ASSESSMENT OF JOINT INVOLVEMENT BY USING BONE SCINTIGRAPHY IN PATIENTS WITH FAMILIAL MEDITERRANEAN FEVER (FMF)

Background: Familial Mediterranean fever (FMF) is an autosomal recessively inherited disorder typically manifested by polyserositis. The articular disease occurs in 75% of patients. The most common articular attack is an acute, large joint monoarthritis usually affecting the knee, hip and ankle joints. Shoulder, sacroiliac and temporomandibular joints are also reported to be in less number of patients. Sacroiliac joint involvement is also reported to be present in asymptomatic patients. Bone scintigraphy may show these joint involvements even plain radiographies are normal.Objectives: To assess joint involvements in FMF patients with or without joint symptoms by using whole-body bone scintigraphy.Methods: 23 consecutive FMF patients (F/M; 10/13, mean age; 26.6±12.1 years, mean disease duration; 10.2±7.3 years), all fulfilling Tel-Hashomer diagnostic criteria, which are followed up by our rheumatology department, were enrolled. A detailed history of joint involvement, disease duration, inflammatory back pain, amyloidosis, and current joint symptoms were all noted. A three phase and whole-body bone scintigraphy was performed for each patient using an intravenous injection of 555-740 MBq (15-20 mCi) of 99TC methylene diphosphonate (99Tc-MMP). Spot images were also taken when needed. Sacroiliac index, equal or greater than 1.4 was accepted as active sacroiliitis. Plain radiographs of sacroiliac joints, vertebrates, bilateral knees, ankles and shoulders were taken. The frequencies, localizations and types of joint involvements were assessed.Results: 2 patients had amyloidosis, one of them on hemodialysis treatment. Only one male patient was symptomatic for inflammatory back pain. He had asymmetric olygoarthritis and radiographical changes in sacroiliac joints that he was accepted as seronegative spondyloarthropathy of FMF. Remaining 22 patients had no history of inflammatory back pain. However 10 of 22 patients (45.5%) had active sacroiliitis according to bone scintigraphy. 6 of these 10 patients had symmetrical involvement in sacroiliac joints. 12 of 22 (54.5%) patients had unilateral knee involvement which are symptomatic intermitantly. One had wrist, one had ankle involvement, which were unilateral. One patient had bilateral shoulder involvement. All patients were asymptomatic while bone scintigraphy was performed.Conclusion: According to our findings, sacroiliac joint involvement is more than reported in the literature. It may be unilateral or bilateral. It should also be searched in asymptomatic FMF patients. Whole-body bone scintigraphy is useful to detect joint involvements in FMF.Citation: , volume , supplement , year 2004, page Session: Miscellaneous rheumatic diseases