Characterization and clinical relevance of liver-pancreas antibodies in autoimmune hepatitis.

The isolation of a marker antigen from rat liver and pancreas tissue, which reacts with antibodies in a subtype of autoimmune hepatitis by complement fixation test, enzyme-linked immunosorbent assay and Western blot, is described. The liver-pancreas antigen could be detected in tissue from different human or animal organs, but liver and pancreas yielded the highest activity. A highly specific antigen fraction was obtained by gel filtration and ion exchange chromatography with a 100,000 g supernatant from rat liver tissue, and this preparation was shown to be devoid of nuclear, mitochondrial and microsomal antigens and cytokeratin 8 and 18, as demonstrated by appropriate marker antibodies. These data and absorption studies with cell organelles indicate that liver-pancreas antigen is a cytosolic protein. By Western blotting, two major epitopes at molecular weights 52 kD and 48 kD could be visualized. Sera from 175 patients previously shown to have high complement-fixing activity to a nonpurified liver-pancreas antigen fraction were further analyzed. All were positive by enzyme-linked immunosorbent assay with the purified liver-pancreas antigen fractions, and 111 were also positive by Western blot. Eighty-six sera reacted with the 52-kD determinant, 33 with the 48-kD determinant and 2 with both determinants. In 117 of the 175 patients, antibody to liver-pancreas antigen was associated with other autoantibodies known to characterize subgroups of autoimmune hepatitis. Thus 19 patients had antibodies to nuclei and 96 to actin but none to liver-kidney microsomes, hereby suggesting that antibody to liver-pancreas antigen may define another subgroup of autoimmune hepatitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-mistletoe lectin antibodies are produced in patients during therapy with an aqueous mistletoe extract derived from Viscum album L. and neutralize lectin-induced cytotoxicity in vitro.

The humoral response components of an aqueous mistletoe extract (HM) was evaluated in 23 tumor patients who had been treated from 2 months up to 6 years with increasing dosages of HM. IgG antibodies against mistletoe lectin and other components of this extract were detected by ELISA, immunodiffusion, and blotting technique, using either the aqueous extract (HM) or a purified lectin preparation (ML). Their activity depended upon dosage of HM and length of therapy. No anti-HM/ML antibodies of the IgM type could be detected. Immunoblotting revealed lectin-specific antigens at 62 kD, 33k D, and 29 kD. In the presence of ML or HM, PHA-induced proliferation of normal lymphocytes was decreased in a dose-dependent manner; this effect was neutralized by adding the IgG fraction from pooled anti-HM-antibody-positive sera, indicating that the cytotoxic effect of lectins was eliminated by these specific antibodies. In view of these findings, it is questionable whether exposing tumor cells to mistletoe extracts in vivo exerts the same direct effect on tumor cells that is observed in vitro.

[Autoantibody profile in collagen diseases. A clinical-serological study of 250 patients from Tuebingen clinics]. / Autoantikörper-Profile bei Kollagenerkrankungen. Eine klinisch-serologische Studie an 250 Patienten aus Tübinger Kliniken.

Sera from 250 patients with connective tissue diseases were tested for antinuclear antibodies by immunofluorescence (IFL) and immunodiffusion. In patients with systemic lupus erythematosus (SLE, n = 49), progressive systemic sclerosis (PSS, n = 30) and Sjögren's syndrome (n = 20), IFL showed antinuclear antibodies with a frequency of 70 to 100%. Patients with localized scleroderma (n = 16) and discoid LE (n = 38) had antinuclear antibodies in 31 and 21% of cases, respectively. In patients with vasculitis (n = 32), fluorescent antinuclear antibodies were only rarely detected (0-6%). In the immunodiffusion LE-specific anti-Sm antibodies were demonstrated in 10%, anti-nRNP nRNP antibodies in 20%, and anti-Ro antibodies in 37% of patients with SLE. In Sjögren's syndrome, anti-Ro antibodies were found in 45% and anti-La antibodies in 35% of patients. 57% of patients with PSS had the disease-specific anti-Scl-70 antibody, while only 19% had antinucleolar antibodies as detected by IFL. In patients with localized scleroderma, dermatomyositis (n = 6) or vasculitis, no precipitating antibodies were detectable. The demonstration by immunodiffusion of nuclear antibodies in patients with discoid LE could be connected with a transition to a systemic course of the disease.

Characterization and clinical relevance of a new complement-fixing antibody--anti-M8--in patients with primary biliary cirrhosis.

A new complement-fixing antimitochondrial antibody--anti-M8--was detected in patients with primary biliary cirrhosis. Anti-M8 was only found in association with anti-M2, however, not all anti-M2 positive patients had anti-M8. Thus, among 66 anti-M2 positive patients, 29 were also positive for anti-M8, whereas sera from patients who had the complement-fixing anti-M2 and anti-M4 antibodies in parallel always strongly reacted with the M8 antigen. This group was previously described as mixed form. The M8 antigen was isolated either from human liver mitochondria or pig kidney microsomes and could be clearly distinguished from the M4 antigen. In contrast to M4, M8 was trypsin sensitive and banded at sucrose densities from 1.16 to 1.24, while M4 was found at densities from 1.08 to 1.14. Like M4, the M8 antigen also co-purified with outer mitochondrial membranes. Fifty-three patients with primary biliary cirrhosis have been followed over a period of up to 16 years and were classified according to their complement-fixing antimitochondrial antibody profile. At the time of the first diagnosis, 95% of 31 patients being anti-M2 positive, but anti-M8 negative (antimitochondrial antibody Profile I) were in Stage I or II. In contrast, only 61% of 13 patients being anti-M2 and anti-M8 positive (antimitochondrial antibody Profile II) and 44% of 9 patients with anti-M2, anti-M8 and anti-M4 in parallel (antimitochondrial antibody Profile III) belonged to Stage I or II.(ABSTRACT TRUNCATED AT 250 WORDS)

An ELISA method for the detection of autoantibodies to adrenal cortex.

An enzyme-linked immunosorbent assay (ELISA) is described for autoantibodies to adrenal cortex. Microsomes were prepared from fresh human adrenal glands, and microtitre ELISA plates were incubated at 4 degrees C overnight with 25 micrograms antigen/ml, the optimal concentration for the system. Optimal dilution of patient's serum was 1/500. Peroxidase-labelled anti-human IgG and IgM sera were used in separate tests and o-phenylenediamine and H2O2 served as substrate. Intra-assay variance of optical density units was 4.5%, and inter-assay variance was negligible when antigen preparations from 2 different adrenal glands were compared. All sera positive or negative at first test gave the same qualitative result in a second. Non-organ-specific binding of sera containing mitochondrial or ribosomal antibodies was eliminated by a blocking ELISA system where the antigen-coated plates were incubated with test sera, and in a second step, peroxidase-labelled IgG from an adrenal antibody-positive control serum was added. In this test, optimal antigen concentration for coating of plates was 6.25 micrograms/ml and optimal serum dilution 1/50. The ELISA proved more sensitive and reproducible than indirect immunofluorescence. Adrenal antibodies detected by ELISA were usually of IgG class alone and only 1 of the 30 positives also contained IgM specificity. 30 out of 38 sera (79%) from patients with 'idiopathic' Addison's disease were positive whereas immunofluorescence revealed only 23 (61%) at first testing and another 4 positives when sera were tested on different adrenal glands. The ELISA described is useful for both scientific work and clinical diagnosis of autoimmune adrenalitis.

Diagnostic relevance of humoral and cell-mediated immune reactions in patients with acute viral myocarditis.

Sera of 177 patients with acute myocarditis (10 coxsackie B 3/4, four influenza, four mumps, 15 cytomegalovirus, 144 undefined) were tested by indirect immunofluorescence for autoantibodies against heart and skeletal muscle and vital or air-dried adult cardiocytes. Antibody-dependent cytolysis, lymphocytotoxicity and antibody-dependent cellular lymphocytotoxicity were assessed using viral adult rat cardiocytes as target cells. Muscle-specific anti-sarcolemmal antibodies of the anti-myolemmal type--often associated with non-organ-specific anti-endothelial antibodies--were demonstrated in nine out of 10 patients with coxsackie B, in all patients with influenza and mumps and in 65 out of 144 patients with undefined myocarditis. In contrast, 13 out of 15 patients with cytomegalovirus myocarditis lacked anti-sarcolemmal antibodies but had low titre anti-inter fibrillary antibodies instead. In the presence of complement, anti-myolemmal antibodies induced cytolysis of vital cardiocytes, whereas hepatocytes remained unaffected. Titres of anti-myolemmal antibodies correlated with the degree of cardiocytolysis. The anti-myolemmal immunofluorescent pattern and the cytolytic serum activity could be absorbed with the respective viral antigens suggesting that these antibodies cross-react with moieties of the virus itself and may be both diagnostic and aetiological markers in acute viral myocarditis. Lymphocyte-mediated cytotoxicity against heterologous cardiac target cells could not be observed in our patients with myocarditis of proven viral aetiology. However, lymphocyte-mediated cytotoxicity was demonstrated in 10 ASA-positive and one ASA-negative patient with myocarditis of unknown origin. ASA-positive sera blocked lymphocytotoxicity in three of these patients.