Colchicine is the mainstay of treatment in FMF. However, in daily practice, it is not easy to maintain effective colchicine doses in substantial number of patients, due to its side effects. In this study, we aimed to investigate prevalence and risk factors for colchicine side effects that limit optimal drug dosing and permanent discontinuation. All patients were recruited from "FMF in Central Anatolia? (FiCA) cohort, 915 adult subjects with minimum follow up time of 6 months and had compliance of treatment were included. Demographic and anthropometric data, FMF disease characteristics, disease severity, complications and treatment features were recorded on a web based registry. Prevalence of colchicine intolerance and characteristics of intolerant patients were analyzed. Effective colchicine doses cannot be maintained in 172 (18.7%) subjects. Main side effects that limit optimal dosing were as follows; diarrhea in 99 (10.8%), elevation in transaminases in 54 (5.9%), leukopenia in 10 (%1.1), renal impairment in 14 (1.3%), myopathy in 5 (0.5%) and allergic skin reaction in two. Colchicine had to be permanently ceased in 18 (2%) patients because of serious toxicity. Male gender and obesity were found to be associated with liver toxicity and having normal body weight was associated with diarrhea. Chronic inflammation and proteinuria were more common in colchicine intolerant patients and they had reported more frequent attacks compared to those tolerating optimal doses. Conclusion Colchicine intolerance is an important problem in daily clinical practice, mainly due to diarrhea and liver toxicity. Suboptimal colchicine dosing associated with complications.

Objective: Familial Mediterranean fever (FMF), is an auto-inflammatory disease characterized by attacks of fever and serositis. Some scoring systems have been developed to evaluate the severity of the disease, however, predicting the severity of FMF is not possible with current knowledge. Our aim in this study was to evaluate the factors affecting disease severity in FMF. Methods: This study included 150 FMF patients. The medical data of the patients were collected retrospectively and the International severity scoring system for Familial Mediterranean fever (ISSF) was used to evaluate disease severity. Results: Patients were sorted into 3 groups based on the ISSF scores; ≤2=mild (Group 1; n: 61), 3-5=moderate (Group 2; n: 70), and ≥6=severe (Group 3; n: 19). Age at the onset of disease and age at diagnosis was younger in patients with severe disease (p: 0.009 and p: 0.031, respectively). Fever, peritonitis, and vasculitis were similar in all 3 groups. Pleuritis, erysipelas-like erythema (ELE), arthritis, myalgia, amyloidosis, and chronic kidney disease (CKD) were more common in Group 3. Conclusion: FMF patients with early onset and early diagnosis, having more frequent pleuritis, ELE, arthritis, and myalgia tended to manifest a more severe form of the disease. Close monitoring of such patients may prevent the development of amyloidosis and CKD and improve the long-term prognosis of the disease. Cite this article as: Yaşar Bilge NŞ, Bodakçi E, Bilgin M, Kaşifoğlu T. Comparison of clinical features in FMF patients according to severity scores: An analysis with the ISSF scoring system. Eur J Rheumatol 2020; 7(2): 68-70.