Familial Mediterranean fever (FMF) is an autosomal-recessive auto-inflammatory disorder characterized by recurrent episodes of fever with serositis.

A new study published in The Turkish Journal of Pediatrics aimed to describe the demographic, clinical, laboratory features and treatment responses of pediatric patients with FMF-related sacroiliitis.

This study comprised seven pediatric patients, younger than 16 years, who were diagnosed with sacroiliitis associated with FMF between 2010 and 2017. Medical records of these subjects were retrospectively evaluated. Sacroiliitis was diagnosed based on magnetic resonance imaging (MRI). Previous studies relating FMF associated sacroiliitis were also reviewed.

It was found that five of the seven children had a M694V (homozygous) mutation; one had a M694V (heterozygous) mutation; and another had a V726A (heterozygous) mutation. All patients were HLA-B27 negative. One of them achieved remission with colchicine plus non-steroidal anti-inflammatory drug treatment (NSAID) while in another, symptoms were managed by the addition of sulfasalazine. Furthermore, four patients responded to etanercept treatment and one patient’s symptoms were suppressed with canakinumab.

In conclusion, it was stated that sacroiliitis can be seen in pediatric FMF patients suffering with inflammatory back pain. This manifestation generally occurs in FMF patients who have M694V mutation. Etanercept could be beneficial in those who are resistant to disease modifying anti-rheumatic drugs and NSAIDs; canakinumab treatment should be considered as a successful alternative therapy.

Source: The Turkish Journal of Pediatrics. 2020;62(2):175-181. doi: 10.24953/turkjped.2020.02.002.