MOLECULAR CHARACTERIZATION OF LIVER ALLOGRAFTS FROM OPERATIONALLY TOLERANT TRANSPLANT RECIPIENTS (Affymetrix)

In clinical organ transplantation complete cessation of immunosuppressive therapy can be successfully accomplished in selected recipients providing a proof-of-principle that allograft tolerance is attainable in humans. The intra-graft molecular pathways associated with human allograft tolerance, however, have not been comprehensively studied before. In this study we analyzed sequential liver tissue samples collected from liver recipients enrolled in a prospective multicenter immunosuppressive withdrawal clinical trial. Tolerant and non-tolerant recipients differed in the intra-graft expression of genes involved in the regulation of iron homeostasis.These results point to a critical role of iron homeostasis in the regulation of intra-graft alloimmune responses in humans and provide a set of novel biomarkers to conduct drug-weaning trials in liver transplantation. The complete database comprised the expression measurements of 54,675 genes for liver inmunotolerance groups: 9 Tolerant (TOL) 10 Non Tolerant (Non TOL).A subset of 5 tolerant samples (TOL POST) were taken 1 year after inmunosuppresive therapy.