Background Anti-citrullinated protein antibodies (ACPA) have been reported as more specific serological markers of rheumatoid arthritis (RA). They provide a superior alternative to the rheumatoid factor (RF) test in laboratory diagnostics of RA (1). Different studies suggest that the enzymatic citrullination and the production of ACPAs may also be associated with other inflammatory arthritis-associated autoimmune diseases (2).

Objectives Is to detect the presence of anti CCP and anti CMV antibodies in SLE & SSc and its correlation to radiological findings and disease activity.

Methods Our study was included 70 SLE patients and 30 systemic sclerosis (SSc) patients diagnosed according to ACR classification criteria. After informed consent, all patients were subjected to detailed history taking, full clinical examination including rheumatological examination, laboratory investigations: included CBC, ESR, CRP with titer, urine analysis, renal & liver function, serum uric acid, Anti CCP antibodies & Anti MCV antibodies by ELISA. X- ray and U/S on both hands and knees and disease activity score using SLEDAI score for SLE patients and SSc disease activity score (Medsgar score) for SSc patients.

Results In our study, anti CCP antibodies were found in 8 (11.4%) of SLE patients and 4 (13.3%) SSc patients, while anti MCV antibodies were found in 14 (20%) SLE patients and 8 (26.7%) of SSc patients.There is association between presence of anti CCP Abs and anti MCV Abs and a clinically evident arthritis in both SLE and SSc. Strong relationship between high CRP level and a severe arthritis and joint erosions was noticed in SLE patients. A significant radiological evident in the form of synovial hypertrophy and bony erosions were found using ultrasonography and plain X-ray with seropositive anti CCP and anti MCV Abs in both SLE and SSc patients.In our study, cut off value of anti CCP which was >12, with sensitivity of 70.42%, specificity of 60% positive predictive value of 80.6%, negative predictive value of 46.2% with diagnostic accuracy of 61.7%, and best cut off value of Anti MCV which was >11, with sensitivity of 98.46%, specificity of 30%, positive predictive value of 75.3%, negative predictive value of 90% with diagnostic accuracy of 60.2% in SLE & SSc.

Conclusions There is a significant association between presence of anti CCP antibodies and anti MCV antibodies and the presence of evident arthritis either clinical or radiologically by using both x-ray and U/S on both hands and knees in SLE and SSc patients.

References

1. Xia L, Rulin J, Jinxia Z, et al. The Role of Anti-Mutated Citrullinated Vimentin Antibodies in the Diagnosis of Early Rheumatoid Arthritis. The Journal of Rheumatology 2009; 36:46.

2. Szodoray P, Szabό Z, Kapitány A., et al. Anti-citrullinated protein/peptide autoantibodies in association with genetic and environmental factors as indicators of disease outcome in rheumatoid arthritis. 22 Autoimmunity Reviews 2010; 9: 140–3.

References

Acknowledgements We thanks all the participating patients.

Disclosure of Interest None declared