Microparticle-enhanced nephelometric immunoassay of anti-thyroid peroxidase autoantibodies in thyroid disorders.

Crude thyroid peroxidase extracted from human thyroid microsomes was covalently bound onto polyacrylic and polyfunctional copolymerized microparticles. We observed agglutination of the thyroid peroxidase-microparticle conjugate with 13 monoclonal antibodies (mAbs) specific for epitopes on four different antigenic domains of human thyroid peroxidase (TPO; EC 1.11.

Interactions of complement fraction C1q, fibronectin, and immunoglobulin G with polyacrylic microparticles used as solid-phase in immunoassay.

A microparticle-enhanced nephelometric immunoassay was recently described, where polyacrylic, hydrophilic, and polyfunctional microparticles are used as the solid phase. It is a one-step immunoassay based on the nephelometric quantification of microparticle agglutination. In such assays, the measurement of analytes at low concentration may be impaired by the need of using undiluted biological samples.

Use of microsphere-antibody conjugates in microparticle-enhanced nephelometric immunoassay.

A new microparticle-enhanced nephelometric immunoassay has been recently described as a sensitive, accurate, and easy-to-perform competitive immunoassay for various analytes. As initially described, this test is based on the nephelometric quantification of the inhibition, by the antigen to be assayed, of immunoagglutination of microparticle-antigen conjugates. Its applicability as a competitive immunoassay is thus limited by the necessary availability of pure antigens to prepare microparticle-antigen conjugates.

Detection of antithyroglobulin autoantibodies with defined epitopic specificity by a microparticle-enhanced nephelometric immunoassay.

To hydrophilic, polyfunctional spherical microparticles of predetermined diameter, produced by copolymerization of acrylic monomers, we covalently bound human thyroglobulin. The thyroglobulin-microsphere conjugate was agglutinated, in the presence of antimouse immunoglobulins antiserum, by four monoclonal antibodies, each recognizing a different antigenic domain on the thyroglobulin molecule. These agglutinations were quantified by measuring with a specially designed nephelometer the light scattered by clusters of the conjugates.

Synthesis of new hydrophilic microspheres: optimized carriers for microparticle-enhanced nephelometric immunoassays.

To optimize antigen-antibody reactions, we have synthesized chemically well-defined hydrophilic microspheres. Proteins or haptens were covalently linked to these carriers. When the microsphere conjugates were agglutinated by the corresponding antiserum, the size of the complex artificially increased during the immunological reaction.

Measurement of eleven serum proteins by microparticle-enhanced nephelometric immunoassay.

Eleven proteins (immunoglobulins IgG, IgA, IgM, orosomucoid, alpha 1-antiproteinase, haptoglobin, ceruloplasmin, C-reactive protein, transferrin, prealbumin and alpha 2-macroglobulin) in human serum were quantitated by a new microparticle-enhanced nephelometric immunoassay. This is a one step competitive assay, based on the nephelometric measurement of light scattered by clusters of protein-coated microparticles specially synthesized for that use. Statistical evaluation (precision, recovery and method comparison) shows that the determination of serum proteins is reliable and accurate for wide ranges of concentration and that the method is quite adequate for strongly increased concentrations.

Microparticle-enhanced nephelometric immunoassay with microsphere-antigen conjugates.

gamma-Irradiation of acrolein and other acrylic monomers allowed the synthesis of spherical polyfunctional hydrophilic microparticles in the size range of 50 to 300 nm, on which antigens (immunoglobulins G, chorionic gonadotropin hormone, prealbumin) could be covalently bound. Microsphere-antigen conjugates clustered together in the presence of specific antiserum or monoclonal antibodies and their agglutination was quantified by light-scattering measurement performed with a specially designed nephelometer. Essential factors concerning the conjugate agglutination and its quantitation (size of microsphere, amount of antigen bound on microsphere, concentration of conjugate, concentration of agglutinating reagent, angle of light-scattering observation) were successively studied.

Microparticle-enhanced nephelometric immunoassay for human C-reactive protein.

Polyfunctional hydrophilic microspheres of 125-nm diameter can be produced by copolymerization of acrylic monomers. Purified c-reactive protein (CRP) was covalently bound to these new micropheres, and the conjugate obtained was used as reagent in a microparticle-enhanced nephelometric immunoassay for human CRP. This assay was based on the measure, with a specially designed nephelometer, of the light scattered by aggregates formed during the immunoagglutination of the conjugate with anti-CRP antiserum.

Development of a rapid microparticle-enhanced nephelometric immunoassay for serum myoglobin in acute myocardial infarction.

A microparticle-enhanced nephelometric immunoassay was developed for myoglobin quantitation in human serum. It uses rabbit antimyoglobin serum and hydrophilic polyacrylic microparticles covalently coated with baboon myoglobin in a competitive immunoagglutination system. The level of microparticle agglutination is assessed with a specially designed nephelometer.

Polyacrylic microspheres as a solid phase for microparticle enhanced nephelometric immunoassay (NEPHELIA (R)) of transferrin.

Polyfunctional hydrophilic microspheres (MS) can be produced by copolymerisation with gamma-irradiation of acrylic monomers. Transferrin (TRF) can be covalently bound to these MS by reaction between aldehyde groups of the MS and primary amino groups of the protein. MS-TRF conjugates thus obtained are agglutinated by specific antiserum and this agglutination is inhibited by free TRF.

A microparticle enhanced nephelometric immunoassay (Nephelia) applied to thymulin measurement.

This article describes a microparticle enhanced nephelometric immunoassay (Nephelia) applied to the quantification of the thymic peptide hormone thymulin. Nephelia uses antibody recognition by the antithymulin antiserum in a competitive reaction between free thymulin and thymulin bound to the microspheres. The binding between microsphere and thymulin is achieved with the aid of a protein carrier.

[In vitro study of the cytocompatibility of 3 biological glues].

Human derived fibrin glues are being used with increasing frequency in periodontal surgery. Three different fibrin glues were tested in an in vitro system for gingival fibroblast proliferation. The results show a cytocompatibility of these products which justifies their employment in periodontal therapy.

Thymulin (facteur thymique serique) and zinc contents of the thymus glands of malnourished children.

Protein-energy malnutrition (PEM) leads to an immune deficiency, which is now well documented. Some investigators have suggested that the associated zinc deficiency is important in thymic involution and changes in cellular immunity. To evaluate the respective roles of nutritional deficiency, infection, and zinc in the alteration of thymic function, we measured the amounts of thymulin (facteur thymic serique, or FTS) and of Zn in the thymus glands of 58 Senegalese children who died in various stages of malnutrition.

[Current pathogenetic data on mesangial glomerulonephritis with immunoglobulin A deposits].

The pathogenesis of mesangial immunoglobulin A nephropathies was elucidated through the analysis of their clinical features and investigation of their biological characteristics. An alteration of the mucosal immune system is currently considered chiefly responsible for these diseases. A dysregulation of other compartments of the immune system is likely to enhance this abnormality and/or contribute to the persistence of immune complexes.

Histoimmunological discrepancies in primary IgA nephropathy and anaphylactoid purpura sustain relationships between mucosa and kidney.

Immunohistomorphometric analysis of the tonsils from a series of patients with anaphylactoid purpura or Berger's disease showed abnormal proportions of gamma- and alpha-isotype-producing cells. Conversely, renal immunofluorescence (IF) performed on kidney biopsies from 2 patients with hematuria and clinical symptoms suggestive of one or the other of these conditions failed to confirm the suspected diagnosis. Immunohistomorphometric analysis of these patient's tonsils showed normal proportions of gamma- and alpha-isotype-producing cells.

Allogeneic bone marrow transplantation in man: in vitro activity of FTS-Zn on T-cell markers and functions.

Thymulin (FTS-Zn) is a synthetic metallo-nonapeptide similar to the serum factor of thymic origin FTS, which induces the maturation of lymphoid cells. The activity of this compound on peripheral blood mononuclear cells from 12 bone marrow recipients was studied in vitro. It was demonstrated that thymulin was able to induce or modulate the expression of T-cell membrane markers, to enhance the proliferative responsiveness of lymphocytes to mitogens or allogeneic cells, and to increase mononuclear cells' natural killer activity.

IgA nephropathy: dimeric IgA-secreting cells are present in episcleral infiltrate.

Recent publications have reported a frequent association between IgA nephropathy and episcleritis. In this article, the authors report on the immunohistologic study of an episcleral biopsy obtained in a female patient with Berger's disease and frequent episodes of episcleritis. Numerous dimeric-IgA-secreting cells were demonstrated in the episcleral inflammatory infiltrate.

Thymulin (FTS-Zn) induced in vitro modulation of T cell subsets markers on lymphocytes from rheumatoid arthritis and systemic lupus erythematosus patients.

Perturbations in T cells and T cell subsets of peripheral blood lymphocytes were looked for, using monoclonal antibodies, in nine patients with rheumatoid arthritis (RA) and four patients with systemic lupus erythematosus (SLE). All SLE patients were in an acute phase of their disease, but had not yet received steroids. Seven of the nine RA patients presented an active illness, recently diagnosed in five cases, and received no steroids nor D-penicillamin.

[Antigenic markers of immunocompetent cells in rheumatoid synovial membrane].

Immunologic characteristics of cells present in rheumatoid synovium from 15 patients were analyzed either "in situ" on frozen sections or after elution. Monoclonal antibodies directed against T cell subpopulation antigens and anti-Ia-like were used. T cells bearing the phenotype T3+, T4+, Ia+ are numerous, and they appeared gathered in lymphoid follicles and in perivascular areas.

Immunoglobulin A nephropathy. Quantitative immunohistomorphometry of the tonsillar plasma cells evidences an inversion of the immunoglobulin A versus immunoglobulin G secreting cell balance.

Primary IgA nephropathy (Berger's disease) is characterized by renal deposits of IgA, the origin of which is still unknown. However, several clinical and biological findings suggest that these immunoglobulins might have a mucosal origin, and that such patients should present mucosal abnormalities. This paper reports the results of the immunohistomorphometrical analysis of tonsillar plasma cells from seven patients suffering from Berger's disease and seven controls also with recurrent tonsillitis.