P-ANCA VASCULITIS-INDUCED RENAL IMPAIRMENT WITH CONCURRENT SPLENIC ARTERY ANEURYSM IN A NEPALI WOMAN WITH RHEUMATOID ARTHRITIS: A RARE OVERLAP SYNDROME OR CO-EXISTING OCCURRENCE

Introduction:

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a severe autoimmune disease characterized by significant morbidity and mortality, with diagnostic delays often correlating with poorer clinical outcomes. Although rare, AAV can coexist with other immune-mediated disorders such as Rheumatoid Arthritis (RA), potentially due to shared genetic susceptibilities, including variations in the HLA region and the PTPN22 gene, which have been implicated in both conditions. Medium-sized vessel involvement in Myeloperoxidase (MPO)-ANCA-associated vasculitis, resulting in mesenteric vascular aneurysms and hemoperitoneum, represents an uncommon but increasingly recognized phenomenon. Given the high mortality associated with aneurysmal rupture, the need for early diagnosis and targeted therapeutic interventions is paramount.

Methods:

This report presents a case of a patient with a history of RA, who was subsequently diagnosed with P-ANCA-associated vasculitis, rapidly progressive glomerulonephritis (RPGN), and hemoperitoneum secondary to a splenic artery aneurysm.

Results:

A 57-year-old female with established RA, receiving pharmacological treatment, was admitted for left-hand cellulitis. During her hospitalization, she developed hematuria and renal impairment. Initial evaluation revealed anemia, pedal edema, renal function derangement, and the presence of numerous red blood cells in her urine. Further testing confirmed a positive MPO/p-ANCA result (titre=192). (Table 1) The patient was initiated on intravenous methylprednisolone for induction therapy, followed by cyclophosphamide. After three doses of methylprednisolone, she developed acute abdominal pain, and subsequent imaging revealed hemoperitoneum secondary to a ruptured splenic artery aneurysm. The patient was transferred to the intensive care unit, where she underwent embolization of the aneurysm. Postoperatively, she received two doses of intravenous cyclophosphamide (500 mg) and remained hemodynamically stable at discharge. Renal biopsy was deferred due to the patient’s critical condition, and she was advised to follow up for further management.

Conclusions:

Medium-sized vessel involvement in MPO-ANCA vasculitis, leading to mesenteric aneurysms and hemoperitoneum, is rare but clinically significant. This case underscores the importance of heightened clinical vigilance in patients with AAV presenting with abdominal symptoms to facilitate prompt diagnosis and effective management of these potentially life-threatening complications. We believe that recognizing this overlap is critical for more efficient serological screening and early detection of potential clinical consequences.

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.