RENAL TRANSPLANTATION DUE TO RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS (RPGN) AND SYSTEMIC AUTOIMMUNE DISORDERS. STUDY OF 42 PATIENTS FROM A SINGLE CENTER.

Background: Rapidly Progressive Glomerulonephritis (RPGN) is characterized by a rapid and severe decline in kidney function that may lead to a kidney transplantation. RPGN is classified in three groups: a) Type I or associated to anti-glomerular basement membrane antibodies (RPGN-GBMa), b) Type II or associated to immunocomplexes (RGPN-immunocomplexes), and c) Type III or pauci-immune (RPGN-pauci-immune). RPGN can be primary, without extra-renal involvement (RPGN-renal-limited), or secondary to systemic autoimmune disorders (RPGN-SAD), infectious diseases or drugs. Kidney transplantation in RPGN-SAD may be associated to a worse outcome. Objectives: To assess a) clinical features of the three types of RPGN, b) comparison of post-transplant survival and graft survival between these three types. Methods: We studied three groups of patients according to renal biopsy: a) RPGN-GBMa (n = 11), b) RPGN-immunocomplexes (n = 2) and c) RPGN-pauci-immune (n=29). All these patients were transplanted in a single reference University Hospital. The main outcome variables were a) graft survival up to 15 years and patient survival up to 30 years and b) evolution of renal function (serum creatinine and proteinuria) in the first 5 years of follow-up. Results: We included a total of 42 patients with renal transplant due to RPGN, mean age at diagnosis 44.87±17.01 years (48.53±17.45 at the time of the transplant). No significant differences at baseline were observed between the three RPGN groups regarding sex, age and cardiovascular risk factors. Renal biopsy had been performed in the 42 patients with RPGN: type I or RPGN-GBMa (n=11, 26.2%), type II or RPGN-immunocomplexes (n=2, 4.8%) and type III or RPGN-pauci-immune (n=29, 69.0%). It was also reported the presence or absence of systemic autoimmune disorders (31% RPGN-SAD and 69% RPGN-renal-limited). According to the presentation and the clinical characteristics of the patients, another classification has been established: a) type I (18.2% (n = 2) Goodpasture-syndrome), b) type II (100% renal-limited), c) type III (13.8% (n = 4) granulomatosis with polyangiitis) and 20.70% (n = 6) microscopic polyangiitis. The evolution of serum creatinine and the proteinuria after the transplant is shown in TABLE 1and 1.1. Neither differences were found in terms of graft and patient survival between the 3 groups (Figures 1 and 2). Conclusion: Our study has shown similar graft and patient survival as well as renal outcome in renal transplant due to the three types of RPGN. Renal transplantation could be the best option for patients with end stage renal disease due to RPGN regardless of systemic manifestations. Disclosure of Interests: Lara Sanchez-Bilbao Grant/research support from: Pfizer, Marina de Cos-Gomez: None declared, Juan Carlos Ruiz-San Millan: None declared, Miguel A Gonzalez-Gay Grant/research support from: Pfizer, Abbvie, MSD, Speakers bureau: Pfizer, Abbvie, MSD, Ricardo Blanco Grant/research support from: AbbVie, MSD, and Roche, Speakers bureau: AbbVie, Pfizer, Roche, Bristol-Myers, Janssen, and MSD