FRI0297 CLINICAL FEATURES, TREATMENT MODALITIES AND RELAPSE RATES IN GREEK PATIENTS WITH RETROPERITONEAL FIBROSIS
Authors: Aliki Venetsanopoulou, Evangelia Zampeli, Sophia Christaki, Ourania Argyropoulou, Kyriaki A. Boki, Menelaos N. Manoussakis, Foteini N. Skopouli, Athanasios Tzioufas, Haralampos M. Moutsopoulos
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Retroperitoneal fibrosis (RPF) is a rare disease of unknown etiology characterized by deposition of fibro-inflammatory tissue around the infra-renal abdominal aorta. The process may involve adjacent structures leading to complications, the most frequent being ureteral obstruction [1]. RPF is mainly idiopathic (iRPF), yet it might be secondary to malignancies, infections, drugs, or radiotherapy [2]. Recent data argue that iRPF could be part of the IgG<sub>4</sub>-related diseases [3]. Diagnosis is aided by imaging studies (abdomen CT/MRI), but in patients with newly diagnosed RPF, excluding malignancy is mandatory [2]. <h3>Objectives</h3> The aim of our study was a) to describe the presenting clinical, laboratory, imaging features and treatment modalities used in patients with iRPF from four tertiary medical units in Greece and b) to evaluate <b>factors potentially associated</b> with <b>disease relapse.</b> <h3>Methods</h3> Medical records of patients diagnosed with RPF from 2000-2018 in four rheumatology units (Laiko, Euroclinic, Sismanoglion and Sotiria Hospitals) were retrospectively evaluated. Sixty-seven patients with iRPF were included in the study. <h3>Results</h3> The median age at diagnosis was 56 years (IQR:52.0–60.0), with median disease duration 8.0 years (IQR:3.0-11.0), 58% were smokers and 73% males. Patients more often presented with constitutional symptoms (57%), low back pain (63%), raised inflammatory markers (78%), anemia (43%) and compromised renal function (15%). Commonest imaging findings were periaortic-periiliac mass (46%), periaortic mass (33%), periaortitis (25%) and hydronephrosis (36%) with envelopment of one (31%) or both ureters (18%). Tissue biopsy was requested in all patients, but was performed in only 10, with 3 having marked numbers of IgG4-positive plasma cells. Serum IgG4 was measured in 36/67 and 36% had elevated levels at diagnosis (median 224 mg/dL, IQR:174-328). Clinical/laboratory/radiological presentation did not differ between patients with elevated and normal serum IgG<sub>4</sub> levels. Steroids were first-line treatment in 93% of patients. Other immunosuppressives used as steroid-sparing agents were azathioprine (70%), cyclophosphamide (19%), mycophenolate-mofetil (18%), D-penicillamine (12%) and methotrexate (8%). Relapse occurred in 19% of patients at a median of 36 months (IQR:18-66) after diagnosis with 69% of them being under therapy. Relapse did not correlate to initial imaging findings or to any treatment modality, yet patients with increased serum IgG4 tended to have higher relapse rate (26% vs 11%, p=0.071). <h3>Conclusion</h3> Diagnosis of iRPF was mostly based on imaging studies in our cohort. Steroids were used as first-line treatment. Relapse occurred in one-fifth of patients independently of initial clinical/radiographic presentation or treatment modality used. RPF patients with initially elevated serum IgG<sub>4</sub> levels tended to have a higher relapse rate. <h3>References</h3> [1] Vaglio A, Salvarani C, Buzio C. Retroperitoneal fibrosis. Lancet2006; 367:241–51. [2] Brandt AS, Kamper L, Kukuk S, Haage P, Roth S. Associated findings and complications of retroperitoneal fibrosis in 204 patients: results of a urological registry. J Urol. 2011; 185:526-31. [3] Khosroshahi A, Carruthers MN, Stone JH, Shinagare S, Sainani N, Hasserjian RP, Deshpande V. Rethinking Ormond's disease: "idiopathic" retroperitoneal fibrosis in the era of IgG4-related disease. Medicine (Baltimore). 2013; 92:82-91. <h3>Disclosure of Interests</h3> Aliki Venetsanopoulou: None declared, Evangelia Zampeli Speakers bureau: Roshe, Astrazeneca, Sophia Christaki: None declared, Ourania Argyropoulou: None declared, Kyriaki A. Boki: None declared, Menelaos N. Manoussakis: None declared, Foteini N. Skopouli: None declared, Athanasios Tzioufas Grant/research support from: ABBVIE, PFIZER, AMGEN, NOVARTIS, GSK, Haralampos M. Moutsopoulos: None declared