Abstract
Amyloidosis comprises a group of disorders that accumulate modified autologous proteins in organs, mainly the kidneys. Few studies have addressed the amyloid compartmental distribution and associated clinical outcomes. The aim of this study was to present a case series of renal amyloidosis correlating histopathological data with glomerular filtration rate (GFR) during kidney biopsy. We studied 53 cases reviewed by nephropathologists from 2000 to 2018 in a single kidney biopsy center in Brazil. GFR was estimated using the CKD-EPI formula. Cases were divided into Group A ≥60 and Group B <60 mL·min−1·(1.73 m2)−1 using the estimated GFR during kidney biopsy. Semiquantitative histopathological study was performed, including extension and distribution of amyloid deposits by compartments (glomeruli, tubulointerstitial tissue, and vessels). Statistical analyses were made to understand associations with lower GFR. No difference was seen for age, gender, proteinuria, hematuria, subtype of amyloid protein, arteriosclerosis, interstitial fibrosis/infiltrate, or glomerular and interstitial amyloid deposits. After a previous P value <0.1 in the descriptive analysis, the following variables were selected: globally sclerotic glomeruli, high blood pressure, and the extension of vascular amyloid deposition. A binary logistic regression model with GFR as the dependent variable showed history of hypertension and vascular amyloid to be robust and independent predictors of Group B <60 mL·min−1·(1.73 m2)−1. Beyond the histopathologic diagnosis of amyloidosis, a semiquantitative approach on renal biopsy could provide new insights. Vascular amyloid is an independent predictor of renal dysfunction in cases of renal amyloidosis.
Highlights
Amyloidosis comprises a group of disorders that share the ability to accumulate modified autologous proteins in certain organs [1]
We investigated 53 histological cases of renal amyloidosis confirmed by two nephropathologists, from January 2000 to December 2018
After division into two groups according to the e-glomerular filtration rate (GFR) cutoff of 60 mL Á min–1 Á (1.73 m2)–1 as explained previously, we obtained 17 patients in Group A and 32 patients in Group B
Summary
Amyloidosis comprises a group of disorders that share the ability to accumulate modified autologous proteins in certain organs [1]. Such proteins, or amyloid deposits, undergo changes in their structural conformation and become insoluble and alter the architecture and function of the compromised organ [2]. Primary amyloidosis is related to blood cell dyscrasia and deposition of immunoglobulin light chains (AL), whereas secondary amyloidosis is associated with chronic inflammatory disorders and consequent deposition of protein A (AA) [10]. Immunofluorescence can be used to identify AL cases in fresh tissue provided from routine kidney biopsies, while immunohistochemistry for amyloid A protein requires a specific marker rarely available in pathology services
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.