ABO- or HLA- Incompatible LDKT Compared to Waitlist/DDKT in Elderly Patients

Survival Benefit of ABO- or HLA- Incompatible Living Donor Kidney Transplantation in the Elderly.

This retrospective multicenter cohort study evaluates the survival outcomes of elderly patients (aged ≥60 years) with end-stage kidney disease who underwent ABO- or HLA-incompatible living donor kidney transplantation compared with those managed with a conventional waitlisting strategy, including deceased donor kidney transplantation or remaining on the waiting list.

Elderly patients often experience prolonged waiting times for deceased donor transplantation, during which dialysis-related complications may increase the risk of morbidity and mortality. Desensitization protocols have enabled transplantation across immunologic barriers, such as ABO or HLA incompatibility, potentially allowing earlier access to transplantation.

Using data from two Korean transplant centers, this study compares overall survival and transplant-related outcomes between patients undergoing desensitized living donor transplantation and those managed with a waitlist-initiated strategy. The objective is to determine whether desensitized living donor kidney transplantation provides a survival advantage and represents a safe and effective treatment option for elderly patients.

Study Overview

• Status: Completed
• Conditions: Kidney Transplant; End Stage Kidney Disease (ESRD)

Detailed Description

This retrospective multicenter cohort study was conducted at Severance Hospital and Seoul National University Hospital between November 2010 and December 2023. The study included patients aged 60 years or older who initiated dialysis and were registered on the kidney transplant waiting list.

Patients were categorized into two groups:

The desensitized living donor kidney transplantation (LDKT) group, which included recipients of ABO-incompatible (ABOi), HLA-incompatible (HLAi), or combined ABOi/HLAi transplantation following desensitization therapy.

The conventional waitlisting strategy (CWS) group, defined as patients managed with a standard waitlisting approach who either underwent deceased donor kidney transplantation (DDKT) during follow-up or remained on the waiting list.

Immunologic assessment included ABO blood typing, isoagglutinin titers, flow cytometry crossmatch testing, and detection of donor-specific antibodies using single-antigen bead assays. Desensitization protocols consisted of rituximab administration, plasmapheresis with or without intravenous immunoglobulin, and risk-adapted induction therapy using basiliximab or anti-thymocyte globulin. Maintenance immunosuppression included tacrolimus, mycophenolate mofetil, and corticosteroids.

To minimize selection bias, propensity score matching was performed to balance baseline characteristics between groups. Time-dependent Cox proportional hazards models were applied to account for immortal time bias related to pretransplant waiting periods. Transplantation (LDKT or DDKT) was treated as a time-dependent exposure in survival analyses.

The primary outcome was overall patient survival. Secondary outcomes included graft survival and biopsy-proven acute rejection. Subgroup analyses were performed according to immunologic incompatibility (ABOi only, HLAi only, or combined ABOi/HLAi).

This study aims to determine whether desensitized living donor kidney transplantation provides a survival benefit compared with a conventional waitlisting strategy in elderly patients with end-stage kidney disease.

• Study Type: Observational
• Enrollment (Actual): 1819

Contacts and Locations

Study Locations

• South Korea
  • Jongno-gu
    • Seoul, Jongno-gu, South Korea, 03080
      • Seoul National University College of Medicine
  • Seodaemun-gu
    • Seoul, Seodaemun-gu, South Korea, 03722
      • Yonsei University College of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This study population was derived from elderly patients registered on the kidney transplant waiting lists at two tertiary referral transplant centers in South Korea (Severance Hospital and Seoul National University Hospital). Participants were identified from institutional transplant databases, and deidentified clinical data were retrospectively collected and analyzed.

Description

Inclusion Criteria:

• Age 60 years or older
• Diagnosis of end-stage kidney disease (ESKD) requiring maintenance dialysis
• Registered on the kidney transplant waiting list between November 2010 and December 2023

Exclusion Criteria:

• Complement-dependent cytotoxicity crossmatch positive

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Elderly Patients on Kidney Transplant Waiting List; Patients aged 60 years or older registered on the kidney transplant waiting list, including those who underwent desensitized living donor kidney transplantation or were managed with a conventional waitlisting strategy, defined as receiving deceased donor kidney transplantation or remaining on the waitlist during follow-up.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient survival	Patient survival was defined as the time from dialysis initiation to death from any cause. Patients were censored at the date of last follow-up if alive. Survival probabilities were estimated using the Kaplan-Meier method and compared between groups using time-dependent Cox proportional hazards models to account for transplantation as a time-dependent exposure.	From dialysis initiation up to 10 years of follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
5-Year Graft Survival	Graft survival was defined as the time from kidney transplantation to graft failure. Graft failure was defined as return to maintenance dialysis, re-transplantation, or death with a functioning graft. Participants without graft failure were censored at the date of last follow-up. Survival probabilities were estimated using the Kaplan-Meier method and compared between groups using Cox proportional hazards models.	Up to 5 years after kidney transplantation

Collaborators and Investigators

• Sponsor: Seoul National University Hospital
• Collaborators: Severance Hospital

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2010
• Primary Completion (Actual): December 31, 2023
• Study Completion (Actual): December 31, 2024

Study Registration Dates

• First Submitted: February 21, 2026
• First Submitted That Met QC Criteria: February 21, 2026
• First Posted (Actual): February 27, 2026

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 21, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: elderly patient; survival outcomes; Desensitized Living donor kidney transplantation; waitlist mortality
• Additional Relevant MeSH Terms: Urogenital Diseases; Pathologic Processes; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Chronic Disease; Disease Attributes; Renal Insufficiency; Renal Insufficiency, Chronic; Pathological Conditions, Signs and Symptoms; Kidney Failure, Chronic
• Other Study ID Numbers: SNUH_Sev_desensitized LDKT

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Individual participant data that are de-identified will be made available upon reasonable request to the corresponding author, subject to institutional review board approval and execution of a data use agreement.
• IPD Sharing Time Frame: Individual participant data and supporting documents will be available beginning 6 months after publication of the primary results and will remain available for 5 years following publication.
• IPD Sharing Access Criteria: Access to deidentified individual participant data, study protocol, statistical analysis plan, and analytic code will be granted to researchers who provide a methodologically sound research proposal. Requests will be subject to institutional review board approval and execution of a data use agreement. Data will be shared through secure data transfer upon approval by the corresponding author and participating institutions.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No