Immunoadsorption apheresis (Selesorb) in the treatment of chronic hepatitis C virus-related type 2 mixed cryoglobulinemia.

In this short-term open label clinical pilot study, conducted at one center, the immune complex dextran sulphate adsorber (Selesorb) was used to treat four female patients aged 59-69 with HCV-related cryoglobulinaemia, vasculitis and/or neuropathy. The primary trial objective was to assess the clinical efficacy of the immunoadsorber. The secondary objective of the trial was to determine the safety of the adsorber and to investigate the adsorption capacity, measured as the adsorption of cryoglobulin-related immune complexes and the resulting influence on plasma components of the immune system. The patients have been submitted to treatment with the immunoadsorber, at approximately 1-3 days intervals, completing six sessions. The follow-up was one month. In the patients treated with Selesorb, we observed a statistically significant decrease in plasma of all classes of immunoglobulins (IgA: 5-28%; IgG: 14-44%; IgM: 8-38%). In two patients with peripheral neuropathy secondary to cryoglobulinemia, the symptomatology was improved. In a third patient the neurological involvement was substantially unchanged, and the same unsuccessful outcome was observed for Sjögren syndrome is concerned. Nevertheless, the two patients with lower extremity vasculitis showed an appreciable improvement. We failed to observe significant side effects directly related to the use of this immunoadsorbent.

Major allergen measurements: sources of variability, validation, quality assurance, and utility for laboratories, manufacturers, and clinics.

The isolation and characterization of prominent allergenic proteins or glycoproteins is an important step in the development of allergenic extracts exhibiting improved definition, consistency, and clinical utility. Quantitative analyses specific for major allergenic components currently are being performed in numerous corporate and academic laboratories but have not been validated within or across laboratories in a systematic manner. In our laboratory, validation of double-bind (sandwich) ELISA assays for a diverse group of major allergens or extract components revealed a number of critical assay variables and reagent incubation conditions that directly influenced the precision, accuracy, specificity, and robustness of these tests. Data from ELISA methods for six allergens (Dermatophagoides farinae Der f 1, Alternaria Alt a 1, dog albumin, dog Can f 1, fire ant Sol i 3, and yellow jacket venom Ves 5) showed that up to twofold differences in results were observed when analysts or microplates were varied. Analyses of dog allergens using multiple reagents and concentrations indicated that twofold variations in results also can be produced by distinct combinations of materials or incubations from different assay steps. Data from Can f 1 and egg white analyses produced up to fivefold differences in antigen concentrations based on changes in the capture antibody source (mouse monoclonal versus rabbit polyclonal) or storage buffer. These results suggest that differences in major allergen concentrations reported by different testing laboratories may be related to assay differences as well as extract variations and raise questions as to the accuracy of major allergen concentrations and therapeutic dose recommendations reported at regional and national allergy meetings. Validated double-bind ELISA methods may be well suited for consistency monitoring and standardization of extracts provided that reference materials, reagent qualifications, and interlaboratory comparability are defined precisely.

Current status in extracorporeal immunomodulation: immune disorders.

Today, clinicians can choose from a variety of extracorporeal immunomodulatory procedures such as plasma exchange, double filtration, immunoadsorption, chemoadsorption, photopheresis, and cytoapheresis. The mechanisms underlying extracorporeal immunomodulation (ECIM) comprise removal of pathogenic antibodies and circulating immune complexes as well as reticuloendothelial system deblockage; modification of immune complex structure and processing can be induced by changing the antigen/antibody ratio and by modulation of immune complex solubility via complement activation. Finally, cellular components like lymphocyte subsets, can be modified. Clinical examples of ECIM include lupus erythematosus, Goodpasture's syndrome, anti-neutrophil cytoplasmatic antibodies-mediated systemic vasculitis, myasthenia gravis, and, hypothetically, sepsis.