Correlation of cell necrosis and tissue calcification with ischemia/reperfusion injury after liver transplantation

Background. The cellular events following liver ischemia/reperfusion (I/R) during transplantation are largely unknown. The spectrum of I/R damage to the liver can be clinically revealed by the development of primary graft dysfunction or nonfunction. Because viral-induced liver necrosis has been associated with the development of calcifications in an animal model, we investigated the spectrum of I/R changes identified at an ultrastructural level among livers after liver transplant (LT). Materials and Methods. Random liver biopsies from five recipients with different degrees of liver dysfunction (LD) were processed for light (LM) and electron (EM) microscopic examination. The degree of calcification was estimated as mild-moderate or severe. The degree of cell vacuolization, used as a surrogate marker of cell necrosis, was reported as mild-moderate or severe. Results. Two patients with severe LD had obvious calcifications by LM and EM examinations. Both showed significant vacuole formation, suggesting a severe degree of cell necrosis, and both succumbed to the sequelae of their LD. One patient showed evidence of mild calcifications at EM (but not LM) examination, with mild vacuole formation. The remaining two patients displayed no microcalcifications. Both presented only mild vacuole formation. Both patients recovered from LD and are currently alive. Conclusion. In this preliminary report, we conclude that the clinically observed degree of LD after orthotopic liver transplant (OLT) correlates well with ultrastructural modifications. These include calcification and vacuole formation. We believe that both findings can be used as surrogate markers of a clinically significant hepatic I/R injury.