Background: Idiopathic retroperitoneal fibrosis (IRPF) is an uncommon, but increasingly recognized, disease. Autoimmune mechanisms probably participate in its pathogenesis. Patients have been treated with high-dose steroids and sometimes immunosuppressive drugs, resulting in toxicity risk during prolonged treatments; thus, it would be wise to look for safer drugs. Colchicine has antifibrotic, anti-inflammatory, and immunosuppressive effects. Hence, it is a potential therapeutic resource.
Study design: Case series.
Setting & participants: 7 consecutives patients with IRPF diagnosed since 1993 at a navy hospital were prescribed colchicine plus prednisone or deflazacort. After reaching a clinical response, the steroid dose was tapered, maintaining daily colchicine therapy.
Outcomes & measurements: Symptomatic improvement was defined as time to relief of symptoms; clinical improvement, time to normalization of inflammatory parameters with symptomatic improvement; radiological changes, percentage of decrease in retroperitoneal mass; recurrence, as the need to increase steroid dose or add immunosuppressors because of reactivation of inflammation; and treatment failure, as persistence of signs of active inflammation and/or decrease in retroperitoneal mass less than 50% and/or deterioration in kidney function at the last visit.
Results: At month 3 of treatment, all patients had symptomatic improvement and 67% had clinical improvement. Between 8 and 12 months, 67% of patients had a decrease in retroperitoneal mass greater than 50%. No recurrence or treatment failure was observed during follow-up (mean, 72.5 months). At the last visit, all patients had a significant decrease in retroperitoneal mass (mean, 79.8% +/- 19.7%). One patient died of septic shock on day 21 of treatment.
Limitations: This series did not have a control group.
Conclusions: Colchicine in association with a low induction dose of steroids (<0.5 mg/kg/d) produced remission rates in patients with IRPF similar to those for regimens using greater steroid doses alone or in combination with immunosuppressive drugs. In addition, colchicine may have contributed to recurrence prevention.