Whipple's Disease - Diagnosis

Diagnosis

Common clinical signs and symptoms of Whipple's disease include weight loss, joint pain or arthritis, diarrhea, skin rashes, fever, and adenopathy. Weight loss and diarrhea are the most common symptoms that lead to identification of the process, but may be preceded by chronic, unexplained, relapsing episodes of non-destructive seronegative arthritis, often of large joints.

Diagnosis is made by biopsy, usually by duodenal endoscopy, which reveals presence of the organism as PAS-positive, non-acid-fast macrophage inclusions. Immunohistochemical staining for antibodies against T. whipplei has been used to detect the organism in a variety of tissues, and a PCR-based assay is also available. PCR can be confirmatory if performed on blood, vitreous fluid, synovial fluid, heart valves, or cerebrospinal fluid. PCR of saliva, gastric or intestinal fluid, and stool specimens is highly sensitive, but not specific enough, indicating that healthy individuals can also harbor the causative bacterium without the manifestation of Whipple's disease, but that a negative PCR is most likely indicative of a healthy individual.

Endoscopy of the duodenum and jejunum can reveal pale yellow shaggy mucosa with erythematous eroded patches in patients with classic intestinal Whipple's disease, and small bowel X-rays may show some thickened folds. Other pathological findings may include enlarged mesentric lymph nodes, hypercellularity of lamina propria with "foamy macrophages", and a concurrent decreased number of lymphocytes and plasma cells, per high power field view of the biopsy.