#2724 Renal amyloidosis cohort registry in our health area

Abstract Background and Aims Renal amyloidosis is the pathological phenomenon of amyloid deposition in the kidney with marked differences in renal function impairment, proteinuria, need for renal replacement therapy (RRT) and exitus, depending on the protein involved. Light chain amyloidosis (AL) and serum protein A (AA) amyloidosis are the most common. Typical symptoms are severe proteinuria, nephrotic syndrome, and end-stage chronic kidney disease (ESRD). Method Retrospective study of a cohort of patients with renal amyloidosis. Data extracted from the biopsy registry of the HUVM Nephrology Service (2013-2022). We collected demographic, clinical, analytical, histological and clinical outcome variables (RTT, Exitus). Results are analyzed using Mayo Clinic staging criteria. Results 19 patients with a mean age of 63.4a; 57.9% male. Mean laboratory values at diagnosis: creatinine (Cr) 1.56 mg/dl and proteinuria 3.9 g/24 h. Abdominal fat biopsy in 13 cases; 3 (23%) tested positive. Comparative analysis of AL vs non-AL forms, Cr values (1.14 vs 2.27 mg/dl respectively) (p=0.57) differed. Proteinuria according to the histological location of the amyloid: 4.6 g/24 h in glomerular involvement vs. 0.3 g/24 h in those who did not present it (p<0.05). 31.6% required RTT with a mean onset time of 250.6 d from biopsy. Exitus of 21.1%: average time of 426.5 d. (See analysis in attached table). Conclusion We did not observe significant deterioration of renal function, which is greater in non-AL forms of amyloidosis. Fat biopsy was less cost-effective than reported in the literature. Significantly lower levels of proteinuria were found in the amyloidosis group without glomerular involvement. In our series, the prognostic capacity associated with the MAYO staging was confirmed.