Gastrointestinal and renal involvement in systemic vasculitis.

Area of Science:

• Gastroenterology
• Nephrology
• Rheumatology

Background:

• Vasculitis, particularly IgA and ANCA-associated types, can manifest with gastrointestinal (GI) or solid organ involvement.
• Gastrointestinal involvement in vasculitis presents diagnostic challenges, often mimicking other GI disorders.

Observation:

• A 56-year-old female with acromegaly and chronic kidney disease presented with nausea, vomiting, epigastric pain, and fever.
• Abdominal CT revealed duodenal thickening and pancreatic edema; EGD showed nodular duodenal mucosa with ulcerations.
• Initial differential diagnoses included infectious enteritis, Whipple disease, infiltrative disorders, and GI vasculitis.

Findings:

• Multidisciplinary discussion led to oral glucocorticoid initiation due to worsening renal function, resulting in symptom resolution and renal stabilization.
• Subsequent testing revealed positive myeloperoxidase antineutrophilic-cytoplasmic antibodies (MPO-ANCA).
• Histopathology confirmed duodenal vasculitis, a rare finding in endoscopic biopsies, especially limited to the duodenum in MPO-ANCA vasculitis.

Implications:

• This case underscores the importance of considering GI vasculitis in patients with unexplained GI symptoms and renal dysfunction, particularly those with ANCA positivity.
• Successful treatment with glucocorticoids highlights their efficacy in managing this rare presentation.
• The findings emphasize the diagnostic value of endoscopic biopsies in confirming vasculitis, even in unusual locations like the duodenum.