puzzle of the false positive reaction in Cr neoformans'es capsular antigen slide latex agglutination test by sera of patients with rheumatoid arthritis

ABSTRACT

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 latex agglutination tests. This is because of Iron's Ion reaction with reagent's preservative sodium azid and/or negative charge of the antigens fixed to the latex particles