The Possible Relationship Between Familial Mediterranean Fever and Chronic Nonbacterial Osteomyelitis: Coincidence or Coexistence?

Chronic Nonbacterial Osteomyelitis Associated With Familial Mediterranean Fever in Children

OBJECTIVE

Chronic nonbacterial osteomyelitis (CNO) is a noninfectious autoinflammatory bone condition that frequently occurs alongside other inflammatory diseases, such as familial Mediterranean fever (FMF). We aimed to determine the demographic, clinical, laboratory, and radiological characteristics of patients diagnosed with both FMF and CNO.

METHODS

We reviewed the medical records of pediatric patients with both CNO and FMF at 3 pediatric rheumatology centers in Turkey from December 2008 to 2022. Patients' demographics, laboratory features, imaging findings, and treatment were recorded.

RESULTS

Twelve patients with FMF and CNO were included in the study. Half of them were female. The mean ages at onset for FMF and CNO symptoms were 80 and 116 months, whereas the ages at diagnosis for FMF and CNO were 100 and 125 months, respectively. Ten patients (83.3%) had M694V mutation on at least 1 allele of the Mediterranean fever (MEFV) gene. The most common sites of osteitis were the long bones (58.3%), pelvis (50%), and clavicles (25%). Ten patients (83%) received nonsteroidal anti-inflammatory drugs; 8 (66%) received disease-modifying antirheumatic drugs; biological therapy was administered to 5 patients (41%), who did not respond to these treatments; and all patients received colchicine.

CONCLUSION

The increased frequency of FMF in patients with CNO is of interest. Because most patients with CNO and FMF carried a homozygous or combined heterozygous M694V mutation, we speculated that the M694V mutation may play a role in the development of osteitis. Further studies are needed to elucidate the link between FMF and CNO.

Colchicine-responsive chronic recurrent multifocal osteomyelitis associated with familial Mediterranean fever in the presence of MEFV mutation: A case report

A 38-year-old female was referred with a history of fever, polyarthralgia, and bone pain. She was diagnosed with chronic recurrent multifocal osteomyelitis based on imaging and biopsy findings. Non-steroidal anti-inflammatory drugs and bisphosphonate caused no improvement. Then, she developed recurrent diarrhoea and abdominal pain. Genetic testing revealed MEFV mutation. Based on the symptoms and genetic mutation results that emerged during the course of these events, she was diagnosed with familial Mediterranean fever. All symptoms, including bone pain, improved with daily colchicine administration. This case was considered familial Mediterranean fever complicated with a clinical diagnosis of chronic recurrent multifocal osteomyelitis, which is included in the spectrum of pyrine autoinflammatory diseases. Considering this case, patients with chronic recurrent multifocal osteomyelitis with MEFV gene variants may respond to colchicine.