Autoantibodies In Sera Of Patients Research Articles

Molecular cloning of a major CENP-B epitope and its use for the detection of anticentromere autoantibodies.

An enzyme-linked immunosorbent assay (ELISA) has been developed for the detection of anticentromere autoantibodies in sera of patients with suspected or manifest rheumatic diseases. The antigen source used in this assay consists of the recombinant protein of glutathione S-transferase (GST) fused to the last 60 C-terminal amino acid residues of the major centromere protein CENP-B. Although this CENP-B segment is only a small part of the complete polypeptide, we show that it constitutes an important autoimmune antigenic domain which is recognized by all patient sera in which ACA can be detected using the immunoblotting technique with a HeLa S3 nuclear protein extract as antigen source.

Antinuclear Autoantibodies in Sera of Patients with IgA Nephropathy

IgA nephropathy (IgAN), assumed to be a chronic immune complex glomerulonephritis, has been sometimes associated with various autoimmune diseases and autoimmune phenomena including autoantibody production. The current study was aimed at thoroughly investigating the frequency of raised autoantibody titers against five common nuclear autoantigens in a large number of patients with IgAN as well as patients with other primary immune complex glomerulopathies and normal controls. The incidence of autoantibodies (greater than 2 SD less than 3 SD of controls) in the IgAN group ranged between 13% in the case of anticardiolipin antibodies, and 19% in the case of antiribonucleoprotein antibodies, yet was not found to be significantly different from the incidence observed in the other control groups. In none of the subjects a titer above 3 SD of the means of controls was found. Our study clearly points to the fact that IgAN, while being an immune-mediated disease, is not a clear-cut autoimmune condition. The finding of autoantibodies in these patients may be merely incidental.

Monoclonal antibodies to P2 basic protein and their use in the investigation of some aspects of the Guillain-Barré syndrome

The production and characterization of two mouse monoclonal antibodies (MAbs) raised against human basic protein P2 is described. The two MAbs recognise two non-overlapping epitopes on P2. Using these two MAbs as a probe, a search was made for the presence of anti-idiotype (Ab2) antibodies directed against anti-P2 (Ab1) autoantibodies in sera of patients with Guillain-Barré syndrome (GBS). In sera of twenty GBS patients no such Ab2 antibodies could be demonstrated. Epitopes present on cytomegalo virus- or Epstein-Barr virus-infected cells, which may play a part in triggering GBS, were not recognised by the two MAbs.

The effect of sulphydryl reagents on the human thyroid microsomal antigen

High sensitivity of the microsomal antigen epitopes recognized by autoantibodies in sera of patients with thyroid autoimmune diseases to disulphide bridge reducing agents have been detected. The shape of the inactivation curve is different for sera obtained from different patients, but for most sera 50% inactivation is obtained below 1 mM of dithioerythritol. The inactivation strongly depends on the pH of the incubation buffer and is most pronounced at alkaline pH (9.6). Cross-linking of the soluble microsomal antigen by glutaraldehyde makes the epitopes resistant to DTE. Binding of the microsomal antigen to polystyrene makes it up to 5 times more resistant to DTE. The microsomal peroxidase enzymatic activity is destroyed by low concentration of dithioerythritol and the inactivation is not dependent on the buffer pH (7.4-9.6). The data demonstrated that the major microsomal antigen epitope is discontinuous (conformation dependent).

Clinical correlations and prognosis based on serum autoantibodies in patients with systemic sclerosis.

Of 397 systemic sclerosis (scleroderma) patients from the University of Pittsburgh, who had serum determinations of both anti-Scl-70 and anticentromere antibody (ACA), 26% had anti-Scl-70 and 22% had ACA. No patient had both autoantibodies. Weak associations with HLA-DR5 and HLA-DR1 were detected with anti-Scl-70 and ACA, respectively. ACA was found almost exclusively (96%) in patients with limited cutaneous scleroderma (the CREST syndrome variant), but the majority (57%) of patients with limited scleroderma did not have this antibody. Among patients with limited scleroderma, those with ACA more often had calcinosis and telangiectasias and less often had pulmonary interstitial fibrosis and restrictive lung disease. However, the frequency of pulmonary hypertension and the survival rates were similar in the ACA+ and ACA- limited scleroderma patients. Two-thirds of patients with anti-Scl-70 had diffuse scleroderma, but only 33% of all diffuse scleroderma patients had this antibody. Within the subset of diffuse scleroderma, anti-Scl-70 was associated with peripheral vascular disease (digital pitting scars) and pulmonary interstitial fibrosis, but was not predictive of cardiac or renal involvement or survival. ACA and anti-Scl-70 are useful in diagnosing and classifying systemic sclerosis variants and in predicting the natural course of the disease. Their mutually exclusive occurrence suggests either 2 separate clinical entities or important host factors determining their production.

Antibody to discrete areas of the brain in normal individuals and patients with schizophrenia

Autoimmune syndromes are frequently associated with the presence of serum antibodies that bind to autoantigens of the involved tissue (Botazzo et al. 1974). Reports of antibrain antibody in patients with schizophrenia have produced conflicting results (Kuznetsova and Semenov 196 1; Fessel 1963; Rubin 1965; Heath and Krupp 1967; Whittingham et al. 1968; Logan and Deodhar 1970; DeLisi et al. 1985; Pandey et al. 1981). In the work reported here, an enzymelinked immunoabsorbent assay (ELISA) was used, with antigen extracted from discrete areas of the brain, to look for serum autoantibodies in patients with schizophrenia.

Epitopes, structural domains, and asymmetry of amino acid residues in SS-B/La nuclear protein.

SS-B/La is a conserved cellular phosphoprotein of 46 to 48 KD that is the target antigen of autoantibodies in sera of patients with Sjogren's syndrome and systemic lupus erythematosus. SS-B/La is also known to be associated with certain small cellular and viral RNA, including adenovirus VAI and VAII RNA. Two relatively protease-resistant domains (X and Y) were defined in SS-B from HeLa cells by using human autoantibodies as reagents. Domain X, a methionine-containing nonphosphorylated 28 KD polypeptide, was found to be resistant to partial digestion with six different proteases. Similar domains were also found in calf and rabbit SS-B. Domain Y, a 23 KD polypeptide, was detected after limited digestion with S. aureus V8 and trypsin. This domain contained little if any methionine, but all the detectable phosphorylated amino acids. Among 16 anti-SS-B sera tested by immunoblotting, 11 (69%) were reactive with both domains, three (19%) only with domain X, and two (13%) only with domain Y. These results showed that there are at least two distinct antigenic epitopes on the 46 to 48 KD SS-B/La protein, each located on a separate structural domain. The asymmetric distribution of methionine and phosphorylated amino acid residues in SS-B/La show striking similarity to the two reported domains of the adenovirus 72 KD DNA-binding protein, and raises questions concerning functional similarities that await investigation.

A new autoantibody in patients with rheumatoid arthritis

In this study, a new autoantibody was identified in patients with rheumatoid arthritis (RA), which was tentatively named as anti-HaT-1 antibody.It was shown by double immunodiffusion method that anti-HaT-1 antibody had independent specificity from the hitherto reported autoantibodies in sera of patients with connective tissue diseases.The antigenicity of the HaT-1 antigen was destroyed with treatment by trypsin, whereas it was not inactivated by digestions with either DNase or RNase.The HaT-1 antigen was considered to be an acidic protein with approximate molecular weight of 150, 000 daltons. The HaT-1 antigen was present in soluble extracts of human and rat livers but not detected in those of rabbit and calf thymus or Raji cell. The HaT-1 antibody was detected in sera of 9 out of 45 RA patients, 2 out of 16 RA patients with Sjogren's syndrome. And RA patients with anti-HaT-1 antibody had higher incidence of digital angitis (nailfold thrombosis) and subcutaneous nodule than those without this antibody (p<0.01).It was suggested that anti-HaT-1 antibody is a new antibody which was specific to RA.

Serum Autoantibodies in Patients With Sickle Cell Anemia

The prevalence of serum autoantibodies was determined in 50 black adult patients with sickle cell anemia. and in 33 age-and sex-matched healthy black individuals. Twenty-seven of the patients (54%) had at least one type of autoantibody. in contrast to only four (18.2%) of the control subjects (P < .01). Antismooth muscle. antiskeletal muscle and antinuclear antibodies were the most frequently seen autoantibodies. There was no correlation between the presence of autoantibodies and history of hepatitis. number of blood transfusions or concurrent drug therapy. Sickle cell anemia is associated with the induction of autoimmune phenomena.

Identification of cytoskeletal intermediate filaments of vascular endothelial cells as targets for autoantibodies in patient sera

Autoantibodies present in sera of patients suffering from various inflammatory conditions react with fibrillar structures, “microfibrils” (MF), which are abundant in developing fetal connective tissue. The purpose of this study was to further characterize the target antigens and to look for potential antigenic target structures in the adult organism using the indirect immunofluorescence (IFL) technique. Bright vascular endothelial staining was regularly observed in various tissues, e.g., kidneys, skin, and vessels accompanying nerves using anti-MF-positive patient area. A weak staining of the media was seen in arteries. Placental vessels were convenient in vitro targets in a screening assay for anti-MF antibodies. The cytoplasmic structures responsible for the endothelial cell fluorescence were identified using cultured umbilical vein endothelial cells as the IFL substrate. In these cells the fluorescence had the typical perinuclear distribution and fibrillar appearance of cytoskeletal intermediate filaments (IMF). We could further show that anti-IMF and anti-MF autoantibodies gave indistinguishable staining patterns. Some anti- MF IMF -positive sera could be neutralized by “insoluble” placental preparations obtained by procedures for preparation of IMF polypeptides. Immunization with a 50,000-dalton “insoluble” polypeptide produced antibodies with a reactivity similar to that of the autoantibodies. The IFL staining and absorption results were consistent with the ultrastructurally demonstrated large amounts of intermediate filaments in vascular endothelial cells. The results suggest that circulating anti-IMF autoantibodies might be involved in inflammatory reactions in cases of vascular endothelial injury.

Incidence of virus-specific antibodies and autoantibodies in sera of patients with warts.

Summary Sera from fifty-two patients with warts and control subjects, the majority of whom were age and sex matched, were tested for antiviral antibody, anticellular antibody against wart cells, fibrillar anticellular antibody and smooth muscle antibody (SMA). There was a higher prevalence of the autoantibodies in patients with warts as compared to control subjects. There was no correlation between the presence of virus-specific antibodies and the autoantibodies.

Immunopathological Studies of Chronic Thyroiditis : Part 2. Determination of Various Thyroid Autoantibodies in Sera of Patients with Chronic Thyroiditis

Immunopathological Studies of Chronic Thyroiditis : Part 2. Determination of Various Thyroid Autoantibodies in Sera of Patients with Chronic Thyroiditis

Demonstration of tissue autoantibodies in the blood serum with certain skin diseases.

Demonstration of tissue autoantibodies in the blood serum with certain skin diseases.