Interleukin-6 Levels and Interleukin-6 rs1800795 Variant in Pediatric Familial Mediterranean Fever: Associations with Clinical Manifestations, Inflammatory Markers, and MEFV Mutation Status.

Background/

Objectives

Interleukin-6 is a key proinflammatory cytokine involved in the pathophysiology of Familial Mediterranean Fever (FMF). This study aimed to evaluate interleukin-6 levels and the interleukin-6 rs1800795 variant in pediatric FMF participants and to investigate their associations with clinical manifestations, laboratory findings, and Mediterranean fever (MEFV) mutation status.

Methods

The research involved 69 pediatric FMF participants and 50 healthy children. Interleukin-6 levels, laboratory findings, and genotype distributions of the interleukin-6 rs1800795 variant were compared between FMF and control groups. Moreover, the relationship between interleukin-6 levels and clinical findings, MEFV mutation status, and laboratory parameters were evaluated in the FMF group.

Results

In the FMF group, interleukin-6, serum amyloid-A (SAA), white blood cell count (WBC), neutrophil, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) levels were higher compared to the control group. In the FMF group, interleukin-6 levels showed a positive correlation with ISSF score, annual attack frequency, the number of concomitant symptoms, disease duration, SAA, CRP, and ESR. The allele and genotype distribution of the interleukin-6 rs1800795 variant was similar to those in the control and FMF groups. In the FMF group, interleukin-6 values were higher in patients with abdominal pain, fever, chest pain, or arthralgia compared to those without these symptoms. Interleukin-6 levels were higher in both homozygous and compound heterozygous subgroups compared to the heterozygous subgroup.

Conclusions

Elevated interleukin-6 levels in symptomatic pediatric FMF patients and those with homozygous or compound heterozygous MEFV mutations suggest that interleukin-6 may reflect both clinical disease severity and MEFV mutation status.