Search

Fibroblasts growing on glass have microfilaments arranged in bundles. These can be demonstrated by indirect immunofluorescent technique using human antiactin serum or experimentally produced rabbit anti-actin serum. When monolayer cultures of epithelial cells and fibroblasts are infected with paramyxovirus, such as measles, mumps, Sendai and NDV, there is a striking decrease of the bundles. Rabies and adenoviruses do not seem to influence the staining of microfilaments. The microfilament decreasing effect in the cells correlates to the finding by SDS-polyacrylamide-gel-electrophoresis of actin within virions of the paramyxoviruses.

The effects of 10 days of total energy deprivation on serum levels of immunoglobulins, antibodies acute phase reactants and on interferon production were evaluated in fourteen healthy, normal-weight males. A significant depression was noted of the serum levels of complement factor 3, haptoglobin and orosomucoid. The titres of mercaptoethanol-sensitive specific antibodies to flagellin were higher in the subjects inoculated at the end of the starvation period than in controls and those inoculated at the start of the period. The serum levels of IgG, IgM, IgA, IgE, alpha-1-antitrypsin and complement factor 4, and the interferon-producing capacity of blood lymphocytes, were not changed. Thus, 10 days of total energy deprivation depresses the serum levels of several acute phase reactants and re-feeding may enhance antibody production.

The reaction of spontaneously occurring human anti-human antibodies and experimentally produced rabbit anti-actin antibodies was investigated in a solid-phase radioimmunoassay (RIA). Three structurally different in vitro forms of actin monomeric G-actin filamentous F-actin and aggregated denatured actin were used as antigens. Human anti-actin antibodies reacted with F- and G-actin but not with aggregated actin, while rabbit anti-actin antibodies gave a strong reaction with all 3 forms of actin indicating differences in antibody specificities. The results of the anti-actin RIA were compared with those obtained by indirect immunofluorescence (IFL) on cryostat sections of rat stomach. The anti-actin RIA discriminated between patients' sera and control sera in most cases, although the indirect IFL test gave more conclusive results. The seemingly low sensitivity of the anti-actin RIA compared with that of indirect IFL test for detection of human anti-actin antibodies is probably due to favourable antigen distribution in tissue, not available in the solid phase. The anti-actin RIA was able to detect anti-actin antibodies in 8 out of 8 immunized rabbits although only two produced antibodies detectable by indirect IFL. The differences in reactivity between the two methods may depend on the presence of aggregated denatured actin in the antigen preparation used for immunization and exposure of the corresponding antigenic determinants of actin on the solid phase.

Antibodies to soluble ribonucleoprotein (sRNP) are by definition a prerequisite for the diagnosis mixed connective tissue disease (MCTD). They are also found in 30--40% of other rheumatic conditions with a high titred speckled IFL reaction. The same is true for the most characteristic clinical features of MCTD, viz. Raynaud's syndrome and polymyositis--polymyalgia. The serological and clinical symptoms mentioned are closely associated. An association between anti-Sm and the SLE symptoms butterfly erythema, nephropathia, other visceropathias and cerebrovascular disease is confirmed by the present study. Although anti-Sm has less diagnostic specificity for SLE than has anti-ds-DNA, it is useful as a diagnostic aid in SLE cases lacking the latter antibody. The results of the present study tend to support the hypothesis that anti-sRNP may be associated with a prophylactive effect against serious vasculitis and nephropathia. When anti-sRNP and anti-Sm occur together they seem to act competitively so that the symptom associated with the antibody having the highest titre tends to dominate the clinical picture. Both anti-sRNP and anti-Sm produce speckled nuclear patterns in the indirect immunofluorescence test. Sera with immunofluorescence titres below 1/25 were not found to react against either sRNP or Sm. On the other hand all sera tested that had a speckled IFL reaction greater than or equal to 1/800 also had anti-sRNP.

F-actin depolymerizing factor (ADF) of human serum was purified 250-400-fold to more than 98% purity with high reproducibility. The purification included (1) 30-50% (NH4)2SO4 precipitation, (2) ion-exchange chromatography on DEAE-Sepharose, (3) chromatofocusing on Polybuffer exchanger 94 and (4) affinity chromatography on ConA-Sepharose. The recovery of ADF was estimated to be 20-30% whereas the ADF activity yield was 5-17%. The lower activity yield was thought to be due-partly to proteolysis and partly to destabilization of highly purified ADF.

Immunologic investigations were performed on sera from 99 women with habitual abortion (three or more consecutive miscarriages). All were considered healthy and clinical investigations had not revealed any cause for the miscarriages. Sixty-eight were considered to have primary habitual abortion whereas 31 had secondary habitual abortion. Increased anticardiolipin antibody levels were found in 42 patients. None had a primary diagnosis of systemic lupus erythematosus, but at follow-up studies one of them fulfilled the diagnostic criteria of systemic lupus erythematosus. Ten sera, all from patients with primary habitual abortion, showed high anticardiolipin antibody values (greater than or equal to 10 units) concomitant with significantly lower levels of complement factor C4 than those found in sera with moderate or normal anticardiolipin antibody levels. There was no indication of genetic defects explaining the low C4 values, which could be explained at least in part by an activation of complement by the classical pathway.

The nucleoplasmic autoantigens RNP and Sm are of particular interest because of their associations with certain symptoms of mixed connective tissue disease and systemic lupus erythematosus. The RNP is generally thought to be a ribonucleoprotein and there is evidence that its RNA may be single-stranded. Experiments presented in this report are in support of the concept that the Sm-antigen may also be an RNA protein. Purified Sm-anti-Sm precipitates were shown to have high RNA contents and treatment of Sm-antigen with RNAase in a hypotonic medium strongly reduced in antigenicity. The latter effect indicates that the Sm-antigen may in contrast to the RNP contain double-stranded RNA, a possibility also suggested by the finding that the Sm-antigen was soluble in 2 M LiCl. The Sm-antigen was found further to differ from RNP in being selectively absorbed in BD-Sephadex, while RNP remained active in the supernatant. Cytochemical studies involving stimulation and inhibition experiments with lectins and RNA polymerase inhibitors showed that the Sm-antigen was, in distinction to RNP, sensitive to rifampicin but not to alpha-amanitine. This suggests that the RNAs of the nucleoplasmic antigens may be synthesized by different RNA polymerases.

Eighteen of 24 patients with rheumatoid arthritis showed intermediate IgG-containing complexes on preparative ultracentrifugation before treatment with D-penicillamine. Serial analyses of these showed strikingly close correlation in reduction of IgG as well as alpha 1-antitrypsin-IgA complexes. Three patients did not respond to treatment clinically, and retained both types of complexes. Complexes virtually disappeared in all responders. Only small changes were found in total IgG or IgM levels and the reduction of IgA levels was moderate, except for one case who developed IgA deficiency. The importance of further analysis of non-responders is stressed.

The prevalence of symptomatic secondary Sjögren's syndrome in 66 patients with SLE recruited from a defined population in southern Sweden was 59%. In 26 patients (39%) the symptoms were mild and variable, related to disease activity, while in a smaller group (20%) the symptoms appeared to be constant. The latter patients had an increased frequency of thyroid disease and autoantibodies to SS-A. The patients in this group were older, but did not seem to differ in regard to other disease manifestations.

The reactions of sera from patients with connective tissue disease with Chrithidia lucillae kinetoplasts were examined with the indirect immunofluorescence technique on untreated smears and smears pretreated with DNAse, RNAse or trypsin. Of 28 completely examined reacting sera, 20 had their reactions inactivated by DNAse alone, two by DNAse and trypsin, and 6 by DNAse and RNAse. This suggests that although the Chrithidia test is probably at present the method of choice for the diagnostic demonstration of DNA antibodies, its results are not completely unambigous. The kinetoplast DNA is probably conjugated to a non-histone protein and antibodies to the conjugate may occur in some instances. In other instances, antibodies may be directed against DNA-RNA complexes. If the Chrithidia kinetoplasts contain a protein moiety, the latter is apparently not identical with the protein contained in the Chrithidian cell nuclei.

It was attempted to evaluate passive haemagglutination of antigen coated, tanned erythrocytes as a test by which to demonstrate anti-DNA in systemic lupus erythematosus. The antigens was prepared using a minimum of procedures in order to produce a native preparation. The resulting material had most of the criteria applying to native DNA, but the protein content was about 9%. It contained a thymocyte specific component, but no demonstrable trace of bovine species antigen. The reactions between the antigen and an anti-DNA serum from a patient with suspected SLE were inhibited by DNA and DNA-histone, but not appreciably by ENA, RNA or desoxyribonucleosides. Passive haemagglutination reactions against the antigen were positively correlated to a homogeneous immunofluorescence nuclear pattern and negatively correlated to a speckled pattern. Passive haemagglutination titres against ENA and DNA antigen were not correlated. Seventy-three per cent of randomly selected sera gave either purely DNase sensitive reactions (19%) or reactions of combined sensitivity to DNase and other enzymes. Twenty-eight out of 53 sera reacting in the passive haemagglutination test reacted also in the immunofluorescence test against Chrithidia luciliae kinetoplasts. The latter reactions were DNase sensitive. It applies to both tests that DNase sensitive, but RNase resistant, reactions were well correlated, irrespective of their sensitivity to trypsin while DNase resistant or DNase and RNase sensitive reactions were not correlated. The passive haemagglutination test using a native but relatively crude DNA-preparation coated on tanned sheep erythrocytes supplemented by specificity tests with DNase and RNase treated antigen gives about the same information as the indirect immunofluorescence test against Chrithidia luciliae kinetoplasts. Furthermore, the results show that patients' sera reacting with a homogeneous nuclear pattern in the indirect immunofluorescence test may contain not only anti-DNA and anti-nucleohistone antibodies, but also antibodies to a number of non-histone chromatin associated proteins some of which contain RNA.

Isolated IgM RF inhibited the IgG-induced release of lysosomal substances, measured as 'large molecular size vitamin B12-binding protein' (LBP) and beta-glucronidase, from separated human granulocytes. The effect was most marked when cytochalasin B was added to the experimental system. The results indicate that the RFs interact with the granulocyte binding region of IgG.

The distribution of phenotypes of the group specific component (Gc) was examined in 85 AIDS patients and in 40 couples, each consisting of one HIV seropositive patient and one seronegative sexual partner. Phenotype and allele frequencies in these groups did not differ significantly from those in a Swedish control population. Our observations did not indicate any involvement of the Gc system in susceptibility to HIV infection or progression to AIDS.

Monocyte yeast cell phagocytosis (YCP) was low in presence of cryoglobulins(CG) from 7 of 7 patients with SLE and RA with vasculitis and from 2 of 5 patients with essential cryoglobulinaemia. IgM and C3 were detected only in CG associated with low YCP. Furthermore, low YCP was only found with CG isolated from hypocomplementaemic sera. The results also showed low YCP when heat-aggregated IgG (HAG) greater than or equal to 19S was added to the culture medium. In the presence of HAG or SLE-sera, preopsonized yeast cells could be adequately phagocytosed by monocytes whereas, in parallel cultures, the phagocytosis of untreated yeast cells was low. It is possible that CG and HAG impair YCP in the same way as SLE-sera. The nature of this presumed common mechanism has not been clarified in this limited study. The findings are, however, compatible with the possibility that immune complexes may interfere with the opsonization of the yeast cells, possibly through inactivation of complement components.

Two patients developed antinuclear antibodies (ANA) including antibodies directed against double-stranded DNA (dsDNA) after bone marrow transplantation. In one of the patients very high levels of IgM, IgG as well as IgA anti-dsDNA were found during 6 months in the absence of symptoms of systemic lupus erythematosus (SLE). The other patient made IgM anti-dsDNA antibodies for a period of more than 3 years, also in the absence of SLE symptoms. The ANA were restricted to the IgG1 and IgG3 isotypes as is the case in SLE but did not express idiotypes commonly found in this autoimmune disease. The occurrence of these antibodies may reflect a non-antigen induced expansion of the existing donor B-lymphocyte repertoire.

Immunoglobulin allotypes G1m(a), G1m(x), G3m(b) and Km(1) were determined in 83 Swedish AIDS patients. Twenty of the patients had Kaposi's sarcoma and 29 had Pneumocystis carinii pneumonia. The distribution of the Gm and Km allotypes did not significantly differ between these different disease categories and the general Swedish population.

A case of prolonged gonococcal speticemia is presented. Lack of genital symptoms, of demonstrable gonococcal antibodies in whole serum, and initially also of skin lesions contributed to a delayed diagnosis that was finally confirmed by positive blood culture. Evidence of circulating immune complexes was obtained by the demonstration of gonococcal IgG antibodies after dissociation of serum by gradient centrifugation of pH 4.0. The possibility that circulating immune complexes may contribute to the symptomatology of gonococcal septicemia is pointed out.

Non-heated human and animal sera contain a factor which exhibited an inhibiting activity on the staining of actin-containing structures by anti-actin antibodies in indirect immunofluorescence experiments. The presence of this factor lowered the viscosity of F-actin preparations and caused, as studied by electron-microscopy, a depolymerization of F-actin filaments as well as inhibition of filament formation of G-actin. The factor was, after its reaction with F-actin, liberated seemingly unaffected, indicating an enzymatic activity. The factor tentatively termed 'F-actin depolymerizing factor' was heat-sensitive and trypsin sensitive but resisted reduction. It was Ca2+ dependent and the staining inhibiting reaction was faster at 30 degrees C and 37 degrees C than at lower temperatures. Gel filtration experiments on Sephadex G-200 suggested a molecular size of the actin depolymerizing factor slightly higher than that of albumin. The electrophoretic mobility was that of gamma 2 globulin. The physiological role of the factor might be to prevent the presence of F-actin filaments within the circulation.

Anticardiolipin antibodies which seldom occur in healthy persons are frequently found in systemic lupus erythematosus (SLE). Their presence, especially at high levels (greater than 10 units) are often accompanied by thromboembolic manifestations as well as thrombocytopenia and recurrent abortions. The incidence of cardiolipin antibodies was as great in SLE as in women with clinically unexplained recurrent abortions. The anticardiolipin levels remained unchanged in most patients for long periods and were remarkably unaffected by disease activity and therapy. On the other hand, in several cases the activated partial thromboplastin time which was prolonged in most patients with persistently high cardiolipin antibody levels, approached normal during treatment with prednisolone and salicylic acid. This seemed to facilitate a successful outcome of pregnancy. Absorption of sera with cardiolipin and other negatively charged phospholipids but not with uncharged phospholipids abolished the anticardiolipin activity in enzyme linked immunosorbent assay. In most sera with cardiolipin antibody levels greater than 10 units complement activation by the classical pathway could be demonstrated. Whether the anticardiolipin antibodies contributed to complement activation could not be determined.

Thirty sera reacting by IFL technique in titres greater than or equal to 100 with smooth muscle fibres of rat stomach, rat renal glomeruli, and with the membrane region of thyroid cells were randomly chosen among sera sent in for routine testing of tissue antibodies. All sera but one were found to be derived from patients with chronic active hepatitis. The smooth muscle and other relevant cell staining were abolished after absorption of sera with actin, prepared from rabbit skeletal muscle and found to be homogeneous by SDS gel-electrophoresis and by electron microscopy. The actin anti-bodies were purified by precipitation of sera with F-actin and elution of the precipitates at acid pH. The purified antibodies stained all tissues in the same way as the original sera. In double immunodiffusion tests all thirty sera gave precipitation with actin. Thus, it was concluded that these broad-reacting SMA are directed against actin. The finding of high-titred SMA is of diagnostic value and supports the clinical diagnosis of active chronic hepatitis. In addition, anti-actin antibodies eluted from human sera are a suitable tool for studying actin-containing cellular structures.

A double blind placebo-controlled efficacy trial of two acellular pertussis vaccines was conducted in 3801 6- to 11-month-old children. Four vaccinated children died during 7 to 9 months follow-up as a result of Haemophilus influenzae type b meningitis, heroin intoxication with concomitant pneumonia, suspected septicemia, and Neisseria meningitidis Group B septicemia. From the actual death rate in children belonging to the same birth cohort in Sweden that could have been eligible for the trial, one death was expected among vaccinated children. Several investigations were carried out to examine the possibility that the deaths could be causally related to the vaccination. The relative risk for hospitalization due to systemic or respiratory infections was 1.07 (95% confidence interval, 0.95 to 1.20) and 0.83 (95% confidence interval, 0.64 to 1.08) in the vaccine groups as compared with the placebo group. Subsets of the population were studied for signs of immunosuppression. There was no indication of immunoglobulin deficiency or any sign of clinically significant leukopenia or lymphocytosis in vaccine recipients. The results of this analysis provide no evidence for a causal relation between vaccination with the studied acellular pertussis vaccines and altered resistance to invasive disease caused by encapsulated bacteria. The hypothesis that the two variables are related, however, cannot be refuted from these data.

The staining pattern of anti-actin sera on various cells smeared on glass was compared to the relative amount of cellular actin estimated by SDS-polyacrylamide-gel electrophoresis with subsequent scanning of the gel. Although the cells showed a varying stainability the actin content was fairly constant. Thus, the staining differences reflected changes in the organization of cellular actin rather than actual differences in the amount of actin.

A group of 17 patients, having undergone modified radical mastectomy for breast cancer, received 12 cycles of chemotherapy with methotrexate, 5-fluorouracil, and chlorambucil during 17 months. The number of circulating T and non T lymphocytes, as defined by E, EAC, and ME rosette formation, were reduced during treatment. The Non-T lymphocytes, however, were reduced to the highest relative extent. Relative phytohemagglutinin and mixed lymphocyte culture responses of the cells decreased, whereas purified protein derivative responses were unchanged. Serum concentrations of IgM were reduced, but IgA and IgG concentrations were unchanged or slightly increased. Antibody titres to morbilli and herpes simplex were not changed, whereas the antibody activity against cytomegalovirus (CMV) increased in several seropositive patients. None of these patients, however, developed signs of a CMV infection.

Six girls and one boy with cronic active hepatitis (CAH) of unknown etiology were between 9 and 15 years at the clinical onset of their illness. After beginning immunosuppressive therapy the course of their disease was followed from one to ten years. All had markedly increased IgG, high titres of smooth muscle antibodies (SMA) and antinuclear antibodies of IgG class in the earliest serum specimens tested. Therapy resulted in an improved sense of well-being and a decrease in SGOT, IgG and titres of SMA. Very high titres of measles antibodies were observed in all cases. In one of the cases CAH manifested itself after measles and in another after rubella infection. The first case in our series of patients died of liver failure after 5 years of illness. The other patients have survived and are able to live a normal life. The possibility of CAH should be considered when children develop symptoms of hepatitis. Longterm immunosuppressive treatment with regular clinical and laboratory evaluation is important. Estimation of titres of SMA is an additional parameter of value in following of the activity of CAH in these young patients.

In the diagnostic routine for tissue antibodies, using indirect immunofluorescence on cryostat sections of human thyrotoxic thyroid, rat stomach and kidney, ninety-six out of 48,388 sera showed a marginal staining of the membrane region of thyroid epithelial cells but no other reaction. Twenty-six of these sera were from patients with acute Yersinia enterocolitica serotype 3 infection but without signs of thyroid disease. Fifty of sixty-three sera with agglutinins against Y. enterocolitica serotype 3 and three out of four sera with agglutinins against Y. enterocolitica serotype 9 also showed this reaction on thyroid sections. It was due to antibodies, mostly of the IgG class, occurring in low titre, which react with intracytoplasmic antigens in thyroid, as staining of live thyroid epithelial cells was negative. The pattern of immunofluorescence on thyroid sections caused by these antibodies could not be distinguished from that caused by smooth muscle antibodies by appearance only. However, smooth muscle antibodies react also on other tissue sections and extracts of contractile proteins which absorb out these, did not change the reaction on thyroid of Y. enterocolitica sera. Absorption with sonicated Y. enterocolitica 3 and 9 antigens, but not with heat-killed whole bacteria, extinguished the reaction on thyroid. This indicates the presence of a cross-reactivity between antigens in these bacteria, different from the O antigen, and antigens in thyroid epithelial cells. Knowledge of this pattern of immunofluorescence on thyroid sections can be of diagnostic significance.

A monoclonal antibody specific for the major primary biliary cirrhosis (PBC)-associated mitochondrial antigen (subunit I of NADH-ubiquinone reductase) was produced and used to study the binding sites recognized by anti-mitochondrial autoantibodies (AMA) in PBC sera. Immunization of mice with purified beef heart mitochondrial inner membranes resulted in one monoclonal antibody which reacted with mitochondrial proteins. This antibody (PBC-MoAb), which was of the IgG2b subclass with kappa light chains, exhibited a pattern of immunofluorescence reactivity with rat kidney, human thyroid, and cultured human epithelial cells (Hep-2) similar to that obtained with sera from PBC patients. Similar binding patterns between PBC-MoAb and AMA were also found in western blot analysis using mitochondria as antigen. Both types of antibodies revealed a major antigen of 75 kDa, a minor antigen of 60 kDa, and a third antigen (70 kDa), which was detected only in samples that had not been boiled prior to electrophoresis. Furthermore, optimal binding of the PBC-MoAb and AMA to the 75 and 70 kDa antigens required reduction of the antigen with mercaptoethanol prior to electrophoresis. Competition ELISA experiments were conducted to compare the epitopes recognized by PBC-MoAb and AMA. Of 28 PBC sera tested, 27 inhibited the binding of PBC-MoAb to mitochondrial inner membranes by almost 100% and one serum inhibited binding by 50%, indicating that most PBC sera contain autoantibodies reactive with the same or a closely related antibody binding site as the PBC-MoAb. PBC-MoAb inhibited AMA binding to the inner membrane by more than 80% in 10 sera, 60-80% in 11 sera, and 40-59% in seven sera, with an average inhibition of 71%. Our observations strongly indicate that anti-mitochondrial autoantibody binding sites are restricted to a highly immunogenic epitope on the major PBC-specific antigen (NADH-ubiquinone reductase subunit I), and that the anti-mitochondrial monoclonal antibody obtained has a specificity identical with the human PBC-specific M2 type anti-mitochondrial autoantibody.

Precipitin reactions apparently not involving specific antibodies were obtained in immunodiffusion experiments performed at low salt concentration between IgG and the muscle proteins, actin and tropomyosin. The precipitates, which dissolved at physiologic ionic strength, may result from electrostatic interaction of molecules of different net charge and different distribution and number of charged groups.

Platelets, prepared from fresh human platelet-rich plasma smeared on slides and stained with human serum containing smooth muscle antibodies (SMA) in indirect IFL, showed a bright cytoplasmic fluorescence with numerous projections extending from the surface. A prerequisite for obtaining a positive reaction with SMA-positive serum was that a chelating agent was present in the suspending medium when preparing the smears. The projections could be demonstrated also by anti-HeLa cell (anti-species) serum. This indicates that the projections had a membraneous cover. Staining of live platelets was always negative. Platelets treated with cytochalasin B for 1 hr were smooth and spherical and did not show any surface projections.

Non-specific binding in an ELISA test for antibodies to cardiolipin (ACA) was investigated in sera from patients with primary biliary cirrhosis, rheumatological disorders, and repeated abortion. Binding to wells without phospholipid was most frequent in ELISA assay for IgM class ACA and correlated with levels of serum polyclonal IgM in patients with repeated abortion and rheumatologic disorders (r = 0.79, 0.76). Using added polyclonal IgM we demonstrated that the increase in non-specific binding was most significant when levels of ACA were low; subtraction of binding to the unoccupied well over-corrected specific antibody estimates when a high affinity antibody was present. Absorption studies on three sera suggest that this 'non-specific' binding includes low affinity antibody binding. Elevated levels of polyclonal IgM in sera from patients with repeated abortion may account for some reports of elevated IgM class antibodies in other ELISA assays. The prevalence of a positive test for ACA in a sequential series of 412 such patients was reduced to 6.1% (95% confidence limits 4-9%) after subtraction of non-specific binding.

Immunologic investigations were performed on 337 healthy women with unexplained habitual abortion. Their sera were investigated for antinuclear antibodies (ANA), antibodies against DNA, and anti-cardiolipin antibodies, and the activated partial thromboplastin time (APTT) and complement levels of their plasma were determined. Cellular reactivity and blocking antibody were studied in one-way mixed lymphocyte culture (MLC). None of the women had any signs of autoimmune disease. However, in 77 of the 337 women (22%) increased anti-cardiolipin antibody levels were found, in 19 (7%) above 10 units. Most patients with high anti-cardiolipin antibody levels had lowered values of complement factor C4. We consider the mere occurrence of anti-cardiolipin antibody in women with habitual abortion to be no absolute cause for treatment with prednisolone, and this is true even in cases with very elevated anti-cardiolipin values. Treatment with prednisolone and acetylsalicylic acid (ASA) during pregnancy should be given to only those women who have high levels of anti-cardiolipin antibodies concomitant with high APTT values, and low values of complement C4. Anti-cardiolipin antibody was also investigated during pregnancy in 136 normal pregnant women. Eleven of them (8%) were positive at any of four sampling occasions, but only one (1%) had high levels. These data differ significantly from those of the habitual aborters. Thus the development of anti-cardiolipin antibody is no normal feature of pregnancy in Swedish women and so the high frequency found among healthy Swedish women with habitual abortion remains unexplained. We have introduced an immunization programme of third party leukocyte transfusions in habitual abortion.(ABSTRACT TRUNCATED AT 250 WORDS)

The production of actin antisera in rabbits was described and their reaction in various immunological tests were compared with the results obtained with human anti-actin sera (smooth muscle antibodies). Even if the sera may react with different antigenic determinants of actin as suggested by results in immunoprecipitation and blocking experiments, the rabbit and human sera can be used for studies of cells with equal or similar results. A prerequisite was that the rabbit anti-actin titres were high. The difficulty in obtaining strong anti-actin sera in rabbits was confirmed.

All of 15 sera containing anti-mitochondrial antibodies (AMA), type M 5, reacted in ELISA with ssDNA, whereas only four had anti-nuclear antibodies as demonstrated by immunofluorescence technique. Twelve of 15 had biological false-positive seroreaction for syphilis and seven of 11 cases investigated had a positive lupus anti-coagulant test. Cold agglutinins were present in 11 sera. Hyper-gamma-globulinaemia was not a prominent finding, but C4 values below the lower limit were common in spite of C3 within the normal range. Absorption of IgG fractions from three different sera with cardiolipin eliminated the reaction with ssDNA and mitochondria, supporting a certain degree of cross-reactivity among the antibodies. The presence of AMA, type M 5, seemed to discriminate a group of patients with symptoms often consistent with SLE although some of the most prominent findings were often absent.

Antibodies to cardiolipin were measured in 62 survivors of myocardial infarction under age 45 at 3, 12, and 36 months after the acute event. 13 patients (21%) had raised anticardiolipin antibody levels on at least two of the three sampling occasions. Risk-factor profiles and coronary angiographic findings did not differ between the anticardiolipin-positive group and the rest of the patients. No correlation was found between cardiolipin and anti-DNA antibody levels. 8 of the 13 patients with raised anticardiolipin antibody levels experienced additional cardiovascular events during a follow-up of 36-64 months after the first myocardial infarction: cerebral infarction developed in 2, arterial occlusion of the lower limb in 2, new myocardial infarction in 3, pulmonary emboli in 1, and deep-vein thrombosis in 1. These 8 patients had cardiolipin antibody titres of 5 times the mean for voluntary blood donors. Antibodies to cardiolipin are common in young post-infarction patients and should be interpreted as markers of high risk for recurrent cardiovascular events.

Extraocular muscle biopsies from normal individuals and five patients with Graves' ophthalmopathy were analyzed by immunohistochemical staining. Fibroblasts in normal extraocular muscle as well as Graves' extraocular muscles expressed HLA-class II antigens, but the muscle cells did not. There was an increase of interstitial tissue in Graves' extraocular muscles but no visible damage to the muscle cells. In four of the biopsies from Graves' patients the cellular reaction was very weak. In the fifth patient the reaction was more pronounced with macrophages predominating, but with few lymphocytes and almost equal amounts of B and T cells. We could not confirm the earlier described specific extraocular muscle antibodies in sera from Graves' patients and conclude that there seems to be an activation of orbital fibroblasts in Graves' ophthalmopathy. This may contribute to the pathogenesis of the disease.