Mitochondrial abnormalities in non-alcoholic steatohepatitis

Background/Aims: We assessed mitochondrial morphology by electron microscop y and the prevalence of a mitochondrial gene deletion in patients with nona lcoholic steatohepatitis (NASH), alcohol-related liver disease and non-fatt y liver diseases. Respiratory chain function using a cytoplasmic hybrid (cy brid) assay was further studied in NASH patients and healthy controls, Methods: Electron microscopy was performed in 26 specimens. Fifteen patient s were studied by polymerase chain reaction to detect a 520-bp deletion pro duct of the mitochondrial genome (dmtDNA). Cybrids were created by fusion o f platelets with anaerobic neuroblastoma cells in sis NASH patients and 12 controls, Results: Eight of ten NASH, one of seven alcoholics and two of nine other p atients had linear crystalline inclusions in megamitochondria (p<0.05). Thr ee of five patients with alcohol-related li cer disease had dmtDNA compared to one of live NASH patients and one of five non-steatohepatitis controls, Cybrid respiratory chain function in platelets was not different from that of controls, Conclusions: Respiratory chain dysfunction, if present in NASH, is not expr essed in platelet-derived mitochondria. In contrast to alcohol-related live r disease with active drinking, NASH patients do not commonly express the 5 -kb mitochondrial DIVA gene deletion in liver tissue, As previously describ ed in early alcohol-related liver disease, crystalline inclusions of unknow n composition are seen in hepatic mitochondria in NASH, Their presence sugg ests either an adaptive process or mitochondrial injury.