Successful combined partial auxiliary liver and kidney transplantation in highly sensitized cross-match positive recipients

From immunosuppression to tolerance

The past three decades have seen liver transplantation becoming a major therapeutic approach in the management of end-stage liver diseases. This is due to the dramatic improvement in survival after liver transplantation as a consequence of the improvement of surgical and anaesthetic techniques, of post-transplant medico-surgical management and of prevention of disease recurrence and other post-transplant complications. Improved use of post-transplant immunosuppression to prevent acute and chronic rejection is a major factor in these improved results. The liver has been shown to be more tolerogenic than other organs, and matching of donor and recipients is mainly limited to ABO blood group compatibility. However, long-term immunosuppression is required to avoid severe acute and chronic rejection and graft loss. With the current immunosuppression protocols, the risk of acute rejection requiring additional therapy is 10-40% and the risk of chronic rejection is below 5%. However, the development of histological lesions in the graft in long-term survivors suggest atypical forms of graft rejection may develop as a consequence of under-immunosuppression. The backbone of immunosuppression remains calcineurin inhibitors (CNI) mostly in association with steroids in the short-term and mycophenolate mofetil or mTOR inhibitors (everolimus). The occurrence of post-transplant complications related to the immunosuppressive therapy has led to the development of new protocols aimed at protecting renal function and preventing the development of de novo cancer and of dysmetabolic syndrome. However, there is no new class of immunosuppressive drugs in the pipeline able to replace current protocols in the near future. The aim of a full immune tolerance of the graft is rarely achieved since only 20% of selected patients can be weaned successfully off immunosuppression. In the future, immunosuppression will probably be more case oriented aiming to protect the graft from rejection and at reducing the risk of disease recurrence and complications related to immunosuppressive therapy. Such approaches will include strategies aiming to promote stable long-term immunological tolerance of the liver graft.

Incidence and impact of rejection following simultaneous liver-kidney transplantation

BACKGROUND & AIMS

Due to hepatic immunoregulation, simultaneous liver-kidney recipients are presumed to be reasonably protected from kidney rejection and typically receive less immunosuppression compared to kidney transplants alone. However, data to support these conclusions and practices are sparse.

METHODS

We characterized the incidence and types of rejection, graft function, and graft and patient survival in a large population of simultaneous liver-kidney recipients (n=140) with long-term follow-up at our centre (1998-2010).

RESULTS

Acute cellular, antibody-mediated, and chronic kidney rejection was diagnosed in 9 (6.4%), 2 (1.4%), and 1 (0.7%) patient, respectively. Borderline acute kidney rejection was diagnosed in another 16 patients (11.4%). Acute cellular liver rejection occurred in 16 (11.4%) and chronic liver rejection in 4 (2.9%). One-, three-, and five-year patient survival was 86.4%, 78.0%, and 74.0%, respectively, and did not significantly differ by presence or absence of kidney or liver rejection. However, kidney rejection was associated with decreased renal function by lower serum GFR over time (p=0.003).

CONCLUSIONS

Various forms of kidney rejection occurred in ∼20% of our simultaneous liver-kidney recipients and were associated with deterioration in graft function, indicating that the liver may not confer complete protective allo-immunity. More stringent graft monitoring and management strategies, perhaps more akin to kidney transplant alone, should be prospectively studied in simultaneous liver-kidney recipients.

Combined liver and lung transplantation with extended normothermic lung preservation in a patient with end-stage emphysema complicated by drug-induced acute liver failure

Isolated lung transplantation (LuTx) and liver transplantation are established treatments for irreversible lung and liver failure. Combined liver and lung transplantation (cLiLuTx) is a less common, but approved therapy of combined organ failure, mostly applied in patients suffering from progressive cystic fibrosis and advanced liver disease. We report a patient who was listed for LuTx due to end-stage chronic obstructive pulmonary disease and who developed drug-induced acute hepatic failure. The only therapeutic option was hyper-urgent cLiLuTx. To correct the poor coagulation in order to reduce the per-operative risk of bleeding, the liver was transplanted first. In anticipation of the longer lung preservation time, cold flushed lungs were preserved on a portable lung perfusion device for ex vivo normothermic perfusion for 11 h 15 min, transplanted sequentially off-pump, and reperfused after a total ex vivo time of 13 h 32 min and 16 h for the first and second lung, respectively. Ten months later, the patient is doing well and no rejection occurred. Normothermic ex vivo lung perfusion may help to prolong preservation time, facilitating long-distance transport and combined organ transplantation.

Combined liver and kidney transplantation in children

Simultaneous combined liver-kidney transplantation (CLKT) is a rare operation in pediatric patients so that annually only 10-30 operations are performed worldwide. The main indications for CLKT are primary hyperoxaluria type 1 and autosomal recessive polycystic kidney disease. In addition, CLKT is indicated in individual patients with metabolic or cirrhotic liver diseases and end-stage kidney disease. The surgery and immediate post-operative management of CLKT remain challenging in infants and small children. The patients should be operated on before they become severely ill or develop major systemic manifestations of their metabolic disorder. The liver allograft is immunologically protective of the kidney graft in simultaneous CLKT, often resulting in well-preserved kidney function. The long-term outcome after CLKT is nowadays comparable to that of isolated liver and kidney transplantations.

Antibody-mediated rejection in liver transplantation: current controversies and future directions

Interest in the role of donor-specific human leukocyte antibodies in liver transplantation has been rekindled recently. Emerging evidence suggests that these antibodies may cause injury to the liver allograft. Here we review the clinical literature, highlight controversial results, and propose a path forward for the definition and better understanding of antibody-mediated injury to the liver.

Excessive immunosuppression as a potential cause of poor survival in simultaneous liver/kidney transplantation for hepatitis C

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% vs. 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% vs. 8.8%, P < 0.001 and 24% vs. 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.

Issues in solid-organ transplantation in children: translational research from bench to bedside

In this review, we identify important challenges facing physicians responsible for renal and cardiac transplantation in children based on a review of the contemporary medical literature. Regarding pediatric renal transplantation, we discuss the challenge of antibody-mediated rejection, focusing on both acute and chronic antibody-mediated rejection. We review new diagnostic approaches to antibody-mediated rejection, such as panel-reactive antibodies, donor-specific cross-matching, antibody assays, risk assessment and diagnosis of antibody-mediated rejection, the pathology of antibody-mediated rejection, the issue of ABO incompatibility in renal transplantation, new therapies for antibody-mediated rejection, inhibiting of residual antibodies, the suppression or depletion of B-cells, genetic approaches to treating acute antibody-mediated rejection, and identifying future translational research directions in kidney transplantation in children. Regarding pediatric cardiac transplantation, we discuss the mechanisms of cardiac transplant rejection, including the role of endomyocardial biopsy in detecting graft rejection and the role of biomarkers in detecting cardiac graft rejection, including biomarkers of inflammation, cardiomyocyte injury, or stress. We review cardiac allograft vasculopathy. We also address the role of genetic analyses, including genome-wide association studies, gene expression profiling using entities such as AlloMap®, and adenosine triphosphate release as a measure of immune function using the Cylex® ImmuKnow™ cell function assay. Finally, we identify future translational research directions in heart transplantation in children.

Matching donor to recipient in liver transplantation: Relevance in clinical practice

Achieving optimum outcomes after liver transplantation requires an understanding of the interaction between donor, graft and recipient factors. Within the cohort of patients waiting for a transplant, better matching of the donor organ to the recipient will improve transplant outcomes and benefit the overall waiting list by minimizing graft failure and need for re-transplantation. A PubMed search was conducted to identify published literature investigating the effects of donor factors such as age, gender, ethnicity, viral serology; graft factors such as size and quality, recipient factors such as age, size, gender and transplant factors such as major or minor blood group incompatibility and immunological factors. We also report technical and therapeutic modifications that can be used to manage donor-recipient mismatch identified from literature and the authors’ clinical experience. Multiple donor and recipient factors impact graft survival after liver transplantation. Appropriate matching based on donor-organ-recipient variables, modification of surgical technique and innovative peri-transplant strategies can increase the donor pool by utilizing grafts from marginal donors that are traditionally turned down.

Liver transplant tolerance and its application to the clinic: can we exploit the high dose effect?

The tolerogenic properties of the liver have long been recognised, especially in regard to transplantation. Spontaneous acceptance of liver grafts occurs in a number of experimental models and also in a proportion of clinical transplant recipients. Liver graft acceptance results from donor antigen-specific tolerance, demonstrated by the extension of tolerance to other grafts of donor origin. A number of factors have been proposed to be involved in liver transplant tolerance induction, including the release of soluble major histocompatibility (MHC) molecules from the liver, its complement of immunosuppressive donor leucocytes, and the ability of hepatocytes to directly interact with and destroy antigen-specific T cells. The large tissue mass of the liver has also been suggested to act as a cytokine sink, with the potential to exhaust the immune response. In this review, we outline the growing body of evidence, from experimental models and clinical transplantation, which supports a role for large tissue mass and high antigen dose in the induction of tolerance. We also discuss a novel gene therapy approach to exploit this dose effect and induce antigen-specific tolerance robust enough to overcome a primed T cell memory response.

Preformed class II donor-specific antibodies are associated with an increased risk of early rejection after liver transplantation

Preformed donor-specific human leukocyte antigen antibodies (DSAs) are considered a contraindication to the transplantation of most solid organs other than the liver. Conflicting data currently exist on the importance of preformed DSAs in rejection and patient survival after liver transplantation (LT). To evaluate preformed DSAs in LT, we retrospectively analyzed prospectively collected samples from all adult recipients of primary LT without another organ from January 1, 2000 to May 31, 2009 with a pre-LT sample available (95.8% of the patients). Fourteen percent of the patients had preformed class I and/or II DSAs with a mean fluorescence intensity (MFI) ≥ 5000. Preformed class I DSAs with an MFI ≥ 5000 remained persistent in only 5% of patients and were not associated with rejection. Preformed class II DSAs with an MFI of 5000 to 10,000 remained persistent in 23% of patients, and this rate increased to 33% for patients whose MFI was ≥10,000 (P < 0.001). Preformed class II DSAs in multivariable Cox proportional hazards modeling were associated with an increased risk of early rejection [hazard ratio (HR) = 1.58; p = 0.004]. In addition, multivariate modeling showed that in comparison with no DSAs (MFI < 1000), preformed class I and/or II DSAs with an MFI ≥ 5000 were independently correlated with the risk of death (HR = 1.51; p = 0.02).

Impact of donor-specific antibodies on results of liver transplantation

PURPOSE OF REVIEW

To critically examine the recent literature evaluating the importance of HLA donor-specific antibody (DSA) impact on liver transplant and simultaneous liver-kidney transplant (SLKT) outcomes.

RECENT FINDINGS

Many preformed DSAs, especially of low mean fluorescence intensity (MFI), are absorbed by the liver at transplant. However, patients with post-liver transplant DSA, especially of higher MFI, are at increased risk of acute and chronic rejection. C4d staining, when positive, may be helpful but lacks sensitivity especially in formalin tissue. SLKT recipients may need close follow-up when class II DSA is found, as the liver protects the kidney from hyperacute rejection, but can still cause early renal antibody-mediated rejection, liver allograft rejection, and impair patient, liver allograft, and renal allograft survival.

SUMMARY

Some DSAs are relevant in liver transplant and can lead to acute and chronic allograft rejection. However, before clinical practice patterns can change we must create unified diagnostic criteria, define the pathologic potential of different DSAs, and improve the specificity of current testing.

Four-year allograft survival in a highly sensitized combined liver-kidney transplant patient despite unsuccessful anti-HLA antibody reduction with rituximab, splenectomy, and bortezomib

Although donor-specific lymphocytotoxic antibodies are regarded as a contraindication for kidney transplantation (KTx), the data available for liver or combined liver or kidney transplantation (cLKTx) are scarce. Here, we report a case of a highly sensitized young man receiving his sixth liver and second kidney graft. Multiple anti-HLA antibodies were present at the time of transplantation. As a result of suspected antibody-mediated graft damage, the patient was treated with rituximab, plasmapheresis, intravenous immunoglobulins, splenectomy, and bortezomib to decrease the antibody production. So far, patient and allograft survival has reached 4 years despite failure to achieve a permanent reduction of anti-HLA antibodies, and particularly nondonor directed antibodies.

Combined heart and liver transplant attenuates cardiac allograft vasculopathy compared with isolated heart transplantation

BACKGROUND

We evaluated whether combined heart and liver transplant (H+LTx) can protect the heart graft from the development of cardiac allograft vasculopathy using coronary three-dimensional (3D) volumetric intravascular ultrasound (IVUS).

METHODS

From 2004 to 2009, we identified 24 isolated heart transplant (HTx) and 10 H+LTx recipients in whom two coronary 3D IVUS studies were performed 1 year apart. Baseline 3D IVUS was performed at 0.22 (0.17-1.16) years after transplantation, with follow-up 3D IVUS exams performed after baseline exam (0.96 [0.83-1.08]).

RESULTS

Rate of plaque volume and plaque index (plaque volume/vessel volume) progression was attenuated in the H+LTx group (0.3±1.1 vs. 1.5±2.9 mm/mm; P=0.08 and 0.01±0.03 vs. 0.1±0.1; P=0.004, respectively). Rejection burden was much lower in the H+LTx patients. Outcome analysis in 66 consecutive patients (56 HTx and 10 H+LTx) was performed irrespective of performance of second coronary IVUS. H+LTx was associated with reduced rate of cardiac events (P=0.04), which remained significant when adjusted for the difference in the primary etiology for heart disease (P=0.05).

CONCLUSIONS

Our preliminary serial 3D coronary IVUS data show that H+LTx attenuates cardiac allograft vasculopathy by decreasing the rate of plaque volume and plaque index progression and improves coronary-related outcomes. Because of the small numbers and the differences in etiology of heart disease, our data should be interpreted cautiously, and larger clinical trials would be required to recommend H+LTx for improved coronary remodeling.

Class II alloantibody and mortality in simultaneous liver-kidney transplantation

Hyperacute kidney rejection is unusual in crossmatch positive recipients of simultaneous liver-kidney transplants (SLKT). However, recent data suggest that these patients remain at risk for antibody-mediated kidney rejection. To further investigate the risk associated with donor-specific alloantibodies (DSA) in SLKT, we studied 86 consecutive SLKT patients with an available pre-SLKT serum sample. Serum samples were analyzed in a blinded fashion for HLA DSA using single antigen beads (median florescence intensity≥2,000=positive). Post-SLKT samples were analyzed when available (76%). Thirty patients had preformed DSA, and nine developed de novo DSA. Preformed class I DSA did not change the risk of rejection, patient or allograft survival. In contrast, preformed class II DSA was associated with a markedly increased risk of renal antibody mediated rejection (AMR) (p=0.006), liver allograft rejection (p=0.002), patient death (p=0.02), liver allograft loss (p=0.02) and renal allograft loss (p=0.045). Multivariable modeling showed class II DSA (preformed or de novo) to be an independent predictor of patient death (HR=2.2; p=0.043) and liver allograft loss (HR=2.2; p=0.044). These data warrant reconsideration of the approach to DSA in SLKT.

Incompatible kidney transplantation: a brief overview of the past, present and future

Live kidney donor transplantation across immunological barriers, either blood group or positive crossmatch [ABO- and human leucocyte antigens (HLA)-incompatible kidney transplantation, respectively], is now practised widely across many transplant centres. This provides transplantation opportunities to patients that hitherto would have been deemed contra-indicated and would subsequently have waited indefinitely for a suitably matched kidney. Protocols have evolved with time as experience has grown and now a variety of desensitization strategies are currently practised to overcome such immunological barriers. In addition, desensitization protocols are complemented by kidney paired donation exchange schemes and therefore incompatible patients now have strategies to either confront or bypass immunological barriers, respectively. As the field expands it is clear that non-transplant clinicians will be exposed to incompatible kidney transplant recipients outside of experienced centres. It is therefore timely to review the evolution of practice that have led to current desensitization modalities, contrast protocols and outcomes of current regimens and speculate on future direction of incompatible kidney transplantation.

Sequential liver-kidney transplantation in a boy with congenital hepatic fibrosis and nephronophthisis from a living donor

A five-yr-old boy developed chronic liver failure and ESKD because of CHF and juvenile NPHP. He underwent sequential liver and kidney transplantation with a compatible blood type from his father, at five yr, seven months and five yr, 11 months old, respectively. Because the patient was not in ESKD, we initially performed LDLT because of significant portal hypertension. Even after LDLT, his ascites was not ameliorated, and he needed continuous drainage of ascites and daily albumin and gamma globulin infusion. Thereafter, he progressed to ESKD and needed hemodialysis for one month before LDKT. CDC crossmatch for donor B cells in the warm test, FCXM for B cell IgG, and flow PRA for donor class II were positive before LDKT. After pretreatment of three courses of plasma exchange and intravenous gamma globulin, LDKT was performed. Two weeks after LDKT, AIHA concomitant with autoimmune thrombocytopenia, also called Evans syndrome, occurred because of passenger lymphocytes from the donor; however, the patient was successfully treated with intravenous methylprednisolone. Eighteen months have passed since LDKT, and liver and kidney function in both the recipient and donor are normal.

Prevalence, course and impact of HLA donor-specific antibodies in liver transplantation in the first year

The presence of preformed donor-specific HLA antibodies (DSA) in liver transplant recipients is increasingly recognized; however, the prevalence of DSA and their impact on early allograft function remains unknown. We prospectively followed serum DSA levels of 90 consecutive liver transplant recipients from baseline to 4 months. Twenty recipients (22.2%) had preformed DSA. No antibody-targeting treatments were undertaken. Seven days after transplantation, DSA levels decreased markedly in all but three patients. Day 7 protocol biopsies showed diffuse C4d deposition along the portal stroma, central vein, subendothelial and stromal space in the patients with persistent high DSA levels. The rate of acute cellular rejection was not significantly different in patients with DSA. The transaminase and bilirubin levels remained comparable during the first year despite the presence of DSA. The three patients with persistently high DSA levels continue to have normal allograft function. We conclude that in most cases, DSA disappear after liver transplant, however in rare instances where they persist, there is evidence of complement activation in the liver allograft, without significant clinical impact in the first year.

Auxiliary liver transplantation in children

PURPOSE OF REVIEW

Auxiliary liver transplantation (ALT) has developed as a technique for treating patients with acute liver failure. The surgical techniques of ALT have been refined and current patient survival appears to be similar to that observed with conventional liver replacement for acute liver failure.

RECENT FINDINGS

Our understanding of liver regeneration has improved with experience and it is possible to identify patient and disease groups that are more likely to regenerate and wean off immunosuppression after ALT. Withdrawal of immunosuppression is possible in at least two thirds of survivors up to 4 years post transplant. Young patients have most to gain in the long term from immunosuppression withdrawal. Documentation of liver regeneration should be performed by liver histology, nuclear medicine scanning and CT volumetry. Weaning should be gradual to allow for graft atrophy to avoid complications. ALT has also been utilised for the management of inborn errors of metabolism based in the liver and for other rare problems and these will be briefly addressed in the review.

SUMMARY

Auxiliary liver transplantation should be considered for the treatment of children with acute liver failure satisfying current criteria for liver transplantation.

Modifiers of complement activation for prevention of antibody-mediated injury to allografts

PURPOSE OF REVIEW

Improvements in prevention and management of cellular rejection of solid organ transplants, coupled with increasing numbers of sensitized patients, have focused attention on antibody-mediated rejection (AbMR). Complement is a critical component of AbMR, in addition to interfacing between innate and adaptive immunity and the coagulation cascade. This article reviews complement biology and strategies to overcome complement in AbMR, cognisant that antibody can act independently of complement.

RECENT FINDINGS

The past decade has witnessed an improvement in the prevention and treatment of AbMR as a result of solid-phase assays to determine antibody specificity, definition of histopathological criteria, and use of plasmapheresis and/or intravenous immunoglobulin (IVIG). Nonetheless, AbMR continues to impact adversely on short- and long-term graft survival. Use of B and/or T-lymphocyte-depleting therapies has not shown measurable benefit, and the need remains for therapies that deplete antibody, or provide better protection from complement-mediated damage. Disordered complement activity in human diseases such as paroxysmal nocturnal haemoglobinuria, has provided additional impetus to pursuing therapeutic complement inhibition. Preliminary data from C5 inhibition with eculizumab in the treatment and prevention of AbMR have shown promise. Trials with recombinant human inhibitors of C1 (effective in angioedema) to prevent or treat AbMR are beginning.

SUMMARY

Despite current limitations, 'protection' of the transplant through plasmapheresis and/or IVIG enables many allografts to survive in sensitized recipients. Elucidating the pathways mediating graft acceptance, by constitutive antibody deletion, or 'accommodation' (wherein donor organ remains uninjured despite antibody binding), or other local protective mechanism(s), is an equally important challenge in the quest to overcome AbMR.

Significance of complement split product C4d in ABO-compatible liver allograft: diagnosing utility in acute antibody mediated rejection

Diagnosis of liver allograft antibody-mediated rejection (AMR) is difficult and requires a constellation of clinical, laboratory and histologic features that support the disease and exclude other causes. Histologic features of AMR may intermix with those of biliary obstruction, preservation/reperfusion injury, and graft ischemia. Tissue examination for complement degradation product 4d (C4d) has been proved to support this diagnosis in other allografts. For this reason, we conducted a retrospective review of all ABO compatible/identical re-transplanted liver patients with primary focus on identifying AMR as a possible cause of graft failure and to investigate the utility of C4d in liver allograft specimens. We reviewed 193 liver samples obtained from 53 consecutive ABO-compatible re-transplant patients. 142 specimens were stained with C4d. Anti-donor antibody screening and identification was determined by Luminex100 flow cytometry. For the study analysis, patients were stratified into 3 groups according to time to graft failure: group A, patients with graft failure within 0-7 days (n=7), group B within 8-90 days (n=13) and C >90 days (n=33). Two patients (3.7%) met the diagnostic criteria of acute AMR. Both patients experienced rapid decline of graft function with presence of donor specific antibodies (DSA), morphologic evidence of humoral rejection and C4d deposition in liver specimens. C4d-positive staining was identified in different medical liver conditions i.e., acute cellular rejection (52%), chronic ductopenic rejection (50%), recurrent liver disease (48%), preservation injury (18%), and hepatic necrosis (54%). Univariate analysis showed no significant difference of C4d-positive staining among the 3 patients groups, or patients with DSA (P>.05). In conclusion, AMR after ABO-compatible liver transplantation is an uncommon cause of graft failure. Unlike other solid organ allografts, C4d-positive staining is not a rugged indicator of humoral rejection, thus, interpretation should be done with caution to avoid diagnostic dilemmas.

Combined liver-kidney transplants: allosensitization and recipient outcomes

BACKGROUND

A pretransplant positive crossmatch in combined liver kidney transplants (CLK) is not considered a contraindication based on the reported immunoprotection conferred by the liver allograft. However, antibody-mediated rejection of the kidney in CLK has been reported recently. This prompted our study to investigate the impact of presensitization on CLK recipient outcomes.

METHODS

We examined kidney allograft and patient survival by indication of sensitization using Scientific Registry of Transplant Recipients data on CLK performed from 1995 to 2008. We defined sensitization as panel reactive antibody (PRA) more than 10% or a positive T-cell crossmatch (TXM).

RESULTS

Among 2484 CLK recipients with available PRA or TXM information, 30% had positive TXM or PRA more than 10%. Among those with TXM information, 12% had a positive crossmatch (n=234). In univariate analyses, patient (P=0.002) and overall kidney graft survival (P=0.015) were significantly diminished among sensitized patients. Differences in patient survival translated to estimated half-lives of 10.3 years among nonsensitized recipients versus 7.8 years among sensitized recipients, In multivariable Cox models, allosensitization was independently associated with patient death (adjusted hazard ratio=1.22, 95% CI, 1.04-1.43) and overall kidney graft loss (adjusted hazard ratio=1.16, 95% CI, 1.00-1.36).

CONCLUSIONS

These results suggest a negative impact of presensitization on patient and overall renal allograft survival in CLK. Accordingly, presensitization may need to be considered in risk stratification and clinical management of CLK.

Postischemic inflammatory response in an auxiliary liver graft predicts renal graft outcome in sensitized patients

BACKGROUND

The liver is considered a tolerogenic organ that favors the induction of peripheral tolerance and protects other organs from the same donor from rejection. This has been exploited in combined auxiliary liver-kidney transplantation, where a renal graft is transplanted against a positive crossmatch under the protection of a liver transplanted from the same donor.

METHODS

To elucidate mechanisms behind the liver protective effect, we studied early transcriptional changes of inflammatory mediators in the grafts during combined auxiliary liver-kidney transplantation using microarrays and real-time polymerase chain reaction. The results were correlated to clinical data.

RESULTS

Liver and kidney grafts both exhibited an upregulation of the leukocyte-recruiting chemokines CCL2, CCL3, and CCL4. Notably, liver grafts strongly upregulated CCL20, a dendritic cell, and T-cell recruiting chemokine. By comparing the gene expression in liver grafts with the clinical outcome, we found that 14 of 45 investigated inflammatory genes were expressed significantly higher in patients without early rejection when compared with those with early rejections. This included the above-mentioned chemokines and the T-cell-recruiting CX3CL1, NFKB1, and the tolerance-inducing gene indoleamine 2,3-dioxygenase.

CONCLUSIONS

In this study, the protective role of the liver was associated with a proinflammatory reaction within this organ after ischemia-reperfusion. In particular, we found an increased expression of leukocyte-recruiting chemokines in patients without rejection, indicating a protective role of host inflammatory cells infiltrating the auxiliary liver graft in presensitized patients. Second, gene expression profiling of transplant biopsies shortly after reperfusion predicted the risk of early rejection in these patients.

Donor-directed MHC class I antibody is preferentially cleared from sensitized recipients of combined liver/kidney transplants

For patients with chronic renal and liver diseases, simultaneous liver and kidney transplantation (SLKT) is the best therapeutic option. The role of a pretransplant donor-specific antibody (DSA) in SLKT is unclear. We report the results of a retrospective review from 7/08 to 10/09 of SLKT at our institution. Monitoring of DSA was performed using single antigen bead assay. Between 7/08 and 10/09, there were six SLKT who had preformed DSA and positive XM (four class I and II DSA, one class I DSA only, one class II only). One-year patient and renal graft survival was 83%. Death-censored liver allograft survival was 100%. Acute humoral rejection (AHR) of the kidney occurred in 66% (three with both class I and II DSA and one with only class II DSA) of patients. In those with AHR, class I antibodies were rapidly cleared (p < 0.01) while class II antibodies persisted (p = 0.25). All patients who had humoral rejection of their kidney had preformed anticlass II antibodies. Liver allografts may not be fully protective of the renal allograft, especially with pre-existing MHC class II DSA. Long-term and careful follow-up will be critical to determine the impact of DSA on both allografts.

Immunosuppression in the sensitized heart transplant recipient

PURPOSE OF REVIEW

The proportion of heart transplant candidates who are allosensitized has increased over time. Advances in tissue typing and immunosuppression have improved the rate of successful transplant in this challenging population. Recently published data regarding contemporary approaches to desensitization prior to and immunosuppression following transplant are summarized.

RECENT FINDINGS

Continued progress in measurement and characterization of antibodies and strategies to abrogate antibody production both prior to and following heart transplant have been encouraging. Updates on the role of non-human leukocyte antigen antibodies and the impact of mechanical circulatory support on allosensitization are provided. Data on current desensitization strategies, including the increasing use of monoclonal antibodies, are provided and the potential role of complement inhibitors will be reviewed. Increasing experience with potent novel agents is likely to provide the opportunity to improve transplant outcomes for highly sensitized patients.

SUMMARY

Although allosensitized heart transplant candidates remain a management challenge, excellent outcomes can be achieved with contemporary approaches. Advances in the understanding of B-cell biology are anticipated to further broaden options and improve outcomes.

Double filtration plasmapheresis in antibody-incompatible kidney transplantation

Double filtration plasmapheresis (DFPP) was used in preference to plasma exchange in our program of antibody-incompatible transplantation, to treat higher volumes of plasma. Forty-two patients had 259 sessions of DFPP, 201 pre-transplant and 58 post-transplant. At the first treatment session, the mean plasma volume treated was 3.81 L (range 3-6 L), 55.5 mL/kg (range 36.2-83.6 mL/kg). Serum IgG fell by mean 59.4% (SD 10.2%), and IgM by 69.3% (SD 16.1%). Nine patients did not require increases in plasma volumes treated, and six did not tolerate higher plasma volumes. In the remaining patients, the mean maximum plasma volume treated pre-transplant was 6.67 L (range 4-15 L), 96.1 mL/kg (range 60.2-208.9 mL/kg). The complement dependent cytotoxic crossmatch was positive in 14 cases pre-treatment, and remained positive in six (42.8%) cases. The flow cytometric crossmatch was positive in 29 cases pre-treatment, and in 21 (72.4%) after DFPP. Post-transplant, DFPP was ineffective at reducing donor specific antibody levels during periods of rapid donor specific antibody synthesis. Post-transplant, the one year graft survival rate was 94%, although there was a high rate of early rejection. In summary, DFPP enabled the treatment of plasma volumes that were almost double those that would have been feasible with plasma exchange. Despite this, most patients were transplanted with a positive crossmatch, and DFPP post-transplant was unable to control rising antibody levels.

The kinetics of donor HLA class I-specific antibody absorption following a combined split liver and kidney transplant

Hyperacute rejection of a transplanted liver is rare even when the recipient has circulating donor-specific alloantibodies (DSA). There is also evidence that a transplanted liver may provide immunological protection for other organs transplanted from the same donor. We monitored the kinetics of circulating DSA in a highly sensitized recipient of a combined split liver and kidney transplant and demonstrated a reduction in antibody titres immediately after liver perfusion. The absorption of DSA was not compromised by the smaller liver mass transplanted. DSA titres remained low at 3 months post-transplant, and the recipient did not experience antibody-mediated rejection.

A single center experience of combined liver kidney transplantation

With advancements in the operative techniques, patient survival following liver transplantation (LTx) has increased substantially. This has led to the acceleration of pre-existing kidney disease because of immunosuppressive nephrotoxicity making additional kidney transplantation (KTx) inevitable. On the other hand, in a growing number of patients on the waiting list to receive liver, long waiting time has resulted in adverse effect of decompensated liver on the kidney function. During the last two decades, the transplant community has considered combined liver kidney transplantation (CLKTx) to overcome this problem. The aim of our study is to present an overview of our experience as well as a review of the literature in CLKTx and to discuss the controversy in this regard. All performed CLKTx (n = 22) at our institution as well as all available reported case series focusing on CLKTx are extracted. The references of the manuscripts were cross-checked to implement further articles into the review. The analyzed parameters include demographic data, indication for LTx and KTx, duration on the waiting list, Model for End-Stage Liver Disease (MELD) score, Child-Turcotte-Pugh (CTP) score, immunosuppressive regimen, post-transplant complications, graft and patient survival, and cause of death. From 1988 to 2009, a total of 22 CLKTx were performed at our institution. The median age of the patients at the time of CLKTx was 44.8 (range: 4.5-58.3 yr). The indications for LTx were liver cirrhosis, hyperoxaluria type 1, polycystic liver disease, primary or secondary sclerosing cholangitis, malignant hepatic epithelioid hemangioendothelioma, cystinosis, and congenital biliary fibrosis. The KTx indications were end-stage renal disease of various causes, hyperoxaluria type 1, polycystic kidney disease, and cystinosis. The mean follow-up duration for CLKTx patients were 4.6 +/- 3.5 yr (range: 0.5-12 yr). Overall, the most important encountered complications were sepsis (n = 8), liver failure leading to retransplantation (n = 4), liver rejection (n = 3), and kidney rejection (n = 1). The overall patient survival rate was 80%. Review of the literature showed that from 1984 to 2008, 3536 CLKTx cases were reported. The main indications for CLKTx were oxalosis of both organs, liver cirrhosis and chronic renal failure, polycystic liver and kidney disease, and liver cirrhosis along with hepatorenal syndrome (HRS). The most common encountered complications following CLKTx were infection, bleeding, biliary complications, retransplantation of the liver, acute hepatic artery thrombosis, and retransplantation of the kidney. From the available data regarding the need for post-operative dialysis (n = 673), a total of 175 recipients (26%) required hemodialysis. During the follow-up period, 154 episodes of liver rejection (4.3%) and 113 episodes of kidney rejection (3.2%) occurred. The cumulative 1, 2, 3, and 5 yr survival of both organs were 78.2%, 74.4%, 62.4%, and 60.9%, respectively. Additionally, the cumulative 1, 2, 3, and 5 yr patient survival were 84.9%, 52.8%, 45.4%, and 42.6%, respectively. The total number of reported deaths was 181 of 2808 cases (6.4%), from them the cause of death in 99 (55%) cases was sepsis. It can be concluded that there is still no definitive evidence of better graft and patient survival in CLKTx recipients when compared with LTx alone because of the complexity of the exact definition of irreversible kidney function in LTx candidates. Additionally, CLKTx is better to be performed earlier than isolated LTx and KTx leading to the avoidance of deterioration of clinical status, high rate of graft loss, and mortality. Shorter graft ischemia time and more effective immunosuppressive regimens can reduce the incidence of graft malfunctioning in CLKTx patients. Providing a model to reliably determine the need for CLKTx seems necessary. Such a model can be shaped based upon new and precise markers of renal function, and modification of MELD system.

Outcomes after liver transplantation: chronic kidney disease

1. Chronic kidney disease is a common complication after liver transplantation and has a major impact on graft and patient survival. 2. Pretransplant renal dysfunction is the most important determinant of posttransplant chronic kidney disease; other factors include the presence of diabetes/hypertension, acute kidney injury pre-transplant and post-transplant, and the use of calcineurin inhibitor-based immunosuppression. 3. The most common cause of end-stage renal disease post-orthotopic liver transplantation is calcineurin inhibitor toxicity, and this emphasizes the need for calcineurin inhibitor minimization protocols post-transplant. 4. The presence of chronic kidney disease post-orthotopic liver transplantation not only is important with respect to the need for renal replacement therapy and kidney transplantation but also increases cardiovascular risk dramatically. 5. The Model for End-Stage Liver Disease score is partly driven by creatinine, and it is not uncommon to have an elevated creatinine level in those who have a high Model for End-Stage Liver Disease score and are close to having an organ allocated. Thus, evaluating patients with advanced liver disease and pretransplant acute kidney injury is challenging. It is important to identify pre-liver transplant patients at high risk for early evolution of chronic kidney disease post-transplant in order to appropriately select patients for combined liver/kidney transplantation.

Indications for combined liver and kidney transplantation in children

A significant number of patients awaiting liver transplantation have associated renal failure and renal dysfunction is associated with increased morbidity and mortality after LT. There has been a recent increase in the number of CLKT in adults. The common indications for CLKT in children are different from those of adults and include metabolic diseases affecting the kidney with or without liver dysfunction and congenital developmental abnormalities affecting both organs. The results are generally encouraging among these groups of patients. Early evaluation and listing of patients before they become severely ill or have major systemic manifestations of their metabolic problem are important.

Current indications for combined liver and kidney transplantation in adults

A significant number of patients awaiting liver transplantation have associated renal failure. Combined Liver and Kidney Transplantation (CLKT) is increasingly offered especially since the introduction of Model for End-Stage Liver Disease (MELD). Decision to perform CLKT is straightforward when both organs suffer end-stage failure. However, the indications for CLKT are not well defined and there is controversy concerning some. We reviewed available data on PUBMED, United Network for Organ Sharing (UNOS), Organ Procurement Transplantation Network (OPTN), European Society for Organ Transplantation (ESOT) and discuss all current indications for CLKT.

CONCLUSION

Overall long-term outcome following CLKT is acceptable. There is an urgent need to further refine our ability to identify the cases with reversible renal injury in the setting of end-stage liver disease to avoid unnecessary CLKT. Liver protects the kidney from disease recurrence and allograft loss in metabolic diseases. However, the use of liver allograft for immunological protection of kidneys in highly sensitised patients with positive cross-match and previously failed renal transplants is still experimental.

Current state of combined heart-liver transplantation in the United States

BACKGROUND

Combined heart-liver transplantation (CHLT) has been increasingly performed in the USA, but published data on overall patient and graft outcomes have been limited.

METHODS

This study aimed to review the indications, immunosuppression, complications and outcomes of CHLT in the USA. From October 1987 to December 2005, a total of 47 cases of combined heart-liver (n = 41) and heart-liver-kidney transplantation (n = 6) were reported to the United Network for Sharing (UNOS) database. One pediatric case was excluded from the analysis. The mean age of recipients was 46 years (range, 22 to 65 years) and included 31 (67%) men and 16 (33%) women.

RESULTS

The most common indication for both heart and liver transplantation was amyloidosis (30%). Patients were followed for a mean duration of 1,362 days or 3.7 years (range, 1 to 4,598 days or 0 to 12.6 years). Patient, heart and liver graft survival rates were 84.8%, 84.8% and 82.4% at 1 year, and 75.6%, 75.6% and 73.5% at 5 years, respectively. At the latest follow-up of patients who survived at least 6 months after transplantation (n = 39), 28.2% of patients were on a single immunosuppressive agent.

CONCLUSIONS

Combined heart-liver transplantation is a viable option for candidates who require the combined transplantation, with outcomes comparable to those of single-organ recipients.

[Renal graft outcome in patients with associated liver transplant]

INTRODUCTION

Nearly 50% of liver transplant recipients have some degree of renal failure; patients in haemodialysis treatment have a higher risk of suffering hepatic diseases related to viral infections or concomitant pathologies. Improvement in surgical and organ preservation techniques and immunosuppressive therapy has permitted multiorganic transplants in patients needing both liver and kidney organs.

OBJECTIVES

To review our results in renal transplants in those patients with liver and kidney transplants.

MATERIAL AND METHOD

Retrospective study of the 15 patients with liver and kidney transplants performed in our Hospital. We have reviewed patients main characteristics, liver and renal failure causes, renal graft and patient outcome and complications relate to renal transplant.

RESULTS

Between 1975 and December 2006 we performed 1483 kidney transplants and between 1991 and December 2006, 409 liver transplants. We performed multiorganic liver and kidney transplants to 15 patients (4 women and 11 men). The average for liver transplant recipients was 52.5+/-9.3 years (range 37-61) and for kidney transplant recipients was 51+/-12.5 years (35-66). Cold ischemia was 6.4+/-5.4 hours (6-8) in simultaneous liver-kidney transplant and 20.5+/-5.4 (8-27 hours) in non-simultaneous ones. Three patients had a renal transplant before the liver one (two functioning which had no changes after hepatic transplant but the other was lost due to IgA glomeruloneprhitis relapse and received a simultaneous kidney-liver transplant). Six patients received a simultaneous kidney-liver transplant and eight patients a renal transplant between 16 and 83 months (x=50.5+/-25.9 months) after the liver transplant. A renal graft was lost due to renal vein thrombosis and two due to IgA relapse; the others were functioning between 6 and 264 months of follow-up (x=92.5+/-66.7) with creatinine levels of 1.86+/-mg/100, (range 1-4.5). Four patients died due to hepatic failure between 8 months and 21 years after renal transplant and another died of oesophagus cancer 14 years after the kidney transplant, in all cases with functioning renal graft. There were no cases of kidney graft acute rejection in simultaneous transplants but there were five in non-simultaneous ones. Immunotherapy was based on steroids and tacrolimus.

CONCLUSIONS

Liver-kidney transplants are worthy options in patients with hepatic and renal end failure. Acute rejection seems to have fewer incidences in simultaneous liver-kidney transplantation.

Preformed antibodies detected by cytotoxic assay or multibead array decrease liver allograft survival: role of human leukocyte antigen compatibility

The significance of human leukocyte antigen (HLA) compatibility and preformed antibodies in liver transplantation remains unclear. The objectives of this study were to evaluate, in a single-center cohort comprising 896 liver transplants, whether the degree of donor-recipient compatibility and preformed antibodies modified graft survival. Univariate Kaplan-Meier analysis demonstrated that donor-recipient HLA compatibility had a marginal impact on allograft survival. As for compatibility at individual antigen loci, 2 mismatches at HLA-A conferred a survival advantage in retransplanted allografts (P = 0.011). HLA-B and HLA-DR loci did not play a significant role in outcome in any pathology. The concordance of results on preformed antibodies detected by complement-dependent cytotoxicity (CDC) and a multiple bead assay (Luminex xMAP) showed a strong correlation between both techniques (P < 0.0001). Both CDC-detected and Luminex-detected antibodies were associated with shorter graft survival within the first year post-transplant (P = 0.01 and P = 0.016, respectively). Positive CDC T crossmatches and Luminex-detected HLA class II antibodies played a significant role in decreasing graft survival (P = 0.043 and P = 0.0019 at 1 year, respectively, and P = 0.005 and P = 0.038 at 5 years, respectively). A correlation was also observed between the presence of preformed Luminex-detected class II or Luminex I and II antibodies and allograft rejection (P = 0.001 and P = 0.042, respectively). In conclusion, although HLA typing is not a prerequisite for transplantation, screening of HLA antibodies with Luminex techniques and CDC crossmatch may be useful in the detection of at-risk patients that could benefit from increased surveillance and tailored therapy following transplantation.