HEPATIC STEATOSIS IN LIVER-TRANSPLANT DONORS - COMMON FEATURE OF DONOR POPULATION

Fatty change in donor livers is a risk factor for poor function after orthotopic liver transplantation. Various prevalences of steatosis hav e been reported in time 0 biopsies. The aim of this research was to de termine, in a longitudinal study, the degree (percent of hepatocytes i nvolved) and type (size of vacuoles) of fatty change shown by various histologic techniques. Four staining methods were used on sections fro m three liver wedge biopsies-at liver procurement, at the back-table, and after reperfusion-from 83 consecutive donor livers. Results in Sud an III-stained (SS) sections showed the greatest sensitivity (87.1%), negative predictive value (91.8%), and agreement rate (kappa = 0.77) w hen compared with results in thin (1 mu m) plastic-embedded toluidine blue-stained (TBS) sections. High-grade steatosis (>30% steatotic hepa tocytes) was identified in 49.4% of SS sections, 46.9% of TBS sections , 38.5% of frozen hematoxylin-eosin (H&E)-stained sections, and 20.7% of deparaffinated H&E-stained sections. Microscopic observations discl osed two types of steatotic pattern: (1) A predominantly small-droplet lipid vacuolzation thigh-grade microsteatosis), similar to the steato sis associated with Reye syndrome, was seen in 29% of SS sections and 25% of TBS sections-approximately one-fourth of grafts; and (2) a comb ined pattern of large and small fat drops thigh-grade macromicrosteato sis) was seen in 20% of SS sections and 22% of TBS sections. We conclu ded that moderate to severe steatosis is a frequent finding in donor l ivers. The difficulty in detecting lipidic microvacuoles in H&E-staine d sections may be the reason for underestimating the grade of fatty ch ange or even for diagnosing as normal some biopsies with high-grade mi crosteatosis.