OBJECTIVE: The aim of this observational study was to evaluate whether there was any correlation between the acute phase reactants in children with familial Mediterranean fever (FMF) during attack and attack-free periods. METHODS: The study was conducted between June 2016 and January 2018. Clinical features and laboratory parameters of children with FMF during attack and attack-free periods were recorded longitudinally. RESULTS: The cohort consisted of 168 children with FMF (84 boys, 84 girls). Median values of acute phase reactants during FMF attacks were 433.5 mg/L (34.0-1780.0 mg/L) for serum amyloid A (SAA), 56.7 mg/L (7.6-379.0 mg/L) for C-reactive protein (CRP), and 37.5 mm/h (5-100 mm/h) for erythrocyte sedimentation rate (ESR). Median values for the same tests in attack-free periods were 3.2 mg/L (0.1-25.0 mg/L), 1.7 mg/L (0.1-12.7 mg/L), and 8 mm/h (1-30 mm/h), respectively. Correlation analyses showed that SAA and CRP were highly correlated in FMF attack (r = 0.67, p < 0.01), but no correlation was found between SAA and ESR levels. C-reactive protein was elevated in 13.6%, ESR in 20.8%, and SAA in 28.5% of the patients during attack-free period. Age at onset, sex of the patients, and characteristics of attacks were found to be not associated with elevated SAA in attack-free period. On the other hand, having homozygous exon 10 mutation and having elevated CRP were found to be associated with high SAA in attack-free period. CONCLUSIONS: C-reactive protein and SAA correlate well with FMF attacks. Therefore, checking for SAA during a FMF attack is not required. However, SAA seems to be the most sensitive method for demonstrating subclinical inflammation in attack-free period. Thus, checking SAA levels might be a valuable tool in selected FMF patients.
OBJECTIVE: The aim of this observational study was to evaluate whether there was any correlation between the acute phase reactants in children with familial Mediterranean fever (FMF) during attack and attack-free periods. METHODS: The study was conducted between June 2016 and January 2018. Clinical features and laboratory parameters of children with FMF during attack and attack-free periods were recorded longitudinally. RESULTS: The cohort consisted of 168 children with FMF (84 boys, 84 girls). Median values of acute phase reactants during FMF attacks were 433.5 mg/L (34.0-1780.0 mg/L) for serum amyloid A (SAA), 56.7 mg/L (7.6-379.0 mg/L) for C-reactive protein (CRP), and 37.5 mm/h (5-100 mm/h) for erythrocyte sedimentation rate (ESR). Median values for the same tests in attack-free periods were 3.2 mg/L (0.1-25.0 mg/L), 1.7 mg/L (0.1-12.7 mg/L), and 8 mm/h (1-30 mm/h), respectively. Correlation analyses showed that SAA and CRP were highly correlated in FMF attack (r = 0.67, p < 0.01), but no correlation was found between SAA and ESR levels. C-reactive protein was elevated in 13.6%, ESR in 20.8%, and SAA in 28.5% of the patients during attack-free period. Age at onset, sex of the patients, and characteristics of attacks were found to be not associated with elevated SAA in attack-free period. On the other hand, having homozygous exon 10 mutation and having elevated CRP were found to be associated with high SAA in attack-free period. CONCLUSIONS:C-reactive protein and SAA correlate well with FMF attacks. Therefore, checking for SAA during a FMF attack is not required. However, SAA seems to be the most sensitive method for demonstrating subclinical inflammation in attack-free period. Thus, checking SAA levels might be a valuable tool in selected FMFpatients.