Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.

Idiopathic Retroperitoneal Fibrosis: Treatment-Related Outcomes and Predictors of Clinical Response.

Kermani1,  Tanaz A., Crowson2,  Cynthia S., Achenbach2,  Sara, Luthra1,  Harvinder S.

Mayo Clinic, Rochester, MN
Mayo Clinic


1) To compare outcomes by treatment type, and 2) to determine baseline variables associated with treatment response, in 151 patients with retroperitoneal fibrosis (RF) followed at a single tertiary-care center.


In this retrospective study, incident cases of RF diagnosed between 1/1/1996 and 12/31/2006 were included. RF was defined by compatible imaging findings. Medical records were reviewed and treatment and outcomes were abstracted.

We defined 4 response types: partial response (stabilization/improvement in imaging findings on stable medical regimen for 1 year), complete response (stabilization/improvement in imaging findings on a stable medical regimen with discontinuation of prednisone for 1 year), remission (stabilization/improvement in imaging findings off all therapy for 1 year), and relapse (worsening imaging findings 1 year after an initial response). Patients were followed until last contact, death or December 31, 2009. Kaplan-Meier methods were used to compare outcomes by treatment group. Cox proportional hazard models were used to evaluate the association between baseline variables and treatment response.


We identified 185 patients with RF, mean age at diagnosis 57.6 (±11.8) years. Follow-up was available in 151 patients which included 87 men (58%) and 64 women (42%); median length of follow-up 4.0 years (total 671 person-years).

Forty-seven patients (31%) were treated with medications only (Group 1), 67 patients (44%) received medications and ureteral stenting (Group 2) and 20 patients (13%) were treated with medications and ureterolysis (Group 3). Commonly prescribed medications were prednisone (96 patients), tamoxifen (107 patients) and methotrexate (46 patients). Five patients (3%) who received no treatment and 12 patients (8%) treated only with stenting or ureterolysis were not analyzed due to small numbers.

At baseline, all 3 treatment groups were similar in age at diagnosis, ethnicity, sex, smoking status, anemia, ESR and CRP (p>0.05). However, baseline creatinine (Cr) was elevated in 2 patients (4.4%) in Group 1 compared to 39 patients (62%) in Group 2 and 11 patients (55%) in Group 3 (p<0.001). Also, more patients in Groups 2 and 3 had hydronephrosis compared to Group 1 (p<0.001).

Kaplan-Meier curves for the 3 groups were similar for all response types (p>0.05). At 2 years from diagnosis, 59% of all patients achieved at least partial response. Relapses occurred in 18 patients. There were no differences in relapse rates by treatment group (p=0.198). Age at diagnosis, ethnicity, sex, smoking status, anemia, ESR, CRP, elevated Cr, or hydronephrosis did not predict any response type.


This is the largest series to systematically evaluate treatment outcomes and predictors of response in RF. We defined 4 response types. While patients with baseline renal insufficiency or hydronephrosis were more likely to undergo a urologic procedure, the outcomes for all treatment groups analyzed were similar. No baseline variables were associated any response type. Our findings suggest that regardless of baseline Cr, with close follow-up and appropriate treatment (medical and surgical), the overall outcomes were good.

To cite this abstract, please use the following information:
Kermani, Tanaz A., Crowson, Cynthia S., Achenbach, Sara, Luthra, Harvinder S.; Idiopathic Retroperitoneal Fibrosis: Treatment-Related Outcomes and Predictors of Clinical Response. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :705
DOI: 10.1002/art.28473

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