Pulmonary Involvement in ANCA-associated Vasculitis Overlapping with Long-standing Systemic Lupus Erythematosus

Area of Science:

• Rheumatology
• Immunology
• Pulmonology

Background:

• Systemic lupus erythematosus (SLE) and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis are distinct autoimmune conditions.
• Coexistence is rare, particularly years after SLE onset.

Purpose of the Study:

• To report a rare case of coexisting SLE and ANCA-associated vasculitis.
• To highlight the importance of ANCA testing in SLE patients with new manifestations.

Main Methods:

• Case report of a 74-year-old woman with long-standing SLE.
• Clinical presentation, chest CT, laboratory findings, and lung histology were analyzed.
• Diagnosis of Granulomatosis with polyangiitis was confirmed.

Main Results:

• The patient presented with fever, pulmonary nodules, acute kidney injury, and elevated ANCA.
• Lung biopsy showed necrotizing granuloma with vasculitis.
• Treatment with glucocorticoids and rituximab led to improvement.

Conclusions:

• ANCA-associated vasculitis can occur in patients with established SLE.
• Consider ANCA testing in SLE patients with new pulmonary or systemic symptoms, especially renal dysfunction.
• Early diagnosis and treatment are essential for favorable outcomes.