title: The low-throughput protein A adsorber: an immune modulatory device. Hypothesis for the mechanism of action in the treatment of rheumatoid arthritis.
abstract: To achieve specific removal of pathogenic antibodies (Ab) or immune complexes (IC), several adsorbers have been developed. We discuss the mode of action of low-throughput staphylococcal protein A (SPA) immunoadsorption. The SPA-based Prosorba apheresis is likely to modify some of the autoantibodies (autoAb) or IC. The low-throughput adsorber showed very limited adsorption capacity of circulating autoAb and/or circulating IC. Besides changes of humoral diagnostic parameters, cellular changes could be observed in the Prosorba-treated patients. These changes were rather similar to those that have been observed in a patient successfully treated with Ab against tumor necrosis factor alpha. We propose an adsorber-catalyzed conversion of small, tissue-penetrating, scarcely detectable, non-complement-binding, proinflammatory IgG-rheumatoid factor (RF)-based IC into the more readily phagocytosed species of IC: intermediate-sized, partially cryoprecipitable, non-tissue penetrating IC that are opsonized with complement. These IC are rather short-lived and could quickly be cleared by the body's scavenging system.
authors.affiliation: Institute for Clinical Immunology, Department of Medicine III, Friedrich-Alexander University of Erlangen-Nuremberg, Glückstrasse 4a, 91054, Erlangen, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Brunner
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kern
authors.forename: Udo S
authors.initials: US
authors.lastname: Gaipl
authors.forename: Luis E
authors.initials: LE
authors.lastname: Munoz
authors.forename: Reinhard E
authors.initials: RE
authors.lastname: Voll
authors.forename: Joachim R
authors.initials: JR
authors.lastname: Kalden
authors.forename: Craig W
authors.initials: CW
authors.lastname: Wiesenhutter
authors.forename: Martin
authors.initials: M
authors.lastname: Herrmann