The impact of preformed and de novo HLA‐DP antibodies in renal transplantation, a meta‐analysis

The impact of preformed and de novo HLA-DP antibodies after renal transplantation remains controversial and unclear. To address the clinical relevance of HLA-DP antibodies on the outcomes in renal transplantation, we performed a random effect model meta-analysis through a systematic review from inception to December 31, 2021. The outcome was graft loss or acute rejection. Finally five articles were identified as our inclusion criteria. The study which reported 1166 patients included in the final meta-analysis of de novo HLA-DP antibodies after transplantation showed an increased risk of graft loss or acute rejection (OR = 3.6, 95% CI = 1.6-8.10, P = 0.002, I2 = 52%). In the subgroup study, we established that patients with HLA-DP DSA after renal transplantation had a 8.85-fold increased risk of graft loss or acute rejection compared with patients without HLA-DP DSA (p = 0.003).While as for HLA-DP NDSA after renal transplantation, 2.73-fold increased risk of graft loss or acute rejection compared with patients without HLA-DP antibodies (p = 0.04). Besides, the studies which reported 487 patients included in the final meta-analysis of preformed HLA-DP antibodies did not show an increased risk of graft loss or acute rejection (OR = 4.55, 95% CI = 0.79-26.16, P = 0.09, I2 = 57%). The results of our meta-analysis suggested that de novo HLA-DP antibodies especially de novo HLA-DP DSA had a significant deleterious impact on the renal transplant risk of graft loss or acute rejection, while preformed HLA-DP antibodies had a no significant deleterious impact on the risk. The routine detection of HLA-DP antibodies after renal transplantation seems to be very important and may be as one of noninvasive biomarker-guided risk stratification.