different examination have shown that rheumatoid factor is not responsible for false positive reaction (f.p.r.) in cr. neoformanse’s free capsular antigen latex agglutination test, whereas high levels of iron in sera of patients with rheumatoid arthritis as well as other sera was responsible not only for this f.p.r. , but also had an important role in the production of f.p.r. in many slide late...