Abstract from:  GASTROENTEROLOGY 1996; 110: 1735-1743

Diagnostic application of a polymerase chain reaction assay for the Whipple´s disease bacterium to intestinal biopsies

Axel von Herbay, Hans-Jürgen Ditton, Matthias Maiwald

Background/Aims: The uncultured Whipple's disease bacterium ( Tropheryma whippelii) was characterized in 1991/92 by polymerase chain reaction (PCR) and sequencing of the bacterial 16S rRNA gene. We have now developed a PCR assay for diagnostic purposes.

Methods: Modified primers for PCR and a specific probe for hybridization were designed. The specificity of this PCR assay was tested using 37 bacterial control strains and intestinal biopsies from 16 patients without Whipple's disease. The sensitivity was tested in 88 intestinal biopsies from 35 patients with Whipple's disease.

Results: PCR and hybridization was negative in all 37 bacterial controls and in all 16 patients without Whipple's disease. Prior to therapy, DNA of Tropheryma whippelii was detected in all 30 Whipple's disease patients from whom formalin-fixed biopsy material was available, while Bouin-fixed material was negative. During and after treatment, PCR was negative in 23 of the 24 patients who were followed up. Generally, conversion to negative occurred within one year. Despite negative intestinal PCR, symptomatic cerebral Whipple's disease appeared in 3 patients.

Conclusions: This PCR assay is specific and sensitive, and applicable as a diagnostic test. However, PCR from intestinal biopsies seems less helpful for monitoring the effect of treatment.

Update 1/2002. Since our publication, we have extented PCR analyses to more than 100 patients with Whipple´s disease. We have reproduced the published findings in the new patients. It has been strengthened that PCR from intestinal biopsies is not reliable to predict the patient´s outcome.