Rituximab for chronic periaortitis without evidence of IgG4-related disease: A long-term follow-up study of 20 patients

Chronic periaortitis (CP) is a rare condition characterised by a peri-aortoiliac fibro-inflammatory tissue. A total of 20%–50% of the cases are immunoglobulin G4 (IgG4)-related, based on histological evidence of IgG4+ plasma cell infiltration (on a background of dense lymphoplasmacytic infiltrates, storiform fibrosis and tissue eosinophilia) and/or increased serum IgG4.1 Glucocorticoids are the first-line therapy for CP.2 However, some patients are refractory, frequently relapsing or have contraindications to glucocorticoids. The anti-CD20 monoclonal antibody rituximab proved efficacious in systemic forms of IgG4-related disease (IgG4-RD) including IgG4-related CP,3 but data on IgG4-unrelated CP are scarce.4–6 In this study, we tested rituximab in CP patients without evidence of IgG4-RD who had relapsing/refractory disease or contraindications to standard-dose glucocorticoids. We included patients with active, IgG4-unrelated CP who received rituximab (October 2009 to April 2017). Online supplementary methods describe the diagnostic and follow-up procedures, the definitions of remission and refractory, and the statistical analysis.