Serum proinflammatory cytokines correlate with diffusion tensor imaging derived metrics and 1H-MR spectroscopy in patients with acute liver failure

Hyperammonemia and inflammation are major contributing factors in the development of cerebral edema (CE) in acute liver failure (ALF). Aim of this study was to look for the relationship between proinflammatory cytokines with diffusion tensor imaging (DTI) derived metrics and H-1-MR spectroscopy (H-1-MRS) derived Glutamate/Glutamine (Glx). Fourteen patients with ALF and 14 age/sex matched controls were included in this study. All subjects had undergone clinical, biochemical, MR imaging and H-1-MRS studies. Serum proinflammatory cytokines (IL-6 and TNF-alpha), blood ammonia level and Glx were computed for independent t-test and Pearson correlation. Serum proinflammatory cytokines, blood ammonia level and brain Glx were significantly increased in ALF patients as compared to controls. Blood ammonia level and Glx showed significant positive correlation with proinflammatory cytokines. Spectroscopy voxel derived spherical anisotropy (CS) showed positive correlation with Glx while mean diffusivity (MD) showed negative correlation. Proinflammatory cytokines showed positive correlation with CS and negative correlation with MD in various brain regions including spectroscopy voxel. Significant correlation of Glx, CS and MD with proinflammatory cytokines suggests that both DTI derived metrics and H-1-MRS measure the synergistic effect of hyperammonemia and proinflammatory cytokines and may be used as non-invasive tools for understanding the pathogenesis of CE in ALF.