[The detection of secondary amyloidosis in rheumatoid arthritis by aspiration biopsy of the subcutaneous fatty tissue].
81 rheumatoid arthritis patients were regularly and periodically examined in rheumatological department of Tartu University Clinic. Depending on the presence of amyloid in subcutaneous fat biopsies the patients were divided into two comparable groups: amyloid-positive (group 1 of 22 patients) and amyloid-negative (group 2 of 59 patients). Between the groups some differences were found: group 1 patients had more active and severe course of rheumatoid arthritis and higher level of rheumatoid factor and circulating immune complexes in the sera. Before biopsy secondary amyloidosis was diagnosed in 17.4% of the examines, biopsy of abdominal subcutaneous fat increased this rate to 27.2%. We could not ascertain any effect of previous treatment on secondary amyloidosis development except the connection with long-term use of corticosteroids. The analysis of 10379 autopsies showed that cases of RA with amyloidosis account for 30.9% of all amyloidosis cases. Multiple stepwise regression analysis determined predisposition factors to secondary amyloidosis as severity of locomotor system involvement, long-term use of corticosteroids, high level of rheumatoid factor and activity of rheumatoid process.