Failure to show mycoplasmas and cytopathogenic virus in rheumatoid arthritis.

Synovial needle biopsies, joint aspirates, and joint tissue obtained at open operation from 41 cases of rheumatoid arthritis were inoculated onto PPLO media, L-form medium, and cell cultures for the isolation of mycoplasmas, L-form bacteria, and viruses. Medium suitable for the isolation of 'T' strain mycoplasmas was not employed. No mycoplasmas, L-form bacteria, or cytopathogenic viruses were shown. Similar specimens from nine patients diagnosed as having Reiter's disease were examined in a like manner and yielded only one Mycoplasma hominis type 1 isolate from a knee joint biopsy. It is concluded that known strains of mycoplasma and bacterial L-forms do not play a direct role in early and established cases of rheumatoid arthritis. Some of the cell cultures used in this study contained mycoplasma contaminants. Bacterial contaminants were also encountered in occasional batches of L-form medium.