Clinical evaluation of anti-mutated citrullinated vimentin by ELISA in rheumatoid arthritis.
OBJECTIVE
Anti-cyclic citrullinated peptide (CCP) antibodies have emerged as sensitive and specific serological markers of rheumatoid arthritis (RA). However, antibodies to several other citrulline-containing proteins, including citrullinated fibrin and vimentin, have been detected in patients with RA, suggesting that citrulline is an essential constituent of autoantigens for RA-specific autoantibodies. We examined the diagnostic performance of the newly developed anti-mutated citrullinated vimentin (MCV) antibody assay.


METHODS
Concentrations of anti-MCV, anti-CCP2, and rheumatoid factors (RF) were determined in the sera of 237 individuals: 119 patients with RA and 118 controls, including patients with other rheumatic diseases and healthy subjects. Diagnostic properties were compared by receiver-operating characteristic curve analysis.


RESULTS
Using manufacturer's recommended cutoff values, sensitivity and specificity of anti-MCV antibodies were 75.6% and 91.5% in RA, compared to 66.4% and 98.3% for anti-CCP2. Introducing cutoff values to obtain the same 95% specificity resulted in decreased sensitivity of the anti-MCV test (69.7%) and increased sensitivity of the anti-CCP2 test (74.8%). At optimal cutoff levels, 29.4% of IgM RF-negative cases as well as 13.3% of anti-CCP2-negative cases in the RA group were anti-MCV-positive. Double-positivity for anti-MCV and anti-CCP2 provided 98.3% specificity with 97.5% positive predictive value in RA.


CONCLUSIONS
Overall, the performance of the novel anti-MCV ELISA for the diagnosis of RA is similar to that of the anti-CCP2 test [area under the curve 0.853 (95% CI 0.801-0.905) vs 0.910 (95% CI 0.873-0.946); p not significant]. As the diagnostic spectrum of the anti-MCV assay is somewhat different from that of anti-CCP2, the combined application of the 2 assays can improve the laboratory diagnostics of RA.
Soós
Lilla
L
Division of Rheumatology, Laboratory of Immunology, Department of Medicine, University of Debrecen, Medical and Health Science Center, Hungarian Academy of Sciences, Debrecen, Hungary.
Szekanecz
Zoltán
Z
Szabó
Zoltán
Z
Fekete
Andrea
A
Zeher
Margit
M
Horváth
Ildikó F
IF
Dankó
Katalin
K
Kapitány
Anikó
A
Végvári
Anikó
A
Sipka
Sandor
S
Szegedi
Gyula
G
Lakos
Gabriella
G
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000175:diagnosis*; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D003882:Dermatomyositis / Q000097:blood / Q000175:diagnosis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000097:blood / Q000175:diagnosis; D010456:Peptides, Cyclic / Q000097:blood / Q000276:immunology*; D012217:Rheumatoid Factor / Q000097:blood; D012680:Sensitivity and Specificity; D012859:Sjogren's Syndrome / Q000097:blood / Q000175:diagnosis; D014746:Vimentin / Q000097:blood / Q000235:genetics / Q000276:immunology*
D001323:Autoantibodies; D015415:Biomarkers; D010456:Peptides, Cyclic; D014746:Vimentin; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor