title: Knee osteoarthritis associated with different kinds of amyloid deposits and the impact of aging on type of amyloid.
abstract: Amyloidosis is a protein conformational disorder in which amyloid fibrils accumulate in the extracellular space and induce organ dysfunction. Recently, two different amyloidogenic proteins, transthyretin (TTR) and apolipoprotein A-I (Apo A-I), were identified in amyloid deposits in knee joints in patients with knee osteoarthritis (OA). However, clinicopathological differences related to those two kinds of amyloid deposits in the knee joint remain to be clarified. Here, we investigated the clinicopathological features related to these knee amyloid deposits associated with knee OA and the biochemical characteristics of the amyloid deposits. We found that all of our patients with knee OA had amyloid deposits in the knee joints, especially in the meniscus, and those deposits were primarily derived from TTR and/or Apo A-I. Some patients with knee OA, however, had unclassified amyloid deposits. One of our interesting observations concerned the different effects of aging on each type of amyloid formed. The frequency of formation of ATTR deposits clearly increased with age, but that of AApo A-I deposits decreased. Furthermore, we found that ∼16% of patients with knee OA developed ATTR/AApo A-I double deposits in the meniscus. Amyloid deposition may therefore be a common histopathological feature associated with knee OA. Also, aging may induce ATTR formation in the knee joint in elderly patients with knee OA, whereas AApo A-I formation may be inversely correlated with age.
authors.affiliation: a Department of Orthopaedic Surgery , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .|b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yanagisawa
authors.affiliation: b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Ueda
authors.affiliation: a Department of Orthopaedic Surgery , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Takanao
authors.initials: T
authors.lastname: Sueyoshi
authors.affiliation: a Department of Orthopaedic Surgery , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Eiichi
authors.initials: E
authors.lastname: Nakamura
authors.affiliation: b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Tasaki
authors.affiliation: b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Genki
authors.initials: G
authors.lastname: Suenaga
authors.affiliation: b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Motokawa
authors.affiliation: b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Risa
authors.initials: R
authors.lastname: Toyoshima
authors.affiliation: b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kinoshita
authors.affiliation: b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Yohei
authors.initials: Y
authors.lastname: Misumi
authors.affiliation: b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Taro
authors.initials: T
authors.lastname: Yamashita
authors.affiliation: c Kumamoto Orthopedic Hospital , Chuo-ku, Kumamoto , Japan , and.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Sakaguchi
authors.affiliation: d Department of Immunology , Genetics and Pathology, Uppsala University , Uppsala , Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Westermark
authors.affiliation: a Department of Orthopaedic Surgery , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mizuta
authors.affiliation: b Department of Neurology , Graduate School of Medical Sciences, Kumamoto University , Chuo-ku, Kumamoto , Japan .
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ando
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000682:Amyloid / Q000378:metabolism; D000686:Amyloidosis / Q000378:metabolism* / Q000473:pathology; D016632:Apolipoprotein A-I / Q000378:metabolism; D002358:Cartilage, Articular / Q000378:metabolism; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000378:metabolism / Q000473:pathology; D008297:Male; D020370:Osteoarthritis, Knee / Q000378:metabolism* / Q000473:pathology; D011228:Prealbumin / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism
chemical_list: C505693:APOA1 protein, human; D000682:Amyloid; D016632:Apolipoprotein A-I; D011228:Prealbumin
keywords: Apolipoprotein A-I; articular cartilage; knee joint; knee osteoarthritis; meniscus; synovial membrane; transthyretin