Search

The aim of this study was to evaluate the prognostic potential of a 3-parameter visual scoring (qualitative score [QS]) system for hepatobiliary phase gadoxetic acid-enhanced magnetic resonance imaging (MRI) in orthotopic liver transplant grafts.This retrospective study of 128 patients was approved by our institutional review board. Two readers independently assigned 3 QSs to T1-weighted MRI scans, 20 minutes after the administration of gadoxetic acid (hepatobiliary phase), based upon the following: (1) liver parenchymal enhancement (EnQS, 0-2); (2) biliary contrast excretion (ExQS, 0-2); and (3) signal intensity of the portal vein relative to the liver parenchyma, that is, the portal vein sign (PVsQS, 0-2). The functional liver imaging score (FLIS) was calculated as the sum score of these 3 parameters. The relative liver enhancement (RLE) was measured as well. Demographic, clinical, laboratory parameters, and imaging findings were included in univariate and multivariate statistical analyses. The primary end point was graft failure, that is, retransplantation or death from liver failure. The probability of graft survival was calculated by Kaplan-Meier estimates and Cox proportional hazards regression.In the univariate analysis, EnQS, ExQS, PVsQS, and FLIS scores, as well as RLE, were significantly associated with the 1- to 3-year probability of graft survival (P0.001). For a FLIS of (0), the 3-year probability of graft survival was 6.5%, whereas it was 51.3% for a FLIS of (1-3) and 100% for a FLIS of (4-6) (P0.001). In the multivariate survival models, EnQS, ExQS, and PVsQS, each independently outperformed the majority of clinical and laboratory parameters, and the FLIS did even better regarding the prediction of 1- to 3-year graft survival.In liver transplant recipients, gadoxetic acid-enhanced MRI-derived QSs (ie, EnQS, ExQS, and PVsQS), as well as the FLIS and RLE, can predict graft survival probability.

Endothelial deposition of the complement split product C4d is an established marker of antibody-mediated acute renal allograft rejection. A contribution of alloantibody-dependent immune reactions to chronic rejection is under discussion. In this study, the association of immunohistochemically detected endothelial C4d deposition in peritubular capillaries (PTC) with morphologic features of chronic renal allograft injury was investigated in a large study cohort. C4d deposits in PTC were detected in 73 (34%) of 213 late allograft biopsies performed in 213 patients more than 12 mo after transplantation (median, 4.9 yr) because of chronic allograft dysfunction. Endothelial C4d deposition was found to be associated with chronic transplant glomerulopathy (CG) (P < 0.0001), with basement membrane multilayering in PTC (P = 0.01), and with an accumulation of mononuclear inflammatory cells in PTC (P < 0,001). Furthermore, C4d deposits in PTC (in biopsies with normal glomerular morphology) were associated with development of CG in follow-up biopsies. Other morphologic features of chronic allograft nephropathy (with exception of tubular atrophy) were not associated with C4d deposits in PTC. Analyses of previous and follow-up biopsies revealed that C4d deposits may occur de novo and may also disappear at any time after transplantation. In conclusion, the data suggest that complement activation in renal microvasculature, indicating humoral alloreactivity, contributes to chronic rejection characterized by chronic transplant glomerulopathy and basement membrane multilayering in PTC.