Impact of immunosuppression minimization and withdrawal in long-term hepatitis C virus liver transplant recipients

AIM:To investigate the effects of different immunosuppressive regimens and avoidance on fibrosis progression in hepatitis C virus(HCV)liver transplant(LT)recipients.METHODS:We retrospectively compared the liver biopsies of well-matched HCV LT recipients under calcineurin inhibitors(CNI group,n=21)and mycophenolate(MMF group,n=15)monotherapy,with those patients who successfully withdrawn immunosuppression(IS)therapy from at least 3 years(TOL group,n=10).To perform the well-matched analysis,all HCV transplanted patients from December 1993 were screened.Only those HCV patients who reached the following criteria were considered for the analysis:(1)at least3 years of post-operative follow-up;(2)patients with normal liver graft function under low dose CNI monotherapy(CNI group);(3)patients with normal liver graft function under antimetabolite(Micophenolate Mofetil or coated mycophenolate sodium)monotherapy(MMF group);and(4)recipients with normal liver function without any IS.We excluded from the analysis recipients who were IS free or under monotherapy for<36 mo,recipients with cirrhosis or with unstable liver function tests.RESULTS:Thirty six recipients were enrolled in the study.Demographics,clinical data,time after LT and baseline liver biopsies were comparable in the three groups.After six years of follow-up,there was no worsening of hepatic fibrosis in the MMF group(2.5±1.5Ishak Units vs 2.9±1.7 Ishak Units,P=0.5)and TOL group(2.7±10.7 vs 2.5±1.2,P=0.2).In contrast,a significant increase in the fibrosis score was observed in the CNI group(2.2±1.7 vs 3.9±1.6,P=0.008).The yearly fibrosis progression rate was significantly worse in the CNI group(0.32±0.35)vs MMF group(0.03±0.31,P=0.03),and TOL group(-0.02±0.27,P=0.02).No differences have been reported in grading scores for CNI group(2.79±1.9,P=0.7),MMF group(3.2±1.5,P=0.9)and TOL group(3.1±1.4,P=0.2).Twenty four patients were treated with low dose ribavirin(8TOL,7 MMF,9 CNI).The hepatitis C titers were comparable in the three groups.No episodes of rejection have been reported despite differences of liver function test in the three groups during the observational period.CONCLUSION:IS withdrawal and MMF monotherapy is safe and seems to be associated with the slowest fibrosis progression in HCV LT recipients.