From the Guidelines
Testing for Whipple's disease should involve a combination of clinical evaluation, small bowel biopsy with periodic acid-Schiff (PAS) staining, and PCR testing of tissue samples or body fluids to detect Tropheryma whipplei bacteria, as recommended in the 2021 AGA clinical practice update on the evaluation and management of seronegative enteropathies 1.
Diagnostic Approach
The diagnostic approach to Whipple's disease involves several key steps:
- Clinical evaluation for symptoms such as joint inflammation, sun-exposed skin, diarrhea, and weight loss.
- Small bowel biopsy with PAS staining to identify characteristic PAS-positive macrophages containing the bacteria.
- PCR testing of tissue samples or body fluids like cerebrospinal fluid to detect the bacterial DNA, which offers high sensitivity.
- Endoscopy with duodenal biopsies to obtain tissue samples.
- Blood tests to show signs of inflammation and malabsorption, although these are not specific to Whipple's disease.
Specific Tests
Specific tests for Whipple's disease include:
- Positive PCR for Tropheryma whipplei, as mentioned in the study 1.
- PAS-positive macrophagic infiltration of the lamina propria, which is a hallmark of the disease.
- PCR testing of cerebrospinal fluid in cases with neurological symptoms.
Importance of Early Diagnosis
Early diagnosis and treatment of Whipple's disease are crucial to prevent long-term complications and improve patient outcomes. Given the rarity but potential fatality of untreated Whipple's disease, testing should be considered in patients with unexplained weight loss, diarrhea, joint pain, and neurological symptoms, especially in middle-aged men who are most commonly affected.
From the Research
Testing for Whipple's Disease
To test for Whipple's disease, the following methods can be used:
- Upper gastrointestinal endoscopy with duodenal biopsy, which can show pathognomonic post-bulbar duodenal lesions 2, 3
- Small intestinal capsule biopsy, which can also be used for diagnosis 2
- Endoscopic small intestinal biopsies, which can reveal gross endoscopic lesions such as erosions, yellow plaques, and a pale yellow shaggy mucosa 3
- Duodenal biopsy, which can be used for diagnosis and follow-up 4, 5
- Magnification endoscopy, which can enhance the mucosal details and reveal engorged and flattened villi, villi filled with white material, and white ring-like structures inside of the villi and multiple yellow spots 5
Endoscopic Findings
The endoscopic findings in Whipple's disease can include:
- Oesophagitis 2
- Erosive gastritis 2
- Atrophic gastritis 2
- Severe erosive bulbitis 2
- Pathognomonic post-bulbar duodenal lesions 2, 3
- Edema, brown discoloration of the mucosa, erythematous spots, subepithelial hemorrhages, and megaduodenum 5
Histological Features
The histological features of Whipple's disease include: