#2390 Does incompatible kidney transplantation provide a reliable alternative? An updated meta-analysis

Abstract Background and Aims The ABO system often poses one of the challenges to kidney transplantation, but due to the scarcity of organs, ABO incompatible kidney transplantation (ABOi-kTx) has gained the clinical attention. So, we aim in this study to evaluate the impact of ABO incompatible kidney transplantation on patients' clinical outcomes in comparison with ABO compatible kidney transplantation (ABOc-kTx). Method We searched six electronic databases: PubMed, Scopus, WOS, Cochrane, Embase, and Medline to identify relevant studies published until October 8th 2023, with no filters applied during the research process. After screening of 8562 studies, we included observational studies that compared any clinical outcomes of ABO incompatible kidney transplantation with ABO compatible kidney transplantation across various age groups. Synthesized odds ratios (ORs) with 95% confidence intervals (CIs) are used to present the differences between the two groups based on random-effects models. Results Our comprehensive search according to the eligible criteria of this study resulted in 102 studies including 254 496 patients in both groups. Due to the clinical heterogeneity, we used random effects models for quantitative synthesis of the eligible studies. Our meta-analysis showed that there was a statistically significant higher mortality ratio after one year, 3 years and 5 years (odds ratio [OR] 2.21 [95% CI 1.56–3.14], P < .00001; I² = 53%), (OR 1.86 [1.35–2.75], P = .0001; I² = 61%), (OR 1.69 [1.20–2.40], P = .003; I² = 75%), respectively. While there was no statistically significant difference at 8-years after transplantation (OR 1.05 [0.76–1.46], P = .77; I² = 58%). Pooled data of graft failure from our studies revealed higher incidence in ABOi-kTx group after one year (OR 2.44 [1.81–3.28], P < .00001; I² = 64%), 3 years (OR 1.57 [1.24–1.98], P < .00001; I² = 54%) and after 5 years (OR 1.57 [1.23–2.01], P =  .0003; I² = 76%), There was not any statistically significant difference between both groups after 8 years. Acute anti-body mediated rejections were noticed to be statistically higher in ABOi-kTx group (OR 2.51 [2.12–2.97], (P < .00001); I² = 20%). Also, there was a significantly higher incidence of CMV infection in ABOi-kTx group (OR 1.27 [1.08–1.48], (P  =  .003); I² = 58%). Conclusion Although that ABOi-kTx is inferior to ABOc-kTx in the first 5 years after the transplantation in patient and graft mortality. Both groups are similar in both outcomes after 8 years post transplantation. Considering the higher incidence of acute rejection in the ABOi-kTx group and increased infection rate, desensitization techniques should be furtherly developed for better survival and complication outcomes.