Risk factors for subclinical inflammation in children with Familial Mediterranean fever

Familial Mediterranean fever (FMF) is the most common autosomal recessive inherited inflammatory disease characterized by attacks of painful inflammation. Some patients with FMF have subclinical inflammation persisting between the attacks. We aimed to identify the demographic, clinical and genetic risk factors for subclinical inflammation in children with FMF. The medical records of the children with FMF were evaluated retrospectively for acute-phase response along with gender, age at the onset of symptoms and at the time of diagnosis, clinical signs and symptoms, the presence of amyloidosis and MEFV genotype. Patients with persistently elevated acute-phase response between the attacks were considered to have subclinical inflammation. Patients with or without subclinical inflammation (Group 1 and Group 2, respectively) were compared for the parameters defined above. Independent risk factors for subclinical inflammation were identified by multivariate logistic regression analysis. There were 105 children (male/female: 52/53) who were compliant on colchicine treatment. Subclinical inflammation was detected in 22 (20 %) patients. Group 1 had significantly higher rate of myalgia, arthritis/arthralgia, erysipelas like erythema, amyloidosis, protracted febrile myalgia and M694V mutation compared with Group 2. However, only the presence of myalgia and erysipelas like erythema were found to be independent risk factors for subclinical inflammation (OR 9.8 and 5.9, respectively). Children with FMF who have myalgia and erysipelas like erythema during the attacks are particularly at risk of ongoing inflammation and should be closely monitored for subclinical inflammation even during attack-free periods.