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Localised foot and ankle amyloid deposition.
Y Uchihara1, E Iwata1, I Papadimitriou-Olivgeri2
1Department of Orthopaedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan.
Pathology, Research and Practice
|September 4, 2018
Summary
Localized amyloid deposits containing transthyretin are age-associated in foot and ankle tissues, often found in degenerated areas. These small deposits are generally not considered pathogenic.
Area of Science:
- Orthopedics
- Rheumatology
- Pathology
Background:
- Localized amyloid deposition, specifically transthyretin-associated amyloidosis, is common in elderly individuals' articular and periarticular tissues.
- The occurrence and characteristics of age-associated amyloid deposition in foot and ankle (F&A) tissues have not been previously investigated.
- This study aimed to assess the nature and frequency of F&A amyloid deposition and its association with age and specific F&A lesions.
Purpose of the Study:
- To investigate the presence and characteristics of amyloid deposits in normal and pathological foot and ankle tissues.
- To determine the association between amyloid deposition, aging, and specific foot and ankle pathologies.
- To identify the protein composition and matrix components associated with F&A amyloid deposits.
Main Methods:
- Histological examination of 25 normal F&A tissues (age range 16-71 years) and various F&A lesions using Congo Red staining.
- Immunohistochemistry was employed to identify the specific amyloid protein.
- Alcian Blue (critical electrolyte concentration) histochemistry was used to determine the type of matrix glycosaminoglycans present.
Main Results:
- Amyloid deposits, identified as transthyretin-positive, were found in 3/25 normal F&A specimens (ages 57, 62, 78 years).
- These deposits occurred in areas of matrix degeneration associated with highly sulphated glycosaminoglycans.
- Small amyloid deposits were observed in F&A lesions of individuals over 47 years old, including osteoarthritis, Charcot arthropathy, bursitis, ganglia, chondrocalcinosis, gout, calcific tendonitis, and Achilles tendonitis.
Conclusions:
- Small, localized amyloid deposits in F&A tissues are composed of transthyretin.
- These deposits are linked to matrix degeneration and highly sulphated glycosaminoglycans, and are age-associated.
- While more common in certain F&A lesions, these amyloid deposits are small and unlikely to be clinically significant or pathogenic.
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