Gary A. Levy

Definition and classification of negative outcomes in solid organ transplantation. Application in liver transplantation.

ObjectiveThis study defined negative outcomes of solid organ transplantation, proposed a new classification of complications by severity, and applied the classification to evaluate the results of orthotopic liver transplantation (OLT). Summary and Background DataThe lack of uniform reporting of negative outcomes has made reports of transplantation procedures difficult to interpret and compare. In fact, only mortality is well reported; morbidity rates and severity of complications have been poorly described. MethodsBased on previous definition and classification of complications for general surgery, a new classification for transplantation in four grades is proposed. Results including risk factors of the first 215 OLTs performed at the University of Toronto have been evaluated using the classification. ResultsAlt but two patients (99%) had at least one complication of any kind, 92% of patients surviving more than 3 months had grade 1 (minor) complications, 74% had grade 2 (life-threatening) complications, and 30% had grade 3 (residual disabity or cancer) complications. Twenty-nine per cent of patients had grade 4 complications (retransplantation or death). The most common grade 1 compications were steroid responsive rejection (69% of patients) and infection that did not require antibiotics or invasive procedures (23%). Grade 2 complications primarily were infection requiring antibiotics or invasive procedures (64%), postoperative bleeding requiring >3 units of packed red cells (35%), primary dysfunction (26%), and biliary disease treated with antibiotics or requiring invasive procedures (18%). The most frequent grade 3 complication was renal failure, which is defined as a permanent rise in serum creatinine levels ≥ twice the pretransplantation values (11%). Grade 4 complications (retransplantation or death) mainly were infection (14%) and primary dysfunction (11%). Comparison between the first and last 50 OLTs of the series indicates a significant decrease in the mean number of grade 1 and 2 complications. This was partially a result of better medical status of patients at the time of transplantation. Using univariate and muftivariate analyses of risk factors, the best predictor of grade 1 complications was donor.

Therapeutic drug monitoring of immunosuppressant drugs in clinical practice

BACKGROUND Therapeutic drug monitoring (TDM) is essential to maintain the efficacy of many immunosuppressant drugs while minimizing their toxicity. TDM has become more refined with the development of new monitoring techniques and more specific assays. OBJECTIVE This article summarizes current data on TDM of the following immunosuppressant drugs used in organ transplantation: cyclosporine, tacrolimus, sirolimus, everolimus, and mycophenolate mofetil. METHODS Published data were identified by a MEDLINE search of the English-language literature through March 2001 using the terms therapeutic drug monitoring, cyclosporine, tacrolimus, sirolimus, everolimus, and mycophenolate mofetil. Relevant conference abstracts were also included. RESULTS TDM of cyclosporine has been well studied, and recent findings indicate that monitoring of drug levels 2 hours after dosing is a more sensitive predictor of outcome than trough (C0) monitoring. C0 levels are being used more widely in TDM of tacrolimus; however, the relationship between C0 and area under the curve has varied widely in clinical trials, with correlations ranging from 0.11 to 0.92. The use of TDM of sirolimus, everolimus, and mycophenolate mofetil is evolving rapidly. CONCLUSIONS TDM of immunosuppressant drugs that have a narrow therapeutic index is an increasingly useful tool for minimizing drug toxicity while maximizing prevention of graft loss and organ rejection.

Treatment of primary liver graft nonfunction with prostaglandin E1

Primary nonfunction following orthotopic liver transplantation is characterized by rapidly rising serum transaminases, minimal bile production, and severe coagulopathy, which can progress to hypoglycemia, hepatic encephalopathy, and acute renal failure. Untreated it has a mortality of over 80% and to date the only treatment has been retransplantation. As a result of the beneficial effect of Prostaglandin E1 infusion in patients with fulminant hepatic failure, this trial was conducted to determine whether PGE1 would be of value in primary nonfunction. We have encountered 16 cases of primary nonfunction in 94 liver transplants, an incidence of 17%. Initially in the program, there were 6 occurrences of nonfunction that did not receive PGE1; 3 underwent retransplantation (2 survivors), 2 died awaiting another liver, and in one recovery of hepatocellular function occurred with supportive care but the patient died of cytomegalovirus infection. Ten patients received PGE1 within 4-34 hr of transplantation. Within 12 hr of treatment, 8 patients responded with a significant fall in the AST (129 U/hr) whereas, in the untreated group, the AST continued to rise (267 +/- 102 U/hr) at the same rate as prediagnosis (337 +/- 95 U/hr). At the conclusion of the infusion (4-7 days) in the 8 responders, there were significant decreases in AST (4386 +/- 546 U/L to 102 +/- 21 U/L), prothrombin time (22 +/- 2 to 12 +/- .4 sec) and partial thromboplastin time (45 +/- 3-29 +/- 4 sec), and significant increases in coagulation factor V (26 +/- 8 to 95 +/- 12%) and factor VII (10 +/- 5 to 61 +/- 4%). No serious side effects occurred, although 2 patients developed diarrhea, and abdominal cramps. Two patients treated with PGE1 were retransplanted at 10-36 hr and were considered nonresponders. Graft survival was 80% in the PGE1-treated group and 17% in the untreated group (P less than 0.05) and patient survival was 90% and 33%, respectively. This study suggests a potential benefit of PGE1 in the treatment of primary nonfunction.

Clinical utility of quantitative cytomegalovirus viral load determination for predicting cytomegalovirus disease in liver transplant recipients

BACKGROUND The early detection of cytomegalovirus (CMV) after liver transplantation may form the basis of a preemptive strategy for prevention of active CMV disease. METHODS We prospectively analyzed the clinical use of weekly quantitative polymerase chain reaction-(PCR) based plasma viral load determinations and the antigenemia assay for predicting the development of active CMV disease in 97 consecutive liver transplant recipients. RESULTS CMV disease occurred in 21/97 patients. Using a positive cut-off of >400 copies/ml plasma, PCR had a sensitivity of 100%, specificity 47.4%, positive predictive value 34.4% and negative predictive value 100% for prediction of CMV disease. Respective values for a positive antigenemia (>0 positive cells/slide) were 95.2, 55.3, 37.0, and 97.7%. Different cut-off points for a positive test were analyzed using receiver-operating characteristic (ROC) curves. The optimal cut-off for viral load was in the range of 2000-5000 copies/ml (sensitivity 85.7%, specificity 86.8%, PPV 64.3%, NPV 95.7% for >5000 copies/ml). The optimal cut-off for antigenemia was in the range of four to six positive cells/slide. Mean peak viral load in symptomatic patients was 73,715 copies per/ml versus 3615 copies/ml in patients with asymptomatic CMV reactivation (P<0.001). In a multivariate logistic regression analysis of risk factors for CMV disease (CMV serostatus, acute rejection, and induction immunosuppression), peak viral load and peak antigenemia emerged as the only significant independent predictors of CMV disease (for PCR, odds ratio=1.40/1000 copy/ml increase in viral load, P=0.0001; for antigenemia odds ratio=1.17/1 positive cell/slide). CONCLUSIONS Plasma viral load by quantitative PCR is useful for predicting CMV disease and could be used in a preemptive strategy.

Improved clinical outcomes for liver transplant recipients using cyclosporine monitoring based on 2-hr post-dose levels (C2)1

Background. A prospective, open-label, study was conducted at 29 centers in 9 countries, involving 307 de novo liver transplant patients to compare the clinical usefulness of monitoring 2-hr post-dose cyclosporine (CsA) levels (C2) with conventional trough cyclosporine blood levels (pre-dose) (C0). Methods. Neoral oral therapy was initiated at 15 mg/kg/day and dose adjusted according to predetermined C2 or C0 target level ranges. The primary efficacy variable was treatment failure at 3 months, where evaluation was based on a composite endpoint of biopsy-proven rejection, treatment for rejection, graft loss, death, or premature withdrawal/discontinuation from the study. Results. Baseline characteristics were similar between groups. Graft loss at 12 weeks (retransplantation or death) occurred in 6.8% C2 and in 7.0% C0 patients. Overall incidence of treated acute rejection was lower for C2 (23.6%) than C0 patients (31.6%) (P =0.144, Cochran-Mantel-Haenszel [CMH] test). In hepatitis C virus (HCV)-negative patients, the incidence of rejection in the C2 group was significantly less than in the C0 group (21.2% vs. 33.0%;P <0.05), whereas in HCV-positive patients, the rejection rate was similar in both groups (26.7% for C2 group vs. 27.3% for C0 group:P =0.81). C2 patients (n=16) who reached minimum target CsA levels by day 3 had a notably low incidence of rejection (12.5%), whereas there was no difference in the incidence of rejection in C0 patients, irrespective of time to reach target level. For biopsy-proven acute rejections (21.6% for C2 vs. 30.4% for C0), the incidence of moderate and severe histological diagnosis was significantly lower in the C2 group than in the C0 group (47% vs. 73%;P =0.01). Safety profiles were similar between the two groups, with few patient withdrawals due to adverse events (9.5% for C2; 7.0% for C0). Conclusions. Using C2 monitoring, the overall incidence of acute cellular rejection was lower compared with the C0 group, and the histological severity of acute rejections was shown to be significantly milder for the C2 group, indicative of good long-term prognosis. These data demonstrate that the use of C2 monitoring is superior to C0 and results in a reduction in the incidence and severity of acute cellular rejection without detrimental effect on the drug safety profile.

Syncytial giant-cell hepatitis. Sporadic hepatitis with distinctive pathological features, a severe clinical course, and paramyxoviral features

BACKGROUND AND METHODS We describe a new form of hepatitis, occurring in 10 patients over a period of six years, characterized clinically by manifestations of severe hepatitis, histologically by large syncytial giant hepatocytes, and ultrastructurally by intracytoplasmic structures consistent with paramyxoviral nucleocapsids. RESULTS The patients ranged in age from 5 months to 41 years. The tentative clinical diagnosis before biopsy was non-A, non-B hepatitis in five patients and autoimmune chronic active hepatitis in the others. Five patients underwent liver transplantation; the others died. The diagnosis of syncytial giant-cell hepatitis was established pathologically. The liver cords were replaced in all 10 patients by syncytial giant cells with up to 30 nuclei. In 8 of the 10 the cytoplasm contained pleomorphic particles of 150 to 250 microns, filamentous strands, and particles of 14 to 17 nm with peripherally disposed spikes resembling paramyxoviral nucleocapsids. Structures resembling degenerated forms were found in the other two patients. One of two chimpanzees injected with a liver homogenate from the index patient had an increase in the titer of paramyxoviral antibodies, probably an anamnestic reaction to previous paramyxoviral infection, suggesting that a paramyxoviral antigen but not viable virus was present in the liver homogenate. CONCLUSIONS Although further virologic studies will be required for precise classification, we believe that paramyxoviruses should be considered in patients with severe sporadic hepatitis.

Patient management by Neoral C2 monitoring: An international consensus statement1

The Consensus on Neoral C2: Expert Review in Transplantation (CONCERT) attendees achieved consensus on the following points, based on currently available data from independent clinical studies using Neoral (cyclosporine microemulsion): 1. Scientific validation of Neoral C2 monitoring1.1 An understanding of cyclosporine pharmacokinetics is critical for designing a monitoring strategy that maximizes clinical outcome following organ transplantation1.2 Neoral absorption during the first 4 hours postdose (AUC0–4) represents the period of greatest variability among patients. Adequate CsA absorption during this period is important for effective rejection prophylaxis in the early posttransplant phase1.3 C0 does not correlate well with AUC0–4 in patients receiving Neoral1.4 C2 is the best single time-point predictor of AUC0–4 in all types of Neoral-treated transplant patient populations that have been studied (adult renal, liver, heart and lung patients, and pediatric renal and liver transplant recipients)1.5 Additional CsA concentration sampling beyond the C2 time point, such as C6, may be required in low absorbers of CsA2. Clinical data in de novo adult renal transplant patients2.1 C0 monitoring in patients receiving Neoral distinguishes poorly between those who will experience acute rejection and those who will remain rejection-free2.2 Existing data indicate that higher C2 levels are highly correlated with a lower risk of acute rejection during the early posttransplant period in patients receiving Neoral. Data on outcomes beyond 1 year are awaited2.3 The association between C2 and risk of acute rejection is maintained in Neoral-treated patients who receive an antibody induction agent or concomitant mycophenolate mofetil (MMF) therapy2.4 Achieving an adequate C2 level early after transplantation is associated with reduced risk of acute rejection in adult renal transplant recipients2.5 Adjustment of Neoral dose based on C2 monitoring does not appear to result in impaired early renal function in the short-term, if slow absorbers are identified and managed appropriately. Long-term data are pending3. Clinical data in de novo adult liver transplant patients3.1 Patient management with Neoral C2 monitoring reduces the incidence and severity of acute rejection compared to C0 monitoring3.2 Renal function is not compromised by C2 monitoring in adult liver transplant patients receiving Neoral4. Clinical outcomes in maintenance renal and liver transplant patients4.1 Patient management with Neoral C2 monitoring can improve renal function in maintenance patients by identifying patients who are receiving excessive CsA4.2 Using C2 monitoring in maintenance patients can also reduce the incidence and severity of hypertension by identifying patients who are receiving excessive CsA4.3 Current data suggest that there is an association between C2 level and risk of chronic allograft nephropathy, in adult renal transplant patients receiving Neoral5. C2 targets for adult renal transplant patients5.1 Guideline C2 targets have been proposed for the first month posttransplant in adult renal transplant patients receiving Neoral, with subsequent step-wise reductions in C2 target over time5.2 Long-term target C2 levels for prevention of chronic allograft nephropathy remain to be confirmed6. C2 targets for adult liver transplant patients6.1 Guideline C2 targets have been proposed for adult liver transplant recipients receiving Neoral7. C2 targets for other transplant patient types7.1 C2 target levels have not yet been established for cardiothoracic organ recipients, living-related liver transplant recipients, kidney-pancreas transplant patients, or pediatric transplant patients receiving Neoral8. Accuracy of C2 sampling8.1 There is a 15-minute “window of opportunity” before and after the 2-hour time point during which the C2 sample can be taken in order to remain within a 10% margin of error8.2 In most instances, C2 targets do not require adjustment for different immunoassay types currently available9. Pharmacoeconomics9.1 Neoral C2 monitoring is at least cost neutral compared to C0 monitoring and may generate cost savings in adult renal transplant patients10. Conclusions of the CONCERT conference10.1 C2 monitoring is the optimal method to monitor Neoral in adult de novo renal and liver transplant patients (2)10.2 Preliminary data indicate that Neoral C2 monitoring may have clinical benefits in maintenance adult renal and liver transplant recipients who are receiving excessive CsA and in whom the Neoral dose is reduced10.3 Maintenance patients who are experiencing suspected CsA-related toxicity may benefit from use of Neoral C2 monitoring to detect CsA overexposure10.4 Further data sre required from prospective, randomized multicenter trials to evaluate the possible long-term clinical benefits of adopting Neoral C2 monitoring in de novo and maintenance transplant patients, both in terms of rejection prophylaxis and overall safety profile

Biliary Strictures in 130 Consecutive Right Lobe Living Donor Liver Transplant Recipients: Results of a Western Center

Biliary strictures remain the most challenging aspect of adult right lobe living donor liver transplantation (RLDLT). Between 04/2000 and 10/2005, 130 consecutive RLDLTs were performed in our center and followed prospectively. Median follow‐up was 23 months (range 3–67) and 1‐year graft and patient survival was 85% and 87%, respectively. Overall incidence of biliary leaks (n = 19) or strictures (n = 22) was 32% (41/128) in 33 patients (26%). A duct‐to‐duct (D‐D) or Roux‐en‐Y (R‐Y) anastomosis were performed equally (n = 64 each) with no difference in stricture rate (p = 0.31). The use of ductoplasty increased the number of grafts with a single duct for anastomosis and reduced the biliary complication rate compared to grafts ≥2 ducts (17% vs. 46%; p = 0.02). Independent risk factors for strictures included older donor age and previous history of a bile leak. All strictures were managed nonsurgically initially but four patients ultimately required conversion from D‐D to R‐Y. Ninety‐six percent (123/128) of patients are currently free of any biliary complications. D‐D anastomosis is safe after RLDLT and provides access for future endoscopic therapy in cases of leak or stricture. When presented with multiple bile ducts, ductoplasty should be considered to reduce the potential chance of stricture.

Biochemical and clinical response of fulminant viral hepatitis to administration of prostaglandin E. A preliminary report.

The effect of PG on patients with fulminant and subfulminant viral hepatitis (FHF) was studied. 17 patients presented with FHF secondary to hepatitis A (n = 3), hepatitis B (n = 6), and non-A, non-B (NANB) hepatitis (n = 8). 14 of the 17 patients had stage III or IV hepatic encephalopathy (HE). At presentation the mean aspartate transaminase (AST) was 1,844 +/- 1,246 U/liter, bilirubin 232 +/- 135 mumol/liter, prothrombin time (PT) 34 +/- 18, partial thromboplastin time (PTT) 73 +/- 26 s, and coagulation Factors V and VII 8 +/- 4 and 9 +/- 5%, respectively. Intravenous PGE1 was initiated 24-48 h later after a rise in AST (2,195 +/- 1,810), bilirubin (341 +/- 148), PT (36 +/- 15), and PTT (75 +/- 18). 12 of 17 responded rapidly with a decrease in AST from 1,540 +/- 833 to 188 +/- 324 U/liter. Improvement in hepatic synthetic function was indicated by a decrease in PT from 27 +/- 7 to 12 +/- 1 s and PTT from 61 +/- 10 to 31 +/- 2 s, and an increase in Factor V from 9 +/- 4 to 69 +/- 18% and Factor VII from 11 +/- 5 to 71 +/- 20%. Five responders with NANB hepatitis relapsed upon discontinuation of therapy, with recurrence of HE and increases in AST and PT, and improvement was observed upon retreatment. After 4 wk of intravenous therapy oral PGE2 was substituted. Two patients with NANB hepatitis recovered completely and remained in remission 6 and 12 mo after cessation of therapy. Two additional patients continued in remission after 2 and 6 mo of PGE2. No relapses were seen in the patients with hepatitis A virus and hepatitis B virus infection. Liver biopsies in all 12 surviving patients returned to normal. In the five nonresponders an improvement in hepatic function was indicated by a fall in AST (3,767 +/- 2,611 to 2,142 +/- 2,040 U/liter), PT (52 +/- 25 to 33 +/- 18 s), and PTT (103 +/- 29 to 77 +/- 44 s), but all deteriorated and died of cerebral edema (n = 3) or underwent liver transplantation (n = 2). These results suggest efficacy of PGE for FHF, and further investigation is warranted.

The Fgl2/fibroleukin prothrombinase contributes to immunologically mediated thrombosis in experimental and human viral hepatitis

Fibrin deposition and thrombosis within the microvasculature is now appreciated to play a pivotal role in the hepatocellular injury observed in experimental and human viral hepatitis. Importantly, the pathways by which fibrin generation is elicited in viral hepatitis may be mechanistically distinct from the classical pathways of coagulation induced by mechanical trauma or bacterial lipopolysaccharide (LPS). In the setting of murine hepatitis virus strain-3 (MHV-3) infection, a member of the Coronaviridae, activated endothelial cells and macrophages express distinct cell-surface procoagulants, including a novel prothrombinase, Fgl2/fibroleukin, which are important for both the initiation and localization of fibrin deposition. To assess the role of Fgl2/fibroleukin in murine viral hepatitis we generated a Fgl2/fibroleukin-deficient mouse. Peritoneal macrophages isolated from Fgl2/fibroleukin-/- mice did not generate a procoagulant response when infected with MHV-3. Fibrin deposition and liver necrosis were markedly reduced, and survival was increased in mice infected with MHV-3. To address the relevance of Fgl2/fibroleukin in human chronic viral hepatitis we studied patients with minimal and marked chronic hepatitis B. We detected robust expression of Fgl2/fibroleukin mRNA transcripts and protein in liver tissue isolated from patients with marked chronic hepatitis B. Fibrin deposition was strongly associated with Fgl2/fibroleukin expression. Collectively, these data indicate a critical role for Fgl2/fibroleukin in the pathophysiology of experimental and human viral hepatitis.