Antibody activity against lipopolysaccharides, lipid A and proteins from Enterobacteriaceae in patients with chronic inflammatory liver diseases.

These studies are concerned with detection of circulating antibodies against various defined enterobacterial antigens in patients with chronic inflammatory liver diseases such as chronic hepatitis type B (n = 46), chronic active hepatitis (CAH) of autoimmune type (n = 10), alcoholic cirrhosis (n = 24) and primary biliary cirrhosis (PBC) (n = 24) as well as in healthy individuals (n = 39). Anti-LPS and anti-lipid A were determined by hemolytic and hemagglutination assay. Immunoblot technique was used to investigate the antibody activity against plasmid encoded proteins from Yersinia enterocolitica. Persistent titers of anti-LPS up to serum dilution 1:32.768 were found with hemolytic and hemagglutination assay in patients with alcoholic cirrhosis or PBC and in healthy control. In contrast nearly 50% of patients with chronic hepatitis B had no hemolytic antibodies against the two LPS E. coli serotypes at the time of liver biopsy. Anti-lipid A was detectable in 58% of patients with alcoholic cirrhosis but in low titers in less than 10% in the other groups (p less than 0.001). Alcoholic cirrhosis was also associated with a high frequency of IgG and IgA antibodies against plasmid encoded proteins from Yersinia enterocolitica. The data indicate that the O-polysaccharides as strong antigens are physiologically exposed to the immune system while lipid A and enterobacterial proteins are solely immunogenic under abnormal conditions.

Antimitochondrial antibodies in patients with chronic graft-versus-host disease.

Chronic graft-versus-host disease (cGVHD) and primary biliary cirrhosis (PBC) have many clinical and laboratory features in common. These include scleroderma or lupus erythematosus-like skin lesions, a Sjögren-like sicca syndrome, cholestatic liver disease and a variety of serological autoimmune phenomena. Furthermore, liver histology in both diseases is characterized by lymphocytic infiltration of the portal fields and destruction of small bile ducts. We investigated whether there were also parallels between both diseases in incidence and characteristics of antimitochondrial (AMA) and other autoantibodies. Sera from patients with cGVHD (n = 11, group 1) were examined by immunofluorescence (IFL) and immunoblot (IBL), and the results were compared with sera from patients without cGVHD (n = 21, group 2) and after autologous BMT (n = 16, group 3). In group 1 AMA was detected by IFL in one and by IBL in nine of 11 (81%) patients. Group 2 and 3 patients were AMA-negative by IFL and AMA positive by IBL in statistically lower incidence of 19% and 6% (p less than 0.001), respectively. cGVHD-associated AMA recognized a spectrum of mitochondrial proteins, the most frequent being molecules of 63/60 kD and 22 kD. Follow-up studies showed a temporal correlation between the emergence of AMA and the clinical occurrence of cGVHD. We conclude that patients with cGVHD have a high incidence of AMA similar to patients with PBC, but the reaction pattern of AMA differs between the diseases. The presence of AMA in cGVHD further emphasizes the concept that both diseases may have a related pathogenetic background.

Glycoproteins of rat liver plasma membranes: their hepatocellular, intestinal and renal expression in rat, rabbit and human.

Expression of six glycoproteins (Mr = 60,000 (gp 60), 80,000 (gp 80), 110,000 (gp 110), 120,000 (gp 120), 140,000 (gp 140), 160,000 (gp 160)) recently purified from rat liver plasma membranes (LPM) were compared in the liver, small intestine and kidney of the rat, rabbit and human. Immunoblotting studies with monospecific antisera showed that five of the six glycoproteins (gp 60, gp 80, gp 110, gp 120, and gp 140) were expressed not only in LPM of the rat but also in LPM from the rabbit and human with Mr corresponding to those of the glycoproteins isolated from the rat. In contrast, the glycoprotein gp 160 was only detected in rat liver. The same pattern of expression was found by immunofluorescence on isolated hepatocytes from the three species. In rat liver, the glycoproteins were localized primarily either in the bile canalicular domain (gp 80, gp 110, gp 120), or in the sinusoidal domain (gp 60, gp 140), or they were distributed over the whole hepatocellular surface (gp 160). In rat, but not in rabbit or human, the glycoproteins gp 110, gp 120 and gp 140 were also found in the small intestine localized either in the brush border membrane (gp 110, gp 120) or over the whole surface membrane of enterocytes (gp 140). Gp 120 was also detected in the luminal pole of tubular epithelial cells of rats kidney. The data show that LPM of different mammalian species share several common glycoprotein antigens. These glycoproteins, that are also partly expressed in extrahepatic tissues, may represent plasma membrane structures conserved among mammalian species.

Immunoisolation of hybrid liver support systems by semipermeable membranes.

Immunoisolation of hybrid liver support systems (LSS) utilizing suitable semipermeable membranes as an immune barrier enables neither immunocompetent cytotoxic factors to cause damage to the hepatocytes in the bioreactor nor xenogenic hepatocyte products to cause immunological side effects in patients. To determine the capability of membranes as an immune barrier, 6 flat membranes were investigated: Cuprophan (C-100), cut-off MW 1000, Cuprophan (C-240), cut-off MW 10,000, Polypropylen hydrophilic and hydrophobic (PPhi, PPho), cut-off MW 500,000-1,000,000, Polysulfon (PS), cut-off MW 1,000,000, Polyamid (PA), cut-off beyond MW 1,000,000. The permeability of the membranes to plasma factors and liver protein fractions (LP) was studied by routine biochemical methods and gel electrophoresis. In a second study, pigs (n=7) were immunised by LP after membrane passage. The results showed PA, PS, and PPhi to be completely permeable for plasma factors and LP C-100 and C-240 for urophanic substances, and C-240 again for LP under MW 14.000. All 7 pig sera studied by Western blot discovered pre-formed xenoreactive natural IgG-antibodies (NAB) against human liver antigen (AG) with MW 26.000. AB de-novo-synthesis was demonstrated for AG with MW 45.000. No AB-synthesis was induced for epitopes under MW 26,000. These results suggest that limiting the cut-off of bioreactor outflow membranes to MW < 26,000 could avoid immunological side effects to patients.

Experimental liver membrane antibodies (LMA) and antibodies against "liver specific protein (LSP)"--a comparative in vitro study.

Experimental antisera against the 26 kD rat liver protein--recently defined as a target antigen of LMA--and against "LSP" were tested on tissue sections and isolated hepatocytes from rat as well as with a variety of subcellular fractions as antigens. Anti-26 kD protein resulted in sharp immunofluorescence staining of hepatocellular plasma membranes in liver sections and on isolated hepatocytes, while the antiserum did not react with intracellular structures and was also negative with tissue sections from kidney and heart. Anti-"LSP" stained the plasma membranes of isolated hepatocytes, the cytoplasma of liver and kidney sections as well as the connective tissue of heart sections. In Western blot studies anti-26 kD protein showed a single band at 26 kD when liver plasma membranes and soluble liver protein fractions were used as antigens; a weak reaction was observed with microsomes and soluble kidney protein fractions, but there was no reaction with mitochondria or soluble heart proteins. Anti-"LSP" reacted with various proteins of the subcellular fractions between 16 and 116 kD. The 26 kD protein was found in peak II of Sepharose 6B chromatography of soluble liver protein fractions but was absent in the "LSP" fraction (peak I). We conclude that experimental LMA and anti-"LSP" recognize different epitopes of the hepatocellular plasma membrane.

[Schoenlein-Henoch purpura in chronic HBsAG-positive hepatitis]. / Schoenlein-Henoch-Purpura bei HBsAg-positiver chronischer Hepatitis.

We report about a 40-year-old male patient suffering from a recurrent vasculitis with purpura since the age of 18. In 1983, a HBsAg-positive chronic active hepatitis with circulating immune complexes which contained HBsAg, immunoglobulin M and G as well as complement (C) was diagnosed. Serum and liver tissue were negative for HBcAg, HBeAg and hepatitis B virus (HBV) DNA; there was no evidence for HBV replication. HBsAg, IgM and C3 were demonstrable in the arteriolar walls of the skin. The results support the concept that complement activating immune complexes containing HBsAg and IgM anti HBs play a role in the pathogenesis of vasculitis as described here.

HBcAg expressed on the surface of circulating Dane particles in patients with hepatitis B virus infection without evidence of anti-HBc formation.

Circulating immune complexes composed of HBcAg and anti-HBc have been demonstrated recently in patients with hepatitis B virus replication. After dissociation of immune complexes by chaotropic ions, HBcAg was quantified radioimmunologically. In the present study, we describe 10 patients with hepatitis B virus replication, absent or delayed anti-HBc formation and exposed HBcAg in serum. Four of the 10 patients had acute hepatitis, and six patients had chronic persistent hepatitis. In seven of 10 patients, a secondary immune defect was apparent due to acquired immunodeficiency syndrome, leukemia, histiocytosis X, sarcoidosis or end-stage renal disease. Electron microscopy demonstrated that Dane particles from anti-HBc-negative patients were agglutinated after addition of monoclonal anti-HBc antibodies, whereas Dane particles from anti-HBc-positive sera did not show agglutination. Monoclonal HBsAg-specific antibodies aggregated Dane particles independent of the presence of anti-HBc. Circulating HBcAg was always associated with the Dane particle fraction after density gradient separation. Hepatitis B virus core proteins from patients with and without anti-HBc studied by immunoblotting after sodium dodecyl sulfate-gel electrophoresis showed identical patterns. Hepatocytes from anti-HBc-negative patients were positive for HBcAg but negative for immunoglobulin G by immunofluorescence technique. The data indicate that HBcAg may also be expressed on the surface of Dane particles, where it is commonly masked by anti-HBc.

[Primary sclerosing cholangitis (PSC)--humoral immune phenomena, pathogenetic aspects and therapeutic possibilities]. / Primär sklerosierende Cholangitis (PSC)--Humorale Immunphänomene, pathogenetische Aspekte und therapeutische Möglicheiten.

There are about 80% antibodies in PSC against cytoplasmatic antigens of neutrophilic granulocytes of the perinuclear type (pANCA), inconstantly there are antinuclear antibodies (ANA) too, but no antimitochondrial antibodies. The frequent association of PSC with colitis ulcerosa suggests an enterobacterial aetiopathogenesis. PSC sera show clear bands at 60-90 kD and at about 10 kD in the immunoblot with enterobacterial proteins as antigens. Antibodies against enterobacterial lipopolysaccharides and lipid A are to be found in patients with PSC corresponding to the normal collective. After long-term immunization with enterobacterial antigens PSC-like changes with circulating ANA can be induced in mice and rabbits. PSC, comparable to primary biliary cirrhosis, also reacts to treatment with ursodesoxycholic acid but it scarcely reacts to immunosuppressive therapy. At the final stage of the disease liver transplantation is indicated. In our clinic up to now 16 patients with PSC have undergone a transplantation with a one-year-survival rate of 88%. Confirmed re-manifestations of PSC in the transplant have not been diagnosed up to now.

Are antimitochondrial antibodies in primary biliary cirrhosis induced by R(rough)-mutants of enterobacteriaceae?

Antimitochondrial antibody (AMA)-positive serum samples from 45 patients with primary biliary cirrhosis (PBC) and AMA-negative serum samples from patients with chronic liver diseases, systemic lupus erythematosus, or rheumatoid arthritis were studied by an immunoblot technique with mitochondria from bovine heart and pig kidney and with several strains of gram-negative bacteria as antigens after separation by sodiumdodecylsulphate polyacrylamide gel electrophoresis. Serum from patients with PBC recognised up to three mitochondrial antigens with molecular weights of 70 kD, 50 kD, and 42 kD. Equivalent patterns were found with bands at 70-80 kD and 50-52 kD with Enterobacteriaceae as antigens. AMA-reactive polypeptides were localised in the ribosomal and membrane fractions from Enterobacteriaceae but differed from known outer membrane proteins. Conversely, PBC-specific mitochondrial antigens at 70 kD and 50 kD were recognised by rabbit antisera against Salmonella minnesota Rb and Rc mutants but not by antisera against wild-type Enterobacteriaceae. Absorption experiments and two-dimensional immunoblotting studies confirmed that mitochondria and gram-negative bacteria share identical PBC-specific determinants. It seems that PBC-specific antigens are expressed in gram-negative bacteria and that these antigens may be immunogenic in mutants with defective polysaccharide synthesis. The data support the hypothesis of a bacterial aetiology for PBC.

Relation between Escherichia coli R(rough)-forms in gut, lipid A in liver, and primary biliary cirrhosis.

Since antimitochondrial antibodies (AMA) specific to primary biliary cirrhosis (PBC) recognise enterobacterial proteins and can be induced by R(rough)-mutants of enterobacteriaceae a study was done to find out the prevalence of enterobacterial R-forms in stool samples of patients with chronic inflammatory liver diseases. Liver biopsy specimens were also examined for lipid A, a common antigenic component of the cell wall in gram-negative bacteria. In all stool samples from the 21 patients with PBC Escherichia coli R-forms constituted up to half of the total amount of E coli. In contrast E coli R-forms were detectable in the stools of only 1 healthy control (n = 20), and in 25% of patients with other cholestatic diseases (n = 10), chronic hepatitis type B (n = 15), type non-A, non-B hepatitis (n = 15), or chronic pancreatitis and fat malabsorption (n = 8). An immunoblot technique showed that E coli R-forms isolated from patients' stools contained PBC-specific AMA-reactive proteins with molecular weights of 70-80 kD and 50 kD. Deposits of lipid A, located primarily in the cytoplasm of hepatocytes, were found in 11 patients with PBC but not in the liver of patients with chronic viral hepatitis. Circulating antibodies against lipid A were found rarely and in low titres. The data support the hypothesis that intestinal enterobacterial R-forms are aetiologically important in PBC and that antigens released from the bacterial cell wall contribute to the pathogenesis of the disease.

Liver membrane antibodies (LMA) recognize a 26-kD protein on the hepatocellular surface.

Sera from 82 patients with chronic inflammatory liver diseases and from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and Hashimoto's thyroiditis were studied by immunoblotting against purified liver plasma membranes (LPM) and soluble liver protein (SLP) fractions from different species after previous separation by SDS-PAGE. Eighteen of 19 sera with LMA of IgG type in immunofluorescence assay and six LMA-negative sera (three sera from patients with RA) showed antibodies of the IgG or IgM classes against a protein with a molecular weight of 26 kD which was present in LPM and SLP fractions from rats, rabbits, pigs and humans. The reaction with 26-kD liver protein did not correlate with other known autoantibody-antigen systems. All sera were negative in the 26-kD region with liver mitochondria, liver microsomes and soluble proteins of kidney (with one exception), heart and gut from the rat. The 26-kD protein was purified by affinity chromatography on immobilized anti-26-kD protein antibodies from patients, eluted from the 26-kD band of immunoblots. Studies with purified 26-kD liver protein and with SLP as antigens after separation in two-dimensional electrophoresis confirmed that patient serum and experimental rabbit antiserum react with the same protein. Eluted patient antibodies and rabbit antisera showed a linear fluorescence pattern on isolated hepatocytes from rat and rabbit. The data indicate that one of the target antigens of LMA is a species-nonspecific 26-kD protein located on the hepatocellular surface.

Long-term follow-up of posttransfusion and sporadic chronic hepatitis non-A, non-B and frequency of circulating antibodies to hepatitis C virus (HCV).

The natural course of chronic hepatitis non-A, non-B (HNANB) was documented for 3-20 yr (mean 8 yr) in 86 patients, who attended our special ambulance between 1981 and 1988. Sixty five of the 86 patients (75%) were positive for circulating antibodies against hepatitis C virus (HCV) (anti-HCV). Twenty four patients had chronic posttransfusion (PT)-HNANB (18 anti-HCV-positive; 75%), and 62 patients had sporadic (S)-HNANB (47 anti-HCV-positive; 75%). Twenty nine per cent of patients with chronic PT-HNANB had sustained normalization of aminotransferases after a period up to 5 yr, 55% demonstrated chronic persistent hepatitis (CPH) and 16% progressed to chronic active hepatitis (CAH) with transition to cirrhosis. In the group with chronic S-HNANB, 2% of patients showed remission, 43% had stable CPH and 55% progressed to CAH or cirrhosis. However, development of cirrhotic complications required many years. Transition from CAH to CPH or remission was not observed. The results indicate that 75% of both patients groups with chronic PT- and S-HNANB are infected with the same agent, of which antibodies are detected by the new anti-HCV assay. There was no statistical association between the severity of the disease and the presence of anti-HCV. The different proportions of progressive courses in chronic PT- and S-HNANB might be explained by the patient recruitment.