Antibodies to mutated citrullinated vimentin and disease activity score in early arthritis: a cohort study.
BACKGROUND
The aim of our study was to investigate the association between arthritic disease activity and antibodies to mutated citrullinated vimentin (anti-MCV), because such a relation has been suggested.


METHODS
Anti-MCV levels were measured in 162 patients with early arthritis (123 with rheumatoid arthritis and 39 with undifferentiated arthritis) at baseline and at 1 and 2 years of follow up. Disease activity was measured using the disease activity score (Disease Activity Score based on 28 joints [DAS28]) and serum C-reactive protein. General estimation equation analysis was used to assess the relation between anti-MCV levels and DAS28 over time.


RESULTS
Both, anti-MCV levels and DAS28 exhibited a significant decrease during the first and second year. However, the association between anti-MCV levels and DAS28, adjusted for dependency on sequential measurements within one individual, was very low (beta = 0.00075). In a population of patients with rheumatoid arthritis or undifferentiated arthritis, anti-MCV had a specificity of 92.3% and a sensitivity of 59.3% when using the recommended cut-off of 20 U/ml. Specificity and sensitivity of antibodies against second-generation cyclic citrullinated peptide, using the recommended cut-off value of 25 U/ml, were 92.1% and 55.3%, respectively. Anti-MCV-positive early arthritis patients had significantly higher Sharp-van der Heijde score, erythrocyte sedimentation rate and C-reactive protein levels than did anti-MCV-negative patients at all time points (P < 0.005), but DAS28 was higher in anti-MCV-positive patients at 2 years of follow up only (P < 0.05).


CONCLUSIONS
Because the correlation between anti-MCV levels and parameters of disease activity was very low, we conclude that it is not useful to monitor disease activity with anti-MCV levels.
Ursum
Jennie
J
Jan van Breemen Institute, Dr Jan van Breemenstraat, 1056 AB Amsterdam, The Netherlands. j.ursum@janvanbreemen.nl
Nielen
Markus M J
MM
van Schaardenburg
Dirkjan
D
van der Horst
Ann R
AR
van de Stadt
Rob J
RJ
Dijkmans
Ben A C
BA
Hamann
Dörte
D
D000328:Adult; D000906:Antibodies / Q000097:blood*; D001168:Arthritis / Q000000981:diagnostic imaging* / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology*; D002956:Citrulline / Q000378:metabolism*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation; D010456:Peptides, Cyclic / Q000276:immunology; D011859:Radiography; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014746:Vimentin / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*
D000906:Antibodies; D010456:Peptides, Cyclic; D014746:Vimentin; C487763:cyclic citrullinated peptide; D002956:Citrulline