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Biomedical subjects

A Falus

Publications and source records attributed to A Falus.

At least 199 records · Page 11Linked to original sources
PubMed1982

IgE and IgE-rheumatoid factors in circulating immune complexes in rheumatoid arthritis.

The sera of 21 patients with rheumatoid arthritis (RA), 11 patients with systemic lupus erythematosus (SLE), and 20 healthy subjects were analysed for the presence of IgE in immune complex fractions. These fractions were isolated by polyethylene glycol precipitation and gel filtration. Thirteen sera from RA patients contained IgE immune complexes (IC) and 11 of these were from patients with extra-articular manifestations. One SLE and none of the control sera contained such material. The serum IgE level did not correlate with IgE content of the IC fractions. Higher mean serum IgE levels were found in RA patients with extra-articular complications than in controls or RA patients with joint disease only, but the differences did not reach statistical significance. IgE anti-rabbit IgG (IgE rheumatoid factors) could be demonstrated in some IgE positive IC fractions. Antibodies to IgE, in 2 instances characterised as belonging to IgG class, were also found in ICs. This suggests the presence of anti IgE complexes. It is suggested that IgE, including some with rheumatoid factor activity, is contained in complexes which may be involved in some extra-articular manifestations of RA.

Antibodies, Anti-Idiotypic↗
PubMed1982

Beta-2-microglobulin-specific autoantibodies cause platelet aggregation and interfere with ADP-induced aggregation.

The anti-platelet activity of beta-2-microglobulin (beta 2m) specific autoantibodies isolated from sera of patients with autoimmune diseases was tested in direct and ADP-induced aggregation assays. It was established that human anti-beta 2m autoantibodies and heterologous rabbit anti-beta 2m antibodies evoke a dose-dependent aggregation of human platelets. Anti-beta 2m autoantibodies also impaired ADP-induced platelet aggregation. Antibodies with anti-beta 2m activity could be desorbed from the platelets and lymphocytes of a patients with systemic lupus erythematosus who was not thrombocytopenic. The possibility that such autoantibodies may alter platelet function is considered.

Adenosine Diphosphate↗
PubMed1981

Evaluation of different methods for detecting circulating immune complexes. Studies in patients with lung cancer.

In a collaborative study involving 7 laboratories, sera from 53 patients with lung cancer, 37 primary and 16 secondary tumours, and sera of 40 healthy blood donors were tested by 19 different assays or assay modifications used for detecting immune complexes. In 12 out of 19 assays, significantly higher immune complex levels were found in the cancer patients than in the healthy subjects. Assays based on interactions between immune complexes and Fc receptors of different cells (lymphocytes, macrophages of platelets) discriminated between cancer patients and health subjects and a high percentage (47-87%) of positivity was observed in such assays in patients with lung cancer. In contrast, none of the tests based on immune complex-complement interactions discriminated between cancer patients and health subjects. Immunochemical analyses of the PEG precipitates obtained from the sera tested revealed that the concentrations of IgG, IgA and C3 were significantly higher in the precipitates obtained from patients sera than from control sera, but no significant differences were seen in IgM and C1q concentrations. A 100% correct classification of individuals tested was obtained on discriminant analysis of results with 3 assays: EA rosette inhibition, ADCC inhibition and C3 concentration in PEG precipitates. Correlation between results obtained with individual sera by the different assays was very poor: significant correlation coefficients were found in only 13% of all possible paired comparisons. Our results suggest that Fc receptor-dependent assays are more suitable for detection and measurement of circulating immune complexes in lung cancer than tests based on interactions with complement.

Adenocarcinoma↗
PubMed1981

Interference of beta 2-microglobulin specific autoantibodies with EA-binding of human peripheral lymphocytes; inhibition of B-cell and enhancement of T-lymphocyte Fc-receptors.

The effect of anti-beta 2 m-specific autoantibodies was investigated on the FcRs of human PBMCs. Anti-beta 2 m autoantibodies inhibited the FcRs of the lymphocyte subpopulation detectable by rosetting with EA(hu). On the contrary, when EA(ox) indicator system was used, in the majority of the cases an enhancement of EA rosette formation was detected. Using separated lymphocyte subpopulations we found that the binding of anti-beta 2 m autoantibodies increased the number of FcR+ non-B-cells and inhibited that of B-lymphocytes.

Animals↗
PubMed1981

Autoantibodies specific to beta-2-microglobulin inhibit the Fc receptor-dependent phagocytosis of human monocytes.

Effect of anti-beta2-microglobulin (beta2m) antibodies was investigated on the in vitro Fc and C3 receptor dependent phagocytic capacity of human peripheral monocytes. Both rabbit and human anti-beta2m antibodies inhibit the Fc receptor-mediated phagocytosis. Anti-beta2m antibodies do not influence the spontaneous or C3b receptor-mediated ingestion. The inhibitory activity by human autoantibodies but not by rabbit anti-human beta2m antibodies was diminished when incubation was performed at 37 degrees C instead of 20 degrees C.

Animals↗
PubMed1981

Human beta 2-microglobulin is a substrate of tissue transglutaminase: polymerization in solution and on the cell surface.

Incubation of purified human beta 2-microglobulin (B2-m) with tissue transglutaminase (Tgase) resulted in the formation of high molecular weight polymers revealed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. In the presence of 30 mM [14C]methylamine, the polymer formation was prevented, but incorporation of methylamine into beta 2-m (equal to 1 methylamine per 1 molecule) could be observed. From the sheddings of peripheral blood mononuclear cells occurring in the presence of Tgase, it is apparent that anti-beta 2-m immunoadsorbent removed, in addition to human leukocyte antigen (HLA) and beta 2-m, some other proteins. The enzyme could incorporate [14C]methylamine into beta 2-m of the shedding cells. On addition of rabbit anti-human beta 2-m antibody, followed by fluoresceine-labeled goat anti-rabbit IgG antibody to human mononuclear blood cells, the otherwise homogeneous distribution of fluorescence turned into spots and patches on cells previously incubated with Tgase or Ca2+-ionophore A23187.

Beta-Globulins↗
PubMed1981

Beta2-microglobulin-containing IgG complexes in sera and synovial fluids of rheumatoid arthritis and systemic lupus erythematosus patients.

The occurrence and composition of complexed beta2-microglobulin (beta2m) in sera and synovial fluids of rheumatoid arthritis and systemic lupus erythematosus patients and control persons was investigated. Beta2m-containing complexes were detected in immune complex (IC)-enriched fractions isolated by precipitation with 3% polyethylene glycol 6000, in the macromolecular peaks after Sephadex G-200 gel filtration, and in IC desorbed from solid-phase Clq. Beta2m complexes were demonstrated also after precipitation of redissolved PEG-insoluble material by anti-human beta2m serum or isolation of the complexes by use of Sephadex-anti-beta2m. IgG was co-isolated with beta2m on Sephadex-anti-beta2m and free beta2m inhibited the binding of IgG to Sephadex anti-beta2m, indicating that IgG was present in the complexed beta2m. Analysis by SDS-polyacrylamide gradient electrophoresis under reducing conditions indicated that the purified beta2m complexes contained IgG and beta2m.

Antigen-Antibody Complex↗
PubMed1981

Prevalence of anti-beta-2 microglobulin autoantibodies in sera of rheumatoid arthritis patients with extra-articular manifestations.

The frequency and concentration of specific factors binding beta 2 microglobulin were investigated in sera and synovial fluids of patients and in sera of normal controls. High anti-beta 2 m activity was detected in the sera of adult RA patients, particularly in those of with extra-articular disease. Similarly, anti-beta 2 m was present in the synovial fluids of RA but not of osteoarthrosis patients. Both the binding of anti-beta 2 m activity to the Sepharose staphylococcal protein A and its elution position in the second 'IgG' peak after Sephadex G-200 gel filtration suggest the antibody nature of the activity. The possibility of differences not only in titre but also in the specificity of heterologous and homologous anti-beta 2 m antibodies are discussed.

Adolescent↗
PubMed1981

In vitro study of complement dependent active adherence on SLE and RA leukocytes.

Immunological disorders may cause altered motility or attachment of leukocytes. Active adherence of buffy cost cells derived from normal subjects and with autoimmune diseases patients and complement dependency of this process was studied on glass surfaces. The adherence of leukocytes of both normal persons and of SLE and RA patients was decreased in the presence of normal human serum compared to serum-free medium. The effects of native and heat inactivated human sera on leukocytes of SLE and RA patients were compared. Adherence of SLE leukocytes was higher, whereas that of RA leukocytes was lower in unheated serum compared to heat inactivated human serum. Supernatants of leukocytes of SLE, RA patients and control subjects were harvested after incubation in serum-free medium. The C3 levels of supernatants were determined by rocket electrophoresis. Surface attached C3 was detected with immunofluorescence mainly on SLE leukocytes. The cellular effects of supernatants on control leukocytes, were consistent with the changes observed with leukocytes derived from SLE, RA or control patients.

Arthritis, Rheumatoid↗
PubMed1980

Evaluation of different methods for detecting circulating immune complexes. An inter-laboratory study.

Forty serum samples of healthy blood donors and 60 sera of SLE patients were tested in parallel by 7 different assays for detecting immune complexes. Significantly higher titres and significant higher incidence of positive results were observed in the patient group than in the control group in 6 tests. No test discriminated between patients in an active stage of the disease and those whose disease was inactive. Significantly higher immune complex levels were found in lupus nephritis than in the non-nephritic patients by the complement consumption test. Significant positive correlation was obtained between the results of the macrophage aggregated IgG uptake inhibition and PEG-precipitation tests and between two tests based on the interaction of the complexes with the complement system. A characteristic 'profile' of the immune complex assay was observed in the course of the repeated testings of the same patients. The results indicate that the different methods detect different types of immune complexes present in the blood of the patients.

Antigen-Antibody Complex↗
PubMed1980

Serological abnormalities in juvenile chronic arthritis: a review of 46 cases.

Data of 46 patients with juvenile chronic arthritis were evaluated. All of them were under the age of 16 at the time of study. Patients with juvenile ankylosing spondylitis, psoriatic arthritis, and arthritis associated with inflammatory bowel disease were excluded from this series. Twenty-six patients had pauciarticular, 9 had systemic, 8 had polyarticular, and 3 patients had seropositive 'adult type' JCA. In all patient groups IgG, IgM, IgA, and C3 levels were significantly higher than in the control group. None of the controls but 13 of 46 patients had high IgE levels. IgA and IgG values were significantly higher in the seropositive subgroup than in the pauciarticular subgroup. There was no other positive correlation between levels of immunoglobulins, C3, and clinical features of disease. Platelet counts were significantly higher in patients with active disease. In the control group 4 out of 10 children had 'hidden' rheumatoid factor. All these children with positive findings were young.

Adolescent↗
PubMed1979

Complexed rheumatoid factor measurements in sera, synovial fluids and in immune complex fractions.

Mild acidic treatment increases the rheumatoid factor titre of some sera and synovial fluids (SF) in rheumatoid arthritis (RA), juvenile RA (JRA) and most frequently in rheumatoid vasculitis. This unmasking of 'hidden' RF in serum and SF samples correlated with the RF-immune complexes (RF-IC) and complexed C4 present in the 3% polyethylene glycol (PEG) precipitates, indicating that by means of 'hidden' RF measurements RF-ICs are possibly detected. This method seems to provide a diagnostic tool for detecting RF-ICs in RA and other related diseases.

Antigen-Antibody Complex↗
PubMed1979

Radioimmune double PEG precipitation technique for detecting complexed IgE.

The presence of IgE in immune complex-enriched fractions prepared by 3% polyethylene glycol (PEG) precipitation was studied. The dissolved PEG-insoluble fraction was incubated with [125I]anti-IgE antibodies an then precipitated again with 3% PEG. Radioactivity in the washed pellets was taken as indicating IgE present in immune complex form. A calibration curve was constructed using artificially prepared IgE-anti-IgE complexes. The method developed may be useful to detect other components present in immune complex fractions.

Antibodies, Anti-Idiotypic↗
PubMed1979

Antibodies to native DNA in connective tissue disease. A comparison of radioimmunoassay, counterimmunoelectrophoresis and indirect immunofluorescence on Crithidia luciliae substrate.

Sera of patients with symptoms of connective tissue diseases were investigated for the presence of antinuclear antibodies by indirect immunofluorescence on rat liver substrate. In positive cases antibodies to native DNA were determined by radioimmunoassay and by counterimmunoelectrophoresis. Twenty seven selected sera were also tested by indirect immunofluorescence on Crithidia luciliae substrate to test the sensitivity and specificity of this method. Immunofluorescent antinuclear antibodies could be found in all groups of connective tissue diseases while anti-native DNA antibody was demonstrated in higher amount only in the cases of systemic lupus erythematosus and therefore determination of anti-native DNA antibody may be helpful in the diagnosis of oligosymptomatic SLE. Counterimmunoelectrophoresis and immunofluorescence on Crithidia smears may serve as screening methods for anti-native DNA while radioimmunoassay provides a quantitative determination, although there are minor differences in the sensitivity and the specificity of these three methods.

Adolescent↗
PubMed1979

Rheumatoid factors bind beta 2 microglobulin. Detection of beta 2 microglobulin-complexes in rheumatoid arthritis.

beta 2 Microglobulin binding rheumatoid factors and occurrence of complexed form of beta 2 microglobulin were found in rheumatoid arthritis (RA) by radioimmunological methods. 1. As related to the appropriate values of control sera and osteoarthritic synovial fluids, one of the six sera and five of the six synovial fluids of RA patients exhibited increased binding activity for 125I-beta 2 microglobulin, 2. Rheumatoid factors (RF) purified by means of immunoadsorbent bound beta 2 microglobulin; 3. Both 19S and 7S components of sera, synovial fluids and purified RF samples had beta 2 microglobulin binding activity, which was inhibited by an excess of unlabeled beta 2 microglobulin; 4. Complexed (3% PEG 6000 insoluble) beta 2 microglobulin was found in three of fourteen sera and in twelve of fourteen synovial fluids of RA patients. Level of complexed beta 2 microglobulin was independent of its total concentration in the original samples; 5. In the fraction of synovial fluids enriched immune complex the amount of beta 2 microglobulin was in positive correlation with quantity of RF. Presumable immunological and pathological significance of "anti-beta 2 microglobulin"-like cross-reactive RF antibodies is discussed.

Arthritis, Rheumatoid↗