The prevalence of Tropheryma whippelii DNA in saliva from healthy controls and patients with spondyloarthropathy

Abstract

Whipple's disease (WD) is a chronic infectious disorder of multi-system caused by Tropheryma whippelii (TW). Although the prominent symptoms are diarrhea, malabsorption, and weight loss, the arthritis may precede the gastrointestinal symptoms [1]. Furthermore, some cases of WD shows the clinical manifestations of spondyloarthropathy (SpA), such as oligoarthritis pattern, axial involvement, sacroiliitis, and association with HLA-B27 [2].The presence of periodic acid-SchiV-staining foamy macrophages in the lamina propria of duodenum is diagnostic of WD [1]. Recently the molecular diagnosis using TW-speciWc gene ampliWcation is promising. The sequencing of 23S ribosomal RNA (rRNA) gene was established and it provided a basis for molecular diagnosis in the absence of reliable culture and serology [3].As an eVort to disclose whether TW is associated with the pathogenesis of SpA, we investigated the prevalence of TW DNA in saliva of patients with SpA and in healthy controls.A total of 108 patients who were diagnosed as ankylosing spondylitis were enrolled. As a control group, we recruited 132 healthy volunteers. There were no diVerences seen in age distribution and sex between the cases and the controls.Participants were asked to rinse the mouth with tap water to remove any remaining food. Approximately 5 ml of whole saliva was collected by having subjects spit into 50 ml sterile collection tubes. The salivary samples were stored at ¡70°C until DNA was extracted.All DNA samples had been tested using semi-nested PCR for hypervariable region of domain III of the 23S rDNA with primers HGC-23InsF and TW-23InsR1 and for nested re-ampliWcation TW-23InsF and TW23InsR2 were used [3].We found two cases and two controls to be PCR-positive in the saliva. This leads to prevalence rates of 1.5% (95% CI 2.0-7.6%) in controls and 1.9% (95% CI 4.0-11.3%) in cases. In contrary to previous western reports [4,5], the prevalence value of TW DNA in Korean patients without WD is signiWcantly low. This may explain that there is so far no any reported case of WD in Korea. All specimens which PCR was positive were analyzed by direct sequencing in order to conWrm. They were identical to the searched sequence for TW (http://www.ncbi.nlm. nih.gov/entrez/query.fcgi?db=Nucleotide).The previous study showed that all PCR results for 16S rRNA were negative in patients with unexplained seronegative oligoarthritis or polyarthritis, and TW does not seem to be frequently involved in this clinical setting [6].

Prevalence and detection of Tropheryma whipplei in the stools of Korean patients with diarrhea using real-time PCRs

“…Similar to previous Korean studies conducted with saliva, T. whipplei was detected low in the stools of patients with diarrhea, with a prevalence of 1.4% [ 22 , 23 ]. A recent study investigating the stools of patients with diarrhea for T. whipplei in three locations on different continents reported that its prevalence may differ between continents [ 26 ].…”

“…This study provides baseline data about the presence of T. whipplei in the stools of Korean patients with diarrhea because it was performed on a large cohort including all ages. In addition, positive controls that were not used for PCRs in previous Korean studies were used in this study [ 12 , 22 , 23 ]. Without positive controls for the PCRs, inaccurate results may have been obtained.…”

“…High prevalence in children has been reported at 27.5% in Ghana and 48% in Laos [ 18 , 21 ]. In Korea, only three studies have reported the prevalence of T. whipplei [ 12 , 22 , 23 ]. The presence of T. whipplei DNA was investigated in 56 joint fluid samples of arthritic patients and in eight saliva and 22 gastric juice samples of healthy individuals; all results were negative [ 12 ].…”

“…The presence of T. whipplei DNA was investigated in 56 joint fluid samples of arthritic patients and in eight saliva and 22 gastric juice samples of healthy individuals; all results were negative [ 12 ]. The prevalence of T. whipplei was 1.9% (2 of 108) and 1.5% (2 of 132) in saliva of spondyloarthropathy patients and healthy individuals, respectively [ 22 ]; it was 1.1% (1 of 89) in saliva of 53 reflux esophagitis and 36 irritable bowel syndrome patients [ 23 ]. To the best of our knowledge, there has been no study in Korea to estimate the prevalence of T. whipplei in stools.…”

High Prevalence of Tropheryma whipplei in Lao Kindergarten Children

“…As far as we aware no one has investigated T . whipplei fecal carriage in Asia, but it has been detected in Korea among 1.5% of healthy peoples’ saliva, but not in any of 108 small-bowel biopsies in Malaysia or in any of ten marginal supragingival plaque samples from Chinese patients with gingivitis [ 17 , 18 , 20 ]. In rural Senegal, the first contact with the bacterium occurred mainly in children before 4 years of age, with the prevalence of T .…”