Antineutrophil cytoplasmic antibody-associated vasculitis with initial gastrointestinal symptoms: case series and literature review.

INTRODUCTION

While antineutrophil cytoplasmic antibody (ANCA)-associated small-vessel vasculitis (AAV) is increasingly recognized, cases presenting with initial gastrointestinal symptoms remain underexplored. This study aimed to analyze the clinical characteristics of AAV patients with gastrointestinal onset.

METHODS

Seven AAV patients meeting ACR/EULAR criteria, who presented with gastrointestinal symptoms between January 2017 and 2024, were retrospectively identified. A literature review was conducted across multiple databases, including PubMed, Web of Science, Cochrane Library, Embase, CNKI, VIP, and Wanfang. In total, 23 patients were included in the study.

RESULTS

Among the 23 AAV patients with gastrointestinal symptoms, 15 (65.2%) were male, with a median age of 54 years (range: 18-79). Common clinical manifestations included hematochezia (56.5%), weight loss (43.5%), and purpura (34.8%). Eight (34.8%) had superficial gastritis, and seven (30.4%) had colonic ulcers, as identified by gastrointestinal endoscopy. Laboratory findings revealed elevated D-dimer levels and anemia in most patients, with impaired renal function and a median hemoglobin level of 105 g/L. Anti-PR3 immunoglobulin G (IgG) and antimyeloperoxidase IgG antibodies were positive in 83.3 and 80% of cases, respectively. Abdominal computed tomography (CT) revealed wall thickening in 39.1% of patients, and chest CT identified interstitial lung disease in 73.9% of patients. Nine patients (39.1%) were initially misdiagnosed, with five (55.6% of those nine) misdiagnosed as having inflammatory bowel disease. Most patients responded well to glucocorticoid and immunosuppressive therapy, with 39.1% receiving a combination of glucocorticoids and cyclophosphamide.

CONCLUSION

Gastrointestinal symptoms in AAV are rare, and misdiagnosis remains a concern. Early detection requires assessing gastrointestinal, pulmonary, and renal involvement.