[IgE rheumatoid factors: occurrence and diagnostic significance]

Sera from 80 patients suffering from rheumatoid arthritis--30 of them with extraarticular manifestations (EAM)--were analyzed for the presence of IgE rheumatoid factors (IgE RF), IgM RF, and immune complexes. Despite of a close correlation between IgM RF and IgE RF, IgE RF allow a better discrimination between patients with and without EAM (73.3 and 38.0%) compared to IgM RF (86.7 and 78.0%). IgE RF could be found in 5% of patients suffering from bronchial asthma, but up to now not in nonrheumatic joint diseases.