Egyptian Rheumatology and Rehabilitation

ORIGINAL ARTICLE
Year
: 2015  |  Volume : 42  |  Issue : 2  |  Page : 62--67

Assessment of serum antimutated citrullinated vimentin antibodies in rheumatoid arthritis


Refaat M El Tanawy, Khaled M Belal, Waleed A Hassan, Emtesal A Said, Shaimaa M Hafez 
 Department of Physical Medicine, Rheumatology and Rehabilitation, Benha University Hospital, Benha, Egypt

Correspondence Address:
Waleed A Hassan
Benha University Hospital, 5 Ahmed Salem Street, Benha Qulubiya
Egypt

Abstract

Background Early diagnosis and treatment of rheumatoid arthritis (RA) leads to better control and prevents irreversible joint damage. Antimutated citrullinated vimentin (anti-MCV) is one of the members of the anticitrullinated antibody family that can function as a serological marker in the early diagnosis of RA. Aim of the work This study aimed to measure serum levels of anti-MCV antibodies and study their relationship using clinical, laboratory, and radiological findings in RA patients. Patients and methods We measured anti-MCV in the serum of 60 RA patients, in 20 patients with psoriatic arthritis, and in 20 healthy controls. In RA patients, the disease activity score (DAS28) and the Health Assessment Questionnaire score were used. The immunoglobulin-M rheumatoid factor titer, anticyclic citrullinated peptide antibody (anti-CCP) titer, and C-reactive protein levels were also measured. The hands of RA patients were radiologically scored using the Larsen method. Results In RA patients the mean anti-MCV antibody serum level was 150.83 ± 125.95 U/ml, which was significantly higher (P < 0.001) compared with the mean serum level in psoriatic arthritis patients and healthy controls (17.4 ± 10.039 and 17.2 ± 10.63 U/ml, respectively). Serum levels of anti-MCV antibodies significantly correlated with DAS28 (r = 0.79, P < 0.05), Health Assessment Questionnaire scores (r = 0.53, P < 0.05), rheumatoid factor titer (r = 0.74, P < 0.05), anti-CCP antibody titer (r = 0.83, P < 0.05), and Larsen�SQ�s score (r = 0.76, P < 0.05). Conclusion The significantly elevated anti-MCV antibody levels that are well correlated with RA disease activity and severity markers are highly suggestive of their potential role in the pathogenesis of RA. The considerable correlation of anti-MCV antibodies with other autoantibodies would imply their consistent diagnostic and prognostic role.



How to cite this article:
El Tanawy RM, Belal KM, Hassan WA, Said EA, Hafez SM. Assessment of serum antimutated citrullinated vimentin antibodies in rheumatoid arthritis.Egypt Rheumatol Rehabil 2015;42:62-67


How to cite this URL:
El Tanawy RM, Belal KM, Hassan WA, Said EA, Hafez SM. Assessment of serum antimutated citrullinated vimentin antibodies in rheumatoid arthritis. Egypt Rheumatol Rehabil [serial online] 2015 [cited 2024 Mar 28 ];42:62-67
Available from: http://www.err.eg.net/text.asp?2015/42/2/62/157862


Full Text

 Introduction



Rheumatoid arthritis (RA) is a chronic systemic disease affecting primarily the synovium, leading to joint damage and bone destruction [1] . Early diagnosis of RA and its early treatment with disease-modifying antirheumatic drugs lead to better control and less joint damage. Therefore, it is very important to find an acceptable serological marker in order to make an early diagnosis and initiate early treatment to avoid complications and disability [2] .

Various serum biomarkers are used to diagnose RA, including many autoantibodies. However, only rheumatoid factor (RF) and anticyclic citrullinated peptide (anti-CCP) antibodies have wide acceptance [3] .

Antibodies targeting citrullinated proteins are found to be highly specific for the diagnosis of RA [4] . They have many targets in rheumatoid synovial tissue, including α-fibrin and β-fibrin chains, fibronectin, collagen type I, and α-enolase (from monocytes and granulocytes) in citrullinated form [5],[6],[7] . These autoantibodies predict clinical and radiological severity and may be implicated in the pathogenesis of RA; however, they have a high value in the early diagnosis and early treatment of RA [8] .

Vimentin is usually not found in citrullinated form in vivo, but deamination of arginine residues on vimentin molecules has been demonstrated to occur in macrophages during apoptosis [9] . In a polymerized form, vimentin constitutes a structure of intermediary filaments, the main component of cytoskeleton in mesenchymal cells (chondrocytes, synovial fibroblasts, and macrophages) [10] .

Antimutated citrullinated vimentin (anti-MCV) is another anticitrullinated antibody reacting with MCV [11] . It was discovered through an anti-Sa autoantibody test and was first identified in a French/Canadian patient whose name began with the letters Sa; it was expressed in fibroblasts like synoviocytes [12] .

Anti-Sa autoantibodies have the same specificity as anti-CCP antibodies but show too low sensitivity to help in RA diagnosis [13] . Genetic modification of citrullinated vimentin to MCV by enzyme linked immunosorbant assay (ELISA) was developed to increase the sensitivity [14] .

This study aimed to measure serum levels of anti-MCV antibodies and study their relationship with clinical, laboratory, and radiological findings in RA patients.

 Patients and methods



Study approval

The study was approved by the Ethical Committee of our institution. All patients gave their written informed consent before participation in this study.

Participants

Sixty patients fulfilling the 2010 ACR-EULAR classification criteria for RA [15] were recruited from among the inpatients and outpatients of the Rheumatology and Rehabilitation department of Benha University Hospitals. Twenty age-matched and sex-matched psoriatic arthritis (PsA) patients with inflammatory peripheral arthritis fulfilling the 2006 CASPAR classification criteria for PsA [16] as well as 20 age-matched and sex-matched apparently healthy individuals from among the hospital personnel, undergraduates, and medical and nursing staff were included as controls.

We excluded patients with a known malignancy or chronic infection (e.g. tuberculosis and hepatitis B or C).

Methods

RA patients' evaluation included full history taking with recording of the disease duration, thorough physical examination, with particular focus on the pattern of joint involvement, the presence of nodules and other extra-articular features, and ongoing medications. Disease activity using the 28 joint counts (DAS28) [17] and Health Assessment Questionnaire (HAQ) score [18] was assessed in all patients. Radiographs (posteroanterior view) of the hands were obtained for all patients and were scored using the Larsen method [19] .

Laboratory investigations

About 10 ml of venous blood was collected and analyzed for complete blood count and for evaluation of the erythrocyte sedimentation rate by Westergren's method [20] in mm/h, C-reactive protein (CRP), RF, and anti-CCP antibodies.

Measurement of serum levels of anti-MCV antibodies

Anti-MCV antibody levels were measured in the serum collected from all RA patients, PsA patients, and healthy controls. All blood samples were allowed to clot and the serum was separated by centrifugation and stored at -20°C until analysis. Assay of anti-MCV antibodies was performed by means of the ELISA technique using the human anti-mutated citrullinated vimentin (MCV) antibody ELISA Kit (Cat.No: CSB-E09565h; Cusabio, Hubei, China). The assay procedures were followed as per the manufacturer's instructions. Detection range was from 5 to 400 U/ml, and anti-MCV antibodies were considered positive if the level was greater than 20 U/ml.

Statistical analysis

The collected data were analyzed using SPSS, version 16 (SPSS Inc., Chicago, Illinois, USA). Categorical data were presented as number and percentages, whereas continuous variables were presented as mean and SD if parametric and as median and range if nonparametric. The χ2 -test, the Z-test, the Mann-Whitney U-test, the Kruskal-Wallis test, and Spearman's correlation coefficients were used as tests of significance. A two-sided P-value less than 0.05 was considered significant.

 Results



Of the 60 patients with RA, 57 were female (95%) and three were male (5%). Their ages ranged from 20 to 64 years (mean ± SD 41.183 ± 9.18 years). Both control groups were age and sex matched to RA patients; PsA patients' ages ranged from 19 to 63 years (mean ± SD 40.6 ± 12.1 years), whereas the ages of healthy controls ranged from 19 to 63 years (mean ± SD of 43.35 ± 10.5 years). The study groups' clinical and laboratory features are shown in [Table 1].{Table 1}

Regarding extra-articular manifestation in RA patients, 14 patients (23.33%) had subcutaneous nodules, eight patients (13.33%) had interstitial pulmonary fibrosis, and one patient (1.7%) had scleritis.

All patients were receiving NSAIDs, whereas 48 patients (80%) were receiving methotrexate (12.5-20 mg/week) in combination with hydroxychloroquine, eight patients (13.33%) were on leflunomide (20 mg/day) in combination with hydroxychloroquine, and four patients (6.66%) were receiving a combination of methotrexate and leflunomide. Twenty-two patients (36.66%) were on corticosteroids, with a dose ranging from 5 to 20 mg/day.

The mean anti-MCV antibody serum level in RA patients was 150.83 ± 125.95 U/ml, with a highly significant increase (P < 0.001) compared with its level in PsA patients and healthy individuals.

No significant difference (P>0.05) was found between the mean anti-MCV antibody serum level in PsA patients (17.4 ± 10.039 U/ml) and the level in healthy individuals (17.2 ± 10.63 U/ml).

Regarding the distribution of autoantibodies in RA patients, both anti-CCP and anti-MCV antibodies were positive in 39 patients (65%) and negative in 10 patients (16.67%). Positive anti-MCV and negative anti-CCP antibodies were found in seven patients (11.67%), whereas negative anti-MCV and positive anti-CCP antibodies were found in four patients (6.67%) ([Table 2]).{Table 2}

Forty-six RA patients (76.6%) were positive for anti-MCV antibodies, with a highly significant increase (P < 0.001) compared with PsA patients (1/20, 5%) and healthy control groups (1/20, 5%).

The receiver operating characteristic curve for anti-MCV antibodies was drawn ([Figure 1]); the area under the curve was 0.881 at 95% confidence interval. Sensitivity was 76.6% and specificity was 95% in diagnosing RA patients, with a positive predictive value (PPV) of 95.83, a negative predictive value (NPV) of 74.07, and accuracy of 84%.{Figure 1}

Sensitivity of anti-CCP antibodies was 71.67% and specificity was 95% in diagnosing RA patients with a PPV of 95.56, NPV of 69.09, and accuracy of 81%. The RF had a sensitivity of 83.33% and specificity of 85% in diagnosing RA patients with a PPV of 89.29, NPV of 77.27, and accuracy of 84%.

The mean anti-MCV antibody serum level in RF-positive RA patients (n = 50) (162.34 ± 128.33 U/ml) showed a highly statistically significant increase (P < 0.001) compared with RF-negative patients (n = 10) (86.3 ± 72.03 U/ml).

Anti-MCV antibody serum levels in RA patients showed a statistically significant correlation with CRP level (r = 0.47, P < 0.05), DAS28 (r = 0.788, P < 0.05), HAQ scores (r = 0.53, P < 0.05), RF titer (r = 0.74, P < 0.05), anti-CCP titer (r = 0.83, P < 0.05), and Larsen score (r = 0.76, P < 0.05) ([Table 3]).{Table 3}

RA patients with positive anti-MCV antibodies showed a statistically significant increase in swollen joints count (P < 0.05), DAS28 (P < 0.05), anti-CCP antibody titer (P < 0.05), and Larsen score (P < 0.05), compared with RA patients with negative anti-MCV antibodies ([Table 4]).{Table 4}

The linear regression curve showed a significant correlation between DAS and anti-MCV antibody serum levels (r = 0.788, P < 0.05) ([Figure 2]) and between DAS and anti-CCP antibodies (r = 0.565, P < 0.05), but no significant correlation existed between DAS and RF titer (r = 0.265, P > 0.05).{Figure 2}

 Discussion



RA is an autoimmune inflammatory disease characterized by the presence of several autoantibodies. The best known is the RF, which is an autoantibody listed among the diagnostic criteria. The value of RF in the diagnosis, assessment, and evaluation of RA may be controversial [21] . Anti-MCV antibody is a member of the family of autoantibodies reactive with citrullinated proteins that seem to be highly specific for RA. They have a possible prognostic value as a marker of a more serious disease [22] .

In our study, serum levels of anti-MCV antibodies were significantly elevated in RA patients than in PsA patients and healthy controls (P < 0.001 and P < 0.001, respectively) and they have a sensitivity of 76.6% and specificity of 95% in diagnosing RA. Our results confirmed the results of other studies that found an elevated serum anti-MCV antibody level in RA patients than in controls [11],[12],[23],[24] .

Tesija-Kuna et al. [25] found anti-MCV antibodies in only two out of 56 (3.6%) PsA patients with polyarthritic disease and claimed that anti-MCV antibodies are primarily related to the polyarthritic pattern rather than to the specific diagnosis of RA as a concomitant disease. This was comparable to our finding of anti-MCV antibodies in 1/20 (5%) PsA patients.

We found anti-MCV antibody serum levels to be significantly correlated with the clinical and laboratory parameters of RA disease activity, DAS28, and HAQ scores. Our results were in agreement with the results of Keskin et al. [26] , who found that anti-MCV antibody levels were strongly correlated with disease activity parameters in 427 RA patients, including DAS28, erythrocyte sedimentation rate, CRP, and tender joint count. In a 3-year follow-up study of these patients, the anti-CCP antibody titer failed to show this correlation.

Mathsson et al. [12] suggested that anti-MCV antibodies are better predictors of RA disease activity compared with anti-CCP.

In contrast, Ursum et al. [27] found low correlation between anti-MCV antibodies and disease activity in early RA patients.

We found anti-MCV antibodies to be positive in 11.7% of RA patients who were negative for anti-CCP. Ronald et al. [28] tested both anti-MCV and anti-CCP in 156 patients and found anti-MCV antibodies to be positive in 5.8% of RA patients who were negative for anti-CCP and suggested that the anti-MCV-positive/anti-CCP-negative profile may have a specific gene polymorphism as in the RF, which is associated with a mutation in the protein tyrosine phosphatase nonreceptor type 22 (PTPN22) [29] , and anti-CCP, which is associated with polymorphism in PTPN22 1858 C/T [30] .

The significant correlations between anti-MCV antibodies and Larsen score in our RA patients were in agreement with many studies. Innala et al. [31] reported that anti-MCV-positive RA patients already had significantly greater radiological damage scores compared with anti-MCV-negative RA patients, whereas Syversen et al. [32] reported that anti-MCV antibodies were strong predictors of radiological progression in RA patients.

 Conclusion



The significantly elevated anti-MCV antibody levels that are well correlated with RA disease activity and severity markers are highly suggestive of their potential role in the pathogenesis of RA. The considerable correlation of anti-MCV antibodies with other autoantibodies would imply their consistent diagnostic and prognostic role.

 Acknowledgements



The authors thank Professor Dr. Samia Abdel Moneim for her great effort in editing the manuscript.

Conflicts of interest

There are no conflicts of interest.

References

1Gravallese E. Bone destruction in arthritis. Ann Rheum Dis 2002; 61 :ii84-ii86.
2 Orozco C, Olsen NJ. Identification of patients with early rheumatoid arthritis: challenges and future directions. Clin Dev Immunol 2006; 13 :295-297.
3 Taylor P, Gartemann J, Hsieh J, Creeden J. A systematic review of serum biomarkers anti-cyclic citrullinated peptide and rheumatoid factor as tests for rheumatoid arthritis. Autoimmune Dis 2011; 2011 :815038.
4 Riedmann JP, Munoz S, Kavanaugh A. The use of second generation anti-CCP antibody (anti-CCP2) testing in rheumatoid arthritis - a systematic review. Clin Exp Rheumatol 2005; 23 :S69-S76.
5 Masson-Bessiere C, Sebbag M, Girbal-Neuhauser E, Nogueira L, Vincent C, Senshu T, et al. The major synovial targets of the rheumatoid arthritis-specific antifilaggrin autoantibodies are deiminated forms of the alpha- and beta-chains of fibrin. J Immunol 2001; 166 :4177-4184.
6 Chang X, Yamada R, Suzuki A, Kochi Y, Sawada T, Yamamoto K. Citrullination of fibronectin in rheumatoid arthritis synovial tissue. Rheumatology 2005; 44 :1374-1382.
7 Kinloch A, Tatzer V, Wait R, Peston D, Lundberg K, Donatien P, et al. Identification of citrullinated alpha-enolase as a candidate autoantigen in rheumatoid arthritis. Arthritis Res Ther 2005; 7 :R1421-R1429.
8 Agrawal S, Misra R, Aggarwal A. Auto-antibodies in rheumatoid arthritis; association with severity of disease in established RA. Clin Rheumatol 2007; 26 :201-204.
9 Vossenar ER, Radstake TR, van der Heijden A, van Mansum MA, Dieteren C, de Rooij DJ, et al. Expression and activity of citrullinating peptidyl argininedeiminase enzymes in monocytes and macrophages. Ann Rheum Dis 2004; 63 :373-381.
10Strelkov SV, Herrmann H, Aebi U. Molecular architecture of intermediate filaments. Bioassays 2003; 25 :243-251.
11Sghiri R, Bouajina E, Bargaoui D, Harzallah L, Fredj HB, Sammoud S, et al. Value of anti-mutated citrullinated vimentin antibodies in diagnosing rheumatoid arthritis. Rheumatol Int 2008; 29 :59-62.
12Mathsson L, Mullazehi M, Wick MC, Sjöberg O, van Vollenhoven R, Klareskog L, et al. Antibodies against citrullinated vimentin in rheumatoid arthritis: higher sensitivity and extended prognostic vale concerning future radiographic progression as compared with antibodies against cyclic citrullinated peptides. Arthritis Rheum 2008; 58 :36-45.
13van der Linden MP, van der Woude D, Ioan-Facsinay A, Levarht EW, Stoeken-Rijsbergen G, Huizinga TW, et al. Value of anti-modified citrullinated vimentin and third-generation anti-cyclic citrullinated peptide compared with second-generation anti-cyclic citrullinated peptide and rheumatoid factor in predicting disease outcome in undifferentiated arthritis and rheumatoid arthritis. Arthritis and rheumatism."Arthritis Rheum 2009; 60 :2232-41.
14Dejaco C, Kotz W, Larcher H, Duftner C, Schirmer M, Herold M. Diagnostic value of antibodies against a modified citrullinated vimentin in rheumatoid arthritis. Arthritis Res Ther 2006; 8 :R119.
15Aletaha D, Neogi T, Silman AJ, Funovits J, Felson DT, Bingham CO3rd, et al. 2010 rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism. Arthritis Rheum 2010; 62 :2569-2581.
16Taylor W, Gladman D, Helliwell P, Marchesoni A, Mease P, Mielants H, et al. Classification criteria for psoriatic arthritis: development of new criteria from a large international study. Arthritis Rheum 2006; 54 :2665-2673.
17Prevoo ML, van′t HMA, Kuper HH, van Leeuwen MA, van de Putte LB, van Riel PL. Modified disease activity scores that include twenty-eight-joint counts. Development and validation in a prospective longitudinal study of patients with rheumatoid arthritis. Arthritis Rheum 1995; 38 :44-48.
18Bruce B, Fries J. The Stanford health assessment questionnaire (HAQ): a review of its history, issues, progress, and documentation. J Rheumatol 2003; 30 :167-178.
19Larsen A, Dale K, Eek M. Radiographic evaluation of rheumatoid arthritis and related conditions by reference films. Acta Radiol Diagn 1977; 18 :481-491.
20Westergren A. Studies of suspension stability of the blood in pulmonary tuberculosis. Am Rev Tuberc 1921; 14 :94.
21Genevay S, Hayem G, Verpillat P, Meyer O. An eight year prospective study of outcome prediction by antiperinuclear factor and antikeratin antibodies at onset of rheumatoid arthritis. Ann Rheum Dis 2002′ 61 :734-736.
22Vencovský J, Machácek S, Sedová L, Kafková J, Gatterová J, Pesáková V, et al. Autoantibodies can be prognostic markers of an erosive disease in early rheumatoid arthritis. Ann Rheum Dis 2003; 62 :427-430.
23Gonzalez-Lopez L, Rocha-Muñoz AD, Ponce-Guarneros M, Flores-Chavez A, Salazar-Paramo M, Nava A, et al. Anti-cyclic citrullinated peptide (anti-CCP) and anti-mutated citrullinatedvimentin (anti-MCV) relation with extra-articular manifestations in rheumatoid arthritis. J Immunol Res 2014; 2014 :536050.
24Mansour HE, Metwalt KM, Hassan IA, Elshamy HA, Elbeblawy MM. Antibody to mutated citrullinatedvimentin in rheumatoid arthritis: diagnosticvalue, association with radiological damage and axial skeleton affection. Clin Med Insight Arthritis Musculoskelet Disord 2010; 3 :33-42.
25Tesija-Kuna A, Grazio S, Miler M, Vukasovic I, Peric P, Vrkic N. Antibodies targeting mutated citrullinated vimentin in patients with psoriatic arthritis. Clin Rheumatol 2010; 29 :487-493.
26Keskin G, Inal A, Keskin D, Pekel A, Baysal O, Dizer U, et al. Diagnostic utility of anti-cyclic citrullinated peptide and anti-modified citrullinated vimentin antibodies in rheumatoid arthritis. Protein Pept Lett 2008; 15 :314-317.
27Ursum J, Nielen MM, van Schaardenburg D, van der Horst AR, van de Stadt RJ, Dijkmans BA, et al. Antibodies to mutated citrulinated vimentin and disease activity score in early arthritis: a cohort study. Arthritis Res Ther 2008; 10 :R12.
28 Roland PN, Mignot SG, Bruns A, Hurtado M, Palazzo E, Hayem G, et al. Antibodies to mutated citrulinated vimentin for diagnosing rheumatoid arthritis in anti CCP-negative patients and for monitoring infliximab therapy. Arthritis Res Ther 2008; 10 :R142.
29Dieudé P, Garnier S, Michou L, Petit-Teixeira E, Glikmans E, Pierlot C, et al. Rheumatoid arthritis seropositive for rheumatoid factor is linked to protein tyrosine phosphatase nonreceptor 22-620w allele. Arthritis Res Ther 2005; 7 :R1200-R1207.
30Kokkonen H, Johansson M, Innala L, Jidell E, Rantapää-Dahlqvist S. The PTPN22 1858 C/T polymorphism is associated with anti cycliccitrulinated peptide antibody positive early rheumatoid arthritis in northern Sweden. Arthritis Res Ther 2007; 9 :R56.
31Innala L, Kokkonen H, Eriksson C, Jidell E, Berglin E, Dahlqvst SR. Antibodies against mutated citrullinated vimentin are a better predictor of disease activity at 24 months in early rheumatoid arthritis than antibodies against cyclic citrullinated peptides. J Rheumatol 2008; 35 :1002-1008.
32Syversen SW, Gaarder PI, Goll GL, Ødegård S, Haavardsholm EA, Mowinckel P et al. High anti-cyclic citrullinated peptide levels and an algorithm of four variables predict radiographic progression in patients with rheumatoid arthritis: results from a 10-year longitudinal study. Ann Rheum Dis 2008; 67 :212-217.