The purpose of this observational study was to see if there was any relationship between acute phase reactants in children with familial Mediterranean fever (FMF) during attack and non-attack periods. Between June 2016 and January 2018, the study was done. Children with FMF had their clinical characteristics and laboratory data monitored longitudinally during attack and non-attack periods. There were 168 children with FMF in the cohort. During FMF attacks, the median values of acute phase reactants were 433.5 mg/L for serum amyloid A (SAA), 56.7 mg/L for C-reactive protein (CRP), and 37.5 mm/h for erythrocyte sedimentation rate (ESR) (ESR). In attack-free times, the median results for the same tests were 3.2 mg/L, 1.7 mg/L, and 8 mm/h, respectively. Association studies revealed that SAA and CRP levels were significantly associated in FMF attacks, while there was no correlation between SAA and ESR levels. During the attack-free period, C-reactive protein was increased in 13.6 percent of patients, ESR in 20.8 percent, and SAA in 28.5 percent. Age at beginning, gender, and assault characteristics were shown to be unrelated to increased SAA during the attack-free period. Having a homozygous exon 10 mutation and having increased CRP, on the other hand, were found to be linked with high SAA during an attack-free period.

C-reactive protein and SAA levels are linked to FMF assaults. As a result, screening for SAA during an FMF assault is not necessary. However, SAA appears to be the most sensitive technique for detecting subclinical inflammation in the absence of an assault. Checking SAA levels may thus be a useful technique in certain FMF patients.