Older ageonsetrheumatoid arthritis with orwithout osteoarthritis

SUMMARY Theclinical features ofa group of79patients witholder age onsetrheumatoid arthritis (ORA)were compared withthose ofa group of414patients with younger age onset rheumatoid arthritis. TheORA group contained approximately equalnumbersofmen and women, were less rheumatoid factor positive, hadaraised erythrocyte sedimentation rate,lower HLA-DR4positivity, anda tendency towards larger joint involvement attheonsetofthe disease. Thesefeatures havebeenreported bymany authors exceptforthelower DR4positivity. Ofthese features, thelower prevalence ofrheumatoid factor positivity andthetendency towards larger joint involvement attheonsetwere characteristic ofa subset ofpatients withORA who hadhadosteoarthritis before theonsetofrheumatoid arthritis. Itissuggested that osteoarthritic large joints may besusceptible totheoccurrenceofrheumatoid synovitis attheonsetofthe disease, butthat theosteoarthritis inducing factor may benegatively related totheprogression of rheumatoid arthritis.