Single-agent immunosuppression after liver transplantation: what is possible?

Recipient and Center Factors Associated With Immunosuppression Practice Beyond the First Year After Liver Transplantation and Impact on Outcomes

BACKGROUND

Immunosuppression is a critical aspect of post-transplant management, yet practices at intermediate and late time points after liver transplantation (LT) are poorly characterized.

METHODS

A retrospective cohort of 11 326 adult first LT alone recipients between 2007 and 2016 was identified by linking United Network for Organ Sharing transplant data to Medicare administrative claims. The immunosuppression regimen was obtained from Medicare billing claims. Factors associated with calcineurin inhibitor (CNI) monotherapy at 1-, 3-, and 5-y post-LT were investigated using mixed-effects logistic regression. Center practice heterogeneity was evaluated. The association of immunosuppression regimen (time-updating) with patient and graft survival was studied.

RESULTS

CNI monotherapy was used in 51.9% at 1-y post-LT and 68.6% at 5-y post-LT. Center-specific rates ranged from 20.0%-79.9% to 15.4%-95.2%, respectively. CNI monotherapy at 1- and 3-y post-LT was less likely among Black recipients ( P = 0.027 and P = 0.015 versus White, respectively). CNI plus antimetabolite was associated with improved adjusted patient (hazard ratio, 0.59; P < 0.001) and graft (hazard ratio, 0.62; P < 0.001) survival versus CNI monotherapy. The benefit of CNI plus antimetabolite on patient and graft survival increased with older age.

CONCLUSIONS

In this first longitudinal analysis of LT immunosuppression practices among Medicare beneficiaries, a CNI plus antimetabolite approach led to improved outcomes. Significant center heterogeneity in practice was observed.

Steroid-Mediated Decrease in Blood Mesenchymal Stem Cells in Liver Transplant could Impact Long-Term Recovery

Orthotopic liver transplant (OLT) remains the standard of care for end stage liver disease. To circumvent allo-rejection, OLT subjects receive gluococorticoids (GC). We investigated the effects of GC on endogenous mesenchymal stem (stromal) cells (MSCs) in OLT. This question is relevant because MSCs have regenerative potential and immune suppressor function. Phenotypic analyses of blood samples from 12 OLT recipients, at pre-anhepatic, anhepatic and post-transplant (2 h, Days 1 and 5) indicated a significant decrease in MSCs after GC injection. The MSCs showed better recovery in the blood from subjects who started with relatively low MSCs as compared to those with high levels at the prehepatic phase. This drop in MSCs appeared to be linked to GC since similar change was not observed in liver resection subjects. In order to understand the effects of GC on decrease MSC migration, in vitro studies were performed in transwell cultures. Untreated MSCs could not migrate towards the GC-exposed liver tissue, despite CXCR4 expression and the production of inflammatory cytokines from the liver cells. GC-treated MSCs were inefficient with respect to migration towards CXCL12, and this correlated with retracted cytoskeleton and motility. These dysfunctions were partly explained by decreases in the CXCL12/receptor axis. GC-associated decrease in MSCs in OLT recipients recovered post-transplant, despite poor migratory ability towards GC-exposed liver. In total, the study indicated that GC usage in transplant needs to be examined to determine if this could be reduced or avoided with adjuvant cell therapy.

Hepatocellular cancer and liver transplantation: a Western experience

Orthotopic liver transplantation is the preferred treatment option in patients with hepatocellular carcinoma developing in chronic liver disease. Unfortunately, based on classical transplantation criteria (Milan criteria), only a minority of patients with hepatocellular carcinoma are candidate to orthotopic liver transplantation. Major improvements in treatment strategy and surgical technique including the use of neoadjuvant locoregional therapies and progresses of post-transplant immunosuppressive treatment have contributed to safely expand transplantation criteria preserving acceptable surgical morbidity-mortality and good oncologic outcome. Further extension of transplantation criteria may have advantages including an increase in the number of transplant candidates and improvement of the prognosis of the disease and also disadvantages including an increase of surgical morbidity and deterioration of global oncologic outcome of orthotopic liver transplantation in hepatocellular carcinoma. In the future, identification of imaging or molecular prognostic markers could help to better define transplantation criteria.

Combination adjuvant chemotherapy with oxaliplatin, 5-fluorouracil and leucovorin after liver transplantation for hepatocellular carcinoma: a preliminary open-label study

The purpose of this study was to evaluate the efficacy of postoperative adjuvant chemotherapy with FOLFOX regimen on the outcome after LT for HCC patients who did not meet the Milan criteria. Ninety-five consecutive HCC patients with liver cirrhosis undergoing LT were enrolled. Fifty-eight who did not meet the Milan criteria were randomized to open-label treatment with or without adjuvant chemotherapy after LT (n = 29/group). The FOLFOX chemotherapy protocol comprised 3-week cycles of oxaliplatin 100 mg/m(2) on day 1, leucovorin (calcium folinate, CF) 200 mg/m(2) on day 1 followed by 3-day, and 5-fluorouracil (5-FU) 2000 mg/m(2) as a 48-h continuous infusion, for up to six courses in the 1st year after transplantation. Median survival was extended by 4.57 months by combination chemotherapy. The 1- and 3-year survival rates were 89.7% and 79.3% with chemotherapy versus 69.0% and 62.1% without chemotherapy. The cumulative 1-year survival was significantly increased by chemotherapy (log-rank test, P = 0.043). The 6-month tumor-free survival rate was 24.1% higher with chemotherapy than without. The recurrence rate after LT was significantly different between the two groups at 6 months (P = 0.036), but not at 3 years (P = 0.102). The chemotherapy regimen was generally well tolerated. Post-LT adjuvant chemotherapy with oxaliplatin/5-FU/CF could not prevent tumor recurrence post-LT but may contribute to improve the survival of HCC patients who do not meet the Milan criteria. These results should be verified in a larger sample with a longer follow-up period.

Daclizumab induction therapy in liver transplant recipients with renal insufficiency

BACKGROUND

The role of interleukin 2 (IL-2) receptor antibodies to avoid the nephrotoxic effects of calcineurin inhibitors in the early post-liver transplant (LT) period is not well defined.

AIM

To examine the use of daclizumab induction in LT recipients with renal insufficiency.

METHODS

Between 2002 and 2005, 62 patients (median pre-LT creatinine 2.4 mg/dL, IQR 1.9-3.7) received daclizumab induction with tacrolimus being administered when serum creatinine was <2.0 mg/dL. A concurrent comparison group (n = 221, 2002-2005) received tacrolimus-based immunosuppression without daclizumab (median pre-LT creatinine 1.1 mg/dL, IQR 0.9-1.4). A second historical comparison group (n = 103, 1995-2005) not receiving daclizumab was matched to the daclizumab patients by pre-LT serum creatinine (2.2 mg/dL, IQR 1.8-3.1). All patients received mycophenolate mofetil and steroids.

RESULTS

Serum creatinine improved in the daclizumab group (-1.0 mg/dL, IQR -2.2 to -0.4) and worsened in the concurrent comparison group (+0.2 mg/dL, IQR 0-0.5) from pre-LT to 4 months. However, there was no difference when daclizumab group was compared with the historical comparison group matched on pre-LT creatinine (median change: -0.8 mg/dL vs. -0.7 mg/dL). Daclizumab induction was not associated with improvement in renal function at 4 months (P = 0.34) after adjusting for pre-LT creatinine, age, gender, hepatitis C status and simultaneous liver kidney transplantation.

CONCLUSION

The incremental benefit offered by induction therapy with IL-2 receptor antibodies to preserve renal function is questionable.

Outcome of recurrent hepatitis C virus after liver transplantation in a randomized trial of tacrolimus monotherapy versus triple therapy

Less potent immunosuppression is considered to reduce the severity of hepatitis C virus (HCV) recurrence after liver transplantation. An optimal regimen is unknown. We evaluated tacrolimus monotherapy versus triple therapy in a randomized trial of 103 first transplants for HCV cirrhosis. One hundred three patients who underwent transplantation for HCV were randomized to tacrolimus monotherapy (n = 54) or triple therapy with tacrolimus, azathioprine, and steroids (n = 49), which were tapered to zero by 3 to 6 months. Both groups had serial transjugular biopsies with hepatic venous pressure gradient (HVPG) measurement. The time to reach Ishak stage 4 was the predetermined endpoint. All factors documented in the literature as being associated with HCV recurrence and the allocated treatment were evaluated for reaching stage 4 and HVPG >or= 10 mm Hg. No significant preoperative, perioperative, or postoperative differences, including the frequency of biopsies between groups, were found. During a mean follow-up of 53.5 months, 9 monotherapy patients and 6 triple therapy patients died, and 5 monotherapy patients and 4 triple therapy patients underwent retransplantation. Stage 4 fibrosis was reached in 17 monotherapy patients and 10 triple therapy patients (P = 0.04), with slower fibrosis progression in the triple therapy patients (P = 0.048). Allocated therapy and histological acute hepatitis were independently associated with stage 4 fibrosis. HVPG increased to >or=10 mm Hg more rapidly in monotherapy patients versus triple therapy patients (P = 0.038). In conclusion, long-term maintenance immunosuppression with azathioprine and shorter term prednisolone with tacrolimus in HCV cirrhosis recipients resulted in a slower onset of histologically proven severe fibrosis and portal hypertension in comparison with tacrolimus alone, and this was independent of known factors affecting fibrosis.

Calcineurin inhibitor minimization in pediatric liver allograft recipients

The use of CNI in pediatric LTx has dramatically improved the outcome for children with end-stage liver disease by significantly reducing the rate of acute and chronic rejection. Long-term concerns about CNI-induced nephrotoxicity and other adverse effects remain an issue, particularly as the emphasis moves from short-term survival to long-term quality of life. This review summarizes lessons learnt from pediatric and adult solid organ transplantation in minimizing CNI use in immunosuppression protocols in children following LTx. There are three models for CNI minimization: dose reduction, withdrawal or avoidance, supplemented by the use of IL-2 receptor blocking antibodies in the peri-transplant period, and early transition to alternate drugs such as MMF or SRL. Prospective studies evaluating reduction or withdrawal protocols in adult and pediatric LTx indicate that rejection rates are comparable with traditional CNI-based immunosuppression and that two and five yr patient and graft survival are similar, with recovery in renal function. There are few studies evaluating complete avoidance of CNI, apart from that in renal transplantation, although the benefits of long-term reduction in cardiovascular, metabolic, and possibly neoplastic side effects may justify this approach. It is not clear yet how CNI minimization will affect the development of tolerance but experimental and preliminary clinical studies indicate that CNI and steroid avoidance or minimization in the peri-operative period may favor the development of long-term graft tolerance. In summary, CNI minimization may be safe and effective in the short term but large-scale pediatric randomized studies are required to evaluate the long-term efficacy of these regimes in the development of chronic rejection, PTLD, and graft tolerance.

Rejection rates in a randomised trial of tacrolimus monotherapy versus triple therapy in liver transplant recipients with hepatitis C virus cirrhosis

BACKGROUND

Reducing immunosuppression not only reduces complications but also may lessen recurrent hepatitis C virus (HCV) infection after liver transplantation.

PATIENTS/METHODS

HCV-infected cirrhotic patients randomised to tacrolimus monotherapy (MT) or triple therapy (TT) using tacrolimus 0.1 mg/kg/day, azathioprine 1 mg/kg/day, and prednisolone 20 mg/day, tapering over 3 months.

RESULTS

Twenty-seven patients (MT) and 29 (TT)--median follow up 661 days (range, 1-1603). Rejection episodes (protocol/further biopsies) within first 3 months and use of empirical treatment were evaluated. New rejection was diagnosed if repeat biopsy (5-day interval) did not show improvement. Treated rejection episodes: 20 MT (15 biopsy-proven) vs. 24 TT (21 biopsy-proven), with 19 (MT) vs. 24 (TT) methylprednisolone boluses. Overall: 35 episodes (MT) and 46 (TT). Fewer MT patients had histological rejection (70%) than TT patients (86%), with fewer episodes of rejection (18.5% vs. 10%), and more moderate rejection (22% vs. 41%). The MT group had higher early tacrolimus levels. Rates of renal dysfunction, retransplantation, and death were not significantly different.

CONCLUSION

Tacrolimus monotherapy is a viable immunosuppressive strategy in HCV-infected liver transplant recipients.

Immunosuppression: evolution in practice and trends, 1994-2004

Over the last 10 years, there have been important changes in immunosuppression management and strategies for solid-organ transplantation, characterized by the use of new immunosuppressive agents and regimens. An organ-by-organ review of OPTN/SRTR data showed several important trends in immunosuppression practice. There is an increasing trend toward the use of induction therapy with antibodies, which was used for most kidney, pancreas after kidney (PAK), simultaneous pancreas-kidney (SPK) and pancreas transplant alone (PTA) recipients in 2004 (72-81%) and for approximately half of all intestine, heart and lung recipients. The highest usage of the tacrolimus/mycophenolate mofetil combination as discharge regimen was reported for SPK (72%) and PAK (64%) recipients. Maintenance of the original discharge regimen through the first 3 years following transplantation varied significantly by organ and drug. The usage of calcineurin inhibitors for maintenance therapy was characterized by a clear transition from cyclosporine to tacrolimus. Corticosteroids were administered to the majority of patients; however, steroid-avoidance and steroid-withdrawal protocols have become increasingly common. The percentage of patients treated for acute rejection during the first year following transplantation has continued to decline, reaching 13% for those who received a kidney in 2003, 48% of which cases were treated with antibodies.

Infusion of nonmyeloablative bone marrow alleviates acute rejection reaction in liver allotransplantation

OBJECTIVE

To study the effect and implication of nonmyeloablative donor specific bone marrow (DSBM) infusion on the immunoreaction of liver allotransplantation.

METHODS

Orthotopic liver transplantation model was used in this study. Groups were set as follows: Group I, syngeneic control (Wistar-to-Wistar); Group II, acute rejection (SD-to-Wistar); Group III, acute rejection treated with cyclosporine A (CsA) by intramuscular injection (SD-to-Wistar+CsA); Group IV, bone marrow infusion at 7 d pretransplantation followed by short-term CsA treatment (SD-to-Wistar+DSBM); Another group of short-term CsA treatment preoperatively without bone marrow infusion was also set as control. General characteristics and survival time were observed. Histological grades of rejection were determined by pathological examination. IL-2 and IFN-gamma level in peripheral blood and donor liver were detected respectively by Enzyme-Linked Immuno-Sorbent Assay (ELISA) and Western blot. Chimerism of donor cells was measured by PCR for a male-specific marker (Y-chromosome-specific sequence, Sry).

RESULTS

No signs of rejection were found in Group I. Acute rejection occurred in both Group II and the short-term CsA treated group. All the recipients died at (9-15) d posttransplantation with a median survival time of (10.7+/-0.5) d and (11.2+/-2.4) d, respectively. Only mild rejection could be seen in Group III. In Group IV, 4 out of 6 recipients had long-term survival (>100 d), the histological grade of rejection was significantly lower than that of Group II, so did the expression level of IL-2 and IFN-gamma in both peripheral blood and grafted liver. Y-chromosome-specific sequence (Sry) of male SD rats could be detected in the bone marrow, spleen and thymus of female recipients at 15 d after bone marrow infusion.

CONCLUSION

Mild preconditioning nonmyeloablative donor specific bone marrow infusion can enhance chimerism formation in recipients, alleviate the rejection of liver allotransplantation and prolong survival of liver allotransplantation.

Apo2L/TRAIL differentially modulates the apoptotic effects of sulindac and a COX-2 selective non-steroidal anti-inflammatory agent in Bax-deficient cells

The nonsteroidal anti-inflammatory drugs (NSAIDs) are believed to mediate their anticancer effects by inducing apoptosis but the molecular mechanisms of their apoptotic effects remain largely unknown. Here we report that two different NSAIDs, sulindac sulfide and SC-'236 engage the death receptor 5 (DR5) and mitochondrial pathways to mediate apoptosis in human colon cancer cells. We show that sulindac sulfide and SC-'236-induced apoptosis is coupled with upregulation of DR5, caspase 8 activation and Bid cleavage. Thus, a cross talk appears to exist between the DR5 and mitochondrial pathways during apoptosis induced by these NSAIDs. We further show that sulindac sulfide and SC-'236-induced DR5 upregulation occurs independent of the COX inhibitory effects of these NSAIDs. Using Bax-proficient (Bax+/-) and Bax-deficient (Bax-/-) HCT116 human colon cancer cells, we further demonstrate that Apo2L/TRAIL differentially modulates the apoptotic effects of sulindac sulfide and SC-'236. For example, sulindac sulfide upregulates DR5 in both Bax-deficient and proficient cells, but Apo2L/TRAIL efficiently potentiates sulindac sulfide-induced apoptosis as well as activation of caspase-8, -9 and -3 only in Bax-proficient cells. SC-'236 also upregulates DR5 in both Bax-proficient and Bax-deficient cells but Apo2L/TRAIL potentiates SC-'236-mediated apoptosis and caspases-8 and -3 activation in both Bax-proficient and Bax-deficient cells. Further, in Bax-deficient cells, neither sulindac sulfide nor SC-'236 in combination with Apo2L/TRAIL effectively promotes the release of cytochrome c from mitochondria into cytosol and caspase-9 activation. Collectively, our results suggest that unlike sulindac sulfide, SC-'236 in combination with Apo2L/TRAIL can overcome Bax deficiency to induce apoptosis. These results have important clinical implications in that the tumors harboring Bax mutations are likely to develop resistance to sulindac but not to SC-'236-like NSAIDs. In conclusion, the data presented herein form the basis of future in-depth studies to further explore the utility of Apo2L/TRAIL and NSAIDs, in combination, as a novel cancer preventive/therapeutic strategy.