• Christian Treitz, Neelis Müller-Marienburg, Rolf Rüdiger Meliß, Peter Urban, Hans-Detlef Axmann, Frank Siebert, Karsten Becker, Klaus Martens, Hans-Michael Behrens, Eva Gericke, Andreas Tholey, and Christoph Röcken.
• Systematic Proteome Research & Bioanalytics, Institute of Experimental Medicine, Christian-Albrechts-University, Kiel, Germany.
• Amyloid. 2023 Dec 1; 30 (4): 394406394-406.

IntroductionHistological examination of tissue specimens obtained during surgical treatment of trigger finger frequently encountered unclassifiable amyloid deposits in the annular ligament. We systematically explored this unknown type by a comprehensive analysis using histology, immunohistochemistry, and quantitative mass spectrometry-based proteomics.Methods205 tissue specimens of annular ligaments were obtained from 172 patients. Each specimen was studied by histology and immunohistochemistry. Tissue specimens obtained from ten patients with histology proven amyloid in annular ligament were analysed by label-free quantitative proteomics. Histological and immunohistochemical findings were correlated with patient demographics.ResultsAmyloid was present as band like deposits along the surface of annular ligament, dot like or patchy deposits within the matrix. Immunohistochemistry identified ATTR amyloid in 92 specimens (mostly patchy in the matrix), while the band like deposits of 100 specimens remained unclassifiable. Proteomic profiles identified the unknown amyloid as most likely of fibrinogen origin. The complete cohort was re-examined by immunohistochemistry using a custom-made antibody and confirmed the presence of fibrinogen alpha-chain (FGA) in a hitherto unclassifiable type of amyloid in annular ligament.ConclusionOur study shows that two different types of amyloid affect the annular ligament, ATTR amyloid and AFib amyloid, with distinct demographic patient characteristics and histomorphological deposition patterns.

13 keywords...

hide…