountered during PP, cost restraints, and concerns regarding higher rates of antibody-mediated rejection, infectious complications, and post-transplant lymphoproliferative disorder as compared to adults. However, given the similar excellent outcomes of both ABOi and ABOc kidney transplantation, clinicians should consider this option sooner if a compatible donor or swap is not available. Here, we describe the outcomes of three pediatric ABOi performed at our institute in India (from 2014 till now), wherein distinct apheresis modalities had been employed in each desensitization protocol, and our techniques evolved with advancing science in apheresis. This case series includes India's first published pediatric ABO-incompatible transplant (Case 2) and the youngest child to undergo ABO-incompatible renal transplant in SAARC nations (Case 3).

Baseline Anti-blood Group Antibody Titers and their Response to Desensitization and Kidney Transplantation

In recent years, immunological barriers historically considered as absolute contraindications to transplantation are being reevaluated. One such barrier is the ABO blood group incompatibility. With better understanding of immunological mechanisms and effective various regimens for controlling it, ABO-incompatible (ABO-I) kidney transplantation is now being performed with increasing frequency. For good outcome, most important is to achieve and maintain low anti-blood group antibody titers (ABGATs). Twenty-two patients with ABO-I donors have been studied. The anti-A and anti-B antibody titers (IgG and IgM) were estimated by column agglutination technology using Automated Ortho BioVue System. For desensitization, pretransplant plasmapheresis and/or immunoadsorption and rituximab were used. ABGAT was determined before transplant and periodically after transplant. It was observed that one-third of the patients have low baseline ABGAT. In these cases with low ABGAT, transplant can be performed without any desensitization. In those with titers <1:256, rituximab (two doses of 200 mg weekly) and 3–6 sessions of plasmapheresis can bring down titers to <1:32. In those with titers >1:256, immunoadsorption may be used from the beginning to reduce ABGAT. After transplant, the titers drop to <1:8 in majority. Rise in titers to >1:64 require close observation and biopsy. If there is evidence of antibody-mediated rejection, treatment should be promptly started. Rise in titers 4–6 weeks after transplant is not associated with any graft dysfunction, and hence not of any clinical significance.