Background Familial Mediterranean fever (FMF) is characterized by recurrent febrile inflammatory attacks of serosal and synovial membranes. Besides well-known febrile attacks, many FMF patients suffer from non-episodic musculoskeletal complaints. Inflammatory back pain is a frequent complaint among FMF patients which is overlooked by physicians. Spondyloarthritis has been observed in 7.5% of FMF patients. However, clinical and radiologic features of this particular patient group are lacking.

Objectives To determine clinical and radiologic (X-Ray and MRI) characteristics of patients with FMF associated spondyloarthritis (FMF-SPA).

Methods Twenty-two patients followed up in our clinic with FMF-SPA confirmed by sacroiliac joint MRI were analyzed. All data were retrieved from patient charts. Clinical and radiologic characteristics of these patients were reported.

Results The mean (min-max) age of patients were 29.2 (19-42) and 54% were female. Mean age at diagnosis of FMF and FMF-SPA were 19.7 (3-40) and 28.5 (19-41), respectively. All patients were negative for HLA-B27. M694V mutation was the most commonly observed MEFV mutation in FMF-SPA patients (77%). Radiographic sacroileitis was evident in 69% of patients. In MRI examination active lesions were observed in 70% of patients. Sacroileitis was bilateral in 77%. There were nine patients with spinal MRI available. Facet joint arthritis was observed in three patients. Vertebral bodies were spared in all. Interestingly, typical chronic spinal lesions of ankylosing spondylitis have not been observed in any of the patients even in those with advanced- stage sacroileitis.

Conclusions Our results confirmed the role of M694V on risk of spondyloarthritis development in patients with FMF. Furhermore, these results suggest that FMF-SPA might be a distinct type in spondyloarthropathy spectrum diseases.

Disclosure of Interest : None declared

DOI 10.1136/annrheumdis-2014-eular.5260