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Abstract: TH-PO649

Prognostic Factors and Outcomes of a Large Brazilian Retrospective Cohort of Renal Amyloidosis

Session Information

Category: Glomerular Diseases

  • 1402 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Feitosa, Valkercyo Araújo, Universidade de Sao Paulo Faculdade de Medicina, Sao Paulo, São Paulo, Brazil
  • Watanabe, Elieser H., Universidade de Sao Paulo Faculdade de Medicina, Sao Paulo, São Paulo, Brazil
  • Neves, Precil D., Universidade de Sao Paulo Faculdade de Medicina, Sao Paulo, São Paulo, Brazil
  • Siqueira, Talita Souza, Universidade de Sao Paulo Faculdade de Medicina, Sao Paulo, São Paulo, Brazil
  • Onuchic, Luiz F., Universidade de Sao Paulo Faculdade de Medicina, Sao Paulo, São Paulo, Brazil

Group or Team Name

  • LIM/29 – Laboratório de Nefrologia Celular, Genética e Molecular.
Background

To date, no large studies have characterized the epidemiology and outcomes of the main types of renal amyloidosis in Brazil or Latin America.

Methods

This retrospective cohort study evaluated 81 patients with biopsy-proven renal amyloidosis, diagnosed from January 1999 to December 2022. Follow-up started at kidney disease presentation and ended at death or December 2022. Clinical presentation, including age, serum creatinine, proteinuria and amyloid type, as well as survival and prognostic factors were analyzed.

Results

From the initial 81 patients, 76 had definite biopsy-proven renal amyloidosis and were analyzed. AL amyloidosis was the most frequent type (68.4%). AA amyloidosis was present in 14.5% and was mainly related to rheumatological diseases (7/11) and familial Mediterranean fever (2/11). Hereditary forms accounted for 11.8% of cases (10.5% AFibE545V, 1.3% ATTRV30M), and the type was inconclusive in 5.3%. The etiologic type was classified as confirmed in 43.1% and probable in 56.9%. AL was associated with lower serum albumin and higher degree of proteinuria compared to the other types. Patients with AL amyloidosis almost always presented with nephrotic syndrome, unlike patients with the AFib amyloidosis, who most often presented with isolated proteinuria and hypertension. The diagnosis of AA was frequently established before 40 years of age (45.5%) and more often displayed glomerular detection of C3 (70.0% in AA, 22.9% in AL and 11.1% in AFib/ATTR). During follow-up, 67.3% of AL, 54.5% of AA and 66.7% of AFib+ATTR progressed to ESKD, and 57.7% of AL, 36.3% of AA, and 22.2% of AFib+ATTR died; median kidney survival was 10 (1-154), 21.5 (1-117) and 56 (10-146) months, respectively (p=0.024). eGFR<60mL/min/1.73m2 at diagnosis (HR 6.50 [95% CI, 1.73-24.40]) and shorter time from symptoms to diagnosis (HR 1.07 [95% CI, 1.01-1.13]) were identified as risk factors for progression to ESKD.

Conclusion

Our data broadly characterized the types of renal amyloidosis in this large cohort and revealed that most cases were AL amyloidosis, which was associated with worse kidney and overall survival. Our findings suggest that clinical presenting features can often distinguish the types. Hereditary forms should be considered when confirmation of AL cannot be obtained and a chronic inflammatory disease is not diagnosed.

Funding

  • Government Support – Non-U.S.