[A new method for rapid and simple adsorption of rheumatoid factors from serum]

It is well known that autoantibodies directed against human gamma-globulin, the so called rheumatoid factor (Rheumafaktor), show interference with immunochemical methods. Especially the enzyme-linked immunoassays for detecting the early immune reaction against virus-infections (e.g. rubella, measles, and others) show irregular positive results, if the tests are performed in samples containing IgM rheumatoid factor. We describe a new method for the rapid adsorption and elimination of rheumatoid factor from rheumatoid factor containing serum samples, using a suspension of glutaraldehyde-cross-linked, aggregated IgG in a combined solid- and liquid-phase technique. The bound rheumatoid factor can be subsequently desadsorbed at acid pH so that after washing in neutral-buffer or physiological saline the adsorption-material can be used again. Specific antibodies were not adsorbed.