THU0180 Should we include ultrasound in the 1987 acr and 2010 acr/eular classification criteria for rheumatoid arthritis?

Background Ultrasound imaging (US) is actually considered as a crucial element of the diagnostic process in rheumatic diseases and could be the method of choice in imaging peripheral synovitis, typical feature during rheumatoid arthritis (RA). The 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria focused on early-stage RA, and were designed to remedy the deficiencies in the 1987 ACR criteria, but still lacking sensitivity. Objectives We undertook this study to investigate whether including the ultra-sonographic data in calculating the 1987 ACR and 2010 ACR/EULAR criteria is useful in diagnosing RA. Methods We performed a cross-sectional study of one hundred patients with inflammatory joint pain or synovitis for more than 6 weeks and less than 2 years. An experienced radiologist performed the MSUS scan of 22 joints (2 wrists, 10 metacarpophalangeal joints MCP and 10 proximal interphalangeal joints PIP) unaware of clinical and biological findings. After US assessment, patients were classified as having RA according to ACR/ EULAR 2010 criteria using clinical, biologic and radiographic data (clinical ACR87 or clinical ACR/EULAR2010). Then we calculate those criteria using US data: US-ACR87 including erosion detected in US as a criterion and US-ACR/EULAR2010 including the number of synovitis detected in US as a criterion. Results One hundred RA patients were included (77 women and 23 men) with a mean age of 51.8 years.16–77 The mean disease duration was 10.96.2 24 Rheumatoid factor and antibodies against cyclic citrullinated peptides were positive in 53% and 25% cases respectively. Sixty-five patients (65%) accomplished the clinical ACR87 criteria and 55 patients (55%) fulfilled the clinical ACR/EULAR2010 criteria for the diagnosis of RA. Using US data eighty patients (80%) accomplished the US-ACR87 criteria and 68 patients (68%) fulfilled the US-ACR/EULAR2010 criteria for the diagnosis of RA. A good correlation was found between clinical and US ACR/EULAR criteria (k=0,684, p=0,000). US score showed a very good sensitivity of 100%, specificity of 67,5%, positive predictive value of 76,9% and negative predictive value of 100% compared to clinical score. In table 1 we summarise correlation between clinical and US ACR/EULAR criteria. Conclusions Our study showed that including US data in the classification criteria of RA, will improve diagnostic impact of those criteria during RA management. Disclosure of Interest None declared