Maddalena Giannella

Background The role of culturing the graft preservation fluid (PF) is controversial and its impact on graft arteritis development remains unclear. Methods Systematic literature search retrieving observational studies comparing solid organ transplant (SOT) recipients with culture‐positive PF versus culture‐negative PF. The quality of included studies was independently assessed according to the ROBINS‐I tool for observational studies. Meta‐analysis was performed using Mantel‐Haenszel random‐effect models. Graft site arteritis within 180 days from transplant was selected as the primary outcome. Results Twenty‐one observational studies ( N = 2208 positive PF vs. 4458 negative) were included. Among positive PF, 857 (38.8%) were classified as high‐risk group pathogens and 1351 (61.2%) as low‐risk pathogens. Low‐risk and negative PF showed similar odds ratios. A significant higher risk of graft arteritis was found in SOT recipients with a PF yielding a high‐risk pathogen (odds ratio [OR] 18.43, 95% confidence interval [CI] 7.83–43.40) compared to low‐risk and negative PF, with low heterogeneity ( I 2 = 2.24%). Similar results were found considering separately high‐risk bacteria (OR 12.02, 95%CI 4.88‐29.60) and fungi (OR 71.00, 95%CI 28.07–179.56), with no heterogeneity ( I 2 = 0%), and in the subgroup analyses of the liver (OR 16.78, 95%CI 2.95–95.47) and kidney (OR 19.90, 95%CI 4.78–82.79) recipients. However, data about diagnostic features of graft arteritis were very limited, indeed for only 11 of the 93 events histological or microbiological results were reported. Conclusions Our results may support the performance of PF culturing and a preemptive diagnostic or therapeutic management upon isolation of high‐risk pathogens. Further studies based on a reliable diagnosis of graft arteritis are needed. image