The clinical and pathological spectrum of antineutrophil cytoplasmic autoantibody-related pulmonary disease. A comparison between perinuclear and cytoplasmic antineutrophil cytoplasmic autoantibodies.

Antineutrophil cytoplasmic autoantibodies (ANCAs), classified as either perinuclear (P-ANCAs) or cytoplasmic (C-ANCAs), have been recently recognized as important markers for the diagnosis and monitoring of systemic vasculitic disorders. The purpose of this study was to review retrospectively the clinical and pathological features in patients with P-ANCA-positive (P-ANCA+) patterns and pulmonary disease who underwent open lung biopsies and to contrast these findings with those found in patients with C-ANCA-positive (C-ANCA+) patterns who underwent open lung biopsies. Nine patients with ANCA+ pattern (five with P-ANCA+ and four with C-ANCA+ patterns) who had evidence of systemic vasculitis and pulmonary dysfunction underwent open lung biopsies. A comparison of the clinical presentation in patients with P-ANCA+ vs C-ANCA+ patterns showed few apparent differences in the clinical presentation or in the organ involvement. Histologic review of the findings from the open lung biopsies showed similar patterns of pulmonary injury, irrespective of the specific ANCA-staining pattern. Major pathologic changes included intra-alveolar hemorrhage (four patients with P-ANCA+ patterns vs three patients with C-ANCA+ patterns), necrotizing capillaritis (four patients with P-ANCA+ patterns vs three patients with C-ANCA+ patterns), vasculitis (three patients with P-ANCA+ patterns vs two patients with C-ANCA+ patterns), and necrotizing granulomatous inflammation (two patients with P-ANCA+ patterns vs one patient with C-ANCA+ patterns). Unusual pathologic findings included chronic interstitial fibrosis (two patients with P-ANCA+ patterns vs two patients with C-ANCA+ patterns), cavitary nodules with necrotic neutrophils and minimal granulomatous inflammation (one patient with P-ANCA+ patterns), and bronchiolocentric granulomatous inflammation (one patient with P-ANCA+ patterns vs one patient with C-ANCA+ patterns). In ANCA-related pulmonary disease, there are few significant clinical or pathological differences when patients with P-ANCA+ patterns are compared with patients with C-ANCA+ patterns.