Serum macrophage migration inhibitory factor (MIF) in the intercritical phase of hereditary periodic fevers and its relationship with the MIF-173G/C polymorphism.

OBJECTIVES

To examine the association of the -173 single-nucleotide G/C polymorphism of the macrophage migration inhibitory factor gene (MIF) and serum macrophage migration inhibitory factor (MIF) concentrations in a group of Italian patients with hereditary periodic fevers (HPF), tested during a symptom-free phase of their disease.

METHODS

Genomic DNA for MIF and serum MIF were evaluated in 22 patients with HPF and compared with healthy controls of the same ethnic group. The MIF-173G/C polymorphism was genotyped using polymerase chain reaction (PCR) and visualized by ethidium bromide staining. Serum MIF levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

MIF-173*C allele frequency and MIF serum concentrations were significantly higher in patients with HPF than in controls, with no statistically significant difference between familial Mediterranean fever (FMF) and hyperimmunoglobulinaemia D/periodic fever syndrome (HIDS) and no correlation with specific MIF genotypes.

CONCLUSIONS

The MIF-173*C allele was found more frequently in patients with HPF than in controls and MIF serum concentrations were considerably elevated in attack-free phases, suggesting a persistent state of subclinical cytokine activation with MIF involvement in the autoinflammatory cascade.