Evaluation of the Prevalence of Occult Fibrin in Donor Organs, Its Origins, and Consequences: Insights From the COPE Studies

Abstract

Microthrombi are often observed in glomerular tufts of peri-transplant renal biopsies and occult fibrin has been described in livers undergoing normothermic perfusion, with its presence being associated with cholangiopathy and poorer transplant survival. To examine the phenomenon further, we measured D-dimers in perfusates of kidneys and livers taking part in organ perfusion studies conducted by the Consortium for Organ Preservation in Europe. Both kidneys and livers were found to contain variable amounts of D-dimers. The need for dialysis in kidneys donated after circulatory death (DCD) was associated with higher levels of D-dimers in the hypothermic kidney perfusate. Higher amounts of D-dimers in the liver perfusate were associated with poorer liver transplant survival. There was no significant difference in D-dimer release from livers and kidneys between donors dying from head trauma, stroke, or hypoxia, but organs from donors dying after euthanasia had significantly fewer D-dimers than other causes. This study shows that occult fibrin is common in both livers and kidneys from deceased donors, and has adverse consequences. The different D-dimer loads by donor cause of death suggests a donor origin for at least some of the occult fibrin.