Hepatic sinusoidal macrophages in alcoholic liver disease

Lysozyme is a bacteriocidal enzyme which is a major stable secretory product of mononuclear phagocytes, including hepatic sinusoidal macrophages (HSM), and serves as a good marker for these cells. Patients with alcoholic liver disease (ALD) have decreased HSM function which is reflected in reduced clearance of microorganisms and endotoxin derived from the gut. The HSM population in 54 liver biopsies from patients with ALD was studied using immunoperoxidase staining of lysozyme and was compared with 15 histologically normal controls. In both groups lysozyme positive HSM were more numerous in periportal than perivenous parenchyma. In each zone there were significantly fewer positive HSM in cases of ALD than in controls, in alcoholic hepatitis than in ALD without hepatitis, and in cirrhosis than in ALD without cirrhosis. These findings suggest a decreased population of functionally active HSM in ALD which correlates with severity of liver damage. This might be due to decreased lysozyme content of the entire HSM population or to the existence of two populations, one positive and one negative for lysozyme. The observed decrease in HSM function explains many of the phenomena observed in ALD.