Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LATEX FIXATION TESTS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed1984

Immunoprecipitates used as a reagent for rheumatoid factors.

IgM and IgG rheumatoid factors (RFs) were purified by affinity chromatography and gel filtration. The preparations thus obtained were used as standards in a radio-immunoassay for RF detection. In this assay, RFs were reacted with immunoprecipitates, and the RFs were detected with radiolabelled (F(ab')2 fragments specific for human IgM or IgG. The reproducibility of the assay was higher when RF content was expressed relative to the standards and not directly relative to tracer binding. It was found that the presence of IgM RF did not affect the measurement of IgG RF in this RIA, since the addition of neither mono- nor polyclonal IgM RF to a donor serum resulted in increased IgG RF measurements. 100 sera were analysed and were consistently positive in only one of the tests: sheep cell agglutination or latex fixation. The 75% of the sera which were positive only in the latex fixation test were positive for IgM RF in the radio-immunoassay, indicating that RFs in this type of serum were not specific solely for human IgG.

Humans↗
PubMed1983

Symposium on the immunodiagnosis of rheumatic and related diseases, Part II. Rheumatoid factors.

Human rheumatoid factors are antibodies of IgG, IgA, or IgM class that show reactions with antigenic determinants present on other immunoglobulin molecules. The most commonly measured rheumatoid factor relates to the 19S IgM type, which reacts by agglutination of latex particles coated with 7S IgG and is often measured in the standard latex fixation test. Approximately 65 to 70 per cent of patients with rheumatoid arthritis show positive serologic tests for rheumatoid factor; however, a number of other chronic disease conditions are also associated with positive rheumatoid factor reactions, including infective endocarditis, sarcoidosis, leprosy, and other hyperglobulinemic conditions. Although extensive serologic and immunochemical studies have identified a number of specific antigenic structural sites on immunoglobulin molecules that react with rheumatoid factors, recent studies have shown that a certain proportion of such antibodies may show cross-reactivity with DNA-histone complexes as well. It is still not entirely clear how rheumatoid factors fit into the pathogenesis of rheumatoid arthritis itself.

Aging↗
PubMed1988

Antibodies to immunoglobulin-G in dog sera, synovial fluids and aqueous humor: a comparative study of rheumatoid factor assays, suitable for routine application.

The incidence of anti-IgG antibodies (rheumatoid factors, RF) in body fluids (sera, synovial fluids and aqueous humor) selected from 62 normal and 275 diseased dogs was studied. Fluids were assayed by canine versions of standard agglutinating and/or precipitating RF assays with routine application in human practice. The number of RF detected by dog IgG-coated particles was substantially higher by latex fixation test (LFT) than by modified Rose-Waaler (RW) test (61/144 vs. 14/144). This did not result from false positives by LFT since latex activity was completely inhibited by aggregated dog IgG. Some evidence is presented indicating that results obtained by standard RW in particular, but also those obtained by standard LFT, might be improved by modifying testing conditions currently used. Body fluids were further studied for the presence of precipitins to aggregated dog IgG in 0.6% agarose (gel precipitation test (GPT]. The frequency of RF was higher by GPT than by LFT, both in normal control fluids (for sera 26/52 vs. 19/52) and patient material (for sera 135/197 vs. 95/197). Thus, the canine RF appear to be a serum component with an unexpectedly high frequency in both normal and diseased dogs, but grossly underestimated by the recommended routine RF assays based on agglutination. The GPT, which combines a superior detection rate of theoretically also agglutinating RF with an inability to detect RF quantitatively, seems an ideal RF 'indicator' test to dictate improvements to the quantitative LFT/RW assays so as to facilitate RF detection at clinically relevant concentrations. Thus optimized, RW/LFT would provide the optimal detection apparatus for the ultimate isolation of the relevant 'RF' repertoire present, for comparative studies aimed ultimately at unraveling the etiopathogenesis of the 'real' RF.

Animals↗
PubMed1988

Enzyme linked (ELISA) immunoabsorbent assay for the detection of hidden 19S IgM rheumatoid factors in juvenile rheumatoid arthritis.

Determination of hidden IgM rheumatoid factors (RF) in juvenile rheumatoid arthritis (JRA) offers advantages for diagnosis and in following disease activity. Sera from 30 patients with JRA were assayed for RF by latex fixation test (LFT), sensitized sheep cell agglutination test (SCAT), nephelometry, and by ELISA. IgM containing fractions were prepared by chromatography and assayed for hidden RF by the hemolytic method and ELISA. Ten patients were seropositive by LFT. All of them gave positive tests on the serum for RF with the SCAT, nephelometry, and ELISA, and on the IgM containing fractions by the hemolytic assay and ELISA. Seventeen patients seronegative by LFT were positive for hidden RF by the hemolytic test and ELISA on the IgM containing fraction. When unfractionated serum was used, 15 were positive by ELISA. Three patients were seronegative and also negative for hidden RF by the hemolytic assay and ELISA. Thus, only 2 of 30 patients had discordant results between the hemolytic assay on the IgM containing fraction and the ELISA on the serum. Our results indicate the ELISA on the serum in conjunction with the LFT offers a simple, rapid, alternative test for hidden 19S IgM RF in JRA patients.

Agglutination Tests↗
PubMed1979

The immunologic and clinical associations of the split products of C3 in plasma in juvenile rheumatoid arthritis.

A qualitative counterimmunoelectrophoretic assay for the complement activation products C3c and C3d was used to study plasma from children with juvenile rheumatoid arthritis (JRA) and other rheumatic diseases. Positive tests for C3c,d were found in all patients with active systemic lupus erythematosus (SLE), 7 of 10 patients with active systemic JRA, 16 of 29 with active polyarticular JRA, 7 of 20 with active pauciarticular JRA, and in only 2 of 20 with inactive joint disease. The incidence of positive assays for C3c,d in JRA was increased in the presence of positive latex fixation tests, antinuclear antibody tests, or elevated values for antiglobulins as determined by affinity chromatography, but these associations were not statistically significant. Three joint fluids from children with pauciarticular JRA were negative for C3c,d. These studies show that the subgroups of JRA defined by clinical criteria are heterogeneous by current laboratory parameters and that evidence implicating antigen-antibody complexes in the pathogenesis of JRA is lacking in many patients.

Antibodies, Antinuclear↗
PubMed1979

Characterization and measurement of anti-IgG antibodies in human sera by radioimmunoassay (RIA).

A sensitive direct binding radioimmunoassay (RIA) was developed which detected low avidity anti-IgG antibodies in sera negative in the latex fixation test (LFT). IgG class antibodies could be detected and were commonly found along with IgM class antibodies. Additionally, the RIA was more reproducible than the LFT, was easily adapted to measure relative avidities of anti-IgG antibodies, and had other technical advantages over the LFT.

Antibodies, Anti-Idiotypic↗