Ethanol-induced dysfunction of hepatocytes and leukocytes in patients without liver failure.

The repeated intake of a great amount of ethanol is followed by functional and organic changes in the body. The intestinal absorption of alcohol is accompanied by an increased absorption of Gram negative bacteria endotoxins in the portal blood. In the liver, endotoxins stimulate CD14 receptors on the membrane of Kupffer cells, with a secondary inflammatory liver response, consisting in the secretion of proinflammatory cytokines and acute phase proteins. Simultaneously, alcohol metabolism in the hepatocytes by alcohol dehydrogenase, microsomal enzymes and catalase pathways determines a large production of ROS (reactive oxygen species), with secondary oxidative aggression on all liver cells: hepatocytes, Kupffer cells, endothelial sinusoidal cells, hepatic stellate cells and liver s lymphocytes. The oxidative aggression, as well as the intermediary products of the alcohol metabolism, cause a structural change of the antigenic structures of the liver and of the released proteins, that induces an immune response on the both pathways (humoral and cellular). The pathophysiological mechanisms and the paraclinical characteristics of the ethanol-induced liver failure are well known, so we were interested to study the patients with chronic alcoholism, but no clinical or paraclinical sign of liver failure, in order to describe the liver's protective mechanisms. For this reason, 153 patients with chronic alcoholism were divided into four test lots, in order to determine: the activity and the serum level of ceruloplasmin, plasma level of MDA (malondialdehyde), lactic and pyruvic acids, serum level of transferrin, alpha1-antitrypsin, CRP (C reactive protein), C3 fraction of the complement, IgA, IgG, IgM, IL-1beta, IL-6 and IL-8, cytosolic level of the cytochrome c in the circulating leukocytes. An immunophenotype study (as normal markers) on the peripheral blood lymphocytes was performed, too. The results demonstrate an important oxidative aggression induced by three sources: the alcohol metabolism in the hepatocytes, activated Kupffer cells and activated neutrophils that have infiltrated the liver, due to the chemoattractant effect of IL-8. This aggression induces apoptosis and necrosis of the liver cells. The major liver protective factor is, in our opinion, IL-6, due to its important antioxidant, antiapoptotic and proregenerative demonstrated actions. This protective effect of IL-6 is accompanied by antioxidant and antiprotease actions of ceruloplasmin, alpha1-antitrypsin and transferrin. We consider that an increased serum level of IL-6 accompanied by a decreased level of IL-1beta signify that antiapoptotic, antioxidant and proregenerative liver mechanisms prevail against proapoptotic and necrotic mechanisms. On the other hand, the ethanol-induced apoptosis of leukocytes (especially of the B cells) is very important, probably due to the absence of IL-6 protective action on these cells. The apoptosis of the circulating leukocytes is proved by their significant increase of the cytochrome c cytosolic level. The ethanol-induced liver immune response is predominantly cellular, as proved by the decreased ratio T helper (CD4+)/T cytotoxic (CD8+) in the peripheral blood. It is very important to observe that these significant immunologic changes appear before clinical or paraclinical signs of hepatic failure start. All these parameters were investigated in three groups of patients: chronic alcoholics, chronic alcoholics in the first 24 hours of the withdrawal and chronic alcoholics with acute alcohol intoxication, so the aggression types and the protective mechanisms were measured and differentiated in each "ethanolic status".