A2/A2B to B kidney transplantation outcomes: A single center 7-year experience

• Published in: Clinical transplantation Vol. 38; no. 4; p. e15295
• Main Authors: El Chediak, Alissar, Shawar, Saed, Fallahzadeh, Mohammad K, Forbes, Rachel, Schaefer, Heidi M, Feurer, Irene D, Rega, Scott, Triozzi, Jefferson L, Shaffer, David
• Format: Journal Article
• Language: English
• Published: Denmark 01-04-2024
• Subjects: ABO Blood-Group System; Adult; Blood Group Incompatibility; Graft Rejection - etiology; Graft Survival; Humans; Immunoglobulin G; Immunoglobulin M; Isoantibodies; Kidney Transplantation; Retrospective Studies; A2/A2B; access; minorities; outcomes; ABO incompatible transplant; kidney transplantation
• ISSN: 0902-0063; 1399-0012
• DOI: 10.1111/ctr.15295

Data on long-term outcomes following A2/A2B to B kidney transplants since the 2014 kidney allocation system (KAS) changes are few. The primary aim of this study is to report our 7-year experience with A2/A2B to B kidney transplants and to compare post-transplant outcomes of A2/A2B to a concurrent group of B to B kidney transplants. Additionally, the study evaluates the impact of pre-transplant anti-A1 titers on survival outcomes in A2/A2B transplants.
This retrospective, single-center analysis included all adults who received A2/A2B to B deceased donor kidney transplants from December 2014 to June 2021 compared to B to B recipients. The effects of pre-transplant IgM/IgG titers, stratified as ≤1:8 and ≥1:16, on death-censored, rejection-free, and overall graft survival were tested.
Fifty-three A2/A2B and 114 B to B adults were included with a median follow-up time of 32 months. Overall graft survival, patient survival, and rejection-free graft survival did not differ between the two groups. There were no differences between the groups' overall kidney function values (p > .80) or their temporal trajectories (time by group interaction p > .11). Unadjusted death-censored graft survival was lower in A2/A2B to B compared to B recipients (p = .03), but the effect was not significant (p = .195) after adjusting for any readmissions (p = .96), rejection episodes (p < .001) or BK infection (p = .76). We did not detect an effect of pre-transplant titer group on death-censored (p = .59), rejection-free (p = .61), or overall graft survival (p = .26) CONCLUSIONS: A2/A2B to B kidney transplants have comparable overall patient and graft survival, rejection-free graft survival, and longitudinal renal function compared to B to B transplants at our center. Allograft survival outcomes were not significantly different between patients with low and high pre-transplant anti-A1 IgM/IgG titers.