• A new test, involving the use of a suspension of latex particles, was applied to 1,606 samples of serum from 907 patients whose clinical diagnoses, whether of rheumatic disease or otherwise, had been established. The latex particles in stock suspension had a fairly uniform mean diameter of 1.17 microns. For the test they were mixed with borate buffer and gamma globulin. When the serum to be tested is added to this mixture it may or may not cause aggregation of the particles. A positive test is indicated by discernible aggregation, which can be read with the naked eye. Of 291 patients who met the clinical criteria for the diagnosis of rheumatoid arthritis, 245 (84.2%) showed positive latex fixation tests; the 46 instances of false-negative reactions have been studied. Of 414 patients with rheumatic disease other than rheumatoid arthritis, 399 (96.3%) gave negative latex fixation reactions; the 15 false-positive reactions have likewise been studied. The test was as reliable as are the various sheep cell agglutination tests now used for serologic detection of rheumatoid arthritis, and it had the advantage of being simple, very inexpensive, fast, and clinically useful.
Rothermich NO, Philips VK. THE SEROLOGIC DIAGNOSIS OF RHEUMATOID ARTHRITIS. JAMA. 1957;164(18):1999–2004. doi:10.1001/jama.1957.02980180001001