The prevalence of subclinical amyloidosis in Polish patients with rheumatoid arthritis

The aims of this study were to determine the proportion of rheumatoid arthritis (RA) patients attending hospital in whom amyloid deposits were present in abdominal fat aspiration (AFA) samples, and to assess possible risk factors for amyloid development in RA. One -hundred and twenty-one patients (16 males, 105 females) with RA referred to the Department of Rheumatology in Wroclaw between 1996 and 2001 were studied regardless of RA duration or laboratory findings. Abdominal subcutaneous fine-needle aspiration was performed, and samples of adipose tissue stained with alkaline Congo red then examined by polarized light microscopy. The presence or absence of amyloid fat deposits (AFD) was determined according to whether typical apple-green birefringence was observed. Amyloid deposits were found in 35 (29%) patients. Amyloidosis was significantly more common in males and in patients with longer disease duration. Patients with AFD had previously undergone less treatment with disease-modifying antirheumatic drugs (DMARDs) than those without AFD, and significantly fewer patients with AFD had previously taken methotrexate than those without AFD (25% vs 45%; p