To study the prevalence of secondary amyloidosis in Asian North Indian patients with rheumatoid arthritis (RA) and to determine its clinical significance.
RA patients with disease duration > 5 years were included in this prospective study over a 2 year period. Abdominal subcutaneous fat pad aspiration (ASFA) was performed, and smears were stained with Congo red and observed for apple-green birefringence under polarized light microscopy. The amyloid deposits were graded from 1+ to 3+. Clinical, radiological, and laboratory variables of the patients were correlated with the presence or absence of amyloidosis.
Thirty out of 113 patients were positive for amyloid by ASFA (26.5%). Out of these, 8 patients had features suggestive of clinical amyloidosis in the form of proteinuria, organomegaly, or symptomatic gastrointestinal involvement. In another 22 patients amyloidosis was subclinical. The majority of patients with clinical amyloidosis had either 2+ or 3+ deposits.
Abdominal fat amyloid deposits are not uncommon in adult Asian North Indian patients with RA. However, only one-fourth of patients had evidence of clinical amyloidosis. A longer followup and a larger multicentric collaborative study is needed to determine the significance of subclinical amyloid deposits.