Wada T, et al. - This study intended to fully characterize longitudinal changes of serum interleukin (IL)-18 in familial Mediterranean fever (FMF). For this purpose, patients with FMF carrying exon 10 mutations were included in the study and assessed for serum levels of pro-inflammatory cytokines, including IL-18, in 12. It was observed that patients exhibited a sustained elevation of serum IL-18 which may be indicative of the presence of persistent subclinical inflammation. Hence, longitudinal assessment of serum IL-18 may contribute to better follow-up in this group of patients.