Pleuritis and Pericarditis in Antineutrophil Cytoplasmic Autoantibody-Associated Vasculitis

Background: Pleural and pericardial involvements are well recognized in eosinophilic granulomatosis with polyangiitis (EGPA) but considered rare manifestations of the other forms of antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV). Research Question: What are the frequency and clinical characteristics of pleuritis and pericarditis in AAV? Study Design: and Methods: Using an institutional database of 1,830 patients with AAV, we analyzed clinical notes and diagnosis codes for key words related to pleuritis and pericarditis. Chart review to confirm these findings was performed. Results: Eighty-eight of 1,058 patients (8.3%) with granulomatosis with polyangiitis (GPA), 27 of 267 (10.1%) with microscopic polyangiitis (MPA), and 35 of 201 (17.4%) with EGPA had a manifestation of pleuritis and/or pericarditis attributable to vasculitis. There was a higher frequency of pericarditis in EGPA compared with that in the other AAVs (P < .01). There was no difference in the frequency of pleuritis in GPA, MPA, or EGPA. In the 156 patients with AAV with pleuritis and/or pericarditis, this was a presenting feature in 127 (81.4%). Overall, it was a presenting feature in 6.9% of all patients with AAV, including 6.5% with GPA, 8.6% with MPA, and 15.9% with EGPA. Interpretation: Pleuritis and pericarditis occur across all the AAVs and, when present, are commonly presenting features of these diseases. Patients with EGPA have a higher proportion of pericardial involvement compared with pleural involvement, whereas this distribution is more equal in patients with GPA and MPA. Pleuritis and pericarditis are underrecognized features of AAV. All forms of AAV should be considered in the differential diagnosis when evaluating a patient with pleuritis or pericarditis.