Delayed Graft Function in Pediatric Kidney Transplant Recipients

Rates of delayed graft function are low in pediatric recipients of living donor kidneys. M. MacConmara and colleagues at UT Southwestern Medical Center, Dallas, Texas, conducted a study designed to assess the incidence, risk factors, and outcomes of delayed graft function in pediatric kidney transplant recipients who received a living donor allograft. Results of the study were reported in a virtual presentation at the 2021 American Transplant Congress. The presentation was titled Delayed Graft Function in Pediatric Living Donor Kidney Transplantation.

The researchers queried the United Network for Organ Sharing database to identify all pediatric patients who received a living donor transplant between 2000 and 2020. The study defined pediatric recipient as one who received the transplant prior to reaching age 18. The analysis included donor and recipient demographic data, as well as data on survival and outcomes. Delayed graft function was defined as the need for dialysis within the first week after transplant.

During the study period, 6480 pediatric patients received a living donor kidney transplant. Of those 4.2% (n=269) developed delayed graft function post-transplant. Donors of patients in the two groups (delayed graft function and control) were similar in age (37.2 years vs 37.0 years, respectively), had similar preoperative creatinine (0.86 mg/dL in both groups), sex, and ethnicity. Donor body mass index (BMI) was higher in the delayed graft function group (27.6 vs 26.8 kg/m², respectively, P=.004). Cold ischemia time was similar in both groups (2.4 vs 2.3 hours).

Among recipients, both groups were similar in age (9.8 vs 10.1 years). Recipients in the delayed graft function group had higher BMI than those in the control group (20.3 vs 19.4 kg/m²; P=.002). Initial and final calculated panel-reactive antibodies were similar in the two groups (2.2% vs 2.4% initial; 10.5% vs 8.9% final). Human leukocyte antigen mismatch was also similar (3.0 vs 2.8). The most common diagnosis (23%) in recipients with delayed graft function was focal segmental glomerulosclerosis (FSGS). FSGS was significantly more frequent in the delayed graft function group than in the control group (23% vs 10%, respectively; P=.001).

Recipients with body weight <15 kg had a significantly higher rate of delayed graft function (24.9% vs 19.8%; P=.04). Length of stay for recipients with delayed graft function was twice that of the control group (23.4 vs 10.1 days, respectively, P<.0001).

At 6 and 12 months post-transplant, rates of rejection were higher among patients in the delayed graft function group than in the control group (24.8% vs 8.0% at 6 months, respectively, P<.0001; 26.4% vs 11.6% at 12 months, respectively, P<.0001). Those in the delayed graft function group had significantly worse allograft survival compared with the control group; 1-year graft survival was more than 30% lower in the delayed graft function group than in the control group (67% vs 98%). Graft thrombosis (25.3%), rejection (17.5%), and recurrent disease (15.6%) were the most common causes of allograft loss.

In conclusion, the researchers said, “Pediatric living donor kidney transplant recipients who experience delayed graft function have significantly poorer allograft survival. Immunologic events, recurrent disease, and technical complications appear to underlie these poor outcomes and should be considered especially in younger recipients with FSGS. Optimizing the donor recipient combination to avoid compounding risks should allow for better outcomes.”

Source: MacConmara M, Shah J, De Gregorio L, Desai D, Vagefi P, Hwang C S. Delayed graft function in pediatric living donor kidney transplantation. Abstract of a presentation at the virtual 2021 American Transplant Congress (Abstract #82), June 5, 2021.