muramidase and Liver-Diseases--Alcoholic

The study was designed to evaluate (a) the role of reduced renal phosphate reabsorptive capacity assessed as the ratio of maximum capacity for renal phosphate reabsorption (TmPO4) to glomerular filtration rate (GFR) in the pathogenesis of hypophosphatemia in alcoholics, (b) possible mechanisms leading to reduced TmPO4/GFR, and (c) the effect of liver function impairment on TmPO4/GFR. The TmPO4/GFR, its major extrarenal determinants, ratios of urinary excretion gamma-glutamyl transpeptidase and of alpha-glucosidase to GFR (uGGT/GFR and uAGL/GFR), indices of structural damage of renal tubular cells, and fractional clearance of lysozyme, an index of proximal renal function, were evaluated in 31 alcoholics with alcohol-related liver disease, 24 alcoholics without alcohol-related liver disease, 14 patients with non-alcohol-related liver disease, and 25 control subjects. Hypophosphatemia was found in 35% of alcoholics with alcohol-related liver disease, 29% of alcoholics without alcohol-related liver disease, and no patients with non-alcohol-related liver disease. A reduced TmPO4/GFR was the major determinant of hypophosphatemia in both groups of alcoholics. No difference in extrarenal determinants of TmPO4/GFR was found between alcoholics with and without hypophosphatemia. Alcoholics with and without alcohol-related liver disease had increased uGGT/GFR and normal uAGL/GFR regardless of serum phosphate level. Fractional clearance of lysozyme, instead, was increased only in hypophosphatemic alcoholics with and without alcohol-related liver disease. The TmPO4/GFR correlated inversely with the fractional clearance of lysozyme in both groups of alcoholics (P less than 0.01). The TmPO4/GFR and urinary enzymes were normal in patients with non-alcohol-related liver disease. It was concluded that a reduced TmPO4/GFR is involved in the pathogenesis of hypophosphatemia in alcoholics. A proximal tubular dysfunction seems to be responsible for the reduced TmPO4/GFR. Liver function impairment is not required for the expression of this tubular dysfunction.

Topics: Adult; Aged; Alcoholism; alpha-Glucosidases; Female; gamma-Glutamyltransferase; Glomerular Filtration Rate; Humans; Kidney Tubules; Liver Diseases; Liver Diseases, Alcoholic; Male; Middle Aged; Muramidase; Parathyroid Hormone; Phosphates; Transaminases

The effect of ethanol on the release and/or intracellular accumulation of lysozyme (LZM) by human monocytes and monocyte-derived macrophages (mø) was investigated in vitro. A reverse haemolytic plaque assay, to detect and quantify LZM release by individual cells was combined with quantitative immunocytochemistry using LZM and the pan-macrophage monoclonal EBM/11 as markers. Ethanol had no effect on monocytes; however it reduced secretion of LZM by a mø subpopulation. Ethanol also reduced both the total number of mø immunoreactive for LZM, (but not EBM/11), and the proportion of LZM-secreting mø containing detectable LZM. The latter was correlated with an increase in the proportion of LZM-secreting mø that were not immunoreactive for this enzyme. These data suggest functional heterogeneity amongst human macrophages with a mø subpopulation which responds to ethanol exposure with a drop in both content and release of LZM. This might have implications for macrophage function in alcoholic liver disease.

Topics: Cell Separation; Cells, Cultured; Ethanol; Hemolytic Plaque Technique; Humans; Liver Diseases, Alcoholic; Macrophages; Monocytes; Muramidase

A quantitative immunohistochemical study of Kupffer cells in liver biopsies from alcoholics was carried out. Two markers were compared, lysozyme and an antimacrophage monoclonal antibody EMB/11. The results showed that there is no significant reduction in Kupffer cell numbers in acute and chronic alcoholic liver disease but that there is a reduction in the number of Kupffer cells staining positively for lysozyme. Thus, those clinical phenomena such as endotoxaemia in alcoholic liver disease are not due to reduction in Kupffer cell number but perhaps to a functional deficit in these cells.

Topics: Antibodies, Monoclonal; Biomarkers; Biopsy, Needle; Cell Count; Humans; Immunohistochemistry; Kupffer Cells; Liver Diseases, Alcoholic; Muramidase

Previous studies indicated decreased numbers and depressed clearance function of hepatic macrophages in alcoholic liver disease (ALD). We examined hepatic macrophages by immunohistochemical techniques in 45 liver biopsies from patients with a spectrum of ALD and compared them with 20 histologically normal biopsies from non-alcoholic patients. Antisera against lysozyme, alpha 1-antitrypsin (alpha 1AT) and a cytoplasmic molecule on macrophages (MAC-387) were used and the number of positively staining hepatic sinusoidal macrophages and portal tract macrophages assessed separately. Portal tract macrophage numbers were increased with all three markers in biopsies exhibiting only fatty change (P less than 0.05) and with MAC-387 in all ALD groups. In agreement with previous studies, lysozyme positive hepatic sinusoidal macrophages were decreased in all ALD groups. However, the other markers did not show any significant decrease and MAC-387 positive macrophages were increased in livers with cirrhosis plus hepatitis (P less than 0.01). The use of three markers revealed phenotypic heterogeneity of hepatic macrophages with antibodies to lysozyme and alpha 1 AT staining more hepatic sinusoidal macrophages than MAC-387, but MAC-387 and anti-lysozyme staining more portal tract macrophages than anti-alpha 1AT. Since hepatic macrophages appear to be heterogeneous and capable of diverse functions including the release of cytotoxic mediators, the finding of increased numbers, even in early ALD, suggests they may contribute to the increased numbers, even in early ALD, suggests they may contribute to the tissue damage.

Topics: Adult; Aged; Aged, 80 and over; alpha 1-Antitrypsin; Antibodies, Monoclonal; Female; Humans; Immunohistochemistry; Liver Diseases, Alcoholic; Macrophages; Male; Middle Aged; Muramidase

Immunologic parameters were evaluated in 22 patients with alcoholic liver disease (ALD). Patients with ALD had increased levels of circulating immune complexes (CIC) and serum immunoglobulins, particularly IgA. The classical complement pathway was preferentially activated in CIC-positive patients. There was no increase in total lymphocyte or total T lymphocyte counts, but a significant rise in both the helper/inducer population (OKT4) and helper/suppressor cell ratio (T4/T8) was noted. The presence of interleukin-2 receptors and HLA-DC/DS and HLA-DR antigens suggested in vivo activation of ALD patients' T cells. The rate of differentiation of B cells to plasma cells was high in both pokeweed mitogen-stimulated and unstimulated cultures of ALD patients' B cells, whereas plasma cell generation doubled when patient T lymphocytes were added to enriched normal B cells. The above data support a role for activated helper (T4+) T cells in the immune response initiated by alcoholic hepatitis. Serum angiotensin-converting enzyme levels and lysozyme levels were increased in ALD patients, and cultured adherent mononuclear cells from ALD patients secreted more lysozyme in vitro than normal cells, suggesting the presence of an activated monocyte-macrophage system in ALD.

Topics: Adult; Aged; Antigens, Surface; Female; Humans; Immunity, Cellular; Liver Diseases, Alcoholic; Lymphocyte Activation; Lymphocytes; Macrophage Activation; Male; Middle Aged; Mitogens; Monocytes; Muramidase; T-Lymphocytes

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.

Topics: Hepatitis, Alcoholic; Humans; Immunoenzyme Techniques; Liver; Liver Cirrhosis; Liver Diseases, Alcoholic; Macrophages; Muramidase