Immunoaffinity Extraction and Alternative Approaches for the Analysis of Toxins in Environmental, Food or Biological Matrices.

The evolution of instrumentation in terms of separation and detection allowed a real improvement of the sensitivity and analysis time. However, the analysis of ultra-traces of toxins in complex samples requires often a step of purification and even preconcentration before their chromatographic analysis. Therefore, immunoaffinity sorbents based on specific antibodies thus providing a molecular recognition mechanism appear as powerful tools for the selective extraction of a target molecule and its structural analogs to obtain more reliable and sensitive quantitative analysis in environmental, food or biological matrices. This review focuses on immunosorbents that have proven their efficiency in selectively extracting various types of toxins of various sizes (from small mycotoxins to large proteins) and physicochemical properties. Immunosorbents are now commercially available, and their use has been validated for numerous applications. The wide variety of samples to be analyzed, as well as extraction conditions and their impact on extraction yields, is discussed. In addition, their potential for purification and thus suppression of matrix effects, responsible for quantification problems especially in mass spectrometry, is presented. Due to their similar properties, molecularly imprinted polymers and aptamer-based sorbents that appear to be an interesting alternative to antibodies are also briefly addressed by comparing their potential with that of immunosorbents.

[Immunoadsorption in dermatology]. / Immunadsorption in der Dermatologie.

Autoimmmune bullous diseases are mediated by pathogenetically relevant autoantibodies against components of the epidermis and/or superficial mucous membranes (in pemphigus) and structural proteins of the dermal-epidermal junction (in pemphigoid diseases). Using immunoadsorption (IA), an already well-established procedure in cardiac and rheumatic disorders, antibodies can be removed from the plasma. At present, most data on the adjuvant use of IA in dermatology are derived from patients with severe and/or refractory pemphigus vulgaris or pemphigus foliaceus and also from patients with pemphigoid diseases. Additionally, in the last few years different protocols for IA in patients with severe atopic dermatitis and elevated total serum IgE levels have been published. While panimmunoglobulin adsorbers are mainly used in dermatology, an IgE-specific adsorber has been used in some patients with atopic dermatitis and in the future, antigen-specific adsorbers are to be expected that will enable the specific reduction of autoantibodies.

Importancia del patrón moteado fino denso y de los anticuerpos anti-DFS70 en el diagnóstico de enfermedades autoinmunitarias del tejido conectivo / Importance of the dense fine speckled pattern and anti-DFS70 antibodies for the diagnosis of systemic autoimmune rheumatic diseases

No disponible

Immunoadsorption therapy in patients with multiple sclerosis with steroid-refractory optical neuritis.

BACKGROUND: In multiple sclerosis relapses refractory to intravenous corticosteroid therapy, plasma exchange is recommended. Immunoadsorption (IA) is regarded as an alternative therapy, but its efficacy and putative mechanism of action still needs to be established. METHODS: We prospectively treated 11 patients with multiple sclerosis who had optical neuritis and fulfilled the indications for apheresis therapy (Trial registration DE/CA25/00007080-00). In total, five IA treatments were performed using tryptophan-IA. Clinical activity (visual acuity, Expanded Disability Status Scale, Incapacity Status Scale), laboratory values and visual evoked potentials were measured before, during and after IA, with a follow-up of six months. Moreover, proteomic analyses were performed to analyze column-bound proteins as well as corresponding changes in patients' sera. RESULTS: After the third IA, we detected an improvement of vision in eight of eleven patients, whom we termed responders. Amongst these, the mean visual acuity improved from 0.15 ± 0.12 at baseline to 0.47 ± 0.32 after the third IA (P = 0.0252) up to 0.89 ± 0.15 (P < 0.0001) at day 180 ± 10 after IA. Soluble interleukin-2 receptor decreased in responders (P = 0.03), whereas in non-responders it did not. Proteomic analyses of proteins adsorbed to IA columns revealed that several significant immunological proteins as well as central nervous system protein fragments, including myelin basic protein, had been removed by IA. CONCLUSIONS: IA was effective in the treatment of corticosteroid-refractory optic neuritis. IA influenced the humoral immune response. Strikingly, however, we found strong evidence that demyelination products and immunological mediators were also cleared from plasma by IA.

Immuno-PCR: high sensitivity detection of proteins by nucleic acid amplification.

Nucleic acid amplification techniques are used for signal generation in antibody-based immunoassays, thereby dramatically enhancing the sensitivity of conventional immunoassays. Methodological aspects, as well as applications of this novel approach, are summarized in this review, with an emphasis on immuno-polymerase chain reaction (IPCR). IPCR is based on chimeric conjugates of specific antibodies and nucleic acid molecules, the latter of which are used as markers to be amplified by PCR for signal generation. The enormous efficiency of nucleic acid amplification typically leads to a 100-10,000-fold increase in sensitivity, as compared with the analogous enzyme-amplified immunoassay. The evolution of IPCR included the development of efficient reagents, the design of assay formats and the maintenance of functionality, even within complex biological matrices. Eventually, IPCR crossed the border from being a research method to a routine laboratory technique, enabling a broad range of applications in immunological research and clinical diagnostics.

New trends in specific immunoadsorption.

Plasma exchange is widely accepted to remove pathogenic substances from patients' blood that cannot be eliminated otherwise like cholesterol in severe forms of familial hypercholesterolaemia or immunoglobulins and circulating immune complexes (CIC) in many autoimmune disorders. But dilution of other plasma proteins, as well as side effects and costs of substitution fluids, limit its efficiency. In immunoadsorption, the pathogen is bound specifically, generally no substitution fluids are needed and plasma can be conducted over the immunoadsorption columns as often as needed to achieve any reduction that one aims at, in some instances below the detection limit (e.g. HLA-antibodies in transplantations). The frequency of aphaereses is determined by the speed of the patients' improvement and the rebound of the eliminated substance, which can in some disorders be slowed down or stopped by concomitant immunosuppression. Generally, immunoadsorption is used in patients, where less expensive and demanding treatment options have failed, like severe hypercholesterolaemia, autoimmune disorders or hyperviscosity syndromes.