Article

Azathioprine in liver transplantation: a reevaluation of its use and a comparison with mycophenolate mofetil.

The Royal Free Sheila Sherlock Liver Centre and University Department of Surgery, Royal Free Hospital, London, UK.
American Journal of Transplantation (Impact Factor: 6.19). 07/2009; 9(8):1725-31. DOI: 10.1111/j.1600-6143.2009.02705.x
Source: PubMed

ABSTRACT Calcineurin inhibitors (CNIs) combined with steroids with or without azathioprine (AZA), have been a standard immunosuppression regimen after liver transplantation (LT). Since 2000 many centers have substituted AZA by mycophenolate mofetil (MMF). However, in LT the superiority of MMF over AZA is not clearly demonstrated. Therefore, we questioned the benefit of MMF versus AZA in LT with regard to rejection, renal dysfunction and hepatitis C virus (HCV) recurrence and survival. Using a literature search, relevant randomized controlled trials (RCT) and cohort studies were identified: two RCTs compared MMF to AZA only for acute rejection. Treated rejection was less with MMF in only one RCT (38.5% vs. 47.7%; p = 0.025), with no difference in patient and graft survival. No RCTs compared MMF and AZA in patients with CNI-related chronic renal dysfunction. Among two studies evaluating MMF, with substitution of AZA, one was stopped due to severe rejection. Recurrent HCV was less severe in 5/9 studies with AZA compared with 2/17 using MMF, six of which documented worse recurrence. Published data in LT show little, if any, clinical benefit of MMF versus AZA. RCTs should reevaluate AZA in LT. Evaluation of HCV replication and recurrence will be particularly important as AZA may have advantages over MMF.

0 Bookmarks
 · 
102 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Early results of a randomised trial showed reduced fibrosis due to recurrent HCV hepatitis with tacrolimus triple therapy (TT) versus monotherapy (MT) following transplantation for HCV cirrhosis. We evaluated the clinical outcomes after a median 8 years of follow-up, including differences in fibrosis assessed by collagen proportionate area (CPA). 103 consecutive liver transplant recipients with HCV cirrhosis receiving cadaveric grafts were randomised to tacrolimus MT (n=54) or TT (n=49) with daily tacrolimus (0.1 mg/kg divided dose), azathioprine (1 mg/kg) and prednisolone (20 mg), the last tailing off to zero by 6 months. Both groups had serial transjugular biopsies with hepatic venous pressure gradient (HVPG) measurement. Time to reach Ishak stage 4 was the predetermined endpoint. CPA was measured in all biopsies. Factors associated with HCV recurrence were evaluated. Clinical decompensation was the first occurrence of ascites/hydrothorax, variceal bleeding or encephalopathy. No significant preoperative, peri-operative or postoperative differences between groups were found. During 96 months median follow-up, stage 4 fibrosis was reached in 19 MT/11 TT with slower fibrosis progression in TT (p=0.009). CPA at last biopsy was 12% in MT and 8% in TT patients (p=0.004). 14 MT/ three TT patients reached HVPG≥10 mm Hg (p=0.002); 10 MT/three TT patients, decompensated. Multivariately, allocated MT (p=0.047, OR 3.23, 95% CI 1.01 to 10.3) was independently associated with decompensation: 14 MT/ seven TT died, and five MT/ four TT were retransplanted. Long term immunosuppression with tacrolimus, azathioprine and short term prednisolone in HCV cirrhosis recipients resulted in slower progression to severe fibrosis assessed by Ishak stage and CPA, less portal hypertension and decompensation, compared with tacrolimus alone. ISRCTN94834276: Randomised study for immunosuppression regimen in liver transplantation.
    Gut 10/2013; · 10.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Appropriate recipient selection of simultaneous liver-kidney transplantation (SLKT) remains controversial. In particular, data on liver graft survival in hepatitis C virus-infected (HCV+) SLKT recipients are lacking. We conducted a single-center, retrospective study of HCV+ SLKT recipients (N = 25) in comparison with HCV− SLKT (N = 26) and HCV+ liver transplantation alone (LTA, N = 296). Despite backgrounds of HCV+ and HCV− SLKT being similar, HCV+ SLKT demonstrated significantly impaired 5-year liver graft survival of 35% (HCV− SLKT, 79%, P = 0.004). Compared with HCV+ LTA, induction immunosuppression was more frequently used in HCV+ SLKT. Five-year liver graft survival rate for HCV+ SLKT was significantly lower than that for LTA (35% versus 74%, respectively, P < 0.001). Adjusted hazard ratio of liver graft loss in HCV+ SLKT was 4.9 (95% confidence interval 2.0–12.1, P = 0.001). HCV+ SLKT recipients were more likely to succumb to recurrent HCV and sepsis compared with LTA (32% versus 8.8%, P < 0.001 and 24% versus 8.8%, P = 0.030, respectively). Ten HCV+ SLKT recipients underwent anti-HCV therapy for recurrent HCV; only 1 achieved sustained virological response. HCV+ SLKT is associated with significantly decreased long-term prognosis compared with HCV− SLKT and HCV+ LTA. This article is protected by copyright. All rights reserved.
    Transplant International 03/2014; · 3.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This review aims to provide an update of the literature on the pharmacology and toxicology of mycophenolate in solid organ transplant recipients. Mycophenolate is now the antimetabolite of choice in immunosuppressant regimens in transplant recipients. The active drug moiety mycophenolic acid (MPA) is available as an ester pro-drug and an enteric-coated sodium salt. MPA is a competitive, selective and reversible inhibitor of inosine-5'-monophosphate dehydrogenase (IMPDH), an important rate-limiting enzyme in purine synthesis. MPA suppresses T and B lymphocyte proliferation; it also decreases expression of glycoproteins and adhesion molecules responsible for recruiting monocytes and lymphocytes to sites of inflammation and graft rejection; and may destroy activated lymphocytes by induction of a necrotic signal. Improved long-term allograft survival has been demonstrated for MPA and may be due to inhibition of monocyte chemoattractant protein 1 or fibroblast proliferation. Recent research also suggested a differential effect of mycophenolate on the regulatory T cell/helper T cell balance which could potentially encourage immune tolerance. Lower exposure to calcineurin inhibitors (renal sparing) appears to be possible with concomitant use of MPA in renal transplant recipients without undue risk of rejection. MPA displays large between- and within-subject pharmacokinetic variability. At least three studies have now reported that MPA exhibits nonlinear pharmacokinetics, with bioavailability decreasing significantly with increasing doses, perhaps due to saturable absorption processes or saturable enterohepatic recirculation. The role of therapeutic drug monitoring (TDM) is still controversial and the ability of routine MPA TDM to improve long-term graft survival and patient outcomes is largely unknown. MPA monitoring may be more important in high-immunological recipients, those on calcineurin-inhibitor-sparing regimens and in whom unexpected rejection or infections have occurred. The majority of pharmacodynamic data on MPA has been obtained in patients receiving MMF therapy in the first year after kidney transplantation. Low MPA area under the concentration time from 0 to 12 h post-dose (AUC0-12) is associated with increased incidence of biopsy-proven acute rejection although AUC0-12 optimal cut-off values vary across study populations. IMPDH monitoring to identify individuals at increased risk of rejection shows some promise but is still in the experimental stage. A relationship between MPA exposure and adverse events was identified in some but not all studies. Genetic variants within genes involved in MPA metabolism (UGT1A9, UGT1A8, UGT2B7), cellular transportation (SLCOB1, SLCO1B3, ABCC2) and targets (IMPDH) have been reported to effect MPA pharmacokinetics and/or response in some studies; however, larger studies across different ethnic groups that take into account genetic linkage and drug interactions that can alter a patient's phenotype are needed before any clinical recommendations based on patient genotype can be formulated. There is little data on the pharmacology and toxicology of MPA in older and paediatric transplant recipients.
    Archives of Toxicology 05/2014; · 5.22 Impact Factor

Full-text (2 Sources)

View
58 Downloads
Available from
May 22, 2014