Detection of Tropheryma whipplei DNA in Joint Fluid of Patients with Arthritis by Polymerase Chain Reaction

ABSTRACT

BACKGROUND: Whipple's disease is a chronic systemic infection caused by Tropheryma whipplei which chiefly involves gastrointestinal tract and joints. Because arthritis is often the first sign of Whipple's disease, Whipple's disease may be misdiagnosed in the early stage of illness as non-infectious inflammatory arthritis. Rheumatoid arthritis may also be caused by infectious agents, including T. whipplei. To elucidate the relationship between T. whipplei infection and various arthritis, we examined T. whipplei DNA in Korean patients by polymerase chain reaction (PCR). MATERIALS AND METHODS: With two T. whipplei-specific primers dervied from the partial heat shock protein 65 gene sequence, PCR was performed on 56 joint fluid samples33 samples from RA patients, 18 samples from OA patients, and 5 samples from patients with other unflammatory arthritis. In addition, the same method was applied to find out the DNA of T. whipplei in 8 normal adults' saliva and 22 patients' gastric juice. Due to the difficulty in obtaining the reference strain of T. whipplei, the PCR was performed without the positive control. RESULTS: The PCR method did not reveal T. whipplei in joint fluid from 56 patients with arthropathies, 8 samples from saliva, and 22 samples from gastric juice. CONCLUSION: Though technical errors can not be excluded as a cause of absence of a positive case, our results suggest that T. whipplei infection may not be a common cause of various arthritis in Korea; T. whipplei may be associated with inflammatory arthritis indirectly by immune-mediated mechanism rather than by direct joint invasion. The examination of specimens other than joint fluid could be helpful and the study of larger number of patient is highly desirable.