Paediatric kidney transplantations in HK: Long-term outcomes favourable

Long-term outcomes of paediatric kidney transplantations in Hong Kong are favourable and comparable to international benchmarks, a territory-wide retrospective cohort study has shown.

 

The study included 61 paediatric patients who received kidney transplants between January 2009 and December 2020 (median age at kidney transplantation, 13.0 years; male, 57.4 percent; deceased donor transplant [DDT], 90.2 percent; living related transplant [LRT], 9.8 percent). The patients were managed at the Paediatric Nephrology Centre of Hong Kong Children’s Hospital and had a minimum of 2 years’ follow-up data available until December 2022. The median duration of post-transplant follow-up was 6.4 years, while median age at last review was 21.9 years. [Nephrology (Carlton) 2025;doi:10.1111/nep.70009]

 

The patients’ survival rates were 100 percent at 1 year, and 96.4 percent at 5 and 7 years. Graft survival rates were 95.1 percent at 1 and 5 years, and 89.9 percent at 7 years (DDT, 94.5, 94.5 and 89 percent, respectively; LRT, 100 percent at all three timepoints).

 

“The number of paediatric kidney transplantations performed in our centre had increased by three-fold from 1992–2002 to 2009–2020,” the authors noted. “Data from this latest cohort demonstrate substantial improvements in outcomes, including patient and graft survival, since the inception of our transplant programme in 1992.” [HK J Paediatr (New Series) 2002;7:173-179]

 

The long-term patient and graft survival rates in this cohort are also comparable to rates reported in international studies. [Paediatr Nephrol 2021;36:685-692; NAPRTCS 2014 Annual Transplant Report; Nat Rev Nephrol 2016;12:301-311; Clin J Am Soc Nephrol 2020;15:392-400; Ann Acad Med Singap 2009;38:300-309; Transpl Intl 2019;32:751-761]

“While advances in immunosuppressive strategies have improved kidney allograft outcomes, significant complications, including infection and malignancy, came in parallel and resulted in morbidity and mortality,” the authors pointed out.

 

Among the four patients who died during the study period of 478.4 patient-years, infection was the leading cause of death (n=3), followed by acute T-lymphoblastic leukaemia (n=1).

 

“There were eight graft losses during the study period. Rejection and chronic allograft nephropathy were leading causes of graft loss after the first month,” the authors reported. “The median time to graft loss was 5.8 years.”

 

“Donor age ≥35 years and development of donor-specific antibodies [DSA] with antibody-mediated rejection [ABMR] were associated with poor graft survival [log-rank p<0.05 for both]. Poor drug compliance was marginally significantly associated with worse graft survival [p=0.056],” they continued.

 

A total of 33 rejection episodes occurred in 19 patients (31.1 percent) during the study period. Seven (21.2 percent) of these were ABMR, with a median onset of 750 days.

 

Cytomegalovirus (CMV) syndrome and biopsy-proven BK virus nephropathy (BKVN) were diagnosed in 12 patients (19.7 percent) and eight patients (13.1 percent), respectively. Two-thirds (n=8) of cases of CMV syndrome were in high-risk patients (donor-positive/recipient-negative). Among patients with BKVN, no graft losses occurred.

 

At the last follow-up, 47.5 percent (n=29) of patients had short stature, and 8.2 percent (n=5) had developed post-transplant diabetes mellitus at a median of 3.6 years.

 

“Preferential allocation of young donors <35 years of age to paediatric recipients, reinforcing compliance with immunosuppressive therapy, and early detection of DSA with prompt treatment of ABMR may improve allograft outcomes in paediatric patients,” the authors concluded.