Plasma Levels and Gene Expression of RANK in Non-Alcoholic Fatty Liver Disease

Background The pathobiology of initiation and progression of nonalcoholic fatty liver disease (NAFLD) has not been completely elucidated. It seems that the RANK/RANKL/OPG cytokine system play an etiologic role in pathogenesis of this disease. This study aimed to investigate the plasma content and gene expression of RANK in NAFLD patients as compared to healthy individuals. Methods This case-control work was performed on 63 patients with NAFLD and 25 healthy subjects. The plasma levels of RANK and biochemical parameters were measured using ELISA and colorimetric methods, respectively. Also, RANK mRNA content was evaluated by quantitative RT-PCR in peripheral blood mononuclear cells. Results RANK plasma contents were shown to be lower in NAFLD patients than in control subjects (1.02 ± 0.75 and 1.41 ± 1 ng/mL, respectively (p = 0.008)). The differences in gene expression of RANK between NAFLD patients and controls were significant (p = 0.001). In the NAFLD patients, RANK was inversely correlated with HDL. Logistic regression showed the association of RANK plasma content with the risk of NAFLD. Moreover, ROC curve analysis showed that RANK has a great ability to differentiate between NAFLD patients and controls. Conclusions This study for the first time showed lower plasma and mRNA levels of RANK in NAFLD patients compared to control individuals. These results recommend a possible association between RANK and pathobiology of NAFLD.