ESPN 51th Annual Meeting

ESPN 2018


 
Evaluation of the current HLA antibody screening protocol in paediatric renal transplant recipients in Amsterdam
AYSENUR DEMIROK 1 ANTONIA BOUTS 1 JUNIOR LARDY 2 CLAUDIA RANZIJN 2 SANDRINE FLORQUIN 1

1- ACADEMIC MEDICAL CENTER-UNIVERSITY OF AMSTERDAM
2- LABORATORY SANQUIN
 
Introduction:

The necessity of the post-transplant monitoring for Donor Specific Antibodies (DSA) is not completely defined yet and needs to be evaluated. This study will assess the clinical relevance of post-transplantation donor specific HLA (Human Leukocyte Antigen) antibodies in paediatric renal transplant recipients. Consequently, we expect to better stratify patients at risk of graft dysfunction and make better recommendations on post-transplant monitoring. 

Material and methods:

We conducted a retrospective study between 2004 and 2014 in a cohort of paediatric kidney recipients which consisted of 76 transplantations. The screening protocol included an assay to detect HLA antibodies at 1, 3, 6 and 12 months after transplantation and yearly thereafter. Samples testing positive were further analyzed to detect DSA. A biopsy was performed on clinical indication. We compared the baseline characteristics of the biopsy and non-biopsy group, of patients with and without DSA and of patients with and without rejection. We assessed the effect of post-transplant DSA on clinical outcome including antibody-mediated acute rejection and GFR decrease.

Results:

 In our cohort DSA prevalence was 19%. Most of the patients with HLA antibodies after transplantation were DSA-positive (13/17). Patients with DSA had a significant shorter time to rejection compared to patients without. A clear association between DSA and rejection was found. Furthermore, significant lower last GFR was found in the biopsy-, DSA- and rejection-positive groups. Time to 25% GFR reduction from the baseline GFR was significant shorter for patients who underwent biopsy compared to patients who did not. 

Conclusions:

Based on our observation we recommend testing on DSA is necessary, especially when HLA antibodies are detected. DSA is related to rejection. Therefore, we might consider performing biopsy when DSA is present, regardless of the levels of creatinine. Further research is needed to investigate the exact correlation between DSA and rejection, and consecutively graft outcome.