Clinical role of the renal transplant biopsy

Abstract

Percutaneous needle core biopsy is the definitive procedure by which essential diagnostic and prognostic information on acute and chronic renal allograft dysfunction is obtained. The diagnostic value of the information so obtained has endured for over three decades and has proven crucially important in shaping strategies for therapeutic intervention. This Review provides a broad outline of the utility of performing kidney graft biopsies after transplantation, highlighting the relevance of biopsy findings in the immediate and early post-transplant period (from days to weeks after implantation), the first post-transplant year, and the late period (beyond the first year). We focus on how biopsy findings change over time, and the wide variety of pathological features that characterize the major clinical diagnoses facing the clinician. This article also includes a discussion of acute cellular and humoral rejection, the toxic effects of calcineurin inhibitors, and the widely varying etiologies and characteristics of chronic lesions. Emerging technologies based on gene expression analyses and proteomics, the in situ detection of functionally relevant molecules, and new bioinformatic approaches that hold the promise of improving diagnostic precision and developing new, refined molecular pathways for therapeutic intervention are also presented.

Renal Allograft Fibrosis: Biology and Therapeutic Targets

“…Renal biopsy Presently, the gold standard to assess and quantify renal fibrosis is renal biopsy (213). Few studies have compared two different biopsy cores to determine whether sampling error is a significant issue.…”

“…Apart from proangiogenic growth factors (150), several proteins have been suggested to play a role in endothelial cell remodeling leading to fibrosis including ephrin-B (208), Crim-1 (209), Id proteins (210), miR-126 (211), and the glycocalyx of glomerular endothelial cells (212). In renal transplantation, peritubular endothelial damage, in particular endothelial C4d staining, reflects rejection (213). Endothelial inflammation is a crucial component of rejection in renal transplants and predicts graft outcomes (214,215).…”

“…Additional analyses might further improve the predictive value of allograft biopsies such as the immunohistochemical detection of CD44 and vimentin (366), activation markers of parietal epithelial cells as markers of FSGS in the renal transplant (367), or immunohistochemistry aided analyses of peritubular capillaries to detect their early and progressive rarefaction in allografts (368). Renal biopsy tissue can also be used for unbiased approaches such as microarray analyses, which may yield diagnostic molecular signatures (213,(369)(370)(371)(372)(373)(374). This ''molecular microscope'' has been shown to improve the diagnosis of rejection but also to reflect molecular alterations in fibrosis (375)(376)(377)(378).…”

Urinary Cell mRNA Profiles and Differential Diagnosis of Acute Kidney Graft Dysfunction

“…5,6 Therefore, there is a need to develop noninvasive tools for the differential diagnosis of acute dysfunction of the kidney allograft.…”

Antibody-mediated rejection across solid organ transplants: manifestations, mechanisms, and therapies

“…In addition, fibrosis is an important characteristic of chronic AMR (31, 172). For example, transplant glomerulopathy is a feature of chronic AMR in renal allografts, with duplication of the basement membrane in the glomerulus and peritubular capillaries (173).…”