P. A. Berg

The presence of perinuclear antibodies against neutrophils (pANCA) has been detected recently in sera of patients with inflammatory bowel disease and primary sclerosing cholangitis. In order to evaluate their clinical significance, sera from 126 patients with inflammatory bowel disease (80 Crohn's disease and 46 ulcerative colitis and 22 patients with primary sclerosing cholangitis were examined for pANCA by indirect immunofluorescence on liver sections and cytocentrifuge slides of neutrophils and by immunoblot. Perinuclear antibodies against neutrophils were found in 83% of patients with ulcerative colitis in 88% of patients with primary sclerosing cholangitis and inflammatory bowel disease, in 40% of patients with primary sclerosing cholangitis but without inflammatory bowel disease, and in 25% of patients with Crohn's disease using the immunofluorescence test. Titres of pANCA ranged from 1:10 to 1:1000 in ulcerative colitis and primary sclerosing cholangitis (median 1:100), whereas in Crohn's disease only four patients had titres of more than 1:10. The occurrence of pANCA did not correlate with clinical activity of Crohn's disease and primary sclerosing cholangitis whereas in ulcerative colitis high titres of pANCA were found mainly in active disease. Using an immunoblot system with sonified neutrophils as antigen, 82% of sera from patients with primary sclerosing cholangitis reacted with up to five different determinants, whereas only 12% of sera from patients with Crohn's disease and 11% of sera with ulcerative colitis detected one of the determinants, suggesting different antigens involved in pANCA reaction.

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.

Using submitochondrial particles (SMP) from beef heart, pig kidney and rat liver in the ELISA, we detected partial organ specific anti-mitochondrial antibodies (AMA) against heart and kidney SMP in sera from patients with different forms of cardiomyopathies. Serum samples from 50 of 159 patients with congestive or hypertrophic cardiomyopathy (31%) and from two of 15 patients with acute myocarditis (13%) were AMA positive. These AMA could be clearly differentiated from other known AMA (anti-M1-M6) and were therefore named anti-M7. Thirteen of the 52 sera (25%) reacted only with heart SMP (type a) and 39 showed a cross-reaction with kidney, lung and pancreas mitochondria (type b). However, using liver SMP, no positive reaction was found. The anti-M7 type a and b activity was abolished completely by absorption with heart SMP. The anti-M7 antibodies were directed against an antigen which co-purified with the inner mitochondrial membrane and had a molecular weight of 67,000-72,000. They seem to be confined to some forms of cardiomyopathies and myocarditis of unknown aetiology and were not detected in sera from patients with other diseases.