[Tropheryma whipplei and Whipple disease: false positive PCR detections of Tropheryma whipplei in diagnostic samples are rare].

Background: PCR can be used to detect T. whipplei (Tw) in samples from variable tissue types and body fluids. We report clinical, evolutive characteristics and final diagnosis in patients with positive Tw PCR assay.

Methods: Retrospective study of Tw PCR realized since 10years in a microbiology laboratory.

Results: Twenty-five Tw PCR assays were positive among 200 realized. Diagnosis was not confirmed in six cases. One patient was missing for follow up. Eighteen patients presented with Whipple's disease. Among these 18 patients, 14 had a classic Whipple's disease, three patients presented an endocarditis and one patient isolated neurological manifestations. Ten patients presented fever, seven a weight loss and 12 joint involvement. Four patients presented cutaneous manifestations, only six had gastrointestinal symptoms. Neurological involvement was reported in five cases, pulmonary symptoms in four cases, cardiac involvement in six cases and ocular signs in two cases. Anemia was reported in four patients and elevated levels of acute-phase reactants in 14 cases. Positive predictive value of Tw PCR for Whipple's disease diagnosis was 75%. Thirteen patients had a good evolution with antibiotics. Three patients presented recurrence and two cases with cardiovascular involvement died.

Conclusion: Whipple's disease is rare but often mentioned in internist experience. The diagnosis should be every time confirmed. Tw PCR assay is an important diagnostic tool but is not sufficient to establish the diagnosis and must be interpreted with histopathology and immunohistochemical testing results.