Hori, Tomohide

Background. Graft pretreatment to limit postoperative damage has the advantage of overcoming a current issue in liver transplantation (LT). The strategic potential of graft pretreatmentin vivoby a specific agonist forγ-aminobutyric acid receptor (GABAR) was investigated in the rat LT model with a small-for-size graft (SFSG).Methods. Recipient rats were divided into three groups according to donor treatments and recipient surgeries: (i) saline and laparotomy, (ii) saline and split orthotopic liver transplantation (SOLT) with 40%-SFSG, and (iii) GABAR agonist and SOLT with 40%-SFSG. Survival was evaluated. Blood and liver samples were collected 6 h after surgery. Immunohistological assessment for apoptotic induction and western blotting for 4-hydroxynonenal, ataxia-telangiectasia mutated kinase (ATM), histone H2AX, phosphatidylinositol-3 kinase (PI3K), Akt, and free radical scavenging enzymes were performed.Results. Pretreatment by GABAR showed improvement in survival, histopathological assessment, and biochemical tests. Apoptotic induction and oxidative stress were observed after SOLT with an SFSG, and this damage was limited by GABAR regulation. GABAR regulation appeared to reduce DNA damage via the ATM/H2AX pathway and to promote cell survival via the PI3K/Akt pathway.Conclusions. Pretreatmentin vivoby GABAR regulation improves graft damage after SOLT with an SFSG. This strategy may be advantageous in LT.

Background. Balancing donor safety and graft volume is difficult. We previously reported that intentional modulation of portal venous pressure (PVP) during living-donor liver transplantation (LDLT) is crucial to overcoming problems with small-for-size grafts; however, detailed studies of portal venous flow (PVF) and a reliable parameter are still required. Patients and Methods. The elimination rate ( k) of indocyanine green (ICG) was measured in 49 adult LDLT recipients. PVP was controlled during LDLT, with a target of <20 mm Hg. ICG reflects hepatocyte volume and effective PVF. The kICG value is divided by the graft weight to calculate PVF. Recipients were divided into 2 groups: those with severe and/or fatal complications within 1 month after LDLT and those without. Results. Survival rates and postoperative profiles were significantly different between the 2 groups. Univariate analysis showed significant differences in ABO blood group, final PVP, final kICG, and the final kICG/graft weight value; however, multivariate analysis showed that only the kICG/graft weight value was significant. The cutoff level for the final kICG/graft weight value for predicting successful LDLT was 3.1175 × 10 −4 /g. Conclusion. Accurate evaluation and monitoring of optimal PVF during LDLT should overcome the use of small-for-size grafts and improve donor safety and recipient outcomes.

AimIf progressive liver injury and subsequent hepatic encephalopathy can be prohibited in fulminant liver failure (FLF), it would be ideal for intensive care of FLF and provide an expanded opportunity for liver transplantation (LT). We hypothesized that matrix metalloproteinase (MMP)‐9 plays an important role in FLF progression, and investigated MMP‐9 behaviors in a murine FLF model, especially at the coma stage.MethodsThe murine FLF model with azoxymethane recapitulates FLF in humans. The detailed coma status was evaluated, on the assumption that LT is indicated at early, but not late, stage 3. To investigate whether MMP‐9 deletion or reduction has beneficial effects, an MMP‐9 inhibitor (GM6001) and transfection of tissue inhibitor of metalloproteinases (TIMP)‐1 cDNA were used. Mice were divided into five groups: control; FLF; FLF with GM6001 pretreatment; FLF with TIMP‐1 plasmid transfection 24 h before disease onset; and FLF with TIMP‐1 plasmid transfection 48 h before disease onset. Neurological findings, including survival, were followed. Samples were obtained at early and late stage 3. Biochemical examinations and histopathological assessments were performed. The expression and function of MMP‐9 and TIMP‐1 were evaluated by western blotting and zymography. A brain permeability study was also performed.ResultsMMP‐9 was strongly increased in FLF. The MMP‐9 inhibitions worked well, and prolonged the survival, interval to stage 3 and duration of early stage 3. MMP‐9 inhibition improved the liver and subsequent brain injuries at early stage 3, with no remarkable improvements at late stage 3.ConclusionMMP‐9 has therapeutic potential for FLF progression.

Blood-brain barrier (BBB) dysfunction in acute liver failure (ALF) results in increased BBB permeability that often precludes the patients from obtaining a life-saving liver transplantation. It remains controversial whether matrix metalloproteinase-9 (MMP-9) from the injured liver contributes to the deregulation of BBB function in ALF. We selectively upregulated a physiologic inhibitor of MMP-9 (TIMP-1) with a single intracerebroventricular injection of TIMP-1 cDNA plasmids at 48 and 72 hours, or with pegylated-TIMP-1 protein. Acute liver failure was induced with tumor necrosis factor-α and D-(+)-galactosamine in mice. Permeability of BBB was assessed with sodium fluorescein (NaF) extravasation. We found a significant increase in TIMP-1 within the central nervous system (CNS) after the administration of TIMP-1 cDNA plasmids and that increased TIMP-1 within the CNS resulted in an attenuation of BBB permeability, a reduction in activation of epidermal growth factor receptor and p38 mitogen-activated protein kinase signals, and a restoration of the tight junction protein occludin in mice with experimental ALF. Pegylated TIMP-1 provided similar protection against BBB permeability in mice with ALF. Our results provided a proof of principle that MMP-9 contributes to the BBB dysfunction in ALF and suggests a potential therapeutic role of TIMP-1 in ALF.

AbstractBackgroundCandidates for orthotopic liver transplantation (OLT) often have porto‐pulmonary hypertension (PPHTN) with pulmonary arterial hypertension (PAH). Poor outcomes of PPHTN contraindicate OLT. There are no guidelines for living‐donor liver transplantation (LDLT) in PPHTN patients.MethodsWe present our experiences of LDLT in six patients with moderate or severe PPHTN, along with our institutional guidelines. Three had liver cirrhosis and three were non‐cirrhotic. Catheterization studies were undertaken before, during and after LDLT, and the mean pulmonary arterial pressure (mPAP), cardiac output (CO), pulmonary vascular resistance and total peripheral resistance (TPR) were monitored.ResultsThe results showed significant differences in CO and TPR between cirrhotic and non‐cirrhotic patients before, during and after LDLT. Cirrhotic patients showed systemic hyperdynamic state. Two cirrhotic patients showed poor responses to pre‐transplant treatment, and continued to have increased PAH and poor clinical courses after LDLT. LDLT has an advantage of flexible timing of LT. Currently in our institution, PPHTN patients with mPAP <40 mmHg are registered for LDLT after treatment and catheterization. However, LDLT is performed when mPAP is ⩽35 mmHg, leading to improved outcomes.ConclusionPPHTN patients with well‐controlled PAH, or secondary PAH resulting from porto‐systemic shunts, may be appropriate candidates for LDLT after careful considerations.

Abstract Background Progressive familial intrahepatic cholestasis (PFIC) results in liver cirrhosis during the disease course, although the etiology includes unknown mechanisms. Some PFIC patients require liver transplantation (LT). Methods In this study, 11 patients with PFIC type 1 (PFIC1) and 3 patients with PFIC type 2 (PFIC2) who underwent living‐donor LT (LDLT) were evaluated. Results Digestive symptoms after LDLT were confirmed in 10 PFIC1 recipients (90.9%); 8 PFIC1 recipients showed steatosis after LDLT (72.7%), which began during the early postoperative period (71.5 ± 55.1 days). Seven of the eight steatosis‐positive PFIC1 recipients (87.5%) showed a steatosis degree of ≥80%, which was complicated with steatohepatitis and resulted in fibrosis. Cirrhotic findings persisted in six PFIC1 recipients even after LDLT (54.5%), and three PFIC1 recipients finally died. The survival rates of the PFIC1 recipients at 5, 10, and 15 years were 90.9%, 72.7%, and 54.5%, respectively. In contrast, the PFIC2 recipients showed good courses and outcomes without any steatosis after LDLT. Conclusions The clinical courses and outcomes after LDLT are still not sufficient in PFIC1 recipients owing to steatosis/steatohepatitis and subsequent fibrosis, in contrast to PFIC2 recipients. PFIC2 is good indication for LDLT. PFIC1 patients require LT during the disease course; therefore, we suggest that the therapeutic strategies for PFIC1 patients, including the timing of LDLT, under the donor limitation should be reconsidered. The establishment of more advanced treatments for PFIC1 patients is required to improve the long‐term prognosis of these patients.

AbstractBackground/purposeRefractory rejections still occur in the liver transplantation (LT) field. The aim of this study was to investigate significant factors for the introduction of therapy with muromonab‐CD3 (MCD3) after LT.MethodsA total of 1415 LT patients were retrospectively evaluated, and 11 of the recipients received MCD3 therapy because of steroid‐resistant rejections. The clinical factors before LT and before MCD3 therapy were investigated.ResultsThe recipients were retrospectively divided into two groups based on responses to MCD3 therapy, including their clinical courses after MCD3 therapy and their outcomes. The MCD3 therapy had positive effects in LT recipients with the following four factors: low score of model for end‐stage liver disease or pediatric end‐stage liver disease; earlier time point of the first incidence of rejection; more frequent steroid pulse therapy (SPT) within 2 weeks after LT; and the expression of CD3 in the peripheral blood before MCD3 introduction.ConclusionOptimal induction of MCD3 triggered recovery from refractory rejections, especially in LT recipients in a stable condition, but not in those in a critical or compromised condition.