Outcomes of ABO-incompatible kidney transplantation in older patients: a national cohort study

A Multicenter Retrospective Cohort Study on Management Protocols and Clinical Outcomes After ABO-incompatible Kidney Transplantation in India

BACKGROUND

There is no robust evidence-based data for ABO-incompatible kidney transplantation (ABOiKT) from emerging countries.

METHODS

Data from 1759 living donor ABOiKT and 33 157 ABO-compatible kidney transplantations (ABOcKT) performed in India between March 5, 2011, and July 2, 2022, were included in this retrospective, multicenter (n = 25) study. The primary outcomes included management protocols, mortality, graft loss, and biopsy-proven acute rejection (BPAR).

RESULTS

Protocol included rituximab 100 (232 [13.18%]), 200 (877 [49.85%]), and 500 mg (569 [32.34%]); immunoadsorption (IA) (145 [8.24%]), IVIG (663 [37.69%]), and no induction 200 (11.37%). Mortality, graft loss, and BPAR were reported in 167 (9.49%), 136 (7.73%), and 228 (12.96%) patients, respectively, over a median follow-up of 36.3 mo. In cox proportional hazard model, mortality was higher with IA (hazard ratio [HR]: 2.53 [1.62-3.97]; P  < 0.001), BPAR (HR: 1.83 [1.25-2.69]; P  = 0.0020), and graft loss (HR: 1.66 [1.05-2.64]; P  = 0.0310); improved graft survival was associated with IVIG (HR: 0.44 [0.26-0.72]; P  = 0.0010); higher BPAR was reported with conventional tube method (HR: 3.22 [1.9-5.46]; P  < 0.0001) and IA use (HR: 2 [1.37-2.92]; P  < 0.0001), whereas lower BPAR was reported in the prepandemic era (HR: 0.61 [0.43-0.88]; P  = 0.008). Primary outcomes were not associated with rituximab dosing or high preconditioning/presurgery anti-A/anti-B titers. Incidence of overall infection 306 (17.39%), cytomegalovirus 66 (3.75%), and BK virus polyoma virus 20 (1.13%) was low. In unmatched univariate analysis, the outcomes between ABOiKT and ABOcKT were comparable.

CONCLUSIONS

Our largest multicenter study on ABOiKT provides insights into various protocols and management strategies with results comparable to those of ABOcKT.

Antithymocyte globulin versus basiliximab induction for kidney transplantation in elderly patients: matched analysis within the Korean multicentric registry

Background

Basiliximab (BSX) and antithymocyte globulins (ATGs), are two major immunosuppressive agents commonly used as induction therapy for kidney transplant (KT) recipients. The superiority of ATG over BSX has not been well established, especially in elderly KT recipients with low immunological risk.

Methods

A total of 847 elderly (≥60 years old), low-risk KT patients in the Korean Organ Transplantation Registry were propensity score-matched at a 1:2 ratio and compared according to ATG or BSX induction therapy. The primary outcome was patient and graft survival and biopsy-proven acute cellular rejection. The secondary outcome was graft function, BK virus nephropathy, infection, cancer, new-onset diabetes mellitus after transplantation (NODAT), and delayed graft function.

Results

In total, 165 patients in the ATG group were matched with 298 patients in the BSX group with average ages of 64.3 and 64.2 years, respectively. During a follow-up of 28.5 ± 10.4 months, the cumulative probabilities of death-censored graft failure at 3 years posttransplantation were 1.3% and 1.4% in ATG and BSX groups, respectively, without a significant difference (p = 0.72). The cumulative probability of NODAT at 3 years posttransplantation was significantly higher in the BSX group (35.6% vs. 21.6%, p = 0.02). The median tacrolimus trough level was significantly lower at 6 months after KT in the ATG group (5.7 ng/mL vs. 6.4 ng/mL, p = 0.001). There were no differences in the other evaluated outcomes.

Conclusion

Compared with BSX, in elderly, low-risk KT patients, ATG reduced tacrolimus and steroid requirements without differences in all-cause mortality, rejection, or infection, resulting in a reduced NODAT incidence.

Risk Due to ABO Incompatibility and Donor-Recipient Weight Mismatch in Living Donor Kidney Transplantation: A National Cohort Study

The effect of donor-recipient weight mismatch is not well established in ABO-incompatible living donor kidney transplantation (LDKT). A total of 2584 LDKT patients in the Korean Organ Transplantation Registry were classified into four groups according to the presence or absence of ABO incompatibility and donor-recipient weight mismatch (donor-to-recipient weight ratio (DRWR) < 0.8). In a multivariable Cox analysis, the combination of ABO incompatibility and DRWR incompatibility (n = 124) was an independent risk factor for graft survival (HR = 2.73, 95% CI = 1.11-6.70) and patient survival (HR = 3.55, 95% CI = 1.39-9.04), whereas neither factor alone was a significant risk factor for either outcome. The combination of ABO incompatibility and DRWR incompatibility was not an independent risk factor for biopsy-proven graft rejection (HR = 1.27, 95% CI = 0.88-1.82); however, it was an independent risk factor for pneumonia (HR = 2.94, 95% CI = 1.64-5.57). The mortality rate due to infection was higher among patients with both ABO incompatibility and DRWR incompatibility than among patients with neither factor or with either factor alone. The combination of ABO incompatibility and DRWR incompatibility was an independent risk factor for graft and patient survival after LDKT, whereas neither factor alone significantly affected graft or patient survival. Thus, donor-recipient weight matching should be cautiously considered in LDKT with ABO incompatibility.