Usefulness of methotrexate in relapsing idiopathic retroperitoneal fibrosis

Objectives: Glucocorticoids are the mainstay for treatment of retroperitoneal fibrosis (RPF), a disease characterised by a periaortic proliferation of fibroinflammatory tissue frequently causing urinary obstruction. The therapeutic approach to patients unsuitable for steroid therapy and to relapsing cases is still undefined. Methods: In this retrospective single-centre study we evaluated 15 patients with RPF who received second-line therapy with methotrexate (MTX) between January 2011 to December 2019. Results: Fourteen out of 15 patients (93%) showed response to MTX. Two patients experienced relapse: one patient when on MTX therapy (28 months), the other, 58 months after MTX was interrupted. Liver toxicity grade 2 was documented in 2 patients and resolved with temporary dosage reduction. One patient stopped MTX autonomously because of nausea. No severe infections were recorded. Conclusions: In selected patients with RPF who are intolerant or refractory to steroid single therapy, MTX may be considered as useful and safe second-line treatment.