Rituximab therapy for chronic periaortitis.

Chronic periaortitis (CP) is a rare condition, hallmarked by periaortic fi bro-infl ammatory tissue which often causes ureteral obstruction, and encompasses idiopathic retroperitoneal fi brosis and infl ammatory abdominal aortic aneurysm (IAAA). CP usually responds to glucocorticoids, but some patients may be steroid-refractory or not tolerate standard glucocorticoid doses. For such cases, valid therapeutic alternatives are lacking.1 2 Combinations of prednisone and immunosuppressants (eg, cyclophosphamide, mycophenolate mofetil) are not of proven superiority to prednisone alone, and their effectiveness in refractory CP is unknown.3 4 Because B cells abundantly infi ltrate CP lesions,5 and CP is often associated with autoimmune diseases,6 we used rituximab in two patients with CP, one refractory to conventional treatments, and the other with contraindications to standard-dose glucocorticoids. Our fi rst patient, a 49-year-old woman, was hospitalised for malaise and back pain. Abdominal CT revealed a soft-tissuedensity periaortic mass suggesting CP, a diagnosis confi rmed by laparoscopic biopsy (fi gure 1). The patient responded to prednisone (initial dose, 1 mg/kg/day), with symptom remission and reduction in CP thickness, but relapsed with back pain and CP enlargement when the prednisone dose was 5 mg/day (8 months after treatment initiation). Further treatment with prednisone (initial dose 0.8 mg/kg/day) plus methotrexate (0.25 mg/week) for 11 months, and subsequently tamoxifen, failed to induce remission. At restaging 24 months after disease onset, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were 64 mm/h and 6 mg/l, respectively, antinuclear antibodies (ANAs) were 1/160, and IgG4 was 15 mg/dl (normal <135). Positron emission tomography (PET)/CT showed increased