scholarly journals Evidence for a subset of rheumatoid factors that cross-react with DNA-histone and have a distinct cross-idiotype.

1980 ◽  
Vol 151 (6) ◽  
pp. 1514-1527 ◽  
Author(s):  
V Agnello ◽  
A Arbetter ◽  
G Ibanez de Kasep ◽  
R Powell ◽  
E M Tan ◽  
...  
Keyword(s):  
Rheumatoid Factor ◽  
Lupus Erythematosus ◽  
Gamma Globulin ◽  
Cross Reactivity ◽  
Rheumatoid Factors ◽  
Histone H2a ◽  
Relative Binding Affinity ◽  
Relative Binding ◽  
High Incidence ◽  
Binding Inhibition

Cross-reactivity of a monoclonal rheumatoid factor with an antigen present on IgG and DNA-nucleoprotein was demonstrated, and evidence presented that the combining site of the antibody was involved in the reaction. The antigen on the DNA-nucleoprotein was shown to involve both DNA and histone fraction H2A + H2B and was trypsin sensitive. The relative binding affinity of the antibody appeared to be greater for IgG than the DNA-histone antigen. Similar polyclonal cross-reactive rheumatoid factors were found in a variety of diseases. A high incidence was found among patients with rheumatoid arthritis and mixed connective tissue disease. None were detected in patients with systemic lupus erythematosus and idiopathic cryoglobulinemia. Studies on one representative isolated polyclonal rheumatoid factor demonstrated the same reactivity with DNA-histone H2A + H2B as the monoclonal antibody. Cross-idiotype studies using antigen-binding inhibition methods demonstrated the same cross-idiotype on the polyclonal and the monoclonal rheumatoid factor which reacted with DNA-histone. This cross-idiotype was shown to be distinct from the cross-idiotypes previously demonstrated on monoclonal IgM proteins with anti-gamma-globulin activity.

OCCURRENCE OF γ-GLOBULIN COMPLEXES IN SERUM AND JOINT FLUID OF RHEUMATOID ARTHRITIS PATIENTS: USE OF MONOCLONAL RHEUMATOID FACTORS AS REAGENTS FOR THEIR DEMONSTRATION

1971 ◽  
Vol 134 (3) ◽  
pp. 286-295 ◽  
Author(s):  
R. J. Winchester ◽  
H. G. Kunkel ◽  
V. Agnello
Keyword(s):  
Rheumatoid Arthritis ◽  
Rheumatoid Factor ◽  
Lupus Erythematosus ◽  
Complement Fixation ◽  
Joint Fluid ◽  
Exact Nature ◽  
Rheumatoid Factors ◽  
Serum Complement ◽  
Systemic Lupus ◽  
Low Incidence

γG globulin complexed in an unusual form has been demonstrated in the serum of many patients with rheumatoid arthritis. Such complexes have been detected and isolated principally through precipitation reactions with monoclonal γM rheumatoid factors. These monoclonal rheumatoid factors exhibited a greater sensitivity to react with small complexes or aggregates of γ-globulin than polyclonal rheumatoid factor from rheumatoid arthritis sera or isolated C1q. The serum complexes consisted in large part of high molecular weight but acid-dissociable 7S γG globulin molecules They however differed from the complexes in the joint fluid by not yielding precipitates with C1q and were not found in association with evidence of marked serum complement fixation or activation. A small number of systemic lupus erythematosus sera, primarily those forming cryoprecipitates, also gave reactions with monoclonal rheumatoid factor. Sera from patients with a variety of nonrheumatic diseases gave a low incidence of reactions. The exact nature of the complexes in the rheumatoid arthritis sera remains somewhat in doubt although γG rheumatoid factors appear partly involved.

scholarly journals IDIOTYPIC SPECIFICITY OF RABBIT ANTIBODIES TO STREPTOCOCCAL GROUP POLYSACCHARIDES

1973 ◽  
Vol 138 (5) ◽  
pp. 1248-1265 ◽  
Author(s):  
Dietmar G. Braun ◽  
Andrew S. Kelus
Keyword(s):  
Rheumatoid Factor ◽  
Hemagglutination Inhibition ◽  
Double Diffusion ◽  
Agarose Gel ◽  
Variable Regions ◽  
Specific Antibodies ◽  
High Incidence ◽  
Binding Inhibition ◽  
F1 Progeny ◽  
Idiotypic Antibody

Anti-idiotypic antisera against six restricted rabbit streptococcal group specific antibodies have been raised in rabbits matched for allotypes. All these antisera reacted specifically with their homologous idiotypes on double-diffusion tests in agarose gel. In addition, they showed a high incidence of cross-specificities with group-specific hyperimmune sera induced in both closely related and unrelated individuals. These precipitating cross-specificities could be explained for two systems by the interference of rheumatoid factor. Two idiotypic antibody systems have been analyzed in detail; these were restricted antibodies produced in a father and in one of his offspring. The methods employed included binding inhibition of radio-labeled homologous Fab fragments and hemagglutination inhibition with homologous idiotypic coat. The data demonstrated that only related rabbits produced, besides non-cross-reacting antibodies, idiotypically similar antibodies raised to the same antigen. About one-third of the cross-reactive idiotypes showed binding inhibition between 31 and 92%. Inhibition of binding above 50% in the paternal idiotypic system was only achieved by one offspring antibody whereas the F1 progeny idiotypic system was inhibited to this extent by seven antibodies of related rabbits. In contrast, 87.5% and 91.7% of antibodies of unrelated rabbits were less than 20% inhibitory. Within this study two idiotypically identical antibodies have not been found. This implies that A-variant-specific antibodies of related rabbits which produced antipolysaccharide antibodies were structurally different. Cross-reaction, even if greater than 90% by binding inhibition, appears to involve only part and not all of the variable regions.

scholarly journals THE INDUCTION OF A RHEUMATOID FACTOR-LIKE SUBSTANCE IN RABBITS

1961 ◽  
Vol 114 (5) ◽  
pp. 791-806 ◽  
Author(s):  
John L. Abruzzo ◽  
Charles L. Christians
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Rheumatoid Factor ◽  
Gamma Globulin ◽  
Cross Reactivity ◽  
Serum Factor ◽  
Heat Stable ◽  
Beta Globulin ◽  
Heat Stable Protein ◽  
Human Gamma Globulin

Hyperimmunization of two groups of rabbits with killed Escherichia coli and Bacillus subtilis has resulted in the formation of a serum factor (RFLS) which resembled the human rheumatoid factor. It was a heat-stable protein that migrated electrophoretically in the gamma-beta globulin range and sedimented rapidly with ultracentrifugation. The serologic properties of the RFLS were destroyed by mercaptoethanol. It reacted primarily with rabbit gamma globulin in an aggregated state (immune complexes or physically aggregated gamma globulin) and demonstrated cross-reactivity with human gamma globulin.

scholarly journals Plasmodium falciparum Histidine-Rich Protein 2-Based Immunocapture Diagnostic Assay for Malaria: Cross-Reactivity with Rheumatoid Factors

2000 ◽  
Vol 38 (3) ◽  
pp. 1184-1186 ◽  
Author(s):  
J. Iqbal ◽  
A. Sher ◽  
A. Rab
Keyword(s):  
Plasmodium Falciparum ◽  
Rheumatoid Factor ◽  
Positive Reaction ◽  
False Positive ◽  
Malaria Infection ◽  
Cross Reactivity ◽  
Rheumatoid Factors ◽  
Optimal Test ◽  
False Positive Reaction ◽  
Rheumatoid Factor Activity

Recently introduced rapid nonmicroscopic immunocapture assays for the diagnosis of malaria infection are being evaluated for their sensitivity and specificity in various epidemiological settings. APlasmodium falciparum histidine-rich protein 2 (PfHRP-2)-based assay (ICT) and a Plasmodium-specific lactate dehydrogenase test (OptiMAL) were evaluated for their specificities in different groups of patients who tested negative for malaria infection by microscopy. The patients were selected from different disease groups: rheumatoid arthritis, hepatitis C, toxoplasmosis, schistosomiasis, and hydatid disease. One hundred thirty-three of the 225 patients were positive for rheumatoid factor. Thirty-five of the 133 (26%) rheumatoid factor-positive patients gave a false-positive reaction with the ICT assay, but only 4 of these gave false-positive reactions with the OptiMAL test. Thirty-three of the 35 false-positive specimens became negative when repeat tested with the ICT assay after absorbing out the rheumatoid factor activity. Our study shows that the PfHRP-2-based ICT assay gave a false-positive reaction in 26% of the patients who had rheumatoid factors, but were negative for malaria by microscopy.

GRAM: A True Null Model for Relative Binding Affinity Predictions

2019 ◽  
Author(s):  
Guanglei Cui ◽  
Alan P. Graves ◽  
Eric S. Manas
Keyword(s):  
Binding Affinity ◽  
Performance Metrics ◽  
Null Model ◽  
Performance Measure ◽  
Interval Estimate ◽  
Empirical Observation ◽  
Binding Affinity Prediction ◽  
Affinity Prediction ◽  
Relative Binding Affinity ◽  
Relative Binding

Relative binding affinity prediction is a critical component in computer aided drug design. Significant amount of effort has been dedicated to developing rapid and reliable in silico methods. However, robust assessment of their performance is still a complicated issue, as it requires a performance measure applicable in the prospective setting and more importantly a true null model that defines the expected performance of random in an objective manner. Although many performance metrics, such as correlation coefficient (r2), mean unsigned error (MUE), and room mean square error (RMSE), are frequently used in the literature, a true and non-trivial null model has yet been identified. To address this problem, here we introduce an interval estimate as an additional measure, namely prediction interval (PI), which can be estimated from the error distribution of the predictions. The benefits of using the interval estimate are 1) it provides the uncertainty range in the predicted activities, which is important in prospective applications; 2) a true null model with well-defined PI can be established. We provide one such example termed Gaussian Random Affinity Model (GRAM), which is based on the empirical observation that the affinity change in a typical lead optimization effort has the tendency to distribute normally N (0, s). Having an analytically defined PI that only depends on the variation in the activities, GRAM should in principle allow us to compare the performance of relative binding affinity prediction methods in a standard way, ultimately critical to measuring the progress made in algorithm development.<br>

scholarly journals Human rheumatoid factor crossidiotypes. I. WA and BLA are heat-labile conformational antigens requiring both heavy and light chains.

1986 ◽  
Vol 164 (5) ◽  
pp. 1809-1814 ◽  
Author(s):  
V Agnello ◽  
J L Barnes
Keyword(s):  
Rheumatoid Factor ◽  
Primary Structure ◽  
Binding Activity ◽  
Light Chains ◽  
Heat Denaturation ◽  
Antigen Binding ◽  
Rheumatoid Factors ◽  
Simple Method ◽  
Heat Labile

Evidence was obtained that both the WA and BLA crossidiotype (XId) groups are conformational antigens requiring both L and H chains and that with heat denaturation the antigens that define the XIds and antigen-binding activity are lost in parallel. In contrast, the primary structure-dependent crossreactive idiotype (CRI), PSL2, which is only weakly detected on native Wa and Bla monoclonal rheumatoid factors (mRFs), became prominently detected on the heated Wa and Bla mRFs. Heat denaturation may provide a simple method for distinguishing Ids determined by conformational antigen from primary structure-dependent Ids. In addition to heat denaturation, some acid conditions commonly used for preparation of RFs were also found to cause marked loss of Id antigen. The finding of PSL2-CRI on Bla mRF indicates that this Id is not unique to the WA XId.

The Association Between Immunodeficiency and the Development of Autoimmune Disease

1996 ◽  
Vol 10 (1) ◽  
pp. 57-61 ◽  
Author(s):  
J.W. Sleasman
Keyword(s):  
Immune System ◽  
Autoimmune Disease ◽  
Lupus Erythematosus ◽  
Iga Deficiency ◽  
Selective Iga Deficiency ◽  
Increased Risk ◽  
High Incidence ◽  
Autoimmune Cytopenias ◽  
The Complement System ◽  
Common Variable

There is a paradoxical relationship between immunodeficiency diseases and autoimmunity. While not all individuals with immunodeficiency develop autoimmunity, nor are all individuals with autoimmunity immunodeficient, defects within certain components of the immune system carry a high risk for the development of autoimmune disease. Inherited deficiencies of the complement system have a high incidence of systemic lupus erythematosus (SLE), glomerulonephritis, and vasculitis. Carrier mothers of children with chronic granulomatous disease, an X-linked defect of phagocytosis, often develop discoid lupus. Several antibody deficiencies are associated with autoimmune disease. Autoimmune cytopenias are commonly observed in individuals with selective IgA deficiency and common variable immune deficiency. Polyarticular arthritis can be seen in children with X-linked agammaglobulinemia. Combined cellular and antibody deficiencies, such as Wiskott-Aldrich syndrome, carry an increased risk for juvenile rheumatoid arthritis and autoimmune hemolytic anemia. Several hypothetical mechanisms have been proposed to explain the associations between autoimmunity and immunodeficiency. Immunologic defects may result in a failure to exclude microbial antigens, resulting in chronic immunologic activation and autoimmune symptoms. There may be shared genetic factors, such as common HLA alleles, which predispose an individual to both autoimmunity and immunodeficiency. Defects within one component of the immune system may alter the way a pathogen induces an immune response and lead to an inflammatory response directed at self-antigens. An understanding of the immunologic defects that contribute to the development of autoimmunity will provide an insight into the pathogenesis of the autoimmune process.

Enzyme-linked immunosorbent assay of autoantibodies reacting with thyroid plasma membrane antigens in sera of patients with autoimmune thyroid diseases

1986 ◽  
Vol 113 (2) ◽  
pp. 255-260 ◽  
Author(s):  
Andrzej Gardas ◽  
Kathleen L. Rives
Keyword(s):  
Plasma Membrane ◽  
Immunosorbent Assay ◽  
Lupus Erythematosus ◽  
Antithyroid Drug ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Autoimmune Thyroid Diseases ◽  
Nodular Goitre ◽  
Membrane Antigens ◽  
Toxic Nodular Goitre

Abstract. A sensitive and specific enzyme-linked immunosorbent assay (ELISA) for the detection of autoantibodies reacting with thyroid plasma membrane antigens has been established. Autoantibodies reacting with thyroid plasma membrane antigens were detected by the ELISA in 95% of untreated hyperthyroid Graves', 68% of antithyroid drug-treated Graves' up to four months of the therapy, in 62% of Hashimoto's thyroiditis and in 8.9% of toxic nodular goitre. The ELISA was negative in 100% healthy blood donors, 100% non-toxic nodular goitre, in 12 patients with rheumatoid arthritis, 18 patients with scleroderma and 94% of patients with systemic lupus erythematosus. The mean value of autoantibodies titre was higher in untreated hyperthyroid Graves' (1:84 000) and lowest in positive patients with autoimmune disease of non-thyroid origin (1:4000). The cross-reactivity of antimicrosomal antigen antibodies was below 10%; there was no influence of antithyroglobulin antibodies on the ELISA; and most of the autoantibodies react with plasma membrane antigens different from the TSH binding sites.

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