Abstract | INTRODUCTION: The aim of this study was to examine seroconversion and the relationship with age and inflammation of autoantibodies in a large group of patients attending an outpatient rheumatology clinic. METHODS: Levels of antibodies to citrullinated proteins/ peptides ( ACPAs) and IgM rheumatoid factor ( IgM-RF) were determined in 22,427 samples collected from 18,658 patients. The diagnosis was derived from a diagnosis registration system. The degree of seroconversion in repeated samples and the correlation of levels with age and inflammatory markers were determined for ACPA and IgM-RF in rheumatoid arthritis (RA) and non-RA patients. RESULTS: Seventy-one percent of RA patients (n = 1,524) were ACPA-positive and 53% were IgM-RF-positive; in non-RA patients (n = 2,245), the corresponding values were 2% and 4%, respectively. In patients with at least two samples (n = 3,769), ACPA status was more stable than IgM-RF status in RA patients. ACPA- or IgM-RF-negative non-RA patients seldom became positive. ACPA positivity was unrelated to age in both RA and non-RA patients. IgM-RF positivity was unrelated to age in RA patients; however, it increased with age in non-RA patients. The correlation between autoantibody levels and inflammatory markers was low in general and was somewhat higher for IgM-RF than for ACPA. CONCLUSIONS: ACPA status is more stable in time and with increasing age than IgM-RF status, further establishing its role as a disease-specific marker. ACPA and IgM-RF levels are only moderately correlated with markers of inflammation.
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Authors | Jennie Ursum, Wouter H Bos, Rob J van de Stadt, Ben A C Dijkmans, Dirkjan van Schaardenburg |
Journal | Arthritis research & therapy
(Arthritis Res Ther)
Vol. 11
Issue 3
Pg. R75
( 2009)
ISSN: 1478-6362 [Electronic] England |
PMID | 19460147
(Publication Type: Comparative Study, Journal Article)
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Chemical References |
- Autoantibodies
- Biomarkers
- Immunoglobulin M
- Citrulline
- Rheumatoid Factor
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Topics |
- Adult
- Age Factors
- Aged
- Aged, 80 and over
- Arthritis, Rheumatoid
(blood, diagnosis, immunology)
- Autoantibodies
(biosynthesis, blood)
- Biomarkers
(blood)
- Citrulline
(blood, immunology)
- Databases, Factual
- Female
- Humans
- Immunoglobulin M
(biosynthesis, blood)
- Male
- Middle Aged
- Rheumatoid Factor
(biosynthesis, blood)
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