AA amyloidosis With Ig-Dominant Staining and Diagnostically Unusual Features.

Autor:	Andeen NK; Department of Pathology and Laboratory Medicine, Oregon Health and Science University, Portland, Oregon, USA., DiFranza L; Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York, USA., Kung VL; Department of Pathology and Laboratory Medicine, Oregon Health and Science University, Portland, Oregon, USA., Henriksen K; Department of Pathology, University of Chicago, Chicago, Illinois, USA., Gupta R; Renal Care Consultants, Medford, Oregon, USA., Dinesh K; Renal Care Consultants, Medford, Oregon, USA., Akilesh S; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA., Kudose S; Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York, USA., Smith KD; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA., Troxell ML; Department of Pathology, Stanford University, Stanford, California, USA.
Jazyk:	angličtina
Zdroj:	Kidney international reports [Kidney Int Rep] 2023 Oct 17; Vol. 9 (1), pp. 162-170. Date of Electronic Publication: 2023 Oct 17 (Print Publication: 2024).
DOI:	10.1016/j.ekir.2023.10.005
Abstrakt:	Introduction: Although serum amyloid A (AA) amyloid may occasionally show nonspecific staining by immunofluorescence (IF), the correct diagnosis can usually be determined by integrating pathologic features and clinical scenario, and using AA amyloid immunohistochemistry (IHC) and/or mass spectrometry. A recent mass spectrometry-based study described false-positive Ig IF staining in a subset of AA amyloid cases. Methods: We sought to delineate clinicopathologic features of AA amyloid with Ig-dominant staining by using a retrospective review. Results: AA amyloid with Ig-dominant staining was identified in 10 patients from 5 institutions, representing 1.2% to 4% of AA amyloid kidney biopsies. Evidence of a monoclonal protein was documented in 0% to 2.7% of patients with AA amyloid screened for inclusion, but 30% of those with Ig-dominant staining. The patient population had equal sex distribution and presented at median age of 68.5 years with nephrotic proteinuria and kidney impairment. Etiologies of AA amyloid included injection drug use (30%), autoimmune disease (20%), and chronic infection (10%); 40% had no identified clinical association. On biopsy, heavy chain (co)dominant staining by IF (in 80%), discordant distribution in Ig staining (in 20%), tubulointerstitial nephritis (in 30%), and/or crescents (in 10%) were present. Two of 3 patients with paraproteinemia had concordant heavy and/or light chain dominant staining within the AA amyloid. Two cases were initially misdiagnosed as Ig-associated amyloidosis. Conclusion: We describe the morphologic spectrum of AA amyloidosis with Ig-dominant staining which may have clinical, laboratory, and pathologic overlap with amyloid light chain (AL), amyloid heavy chain, and heavy and light chain (AHL) amyloidosis. (© 2023 International Society of Nephrology. Published by Elsevier Inc.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu