ESPN 53rd Annual Meeting

ESPN 2021


 
HYPOCALCAEMIA AND HYPERPHOSPHATEMIA ARE ASSOCIATED WITH ALLOGRAFT DYSFUNCTION IN PAEDIATRIC KIDNEY TRANSPLANT RECIPIENTS
Agnieszka Prytula Rukshana Shroff 2 Justine Bacchetta 3 Kai Krupka 4 Ellen Deschepper 5 Dieter Haffner 6 Burkhard Tönshoff 4

1- Department of Pediatric Nephrology and Rheumatology, Ghent University Hospital, Belgium
2- Renal Unit, Great Ormond Street Hospital London, UK
3- Hospices Civils de Lyon, France
4- University Children’s Hospital Heidelberg, Germany
5- Biostatistics Unit, Ghent University, Belgium
6- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
7- On behalf of the ESPN CKD-MBD and Transplantation WGs This work has been supported by the ESPN research grant 05/2020
 
Introduction:

 We aimed to analyse the relationship between calcium (Ca), phosphorus (P) and parathyroid hormone (PTH) levels and allograft outcomes over time in paediatric kidney transplant recipients. 

Material and methods:

 We included patients from the European CERTAIN Registry with up to 5 years follow-up and younger than 19 years at transplantation. Laboratory measures were collected at baseline, 1, 3, 6, 9 and 12 months and every 6 months thereafter. Ca and P were adjusted for age- specific reference values, whereas PTH levels were adjusted for centre- specific reference values and expressed as upper limit of normal (ULN). We performed survival analysis where the event was death, graft loss or allograft dysfunction defined as estimated glomerular filtration rate (eGFR) 30 ml/min/1.73 m². Associations between Ca, P and allograft outcomes were investigated using a stratified Cox proportional hazards model with time-varying covariates.

Results:

 We included 1218 patients from 42 centres in 15 countries, 61% boys, 46% with congenital dysplasia and the mean age at transplantation 9.7 (±5.1) years. 12.3% of patients experienced allograft dysfunction, of whom 3% allograft loss and 0.6% death. There was no difference in time to event between patients with baseline PTH lower or higher than 2-fold ULN. In contrast, hypocalcaemia (HR 1.93, 95% CI 1.29;2.89, p = 0.001), hyperphosphatemia (HR 4.05, 95% CI 2.65;6.18, p < 0.001), and hyperparathyroidism (HR 4.72, 95% CI 2.51;8.89, p<0.001) were associated with allograft dysfunction. In in a multivariable model hypocalcaemia (HR 1.89, 95% CI 1.22;2.93, p = 0.004) and hyperphosphatemia (HR 3.0, 95% CI 1.89;4.77, p<0.001) were independently associated with the hazard of event, adjusted for rejection, body mass index Z score, systolic blood pressure Z score and disease vintage.

Conclusions:

  In conclusion, hypocalcaemia and hyperphosphatemia are associated with allograft dysfunction independently of known risk factors in paediatric kidney transplant recipients.