2bRAD-M reveals circulating microbiome in chronic antibody-mediated rejection (CAMR) and IgA nephropathy (IgAN) after kidney transplantation.

Background: Kidney transplantation is currently the most effective method for treating end-stage renal disease. However, postoperative-related rejection and IgA nephropathy remains a serious obstacle to the long-term survival of kidney transplant patients. Its pathogenesis is not fully understood, and potential causative factors remain to be explored. In this study, we used 2bRAD-M to analyze differences in the peripheral blood microbiome of renal transplant recipients who were stable postoperatively (STABLE) and those who developed chronic antibody-mediated rejection (CAMR) or IgA nephropathy (IgAN) recurrence. Method: Thirty one renal transplant patients were recruited, including 12 STABLE, 8 CAMR and 11 IgAN patients after kidney transplantation. 2bRAD-M was used to characterize the microbiota in peripheral blood to explore the presence of microbial differences. Results: Differences in microbial community composition were observed between CAMR, IgAN and STABLE. The alpha diversity of CAMR and IgAN was all higher than STABLE, there are also differences in beta diversity. LEfSe was performed to identify different abundance taxa, 21 discriminative features between CAMR and STABLE, 39 discriminative features between IgAN and STABLE. The mean decrease Gini index and random forest analysis indicated that Staphylococcus_epidermidis might serve as indicator bacteria for CAMR, Kocuria_palustris might serve as indicator bacteria for IgAN. ROC analysis was performed to assess the performance of some optimal marker models, and the average AUC value achieved 89.6% between CAMR and STABLE, 67.4% between IgAN and STABLE. Functional annotation analysis showed 4353 different COGs and 378 related signaling pathways between CAMR and STABLE, 4396 different COGs and 384 related signaling pathways between CAMR and STABLE. Conclusion: The first 2bRAD-M microbiome study of CAMR and IgAN after renal transplantation showed a potential association between the circulating microbiome and the disease, and provided a possible target and basis for subsequent studies of the mechanisms underlying the development and progression of CAMR and IgAN after renal transplantation. [ABSTRACT FROM AUTHOR]