High sensitive detection of double-stranded DNA autoantibodies by a modified Crithidia luciliae immunofluorescence test.

Anti-double-stranded (ds)DNA antibodies are serological markers of systemic lupus erythematosus (SLE). Of all anti-dsDNA antibody detection methods, the Crithidia luciliae immunofluorescence test (CLIFT) is thought to have the highest specificity for SLE. However, the clinical application is hampered by the low diagnostic sensitivity.

Enzyme kinetic assays with surface plasmon resonance (BIAcore) based on competition between enzyme and creatinine antibody.

A procedure is described which allows the characterization of enzyme by a hybrid approach using an enzyme and an antibody. The presented method is related to the affinity determination of antibodies by the 'affinity in solution' procedure for BlAcore. The antibody is used as an indicator for the concentration of substrate, which is also the antigen.

Antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is a disease characterized by venous and arterial thromboses or spontaneous abortions and the repeated detection of antiphospholipid antibodies (aPL). APS may be associated with another autoimmune disease (secondary APS), particularly systemic lupus erythematosus (SLE), or unrelated to an underlying disease (primary APS). APS affects almost all organs.

Development of a creatinine ELISA and an amperometric antibody-based creatine sensor with a detection limit in the nanomolar range.

Creatinine-specific antibodies have been generated and used for highly sensitive and specific immunochemical creatinine determinations. Creatinine was derivatized at N3 and coupled to KLH carrier protein. On the basis of this immunogen, monoclonal antibodies were developed by hybridoma technology.

C1q: a multifunctional ligand for a new immunoadsorption treatment.

C1q is a highly conserved protein with multiple functions involved in innate and adaptive immunity. It plays an important role in the activation of the classical pathway of the complement system to mediate the scavenging of infectious agents, apoptotic products, and immune complexes by the mononuclear phagocyte system (MPS). Exhibiting this function, C1q is able to bind various molecules (complexed IgG, IgM, fibrinogen, fibronectin, lipopolysaccharides, DNA, C-reactive protein [CRP], and viral proteins).

Quantitative polymerase chain reaction using a DNA hybridization assay based on surface-activated microplates.

A method for DNA quantification on microplates based on the hybridization between single-stranded target and solid-phase bound capture DNA is presented. Binding of the capture DNA to the microplates was attained by surface activation using organosilanes. Detection of hybridized DNA was performed by an enzyme-linked assay taking advantage of the labeled target DNA.

Development of a C1q-adsorbent for the selective removal of circulating immune complexes.

In body fluids circulating immune complexes possess a substantial pathogenic effect on a variety of diseases. Thus it seems to be reasonable to influence the pathogenic mechanism of such diseases by removing the circulating immune complexes out of the body fluids. The selective adsorbent for binding immune complexes were developed as possible alternative of plasmapheresis for specific removal of immune complexes out of the blood plasma.

Development of a DNA-adsorbent for the specific removal of anti-DNA autoantibodies in systemic lupus erythematosus (SLE).

Autoantibodies against DNA are of primary importance for the diagnosis and pathogenesis of systemic lupus erythematousus (SLE). The level of anti-DNA antibodies correlates well with the disease activity and renal involvement. In such patients the removal of anti-DNA antibodies from plasma may lead to a clinical improvement.

Binding of C1q and DNA to support materials by means of a new coupling procedure.

Since several years matrix-bound biologically active substances are widely used in biosciences, biotechnology and medicine. We are presenting a simple and inexpensive activation procedure for support materials which allows stable binding of C1q and DNA. We could not found a remarkable leakage of the bound ligands.

[Antibodies to anticoagulants in rheumatic autoimmune diseases].

The systemic lupus erythematosus (SLE) and the rheumatoid arthritis (RA) as the classic autoimmune diseases exhibit a great number of autoantibodies. Some of them are anticoagulants. Besides inactivating inhibitors against single coagulation factors interfering anticoagulants are known, belonging to the group of anti-phospholipid antibodies and detected as the lupus anticoagulants or anticardiolipin antibodies.

[Rapid determination of C-reactive protein using latex agglutination].

A simple and fast Latex agglutination assay for the determination of C-reactive protein (CRP) is described. The decision range of the assay presented is 7 mg/l; the measuring range extend from 7 mg/l up to 8,000 mg/l. Presented assay allows the cyto-determination of CRP in clinical routine work and therefore is suitable for the early diagnosis of infections in gynecology and obstetrics.

[Establishment and characterization of the pig aortic endothelial cell line BSEz-3 in a serum-reduced medium].

The cell line BSEz-3 was established in a serum-reduced medium MEMPAS. The cells were isolated and cultivated under the same conditions as the calf aortic endothelial cell line BKEz-7. With regard to cell isolation and cell density in the stationary phase, BSEz-3-cells show characteristic differences from BKEz-7-cells.

The use of glass as solid phase in enzyme immunoassay as exemplified by the detection of circulating immune complexes.

This article describes a solid-phase enzyme immunoassay for the quantitative determination of circulating immune complexes based on the covalent binding of proteins to glass. A quantitative comparison between adsorption to polystyrene and covalent binding to glass gave a protein higher concentration on the glass support. This leads, in connection with the strong attachment of the protein, to a higher sensitivity and precision in immunoassay.

Immunoglobulin G binding to human erythrocytes.

The binding of 125iodine labelled human IgG to allogenic erythrocytes was studied at various ratios of free IgG per cell. At low concentrations of free IgG a high affinity binding was measured, which is with respect to its apparent association constant (2.8 x 10(13) mol-1) most likely a specific receptor binding and might indicate aged cells of those destined for elimination.

[Demonstration of circulating immune complexes using a C1q-solid phase enzyme immunoassay].

An enzyme-immunoassay for the quantitative determination of circulating immune complexes in human serum is described. The technique uses alkaline phosphatase-conjugated anti-human IgG to detect immune complexes bound to solid phase C1q. This assay is sensitive detecting 4 ng/ml to 60 micrograms/ml aggregated IgG.