Amyloidosis is frequently undetected in patients with rheumatoid arthritis

Abstract

Prevalence of AA amyloid in rheumatoid arthritis (RA) is still unclear. The objective of this retrospective study was whether dedicated re-examination of autopsy tissues from RA patients increases the detection rate of amyloid compared to routine examination. Amyloid was re-examined in tissue samples and detection rate compared with original reports of 369 consecutively autopsied RA patients and 370 non-RA patients matched for sex, age, and year of autopsy between 1952 and 1991. Re-examination of 90% of the 739 cases showed doubling of the prevalence of amyloid compared with the original reports: from 18 to 30% in RA and from 2 to 4% in non-RA patients. In RA patients, cardiac amyloid was as frequent as renal amyloid. In RA patients with amyloid at re-examination, amyloidosis had been diagnosed before autopsy in 37%, and these patients had more inflammation and longer disease duration than RA patients without amyloid. Only 56% of RA patients with renal amyloid were known to have proteinuria. In conclusion, this autopsy study shows that amyloid in RA is a common finding which remains frequently undetected. In patients with active and long-lasting RA, a systematic search for amyloid may enable early diagnosis of amyloidosis, which will require effective suppression of inflammation.

Keywords:

• Amyloidosis
• autopsy
• mortality
• rheumatoid arthritis

Abbreviations
DMARDs	=	disease modifying anti-rheumatic drugs
ESR	=	erythrocyte sedimentation rate
GC	=	glucocorticoids, HB = hemoglobin
n	=	number
RA	=	rheumatoid arthritis

Abbreviations
DMARDs	=	disease modifying anti-rheumatic drugs
ESR	=	erythrocyte sedimentation rate
GC	=	glucocorticoids, HB = hemoglobin
n	=	number
RA	=	rheumatoid arthritis