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Polyarthritis with perinuclear antineutrophil cytoplasmic antibody inaugurating microscopic polyangiitis. Report of a
P Pizzuti1, F Kemiche, E Pertuiset
1Department of Medicine, René-Dubos Hospital, Pontoise, France.
Abstract:
Microscopic polyangiitis, a condition recently differentiated from macroscopic periarteritis nodosa, is characterized by small vessel damage, pauciimmune necrotizing glomerulonephritis and presence of perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA). Arthralgia is a common symptom often present early in the disease, and other joint manifestations have also been reported. We report a case with polyarthritis as the first manifestation. Perinuclear ANCA was found in a moderate titer. A renal biopsy done six months after the onset of joint symptoms to investigate rapidly progressive renal failure established the diagnosis. The p-ANCA exhibited antimyeloperoxidase specificity. In the discussion we review the diagnosis of microscopic polyangiitis and of concomitant polyarthritis and p-ANCA production. ANCA is present in some patients with rheumatoid arthritis or systemic lupus erythematosus. It is important to determine the specificity of the ANCA since presence of p-ANCA with antimyeloperoxidase specificity in a patient with polyarthritis is highly suggestive of systemic vasculitis.
Insights
Microscopic polyangiitis can present with polyarthritis as an initial symptom. Identifying antimyeloperoxidase specificity in perinuclear anti-neutrophil cytoplasmic antibodies aids in diagnosing this systemic vasculitis.
Area of Science:
- Rheumatology
- Nephrology
- Immunology
Background:
- Microscopic polyangiitis (MPA) is a small vessel vasculitis distinguished by pauciimmune necrotizing glomerulonephritis and perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA).
- Joint symptoms like arthralgia are common in MPA, but polyarthritis as the primary manifestation is less frequently reported.
Observation:
- This case report details a patient whose initial presentation of microscopic polyangiitis was severe polyarthritis.
- The patient was found to have a moderate titer of p-ANCA, which was later determined to have antimyeloperoxidase (MPO) specificity.
- Diagnosis of MPA was confirmed via renal biopsy six months after the onset of joint symptoms, prompted by rapidly progressive renal failure.
Findings:
- The presence of p-ANCA with antimyeloperoxidase specificity in a patient experiencing polyarthritis is a strong indicator of systemic vasculitis.
- This case highlights the importance of considering MPA in patients with polyarthritis and positive ANCA results, even when renal symptoms are not immediately apparent.
Implications:
- Early recognition of MPA, particularly when presenting with polyarthritis, is crucial for timely diagnosis and management.
- Determining ANCA specificity is vital for differentiating systemic vasculitis from other conditions like rheumatoid arthritis or systemic lupus erythematosus that may also exhibit ANCA positivity.