Macrophage Migration Inhibitory Factor is not Associated with Sarcoidosis Susceptibility or Severity in Whites or Blacks.

Background: Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine, and increased expression has been associated with the development and severity of multiple granulomatous, autoimmune diseases. However, association studies have been discordant in sarcoidosis.

Objective: To evaluate associations between macrophage migration inhibitory factor () promoter polymorphisms and sarcoidosis susceptibility and severity.

Methods: Three hundred and fifty one patients with sarcoidosis were recruited through the Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis (GRADS) study. Genomic DNA was isolated from serum, and the 173G/C SNP [] and -794 CATT microsatellite repeat [] were genotyped. Allelic frequencies were compared between cases and healthy controls and associations between alleles and sarcoidosis severity were assessed.

Results: The frequencies of the high expression -173C SNP and the low expression -794 CATT containing genotypes in white and black sarcoidosis patients were the same as those of healthy controls. High expression alleles were not associated with sarcoidosis severity. Associations between alleles and extrapulmonary sarcoidosis phenotypes were limited by small sample sizes.

Conclusions: High expression genotypes were not associated with the susceptibility to or severity of pulmonary sarcoidosis in a large North American cohort. .