Background The presence of anti-CCP antibodies has been shown to be highly specific for rheumatoid arthritis (RA). Testing for anti-CCP antibodies has grown in popularity and has become widely available. Testing may be useful in the early diagnosis of RA and may predict the development of erosive disease. The presence of anti-CCP Ab has been demonstrated in other connective tissue disorders other than RA, including Sjogren’s syndrome, systemic lupus erythematosus, vasculitis, and inflammatory muscle disease;nonetheless, anti-CCP Ab positivity has been noted to be rare in non-rheumatoid connective tissue diseases. Recent data have also demonstrated the presence of anti-CCP Ab in autoimmune hepatitis as well as certain infections.

Objectives To prospectively follow patients with strongly positive anti-CCP antibodies without RA who were referred to the rheumatology service in a tertiary care center.

Methods Patients testing positive for anti-CCP antibodies seen in our rheumatology clinic for the evaluation of rheumatologic complaints who did not fulfill the ACR/EULAR classification criteria for RA were identified and followed prospectively. Subjects were routinely assessed for any progression in presenting symptoms and development of new findings.

Results Nine patients were identified. Five of nine patients were referred for evaluation of diffuse arthralgias yet showed no evidence of synovitis. These patients were diagnosed with ANCA vasculitis, osteoarthritis (OA), parvovirus B19 infection, inflammatory myositis, and OA with concomitant fibromyalgia. One patient with scleritis and one with interstitial lung disease (ILD) were referred to our clinic to be evaluated for underlying connective tissue disease, each with subsequent negative work-up. The remaining two cases presented with oligoarthritis and were diagnosed with disseminated M.chelonae and septic arthritis. The patients in this prospective cohort were followed for a minimum of six and up to 36 months. During this period, patients remained stable and without evidence of RA.

Conclusions Our observation that the presence of anti-CCP Ab can be seen in conditions other than RA is consistent with recent published findings. We cannot rule out early RA, however, as in the setting of scleritis and ILD. As such, routine follow-up to monitor for any clinical significance of anti-CCP Ab positivity is warranted, and additional information is needed. Furthermore, that antibody testing is becoming more widely accepted suggests that the need for collaboration between rheumatologists and other physicians, namely internists, pulmonologists, ophthalmologists, and infectious disease specialists should be recognized and not overlooked.

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Disclosure of Interest None Declared