Microdeposition of amyloid in the joints.

Abstract

SUMMARY The distribution of amyloid in various organs, including the hip and the sternoclavicular joints, was systematically investigated in a prospective necropsy study of 91 unselected individuals whose median age was 70 years. The overall incidence of amyloid microdeposits in both joints was 56%. Their presence correlated significantly with age only. The deposition began earlier in the sternoclavicular joint, where the fibrocartilaginous disc was almost exclusively affected. The myocardium was the next most frequently affected organ, with an incidence of 12.2%. Minor amyloidosis of the articular tissues had no significant clinical counterpart, neither was it associated with any particular disease. It seemingly represents a localised and isolated degenerative phenomenon, whose morphological aspects invite speculation about the pathogenic role of long-lasting mechanical stress.

The association of amyloid deposits and osteoarthritis

“…Our series, as well as other recent reports (9), found a correlation of age with the presence of microdeposits of amyloid. Small deposits of amyloid have been reported in 10-56% of various organs examined at autopsy in elderly subjects (9,22,23). In these studies, the frequency of amyloid increases with age, and the amyloid is generally considered t o be of no pathologic significance.…”

“…T h e surface location of amyloid in the articular cartilage may reflect increased mechanical trauma at this site. The recent report that 39 of 50 fibrocartiliginous discs contained microdeposits of amyloid in their central portion and in areas of fibrillation further supports the theory that amyloid may be related t o chronic mechanical stress (9). Another recent report described amyloid in all of 39 severely calcified malformed aortic valves (24 …”

“…In a followup study, the same authors again found amyloid in 43% of hip capsules in unselected autopsy cases (8). Amyloid has also been described in osteoarthritic cartilage (7,9). Goffin et al recently described amyloid microdeposits in 56% of unselected autopsy specimens of the hip and the sternoclavicularjoints (9).…”

“…Amyloid has also been described in osteoarthritic cartilage (7,9). Goffin et al recently described amyloid microdeposits in 56% of unselected autopsy specimens of the hip and the sternoclavicularjoints (9). In the hip, the deposits were confined to the fibrous capsule, but in the sternoclavicular joint, the deposits were present in the central portion of the fibrocartiliginous disc.…”

Toxicity from methotrexate may be dose related

“…Michaels et al (1) note that the carcinogenic potential of methotrexate is minimal (2)(3)(4). This difference supports the choice of methotrexate when an immunosuppressant, cytotoxic drug is indicated.…”