Fulminant hepatic failure(FHF) is a critical illness that can be comorbid to primary liver damage.FHF shows a high mortality rate,and patients with FHF require intensive therapy,including plasma apheresis.However,intensive care at the present is not enough to restore the severe liver damage or promote hepatocellular reproduction,and a standard therapy for the treatment of FHF has not been established.An 86-year-old female with FHF was admitted to our hospital.Her manifestation demonstrated a clinical situation of systemic inflammatory response syndrome(SIRS) and disseminated intravascular coagulation.A diagnosis of fulminant hepatitis was made according to the definition given in the position paper of the American Association for the Study of Liver Diseases.Her serum hepatocyte growth factor(HGF) level had increased to 11.84 ng/m L.The HGF level indicated massive liver damage as seen in FHF.Recombinant thrombomodulin(r TM) was administered daily from the admission day for 1 wk at 380 U/kg.The patient’s white blood cells and C-reactive protein responded to the r TM treatment within a few days.The HGF level and PT recovered to the normal range.The levels of proinflammatory cytokines(tumor necrosis factor-α and interleukin-1β) were suppressed by the administration of r TM.The patient’s hepatic function(e.g.,PT and albumin) completely recovered without plasma exchange.r TM may modulate the over-response of SIRS with the improvement of proinflammatory cytokines.The underlying mechanism is thought to be the inhibitory effect of r TM on highmobility group box 1(HMBG1).The pathogenesis of HMBG1 protein in fulminant hepatic failure has beenalready known.A novel favorable effect of r TM for SIRS would be promising for FHF,and the wide application of r TM for SIRS should be considered. Fulminant hepatic failure (FHF) is a critical illness that can be comorbid to primary liver damage. FHF shows a high mortality rate, and patients with FHF require intensive therapy, including plasma apheresis. Ultimately, intensive care at the present is not enough to restore the severe liver damage or promote hepatocellular reproduction, and a standard therapy for the treatment of FHF has not been established. An 86-year-old female with FHF was admitted to our hospital. Her manifestation demonstrated a clinical situation of systemic inflammatory response syndrome ( SIRS) and disseminated intravascular coagulation. A diagnosis of fulminant hepatitis was made according to the definition given in the position paper of the American Association for the Study of Liver Diseases. Human serum hepatocyte growth factor (HGF) level had increased to 11.84 ng / m L.The HGF level indicated massive liver damage as seen in FHF.Recombinant thrombomodulin (r TM) was administered daily from the admission day for 1 wk at 380 U / kg. The patient’s white blood cells and C-reactive protein responded to the r ™ treatment within a few days. The HGF level and PT recovered to the normal range. The levels of proinflammatory cytokines (tumor necrosis factor-α and interleukin-1β ) were suppressed by the administration of r TM. The patient’s hepatic function (eg, PT and albumin) completely recovered without plasma exchange. r TM may modulate the over-response of SIRS with the improvement of proinflammatory cytokines. The underlying mechanism is thought to The inhibitory effect of r TM on high motility group box 1 (HMBG1). The pathogenesis of HMBG1 protein in fulminant hepatic failure has been already known. A novel favorable effect of r TM for SIRS would be promising for FHF, and the wide application of r TM for SIRS should be considered.