Prevalence and morphology of leukocyte chemotactic factor 2-associated amyloid in renal biopsies.
Renal pathologists identify the protein component of renal amyloid deposits by immunohistochemistry using antibodies against known amyloidogenic proteins. The majority of amyloid cases can be categorized by a simple antibody panel that includes immunoglobulin light chains lambda and kappa, and serum amyloid A. In some instances, however, these reagents do not recognize materials that stain with Congo red or yield ambiguous staining results, thus creating a diagnostic dilemma. Chemical analysis of fibrils extracted from such a nonreactive renal biopsy led to the discovery of a previously unknown amyloid formed from leukocyte chemotactic factor 2 (LECT2). Over the past 8 years, we received 285 renal amyloid samples, of which 31 remained unclassified. In an effort to determine whether any of the latter samples were LECT2 related, tandem mass spectrometry was performed. In all, 7 of the 31 cases were identified as an amyloid LECT2 (ALECT2), a finding confirmed immunohistochemically using a LECT2-specific antibody. The deposits strongly stained for Congo red and, in most cases, had distinctive morphological features with diffuse involvement of the interstitium, arteries, and glomeruli. Hence, we believe that ALECT2 represents the third common form of renal amyloidosis.
Larsen
Christopher P
CP
Nephropathology Associates, Little Rock, Arkansas 72211, USA. chris.larsen@nephropath.com
Walker
Patrick D
PD
Weiss
Deborah T
DT
Solomon
Alan
A
D000682:Amyloid / Q000737:chemistry* / Q000378:metabolism*; D016564:Amyloid beta-Protein Precursor; D000686:Amyloidosis / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D001706:Biopsy; D016827:CD8 Antigens / Q000378:metabolism; D002630:Chemotactic Factors / Q000378:metabolism; D003224:Congo Red / Q000378:metabolism; D006801:Humans; D007146:Immunoglobulin lambda-Chains / Q000032:analysis / Q000378:metabolism; D007150:Immunohistochemistry; D007668:Kidney / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D007678:Kidney Glomerulus / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D009392:Nephrectomy; D015995:Prevalence; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D000685:Serum Amyloid A Protein / Q000032:analysis / Q000378:metabolism; D013194:Staining and Labeling
D000682:Amyloid; D016564:Amyloid beta-Protein Precursor; D016827:CD8 Antigens; D002630:Chemotactic Factors; D007146:Immunoglobulin lambda-Chains; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D000685:Serum Amyloid A Protein; D003224:Congo Red