Survival and it's predictors in familial mediterrenean fever patients

Objective: Familial Mediterranean fever (FMF) is an autosomal recessive disease, characterized by recurrent attacks of fever and serositis. In studies conducted before colchicine treatment was introduced it was demonstrated that most of the patients died from renal failure secondary to amyloidosis before the age of 40. However continuous colchicine treatment was shown to inhibit the development of amyloidosis. Therefore the aim of this study is to determine causes of death, the rates and the predictors of survival in adult patients with FMF in the colchine era.Patients and Methods: Patients under the care of all specialists (Internal Medicine, Rheumatology, and Nephrology) in one university hospital were included in the study. In total 587 out of 650 patients who had registered since July 1992 were contacted and invited to the outpatient clinic for a formal evaluation. For patients who could not come to the hospital a detailed telephone interview was conducted. We obtained socioeconomic demographic data, presenting and cumulative clinical features, disease severity scores by using a structured questionnaire. During the follow up period mortality was analyzed by calculating age and sex standardized mortality ratio (SMR) by using mortality statistics of Turkish population. Factors predictive of mortality were evaluated by Kaplan-Meier method and the Cox proportional hazard model.Results: A formal inquiry was performed in 381 patients (195 female; mean age 37,7 ± 12,2 years) in outpatient setting and in 206 (106 female; mean age 39,8 ± 13,6 ) by telephone interview. 63 patients (9,7% of all patients; 31 female; mean age 40,2±10,7 years) could not be contacted during the study period but none of them was found in Turkish mortality registry database. Initial demographic and major clinical characteristics of patients who could not be reached were similar with the rest of the group. A total 385 patients has MEFV analysis and M694V was the most frequent mutation (338 alleles; 43,9%). Most of the patients (94,4%) were taken colchicine at the time of the study. 37 patients (6,9%) have biopsy proven amyloidosis and 44 (8,1%) have renal disease. During a mean 6.48 ? 4.3 years of follow-up; 14 patients (nine female) died and amyloidosis and its complication were the leading causes of death in seven patients. Univariate analysis revealed that amyloidosis, renal diseses, icreasing age, paid employement, renal transplantation, coronary heart disease, hypertension and marital status were associated with an increased mortality, but Cox regression analysis showed renal disease as the only significant predictor of mortality (p=0,018). In our patient group overall survival rate was not significantly different from Turkish general population (SMR 1.48 [95% CI 0.81-2.49]).Conclusion: Our findings suggests that although the survival of FMF patients is comparable to the general population in the colchicine era, renal disease still predicts mortality.Key words: Familial Mediterranean fever, Amyloidosis, Standardized Mortality Ratio (SMR)