B cell-activating factor is associated with the histological severity of nonalcoholic fatty liver disease

B cell-activating factor (BAFF) is expressed in adipocytes and affects lipogenesis and insulin sensitivity. In addition, the BAFF receptor is expressed in visceral adipose tissue and liver. The aim of this study was to analyze serum BAFF levels in patients with nonalcoholic steatohepatitis (NASH) and simple steatosis (SS) and to compare their respective clinical and histological findings. A total of 96 patients with nonalcoholic fatty liver disease (20 with SS and 76 with NASH) were enrolled and their serum BAFF levels were analyzed. Comprehensive blood chemistry analysis and histological examination of liver samples were also conducted. Serum BAFF levels were higher in patients with NASH than in those with SS (p = 0.016). NASH patients with ballooning hepatocytes and advanced fibrosis had higher levels of BAFF in sera (p = 0.016 and p = 0.006, respectively). In addition, the prevalence of NASH increased significantly as the serum BAFF level increased (p = 0.004). Higher serum BAFF levels were found to be an independent risk factor for development of NASH (OR 1.003, 95% CI 1.0003-1.006; p = 0.047). Nonalcoholic steatohepatitis patients had higher levels of serum BAFF than patients with SS, and higher levels were associated with the presence of hepatocyte ballooning and advanced fibrosis. The serum BAFF level may be a useful tool for distinguishing NASH from SS.