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Updated: Jun 1, 2026

A Phenotyping Regimen for Genetically Modified Mice Used to Study Genes Implicated in Human Diseases of Aging
Published on: July 14, 2016
Ageing: a risk factor for amyloid A amyloidosis in rheumatoid arthritis
Yasuaki Okuda1, Toshiyuki Yamada, Masaaki Matsuura
1Department of Internal Medicine, Center for Rheumatic Diseases, Dohgo Spa Hospital, 21 -21 Otsu Dohgo-Himezuka Matsuyama-City, Ehime, Japan. yaokuda@ehime.med.or.jp
Objective:
Acceleration of amyloid A (AA) amyloidosis induction by ageing has not been extensively studied in rheumatoid arthritis (RA). The aim of this study is to clarify contribution of ageing to the development of AA amyloidosis associated with RA in our large cohort.
Methods:
388 adult-onset RA patients whose RA was complicated by biopsy-proven AA amyloidosis were enrolled. The ages of RA onset and AA amyloidosis diagnosis were estimated in each patient. The contributions of ageing, inflammatory activity, SAA1 exon 3 polymorphism as well as gender to the pathogenesis of AA amyloidosis in 144 cases were also studied by multiple regression analysis.
Results:
Subjects with RA onset at older age had a shorter period to develop amyloidosis than those with disease onset at younger age (p < 0.001). The interval between RA onset and AA amyloidosis diagnosis was significantly shorter in the SAA1.3 positive group than in the SAA1.3 negative (p=0.001). Multiple regression analysis indicated that the interval from RA onset to diagnosis of AA amyloidosis is determined by age at RA onset (p < 0.001), the most recent median annual CRP concentration (p=0.006) and SAA1.3 allele (p=0.058). Gender did not significantly contribute to the onset of AA amyloidosis (p=0.569).
Conclusion:
Ageing is an independent risk factor for the induction of AA amyloidosis complicating RA.
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