RESEARCH - Antibodies to MCV for diagnosing RA in anti-CCP-negative patients and for monitoring Remicade therapy

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Arthritis Research & Therapy 2008, 10:R142doi:10.1186/ar2570

Antibodies to mutated citrullinated vimentin for diagnosing rheumatoid

arthritis in anti-CCP-negative patients and for monitoring infliximab

therapy

Pascale Nicaise Roland1 , Sabine Grootenboer Mignot1 , Alessandra

Bruns2 , Margarita Hurtado1,3 , beth Palazzo2 , Gilles Hayem2 ,

Philippe Dieudé2 , Olivier Meyer2 and Sylvie Chollet 1,3

1Immunology and Haematology Department, Bichat-Claude Bernard Teaching

Hospital, AP-HP, 46, rue H Huchard 75877 Paris Cedex 18, France

2Rheumatology Department, Bichat-Claude Bernard Teaching Hospital,

AP-HP, 46 rue H Huchard 75877 Paris Cedex 18, France

3Inserm IFR 141, UMR756, Paris-South 11 University, 5 rue JB Clement

92296 Chatenay-Malabry Cedex, France

Abstract

Introduction

Antibodies against cyclic citrullinated peptides (CCPs) are useful for

diagnosing rheumatoid arthritis (RA). Antibodies to mutated

citrullinated vimentin (MCV) were described recently in RA. The aims

of this study were to evaluate the usefulness of anti-MCV for

diagnosing RA in anti-CCP-negative patients and to monitor anti-MCV

titres during infliximab therapy for RA.

Methods

We studied two groups of RA patients, one with (n = 80) and one

without (n = 76) anti-CCP antibodies. The specificity of anti-MCV was

evaluated by investigating 50 healthy controls and 158 patients with

other rheumatic diseases (51 psoriatic rheumatism, 58 primary Sjögren

syndrome, and 49 ankylosis spondylitis). Serum anti-MCV and anti-CCP

titres were measured in 23 patients after 6, 12, 18, and 24 months of

infliximab treatment. Anti-CCP2 and anti-MCV levels were assayed using

a commercial enzyme-linked immunosorbent assay. IgM rheumatoid factor

was determined by nephelometry.

Results

In accordance with the cutoff values recommended by the manufacturer,

the specificity of anti-MCV antibodies was 90.9%. We adjusted the

cutoff values to obtain the same specificity as that of anti-CCP

antibodies (94.2%). With this optimal cutoff, anti-MCV antibodies were

found in 11.8% (9/76) of RA patients without anti-CCP, and similarly,

anti-CCP antibodies were found in 11.2% (9/80) of RA patients without

anti-MCV. Anti-MCV antibodies were positive in 6 patients who tested

negative for both anti-CCP and rheumatoid factor. Anti-MCV titres were

significantly decreased after 18 and 24 months of infliximab therapy

compared with baseline (P < 0.01) as a significant decrease of

anti-CCP levels occurred only at 24 months (P < 0.04). Moreover, an

anti-MCV decrease was significantly associated with DAS28 (disease

activity score using 28 joint counts) improvements 12 months into

therapy.

Conclusions

Our results suggest that anti-MCV antibodies may be valuable for

diagnosing RA in anti-CCP-negative patients without replacing them as

an equivalent number of anti-CCP-positive RA patients test negative

for anti-MCV. Moreover, anti-MCV antibodies could be useful for

monitoring the effects of infliximab therapy.

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http://arthritis-research.com/content/10/6/R142

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