A. Ottobrelli

Exhaled Nitric Oxide and Impaired Oxygenation in Cirrhotic Patients before and after Liver Transplantation

Abnormalities of arterial oxygenation are common in patients with cirrhosis [1], and a widened alveolar-arterial oxygen gradient is reported in more than half of these patients at pretransplantation assessment of pulmonary function [2, 3]. Increasing evidence suggests that the abnormal gas exchange in cirrhotic patients is primarily due to intrapulmonary vasodilatations, which cause ventilation-perfusion mismatch and impaired diffusion [4]. Increased circulation of a pulmonary vasodilator seems to be the favored mechanism for intrapulmonary vasodilatations, and recent evidence points to nitric oxide as the most important vasodilating substance [5]. Increased nitric oxide output in exhaled air has been reported in patients with advanced cirrhosis [6], and a correlation between exhaled nitric oxide concentrations and alveolar-arterial oxygen gradient was recently shown in 45 patients with cirrhosis [7]. After successful liver transplantation, oxygenation has been reported to improve in most patients [3]. In a limited series of three patients with full-blown hepatopulmonary syndrome characterized by severe hypoxemia and evidence of intrapulmonary shunting, the increased amount of exhaled nitric oxide reportedly decreased to within the normal range in one patient after successful liver transplantation [8]. To further investigate the association between nitric oxide produced in the lung and oxygenation abnormalities in patients with cirrhosis, we sought to determine exhaled nitric oxide and oxygenation measures before and after liver transplantation in a selected group of patients with cirrhosis who did not have obvious cardiorespiratory diseases. Methods Patients Twenty patients who underwent successful orthotopic liver transplantation at our hospital from August 1995 to February 1997 were recruited for our study. These patients came from a group of 45 patients who were evaluated at the Outpatient Clinic for Liver Cirrhosis during a scheduled visit [7]. All patients gave their informed consent to participate in the study, which was approved by the ethical committee. Included patients had to have been evaluated within 8 weeks before transplantation. Exclusion criteria were respiratory and cardiovascular disease, including clinically significant pleural effusion (larger than costophrenic angle on chest radiography); tense ascites; inability to perform lung function tests; current smoking habit or a smoking history of more than 10 packs per year (1 pack per year = 20 cigarettes per day for 1 year); forced vital capacity (FVC) and FEV (1) less than 80% of predicted; FEV1/FVC 100 less than 70%; and an airway infection in the previous 4 weeks. All patients were reevaluated 3 to 12 months after transplantation. Laboratory Testing Patients underwent the following studies: pulmonary function tests, arterial blood gas analysis done while patients were breathing room air in a seated position, contrast-enhanced echocardiography, and measurement of nitric oxide in exhaled air. The hepatopulmonary syndrome was defined as an alveolar-arterial oxygen gradient greater than 15 mm Hg and echocardiographic evidence of intrapulmonary vasodilatations [4]. Lung volumes and carbon monoxide diffusing capacity were obtained according to standardized procedures [9, 10]. The reference values of Quanjer were used [11]. Arterial blood gas samples were obtained by percutaneous radial artery puncture while patients were seated and breathing room air. The alveolar oxygen tension was calculated by using the ideal air Equation and assuming a respiratory exchange ratio of 0.8. The alveolar-arterial oxygen difference was then derived. A gradient less than 15 mm Hg was considered normal. Exhaled nitric oxide was measured on a chemiluminescence analyzer (Dasibi Environmental Corp., Glendale, California) that is sensitive to nitric oxide from 1 to 4000 parts per billion (ppb) by volume, adapted for on-line recording of nitric oxide concentration, at a sample gas flow of 250 mL/min according to European Respiratory Society recommendations [12]. The analyzer was calibrated daily against standard gas mixtures. While seated and wearing a noseclip, patients were asked to inhale nitric oxide-free air (<5 ppb) and to perform a slow expiratory vital capacity test over 20 to 30 seconds with a flow of 5 to 15 L/min against a low resistance (5 to 20 cm H2O). Exhaled air was sampled for nitric oxide analysis by way of a Teflon tubing side arm attached to the mouthpiece. Nitric oxide concentration, flow, and pressure were simultaneously displayed against time on a computer screen. Three successive reproducible recordings were made at 2-minute intervals, and the mean values of the plateau (the last part of expiration) of nitric oxide concentration (expressed in ppb) were recorded. Because of flow dependence of exhaled nitric oxide concentration [13], flow rates at which nitric oxide measurements were performed in each patient before and after transplantation were compared and found to not be statistically significantly different (10.2 2.37 L/min compared with 10.6 2.28 L/min). Twenty nonsmoking healthy persons (mean age, 44.6 11.2 years; 12 men) served as normal controls for exhaled nitric oxide concentrations. Saline contrast-enhanced echocardiography was done by use of a peripheral intravenous line, as reported elsewhere [14]. A positive result on contrast-enhanced echocardiography (that is, indicating intrapulmonary right-to-left shunt) was defined as the delayed appearance (three to six beats after the initial appearance of contrast in the right side of the heart) of microbubbles in the left side of the heart. Statistical Analysis The variability of the outcomes (decrease in alveolar-arterial oxygen gradient and exhaled nitric oxide concentration after transplantation) was estimated from previous studies [3, 8]. The sample size was calculated on the basis of an expected 50% decrease in the outcomes after transplantation compared with pretransplantation values, for a two-tailed value of 0.05 and a value of 0.20. Means and SDs were calculated for each variable. The Student t-test for paired data was used to compare data before and after transplantation; the McNemar test was used when appropriate. Regression analysis was performed by using the least-squares method. A P value of 0.05 or less was considered statistically significant. Role of the Funding Source Our funding source had no role in the collection, analysis, or interpretation of the data or in the submission of the paper for publication. Results Eighteen patients (mean age, 48.3 7 years; 14 men) completed the study. Two patients died after surgery (1 of pneumonia and 1 of stroke) 72 and 85 days after transplantation. Cirrhosis was alcoholic in 7 patients; viral in 8 patients; and autoimmune, cryptogenic, and associated with Wilson disease in 1 patient each. According to the Child-Pugh classification [15], 4 patients had class A cirrhosis, 4 had class B cirrhosis, and 10 had class C cirrhosis. Fifteen patients (83.3%) had esophageal varices. Patients were reevaluated 8.5 3.5 months (range, 3 to 12 months) after transplantation. Post-transplantation lung volumes and diffusion did not significantly differ from pretransplantation values: Total lung capacity increased from 95.4% 9.6% of predicted to 96.7% 10.4% of predicted, FEV1 increased from 100.3% 13.3% of predicted to 103% 13.2% of predicted, FEV1/FVC 100 decreased from 80.5% 4.5% of predicted to 79.5% 4.2% of predicted, and the diffusing capacity of the lung for carbon monoxide divided by alveolar volume decreased from 76.5% 20.9% of predicted to 71.6% 17.2% of predicted. Arterial blood gas data, exhaled nitric oxide concentrations, and findings on echocardiographic evaluation of intrapulmonary shunts before and after transplantation are given in Table 1. Before transplantation, the mean exhaled nitric oxide concentration was significantly higher in patients than in controls (13 4.9 ppb compared with 5.75 1.9 ppb; P < 0.001). Table 1. Arterial Blood Gas Analyses, Exhaled Nitric Oxide Concentrations, and Patients with the Hepatopulmonary Syndrome before and after Liver Transplantation* After transplantation, the alveolar-arterial oxygen gradient significantly decreased (from 17.3 7.1 mm Hg before transplantation to 9 5.2 mm Hg; P < 0.001), as did the exhaled nitric oxide concentration (from 13 4.9 ppb to 6.2 2.8 ppb; P < 0.001). The decrease in exhaled nitric oxide concentration after liver transplantation was significantly correlated with the decrease in alveolar-arterial oxygen gradient (r = 0.56; P = 0.014) (Figure 1). Figure 1. Correlation between the differences in alveolar-arterial oxygen gradient and exhaled nitric oxide concentrations before and after liver transplantation. Before transplantation, intrapulmonary shunts were detected by contrast-enhanced echocardiography in five patients, all of whom met the criteria for the hepatopulmonary syndrome and had an alveolar-arterial oxygen gradient greater than 15 mm Hg. In these patients, the pretransplantation exhaled nitric oxide concentration was significantly higher than that in patients without the hepatopulmonary syndrome (18 5.48 ppb compared with 11.07 3.2 ppb; P < 0.005). After transplantation, the hepatopulmonary syndrome was no longer evident; the alveolar-arterial oxygen gradient returned to normal in all affected patients, even the two patients in whom contrast-enhanced echocardiography still showed intrapulmonary vasodilatations. Discussion We found a highly significant decrease in exhaled nitric oxide concentrations after liver transplantation that was correlated with the decrease in alveolar-arterial oxygen gradient. As in other investigations [1-3], respiratory function assessment done before liver transplantation revealed a high prevalence of widened alveolar-arterial oxygen gradient in our patients with advanced liver disease. The high concentration of exhaled nitric oxide in our pati

Treatment of recurrent hepatitis C in liver transplants: efficacy of a six versus a twelve month course of interferon alfa 2b with ribavirin ☆

BACKGROUND/AIMS Interferon (IFN) with ribavirin combination therapy (CT) was proposed for the treatment of hepatitis C recurring in liver transplants. We assessed the efficacy of two protocols of CT in transplanted patients with recurrent severe hepatitis C virus (HCV) hepatitis. METHODS Fifty-seven patients (68% genotype 1b) were treated with IFN alfa-2b 3 million units three times weekly and oral ribavirin 800mg/die for 6 or 12 months. Study end-points were the end of treatment (ETVR) and the 12-month post-therapy sustained virologic response (SVR; negative HCV-RNA). RESULTS ETVR was induced in 9/27 (33%) and in 7/30 patients (23%) treated, respectively, for 6 and 12 months (P=0.4); a SVR was induced in six (22%) of the former and five (17%) of the latter (P=0.4). HCV genotype non-1 patients responded better than genotype 1 (SVR: 43% in genotype non-1 versus 12% in genotype 1, P: 0.02). In ETV responders the hepatitis activity index improved by >2 points in biopsies taken after therapy compared to pre-therapy biopsies. Anemia and leukopenia required reduction of therapy in 51% of the patients. CONCLUSIONS CT is efficacious in controlling HCV disease in about 20% of transplants with recurrent hepatitis C. Six months of therapy are as efficacious as 12 months.

Patterns of hepatitis delta virus reinfection and disease in liver transplantation.

Twenty-seven carriers of the hepatitis B surface antigen who underwent liver transplantation in Italy and Belgium for terminal Hepatitis delta virus (HDV) cirrhosis were investigated. In 22 of the patients, HDV infection recurred. Two patients died of coexisting HDV and hepatitis B virus (HBV) reactivation. Four patients who died of unrelated causes were found to have HDV without signs of HBV reactivation. Five patients (18%) cleared both HBV and HDV after transplantation with no evidence of hepatitis (mean follow-up, 29 months). In many surviving patients. HDV infection recurred early without signs of HBV reactivation. Disease returned in the 11 HDV-infected patients in whom HBV also recurred. Histological hepatitis did not recur during an interim of 12-33 months in the 5 HDV-infected patients in whom HBV did not return. The overall medium-term survival in patients with HDV who underwent transplantation was 77.7%. Liver transplantation offers patients with HDV a hope of cure from disease despite a high risk of reinfection. In the transplantation setting. HDV can cause subclinical infections without any apparent assistance from HBV; these infections become symptomatic only if and when HBV reactivates. Thus, HDV may not be in itself pathogenic but requires cooperation from HBV to cause the appearance of the disease.

Oxidative damage in human liver transplantation

The aim of this study was to evaluate oxygen-dependent hepatic reperfusion injury in humans following orthotopic liver transplantation. To this end, a number of blood indices of impaired tissue redox balance were monitored in 19 adult patients for 3 weeks after liver transplantation. Both red cell malonaldehyde and plasma lipid peroxides increased significantly soon after organ reperfusion. This finding was consistently accompanied by decreased plasma vitamin E and red cell total glutathione. A peak of oxidative stress, as measured by the parameters monitored, was evident within 24 h after reperfusion, together with a maximum expression of cytolysis, as measured by plasma alanine aminotransferase. The occurrence of redox imbalance after hepatic reperfusion was shown to be linearly related to irreversible cell damage. As regards the low plasma levels of the two antioxidants after reperfusion, only that of vitamin E appeared statistically related to oxidative stress. With the background of an increasing body of proof, mainly from animal models, the involvement of toxic oxygen metabolites in hepatic cytolysis following orthotopic liver transplantation appears likely. The statistical correlation among the markers of redox imbalance monitored indicates their combined use in further investigation.

Microscopic vascular invasion detected by anti-CD34 immunohistochemistry as a predictor of recurrence of hepatocellular carcinoma after liver transplantation.

Background. Vascular invasion (VI) is the strongest risk factor for recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT). However, unlike macroscopic VI, microscopic VI has not been acknowledged as a predictor of recurrence in individual patients. This study aimed to determine whether immunohistochemical staining of the vessels could change the judgment on microscopic VI in such a way as to confer clinical relevance to the feature. Methods. Antibodies against the CD34 antigen (endothelial cell marker of hepatocarcinogenesis) were applied to sections from all the HCC nodules found in 136 patients who underwent LT for HCC arising from cirrhosis between 1990 and 2000. Microscopic VI at the periphery of the nodules was searched blindly by the same pathologist who had already examined hematoxylin-eosin slides. Several characteristics of the patients and of the cancers were analyzed to define their respective influence on recurrence. Results. Recurrent HCC was diagnosed in nine patients. Although 6 of the 22 patients in whom microscopic VI had been detected by hematoxylin-eosin staining developed recurrence, 8 of the 16 in whom microscopic VI was detected by anti-CD34 immunohistochemistry developed recurrence, accounting for 5-year cumulative incidences of recurrence of 34% and 70%, respectively. At multivariate analysis, relative risk for recurrence was the highest for microscopic VI found with anti-CD34 antibodies. Conclusions. Microscopic VI detected by anti-CD34 immunohistochemistry implies an extremely high risk for HCC to recur after LT. Trials focusing on patients with evidence of microscopic VI are needed to test the efficacy of adjuvant therapies to prevent recurrence.

The first one thousand liver transplants in Turin: a single-center experience in Italy

The first Italian liver transplant center to reach the goal of 1000 procedures was Turin. The paper reports this single‐center experience, highlighting the main changes that have occurred over time. From 1990 to 2002, 1000 consecutive liver transplants were performed in 910 patients, mainly cirrhotics. Surgical technique was based on the preservation of the retrohepatic vena cava of the recipient. The veno‐venous bypass was used in 30 cases only and abandoned since 1997. Operating time, warm ischemia time and length of hospital stay significantly decreased over the years, while operating room extubation became routine. Immunosuppression pivoted on cyclosporine A. Management of retransplantations, marginal grafts, and of HCV‐positive, HBV‐positive and hepatocellular carcinoma recipients were optimized. Median follow‐up of the patients was 41 months. Overall survival rates at 1, 5 and 10 years were 87%, 78% and 72% respectively. Survival rates obtained in the second half of the cases (1999–2002 period) were significantly better than those obtained in the first half (1990–1998 period) (90% vs. 83% at 1 year and 81% vs. 76% at 5 years respectively). Increasing experience in liver transplant surgery and postoperative care allowed standardization of the procedure and expansion of the activity, with parallel improvement of the results.

Recurrence of hepatitis D (delta) in liver transplants: Histopathological aspects

BACKGROUND The viral/pathological correlates of recurrent hepatitis delta virus (HDV) disease in orthotoptic liver transplants are reported. METHODS We examined the histological features of recurrent HDV disease in nine patients with transplants for terminal HDV cirrhosis were examined; intrahepatic HDV and hepatitis B virus (HBV) antigens were detected by immunoperoxidase techniques. Sera were tested for the battery of HDV and HBV markers. RESULTS In four patients, HDV reinfection was accompanied by the recurrence of an HBV infection with features of active viral replication. In the other five, HDV reinfection was accompanied by an atypical recurrence of HBV infection without evidence of active HBV replication (no expression of intrahepatic hepatitis B core antigen). In four of the latter patients, the atypical HBV pattern changed during the follow-up into a pattern of active viral replication accompanied by chronic necroinflammation detected during histology. CONCLUSION The pattern of recurrent HBV infection can influence the pathological aspects of the relapses of HDV disease in liver grafts.

Hepatitis type C after ortothopic liver transplantation: reinfection and disease recurrence

We determined the prevalence of hepatitis C virus markers and the clinical course in patients transplanted for terminal type C or non-A, non-B cirrhosis. Hepatitis C virus infection recurred in 16 of 17 patients (94%) with type C cirrhosis (seropositive for hepatitis C virus prior to surgery) and in 10 of 11 patients (91%) with non-A, non-B cirrhosis whose hepatitis C virus status prior to surgery had not been determined. Markers of hepatitis C virus were detected in 4 of 16 liver transplants whose donors tested negative for hepatitis C virus prior to surgery; this figure represents the risk of hepatitis C virus acquisition from external sources at or after transplantation. In 18 of 26 reinfected patients aminotransferases increased after grafting and remained elevated throughout the 14 to 79 (mean 46.5) months of follow up. The histological findings varied from mild or moderate hepatitis in 15 patients to severe active hepatitis in two patients. Two patients developed cirrhosis; one of them died of intercurrent infection while she was receiving immunosuppressive therapy for chronic rejection. Patients transplanted for hepatitis C virus or non-A, non-B liver disease are at high risk of hepatitis C virus reinfection. However the course of recurrent hepatitis C is most often mild and compatible with a normal life and an excellent survival rate.

Fifteen years’ experience with transjugular intrahepatic portosystemic shunt (TIPS) using bare stents: retrospective review of clinical and technical aspects

PurposeThe authors present a retrospective analysis of a large series of patients who underwent transjugular intrahepatic portosystemic shunt (TIPS) placement.Materials and methodsBetween March 1992 and December 2006, 658 patients were referred to our centre for TIPS placement. Indications for the procedure were digestive tract bleeding (52.8%), refractory ascites (35.3%), preservation of portal vein patency prior to liver transplantation (3.0%) and thrombosis of the suprahepatic veins (2.3%). Other indications (6.6%) included pleural ascites, portal thrombosis and hepatorenal and hepatopulmonary syndromes. All patients were evaluated with colour Doppler ultrasonography and in a few cases with computed tomography. The portal system was punctured under sonographic guidance. Wallstent, Palmaz and Nitinol thermosensitive stents were used. Embolisation of persistent varices was performed in 6.8% of cases.ResultsTechnical success was 98.9%. During a 1,500-day follow-up, the cumulative incidence of stent revision was 25.7% (Nitinol), 32.9% (Wallstent) and 1.8% (Palmaz). Mortality rates were 31.1%, 38.5% and 56.4%, respectively. The technical complications included six cases of heart failure, six of haematobilia, three of stent migration, two of intrahepatic haematoma and one of haemoperitoneum. Eight patients with severe portosystemic encephalopathy (PSE) were treated with a reduction stent.ConclusionsTIPS placement is safe and effective and may act as a bridge to liver transplantation. Ultrasonography plays a fundamental role in the preliminary assessment, in portal vein puncture and during the follow-up. Stent patency is satisfactory.RiassuntoObiettivoGli autori presentano un’analisi retrospettiva di un’ampia casistica di pazienti sottoposti a TIPS.Materiali e metodiSono giunti al nostro centro per la TIPS 658 pazienti tra il marzo 1992 e il dicembre 2006. Le indicazioni alla procedura erano: sanguinamento digestivo (52,8%), ascite refrattaria (35,3%), “tutela” della pervietà portale pre-trapianto epatico (3,0%), trombosi delle vene sovraepatiche (2,3%). Altre indicazioni (6,6%) erano ascite pleurica, trombosi portale, sindrome epato-renale ed epato-polmonare. I pazienti sono stati studiati con ecocolor doppler, raramente con tomografia computerizzata; la puntura portale è stata ecoguidata. Sono stati impiegati stent Palmaz, Wallstent e termoespandibili. Nel 6,8% dei casi sono state embolizzate varici persistenti.RisultatiIl successo tecnico è stato del 98,9%. Durante un follow-up di 1500 giorni, l’incidenza cumulativa di reintervento sugli stent è stata del 25,7% (Nitinol), 32,9% (Wallstent) e 1,8% (Palmaz); la mortalità è stata rispettivamente 31,1%, 38,5% e 56,4%. Le complicanze tecniche sono state: 6 insufficienze cardiache, 6 emobilie, 3 migrazioni di stent, 2 ematomi intraepatici ed 1 emoperitoneo. Otto pazienti con encefalopatia portosistemica (PSE) grave sono stati trattati con stent riduttore.ConclusioniLa TIPS è sicura ed efficace, può rappresentare un ponte all’OLT. L’ecografia ha un ruolo fondamentale nello studio preliminare, durante la puntura portale e nel follow-up. La pervietà degli stent è soddisfacente.

Impact of viral eradication with sofosbuvir-based therapy on the outcome of post-transplant hepatitis C with severe fibrosis

Several studies have shown that new direct‐acting antivirals maintain their efficacy in liver transplant (LT) recipients with severe hepatitis C virus (HCV) recurrence. We determined the clinical impact of sofosbuvir/ribavirin in LT through the changes in liver function and fibrosis state at 24 and 48 weeks after treatment.