A DESCRIPTIVE STUDY OF ABO-INCOMPATIBLE KIDNEY TRANSPLANTS IN A SINGLE CENTRE IN SOUTH INDIA

Introduction:

Historically, ABO incompatibility was a significant barrier due to high rejection rates. Desensitisation in ABO-incompatible kidney transplants involves apheresis, B cell-depleting therapies, and strong immunosuppression. Outcomes of ABO-incompatible kidney transplants are now comparable to ABO-compatible ones. 

Methods:

This is a retrospective review of renal transplant recipients at our centre. Data was collected from the electronic medical system (Trakcare). 

Results:

There were 26 transplants from September 2013 to August 2024. Most donors were wives (46.1%). HLA match was 1 and 2 had DSA. B to O was commonest (26.9%), others - A to O (23.1%), AB to A (19.2%), AB to B (11.5%),  A to B (7.7%) and one (3.8%) each in B to A, AB to O and O to B. Peak ABO titers pretransplant were: 1:512 (3.8%), 1:256 (11.5%), 1:128 (23.1%), 1:64 (11.5%), 1:32 (11.5%), 1:16 (19.2%), 1:8 (7.7%), 1:4 (7.7%) and 1:2 (3.8%), lowest pretransplant titers were nil (23.1%), 1:2 (23.1%), 1:4 (26.9%), 1:8 (15.4%), increase in titers after transplant in 30.8%. The commonest desensitization was immunoadsorption (IA) and rituximab (34.6%). DGF was seen in 11.5%. 53.3% had C4d (75% accommodation). Urinalysis at 1 year - 30.8% nil, 46.2% trace and 23% >1+. Average creatinine at 1 year was 1.27mg/dl, 15.5% were lost to followup. 1-year and 5-year follow-ups were 80.8% and 26.9%. In the follow-ups, graft survival was 0.3 months-120 months (average of 14.3 months) and 36.3% had graft loss. The 1-year and 5-year graft and patient survival was 76.2%; 14.3% and 90.5%; 71.4%. 

On subgroup analysis, recipients with high pretransplant ABO titers (>1:16) had: 75% used Immunadsorption with rituximab for desensitization, 43.8% had increased titers, 18.8% DGF, 68.8% biopsy - 50% had MVI and 50% had biopsy-proven rejection (all antibody-mediated), 1-year patient and graft survival was 76.9% and 37.5%, no grafts survived at 5years and had all deaths. Recipients with graft loss had: 25% DGF, 75% biopsy -  50% MVI and 66.7% biopsy-proven rejection, 1-year patient and graft survival 75% and 58.3% and all the deaths. Recipients who had mortality were all B to O, all had high pretransplant ABO titers, 33.3% had vascular rejection, average graft survival of 3.67 months and 66.7% had urosepsis. Recipients who had rejection had an average HLA match of 1, 1 had DSA, all had high peak ABO titers, 77.8% ATG induction, all were on tacrolimus, 33.3% DGF with 1-year graft and patient survival of 57.1% and 100%, 50% graft loss with an average survival of 4.3months and 44.4% infection. Patients who had an increase in ABO titers after transplant had higher pretransplant ABO titers, 75% underwent desensitization with immunoadsorption and rituximab, 100% ATG induction, no DGF, 40% rejection (all antibody-mediated), 1-year graft and patient survival of 75%, with 25% graft loss, 37.5% infection and one death. The characteristics are as below tables and charts:

Conclusions:

We above describe favourable clinical characteristics associated with graft survival and unfavourable ones associated with rejection, graft loss, infections and adverse events in ABO-incompatible kidney transplant recipients. 

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.