Mycoplasma infection and rheumatoid arthritis. Analysis of their relationship using immunoblotting and an ultrasensitive polymerase chain reaction detection method



Objective. To examine the relationship between infection with Mycoplasma and the development of rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA).

Methods. Immunoblotting of patient synovial fluid and sera on detergent-phase membrane protein extracts of various Mycoplasma species was carried out to learn whether patients exhibited serologic evidence of previous exposure to mycoplasmas. Moreover, an ultrasensitive polymerase chain reaction (PCR) method was developed for assessing whether Mycoplasma DNA could be detected in synovial fluid from patients and controls.

Results. Immunoblotting provided serologic evidence of previous Mycoplasma exposure in patients and controls. The genus-specific PCR detected known human Mycoplasma species and could reliably detect <5 copies of Mycoplasma hominis, Mycoplasma fermentans, or a molecular mimic control in synovial fluid. Repeat testing revealed no evidence of Mycoplasma DNA in patient synovial samples.

Conclusion. This study provided serologic evidence suggesting that, while previous exposure to Mycoplasma was common, there was no detectable persistence of Mycoplasma DNA in the synovial fluid or tissue of patients with RA or JRA.