Antithymocyte Globulin Use for Corticosteroid Nonresponsive Rejection After Liver Transplantation.

BACKGROUND AND AIMS: Acute cellular rejection after liver transplantation usually responds to intravenous corticosteroids, yet some episodes are corticosteroid-nonresponsive. We report our experience using antithymocyte globulin therapy for corticosteroid-nonresponsive acute cellular rejection in liver transplant recipients. METHODS: From January 1, 2002 to January 1, 2010, 1436 patients underwent 1548 liver or liver with other organ transplantations at our institution. We identified all patients treated with antithymocyte globulin during this timeframe for corticosteroid-nonresponsive rejection. RESULTS: Twenty patients required antithymocyte globulin for 21 episodes of corticosteroid-nonresponsive rejection. Antithymocyte globulin was started a median (range) of 27 (7-2434) days post-transplantation, and median total antithymocyte globulin dose and duration was 10.5 (7.5-26.25) mg/kg and 7 (5-13) days, respectively. Resolution or marked histological improvement of rejection on Day 7 liver allograft biopsies occurred in 90% of rejection episodes treated with antithymocyte globulin. Three-year graft and patient survival rates were 60% and 65%, respectively, compared with 79% and 84% in patients not requiring antithymocyte globulin. CONCLUSIONS: Antithymocyte globulin was an effective therapy for corticosteroid-nonresponsive rejection, with excellent short-term outcomes. Some liver transplant recipients failed to respond, and long-term survival was reduced, even in those who responded to antithymocyte globulin.

Liver transplantation in patients with atrial fibrillation.

In this study we described survival and incidence of perioperative and postoperative complications in liver transplant recipients with known atrial fibrillation. A total number of 717 patients underwent liver transplantation between January 2005 and December 2008 at our institution. In this population, preoperative paroxysmal or chronic-persistent atrial fibrillation was diagnosed in 32 patients (4.5%). Of these, 12 patients died during follow-up and 4 patients required liver retransplantation. Perioperative cardiac complications occurred in 10 patients (31%) resulting in 3 cardiac-related deaths. Median patient survival was 1613 days (range, 22-2492) and median graft survival was 1524 days (range, 10-2492). Twenty patients are still alive with a median survival of 1861 days (range, 1189-2492) after liver transplantation.

Kidney allocation to liver transplant candidates with renal failure of undetermined etiology: role of percutaneous renal biopsy.

The feasibility, value and risk of percutaneous renal biopsy (PRB) in liver transplant candidates with renal failure are unknown. PRB was performed on 44 liver transplant candidates with renal failure of undetermined etiology and glomerular filtration rate (GFR) <40 mL/min/1.73 m(2) (n = 37) or on renal replacement therapy (RRT) (n = 7). Patients with >or=30% interstitial fibrosis (IF), >or=40% global glomerulosclerosis (gGS) and/or diffuse glomerulonephritis were approved for simultaneous-liver-kidney (SLK) transplantation. Prebiopsy GFR, urinary sodium indices, dependency on RRT and kidney size were comparable between 27 liver-transplant-alone (LTA) and 17 SLK candidates and did not relate to the biopsy diagnosis. The interobserver agreement for the degree of IF or gGS was moderate-to-excellent. After a mean of 78 +/- 67 days, 16 and 8 patients received LTA and SLK transplants. All five LTA recipients on RRT recovered kidney function after transplantation and serum creatinine was comparable between LTA and SLK recipients at last follow-up. Biopsy complications developed in 13, of these, five required intervention. PRB is feasible in liver transplant candidates with renal failure and provides reproducible histological information that does not relate to the pretransplant clinical data. Randomized studies are needed to determine if PRB can direct kidney allocation in this challenging group of liver transplant candidates.

Clinicopathological review of 18 cases of liver allografts lost due to bile duct necrosis.

Clinical, radiographic, and pathological features of 18 patients with biliary necrosis in their explanted liver allografts were reviewed. Twelve patients were men and ages ranged from 27 to 72 years. Indications for initial liver transplant (LT) were viral hepatitis (n = 7), steatohepatitic cirrhosis (n = 3), cryptogenic cirrhosis (n = 3), secondary sclerosing cholangitis (n = 2), primary sclerosing cholangitis (n = 1), biliary atresia (n = 1), and nodular regenerative hyperplasia (n = 1). Donor age ranged from 16 to 75 years. Duct-to-duct biliary anastomoses were fashioned in 13 cases; warm and cold ischemia times were not significantly different from general LT population. Seventeen allograft biopsies after recirculation had no significant findings. Post-LT, clinical and radiographic evaluation indicated biliary strictures (n = 7), bile leak (n = 7), intrahepatic abscess (n = 1), and duodenal perforation (n = 1). Radiographic vascular studies suggested hepatic arterial thrombosis or stenosis in 11 cases. Biopsies prior to retransplantation were performed on 17 patients and showed acute rejection (n = 10), biliary outflow impairment (n = 4), normal histology (n = 2), and centrilobular necrosis (n = 1). Retransplantation was performed 14 to 334 days after initial LT. Pathological examination of explants revealed perihilar duct necrosis in all cases, with bacterial colonies (n = 10) and fungal organisms (n = 2). Arterial thrombi were seen in 10 cases, and two had prominent arteriosclerosis. Infarction and centrilobular necrosis were seen in 9 and 13 cases, respectively. Four explants showed features of biliary outflow impairment. Twelve patients were alive 6 to 18 months following retransplantation. We conclude that post-LT biliary necrosis is associated with ischemia, and such a complication is rarely evident in allograft biopsies. Biliary and vascular imaging studies are essential in evaluating patients for this complication.

Glycochenodeoxycholic acid (GCDC) induced hepatocyte apoptosis is associated with early modulation of intracellular PKC activity.

The effect of GCDC-induced apoptosis on PKC activity and PKC's role in GCDC-induced hepatocyte apoptosis is unclear. The specific aims of this study were to determine if GCDC-induced apoptosis changed intracellular PKC activity and if modulation of PKC activity affected GCDC-induced hepatocyte apoptosis. Apoptosis was induced in isolated hepatocytes using GCDC. PKC activity was measured and specific PKC and calpain inhibitors were used to study the effects of PKC and calpain modulation on GCDC-induced apoptosis. After 4 h exposure, 50 microM GCDC induced apoptosis in 42% of hepatocytes. Intracellular PKC activity decreased to 44% of controls 2 h after exposure of hepatocytes to GCDC (p < 0.001). Pre-incubation of hepatocytes with the calpain protease inhibitor restored PKC activity in GCDC exposed hepatocytes to 91 +/- 5% of control cells. Pre-incubation of hepatocytes with a calpain inhibitor decreased GCDC-induced apoptosis as did pre-incubation with the PKC activating phorbol ester, PMA. The combination of calpain inhibition and PMA further reduced GCDC-induced apoptosis but caused low level hepatic apoptosis. Inhibition of PKC with chelerythrine also substantially reduced GCDC-induced hepatocyte apoptosis. GCDC-induced apoptosis is associated with decreases in total cellular PKC activity, which appear to be dependent on intracellular calpain-like protease activity. The combination of protease inhibition and phorbol ester pretreatment preserved total cellular PKC activity and decreased GCDC-induced apoptosis but induced low level apoptosis in the absence of GCDC exposure. PKC inhibition also decreased GCDC-induced hepatocyte apoptosis highlighting the complex interactions of PKC and proteases during GCDC-induced apoptosis.

The effects of various organ preservation solutions on hepatocyte membrane potentials, intracellular calcium concentrations, and outcome following liver transplantation.

BACKGROUND: Hepatocyte membrane potential differences (PDs) may be altered by the preservation solutions used in liver transplantation. Such alterations could impact on the survival of the donor liver, extent of biochemical injury, and flux of important ionic compounds. The purpose of the present study was to document these outcomes in the presence of four different preservation solutions. METHODS: Livers of adult male Sprague-Dawley rats (N = 3 to 4 per group) were impaled with intracellular microelectrodes prior to and at various time periods for 6 hours following complete hepatic resection. Just prior to resection, each liver was perfused with preservation solutions associated with high (normal saline [NS]), moderate (Euro-Collins [EC]), and low (University of Wisconsin solution [UW]) risks of reperfusion injury. RESULTS: Baseline (in situ) PDs were similar in all groups (-37 +/- 4 mV, mean +/- SD). Ten minutes postresection, hepatic PDs were as follows: NS, -23.8 +/- 3.5 mV; EC, -11.4 +/- 0.4 mV; and UW, -8.7 +/- 0.3 mV (P <0.01 for all groups). Maximum depolarization occurred at 6 hours postresection (NS, -8.1 +/- 1.1 mV; EC, -7.7 +/- 1.3 mV; and UW, -8.6 +/- 1.0 mV). To determine whether these changes are of pathophysiologic importance, the NS solution was modified (addition of 0.1% ethanol) to achieve similar PD changes as those observed with UW. Liver transplants were then performed where the donor livers had been perfused and preserved for 6 hours with either NS or the modified NS (MNS) solution. Posttransplant (10 day) survival was 1 of 6 (17%) in the NS group and 4 of 6 (67%) in the MNS group (P <0.05). Regarding the effects of PD changes on ionic flux, intracellular calcium levels were documented for up to 4 hours by fluorescence video microscopy using Fura-2 in isolated hepatocytes exposed to NS, UW, and MNS solutions. Intracellular calcium levels were similar in all solutions at each time point studied. CONCLUSIONS: The results of this study indicate that hepatocytes undergo prompt and marked depolarization following hepatic resection, and the extent of the depolarization correlates with survival following transplantation.

Risk of sedation for upper GI endoscopy exacerbating subclinical hepatic encephalopathy in patients with cirrhosis.

BACKGROUND: The risk of exacerbating subclinical hepatic encephalopathy associated with the administration of sedative drugs in patients with cirrhosis undergoing diagnostic upper gastrointestinal (GI) endoscopy for portal hypertension remains to be determined. METHODS: Ten adult patients with cirrhosis completed number connection tests before sedation for endoscopy and at discharge from the endoscopy unit 2 hours post-procedure. Control patients consisted of five patients with cirrhosis undergoing the same procedure for the same indication who did not receive sedation and 12 patients with no evidence of liver disease who received sedation before diagnostic endoscopy for a variety of GI complaints. The control populations were age, gender, education level, and, in the case of patients with cirrhosis, Child Pugh s score matched to the patients with cirrhosis who received sedation. RESULTS: The mean (+/- SEM) age of patients with cirrhosis who received sedation was 59.6 +/- 3.8 years. Seven of the ten (70%) were men. Their mean Child Pugh s score was 7.2 +/- 1.5. Nine of the ten (90%) had abnormal baseline number connection tests results (mean for the group 52.3 +/- 6.7 seconds) the extent of which correlated with Child Pugh s scores (p < 0.005). Individually, the baseline number connection tests results were normal in one (10%), mild in six (60%), moderate in one (10%), and severe in two (20%). After the procedure (before discharge) the mean number connection tests result was 61.5 +/- 7.9 seconds (p = 0.01 when compared with baseline). The results were now normal in none (0%), mild in four (40%), moderate in four (40%), and severe in two (20%). Pre- and post-procedure number connection tests results did not change in the non-sedated cirrhotic or sedated non-liver disease control patients. CONCLUSIONS: The results of this study indicate that (1) the majority of patients with cirrhosis and suspected portal hypertension have evidence of subclinical hepatic encephalopathy, (2) the extent of encephalopathy correlates with the Child Pugh's score, (3) sedation with midazolam for upper GI endoscopy exacerbates the encephalopathy, and (4) this adverse effect is still evident 2 hours after the procedure.

Profile of a liver transplant follow-up clinic in a nontransplant Canadian urban centre.

Care of the growing number of liver transplant recipients will increasingly fall on the referring centres. Thus, there is a need to define more clearly the demographic, clinical and laboratory profiles of liver transplant recipients, particularly in the setting of a centre where a liver transplantation program does not exist. The present study documented these features in 37 patients attending an adult ambulatory care clinic in an urban, nonliver transplant centre. Mean +/- SD age of the study population was 44 +/- 11.9 years. Twenty-one patients (57%) were male. Annual enrolment in the clinic increased from three patients at the completion of the clinic's first year (1988) to 16 patients in the final year of the study (1993). Time between the transplantation procedure and the patient's return to the referring centre decreased from a mean of 12 weeks in 1988 to four weeks in 1993. During those seven years no patient required an unscheduled return to the transplant centre for surgical complications or problems associated with immuno-suppressive therapy. In conclusion, these data provide a profile of liver transplant patients attending a nonliver transplant centre for follow-up and support the concept that nontransplant centres are capable of providing safe and, in terms of travel, less expensive care for liver transplant recipients.

Thoracic duct-cutaneous fistula in a patient with cirrhosis of the liver: successful treatment with a transjugular intrahepatic portosystemic shunt.

Patients with cirrhosis of the liver have increased hepatic and gastrointestinal lymph flow that may contribute to the formation of ascites and pleural effusions. Increased lymph flow, which is due to postsinusoidal portal hypertension, causes a high rate of flow through the thoracic duct. Because of the high flow rates, disrupted lymphatic vessels in patients with cirrhosis of the liver may fail to close, a situation that results in chylous ascites, pleural effusions, or chylous fistulas. Chylous fistulas deplete proteins, fluid, and lymphocytes and thus lead to volume depletion and coagulopathy. Herein we describe an unusual case in which a high-output traumatic thoracic duct-cutaneous fistula developed in a patient with cirrhosis and led to volume depletion and coagulopathy. Correction of the portal hypertension with placement of a transjugular intrahepatic portosystemic shunt led to closure of the fistula and normalization of accompanying metabolic abnormalities.

Liver cell necrosis: cellular mechanisms and clinical implications.

Based on our current understanding, we have developed a provisional model for hepatocyte necrosis that may be applicable to cell necrosis in general (Figure 6). Damage to mitochondria appears to be a key early event in the progression to necrosis. At least two pathways may be involved. In the first, inhibition of oxidative phosphorylation in the absence of the MMPT leads to ATP depletion, ion dysregulation, and enhanced degradative hydrolase activity. If oxygen is present, toxic oxygen species may be generated and lipid peroxidation can occur. Subsequent cytoskeleton and plasma membrane damage result in plasma membrane bleb formation. These steps are reversible if the insult to the cell is removed. However, if injury continues, bleb rupture and cell lysis occur. In the second pathway, mitochondrial damage results in an MMPT. This step is irreversible and leads to cell death by as yet uncertain mechanisms. It is important to note that MMPT may occur secondary to changes in the first pathway (e.g. oxidative stress, increased Cai2+, and ATP depletion) and that all the "downstream events" occurring in the first pathway may result from MMPT (e.g., ATP depletion, ion dysregulation, or hydrolase activation). Proof of this model's applicability to cell necrosis in general awaits further validation. In this review, we have attempted to highlight the advances in our understanding of the cellular mechanisms of necrotic injury. Recent advances in this understanding have allowed scientists and clinicians a better comprehension of liver pathophysiology. This knowledge has provided new avenues of therapy and played a key role in the practice of hepatology as evidenced by advances in organ preservation. Understanding the early reversible events leading to cellular and subcellular damage will be key to prevention and treatment of liver disease. Hopefully, disease and injury specific preventive or pharmacological strategies can be developed based on this expanding data base.

Calpain activity increases in hepatocytes following addition of ATP. Demonstration by a novel fluorescent approach.

Our aim was to measure calpain protease activity during increases in cytosolic free calcium (Ca2+i) after addition of extracellular ATP. The calpain protease substrate t-butoxycarbonyl-Leu-Met-7-amino-4-chloromethylcoumarin was synthesized. Nonfluorescent t-butoxycarbonyl-Leu-Met-7-amino-4- chloromethyl-coumarin diffuses into the cell where it is conjugated to glutathione forming t-butoxycarbonyl-Leu-Met-7-amino-4-methylcoumarin glutathione conjugate (Boc-Leu-Met-MAC-SG). The nonfluorescent, membrane impermeant Boc-Leu-Met-MAC-SG accumulates in the cell. Intracellular proteolytic hydrolysis of Boc-Leu-Met-MAC-SG releases and unquenches the fluorescence of MAC-SG. Intracellular fluorescence of MAC-SG was quantitated in single, cultured rat hepatocytes using digitized video fluorescent microscopy. Enhancement of intracellular fluorescence generation by increases in Ca2+i and inhibition by a calpain inhibitor indicated the probe was a calpain substrate. After addition of ATP, calpain protease activity increased to 156 +/- 13% of basal concurrent with a 3-fold rise of Ca2+i for 2-4 min. Thereafter, Ca2+i decreased to values of 1.5-fold above basal and protease activity returned to normal. Incubation of cells in Ca(2+)-free buffer abolished the rise in Ca2+i and calpain protease activity. Calpain protease activity increases concomitantly with increases of Ca2+i supporting the hypothesis that calpain proteases participate in Ca(2+)-mediated signal transduction.