Serum cryptococcal antigen determination in the presence of rheumatoid factor

Abstract

Sera from nine patients with cryptococcal infections and from four with rheumatoid arthritis and positive rheumatoid factor were examined for the presence of cryptococcal capsular antigen by the latex agglutination method. Ethylenediaminetetraacetic acid-heat treatment of the sera before testing possibly increased sensitivity as compared with the untreated sera, and the interfering rheumatoid factor activity was eliminated.