1 Unit of HPB Surgery and Abdominal Organ Transplantation, Department of Surgery, "Doce de Octubre" Hospital, Instituto de Investigación (imas12), Faculty of Medicine, Complutense University, Madrid, Spain.
2 Unit of Statistical Analysis, "Doce de Octubre" Hospital, Complutense University, Madrid, Spain.
3 Service of Nephrology and Kidney Transplantation, "Doce de Octubre" Hospital, University Madrid, Madrid, Spain.
4 Service of Immunology, "Doce de Octubre" Hospital, Complutense University, Madrid, Spain.