P0258EVALUATION OF ACUTE - PHASE REACTANTS IN MONITORING DISEASE ACTIVITY AND RESPONSE TO IMMUNOSUPPRESSIVE THERAPY IN IDIOPATHIC RETROPERITONEAL FIBROSIS

Abstract

Abstract Background and Aims Idiopathic retroperitoneal fibrosis (IRF) is a rare disease characterized by fibroinflammatory periaortic tissue that affects the ureters, causing obstructive nephropathy and impairment of renal function. Findings strongly suggest an autoimmune etiology. Medical treatment includes immunosuppressive drugs, but the optimal treatment has not been established. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) represent markers of active inflammation in the early phase of the disease, and hence could be sensitive predictors of the treatment response. Method This retrospective case series study includes patients with IRF treated with two different protocols: corticosteroids in combination with mycophenolate mofetil (MMF) and corticosteroids combined with azathioprine (AZA). The total number of 28 patients (13 in the first group and 15 in the second group) were treated and followed in the Clinic of nephrology in Military Medical Academy. Results At presentation 92.3% of patients had elevated levels of ESR and CRP, and 67.8% of them had acute renal insufficiency. Systemic symptoms resolved after four weeks in all patients. The kidney function improved significantly in both groups after first moth of treatment, although the creatinine level was higher in the MMF group because of the disease recurrence in 23% of the patients. In MMF group was observed faster reduction in the periaortic mass after six months and 53.8% of patients achieve 100% of the mass reduction at the end of the treatment while 33.3% in AZA group. The levels of ESR and CRP after one month of treatment in AZA group correlated with the fibrotic mass reduction after six months and after one year. In MMF group, only the CRP level after one month correlated with the fibrotic mass reduction achieved after one year. Conclusion MMF had more rapid and complete effect in hydrnephrosis withdrawal and total reduction of the fibrotic tissue, comparing with AZA whose effect was slower and without complete mass reduction. CRP strongly correlated with the remission of the disease in both therapeutic protocols.