[Amyloid deposition in chronic joint disease]

As a screening procedure for the detection of amyloidosis secondary to rheumatoid arthritis, abdominal subcutaneous fat tissues were aspirated, and were examined after Congo red staining by polarized microscopy. Positive amyloid deposits were found in 7.1 percent of the rheumatoid patients, and the amyloid in the subcutaneous fat was determined to be AA type by permanganate oxidation. The occurrence of amyloid deposition was significantly correlated with the duration of the articular symptoms, the progression of the class, and also with proteinuria. Additionally the joint capsules, including the synovium and synovial fluid sediment, from patients with rheumatoid arthritis and osteoarthritis were examined for amyloid deposition. Deposits of amyloid in the hip and knee joints were found more frequently in those with rheumatoid arthritis than in those with osteoarthritis. In osteoarthritis, the frequency of amyloid deposition tended to increase with advancing age. However these amyloid deposits in the joint structure were discovered to be resistant to permanganate oxidation. Therefore it was suspected that these amyloid deposits were of a type different from AA amyloid.