Aim: To investigate the macrophage migration inhibitory factor (MIF) expression and -173 G/C polymorphism of the MIF gene in nonalcoholic fatty liver disease (NAFLD).
Method: Ninety-one patients with diagnosis of NAFLD and 104 healthy controls were included in the study. MIF -173 G/C polymorphism was detected using the PCR-restriction fragment length polymorphism based method. NAFLD was stratified as nonalcoholic steatohepatitis (NASH), probable NASH and steatosis, respectively in groups 1, 2 and 3, according to NAFLD Activity Score. MIF expression was detected by immunohistochemistry staining.
Results: Mean age of the patients was 50.1+/-9.6 years, and 54 of them were male. Serum alanine aminotransferase and aspartate aminotransferase were 50/83, 42/63 and 31/32, respectively in groups 1, 2 and 3, (P<0.05). Both the MIF expression of hepatocytes and mononuclear cells were more prominent in groups 1 and 2 than group 3. There was no correlation between MIF expression of hepatocytes and fibrosis stage. However, MIF expression of mononuclear cells significantly increased according to fibrosis stage (P<0.05, R : 0.2). There was no significant correlation between MIF genotype and MIF expression in the liver.
Conclusion: MIF expression is significantly increased especially by mononuclear cells in liver tissue of patients with NASH secondary to inflammation. Thus, it should be considered as a consequence not a causal factor.