SIGNIFICANCE OF A T-LYMPHOCYTOTOXIC CROSSMATCH IN LIVER AND COMBINED LIVER-KIDNEY TRANSPLANTATION

Including the liver in the visceral allograft: Impact on donor-specific anti-HLA antibodies and long-term outcomes

Humoral immunity emerges as a risk factor for graft failure after visceral transplantation (VTx) and development of donor-specific anti-HLA antibodies (DSAs) has been linked with poor outcomes. In most cases, a simultaneous liver transplant can be safely performed in sensitized patients with DSA and appears protective against lymphocytotoxic antibodies. We investigated the incidence of acute (AR) and chronic rejection (CR) in 32 VTx without any B cell-depleting pre-treatment (6 isolated intestinal transplants (IT) and 26 liver-containing, multivisceral transplants (MVT) and assessed the presence of donor-specific antibodies (DSA) pre- and post-transplantation. Twenty-one patients (65 %) developed AR, 15 (57 %) of the MVT and 6 (100 %) of the IT (p = 0.05). CR occurred in 4 IT (60 %, p < 0.001). At one month, de novo DSA were present in 71 % of VTx (66 % MVT vs 100 % IT, p = 0.09). At the last available follow-up, 69 % of the MVT and 50 % of the IT patients were DSA-free. De novo DSA seemed more persistent (7/19, 37 %) than pre-Tx DSA (1/6, 17 %; p = n.s.), de novo DSA were more frequently specific for HLA class II than class I, 16/19 (84 %) vs. 7/19 (37 %; p = 0.003), and HLA-DQ was their most frequent target HLA. DQ mismatches appeared to be a risk factor for developing de novo DSA. In conclusion, liver-containing visceral allografts have superior short- and long-term outcomes compared with liver-free allografts. De novo DSA develop early and frequently after VTx performed without B cell-depleting induction therapy, but the exact role of DSA in the pathogenesis of rejection remains unclear.

Liver Transplantation in Recipients With a Positive Crossmatch: A Retrospective Single-Center Match-Pair Analysis

A positive crossmatch (XM+) is considered a contraindication to solid abdominal organ transplantation except liver transplantation (LT). Conflicting reports exist regarding the effects of XM+ on post-transplant outcomes. The goal of this retrospective single-center analysis is to evaluate the influence of XM+ on relevant outcome parameters such as survival, graft rejection, biliary and arterial complications. Forty-nine adult patients undergoing LT with a XM+ between 2002 and 2017 were included. XM+ LT recipients were matched 1:2 with crossmatch negative (XM-) LT recipients based on the balance of risk (BAR) score. Patient and graft survival were compared using Kaplan-Meier survival analysis and the log-rank test. Comparative analysis of clinical outcomes in XM+ and XM- groups were conducted. Patient and graft survival were similar in XM+ and XM- patients. Rejection episodes did not differ either. Recipients with a strong XM+ were more likely to develop a PCR+ CMV infection. A XM+ was not associated with a higher incidence of biliary or arterial complications. Donor age, cold ischemia time, PCR+ CMV infection and a rejection episode were associated with the occurrence of ischemic type biliary lesions. A XM+ has no effects on patient and graft survival or other relevant outcome parameters following LT.

Long-term outcomes of crossmatch positive simultaneous liver-kidney transplantations in the United States

The long-term outcomes of positive crossmatch (+XM) simultaneous liver-kidney (SLK) transplantations are conflicting. We examined the association between crossmatch status and SLK outcomes in recipients discharged on tacrolimus and mycophenolate with or without steroids. We analyzed the Scientific Registry of Transplant Recipients for all primary SLK recipients between 2003 and 2020 with available crossmatch and induction data. We grouped recipients according to the crossmatch status: negative crossmatch (-XM; n = 3040) and +XM (n = 407). Kaplan-Meier curves were generated to examine recipient, death-censored liver, and death-censored kidney survival by crossmatch status. Cox proportional hazard models were used to investigate the association between crossmatch status and outcomes of interest with follow-up censored at 10 years. Models were adjusted for recipient age, sex, diabetes mellitus, Model for End-Stage Liver Disease score, duration on the liver waiting list, induction immunosuppression, steroid maintenance, hepatitis C infection, donor age and sex, local vs. shared organ, cold ischemia time, and previous liver transplantation status. In the univariable analysis, crossmatch status was not associated with recipient survival (log-rank p = 0.63), death-censored liver graft survival (log-rank p = 0.05), or death-censored kidney graft survival (log-rank p = 0.11). Compared with -XM, +XM recipients had a similar 1-year liver rejection rate, but higher kidney rejection rate (4.6% vs. 8.9%, p = 0.002). In the multivariable models, +XM status was not associated with deleterious long-term recipient, liver, or kidney grafts survival. -XM and +XM SLK transplantations have comparable long-term recipient, liver graft, and kidney survival with a slightly increased risk of early kidney allograft rejection in the +XM group. Crossmatch positivity in SLK transplantations should not influence the decision to use organs from a specific donor.

Clinical progress of auxiliary liver transplantation

After half a century of development, auxiliary liver transplantation (ALT) technology gradually matured and major indications of ALT have been gradually expanded. This review summarized the history of ALT and introduced indications for ALT which including metabolic liver disease, fulminant hepatic failure, highly sensitized kidney transplantation, prevention of hepatic resection of small hepatic syndrome, etc.; at the same time, the hot issues related to ALT were discussed, including the regulation of hepatic portal blood flow of transplanted liver and residual liver, how to treat the graft liver and remaining liver on second stage. Additionally, the expansion of indications for ALT which included the implementation of ALT for patients with liver cancer and ALT for patients with liver cirrhosis was discussed. It was believed that ALT can greatly alleviate the contradiction of insufficient source of graft liver.

Kidney Graft Outcomes in High Immunological Risk Simultaneous Liver-Kidney Transplants

Recipients of simultaneous liver-kidney transplantations (SLKTs) have a lower risk of rejection compared with recipients of kidney transplants alone. However, there is disagreement about the impact of pretransplant anti-human leukocyte antigen sensitization on patient and kidney graft survival in the long term. The aim of the study was to evaluate the impact of the recipient immunological risk and comorbidities in renal graft outcomes on SLKT. We reviewed the SLKTs performed in our center from May 1993 until September 2017. Patient and graft survival were analyzed according to the immunological risk, comorbidities, liver and kidney rejection episodes, immunosuppression, and infections. A total of 20 recipients of SLKT were considered in the high immunological risk (HIR) group, and 68 recipients were included in the low immunological risk (LIR) control group. The prevalence of hepatitis C virus infection, second renal transplant, and time on dialysis prior to transplantation were significantly higher in the HIR group. The incidence of acute kidney rejection was higher in the HIR group (P<0.01). However, death-censored kidney graft survival as well as the estimated glomerular filtration rate at follow-up were not different between the 2 groups. Comorbidities, but not the immunological risk, impact negatively on patient survival. Despite the higher incidence of rejection in the HIR SLKT group, longterm renal function and graft survival were similar to the LIR group.

Impact of Positive Donor-Specific HLA Antibodies Crossmatch on Graft Survival in ABO-Incompatible Liver-Kidney Transplantation: A Case Report

We present a patient with positive donor-specific antibodies (DSA) and crossmatch of ABO-incompatible (ABOi) combined liver and kidney transplantation (CLKT). Antibody-mediated rejection did not occur and the graft had survived for over one year at the time of writing without infectious complications. A 56-year-old man with positive DSA and positive crossmatch underwent living donor CLKT. The preoperative protocol for ABOi consisted of a single dose of rituximab and total plasma exchange (TPE). The result of anti-B antibody titer for IgG was 1:32. The evaluations of complement-dependent cytotoxicity and flow cytometry cross-match revealed a change from T+/B+ to T-/B+. The patient required adult living donor CLKT. Acute rejection episodes were treated using antithymocyte globulin, and the kidney required 7 days' treatment to recover. No further rejection and infectious episodes have been observed in past 13 months since the transplant. DSA and crossmatches are important for antibody detection and analysis. In the rituximab era, TPE can be used to achieve a successful decrease in antibody titer. In countries with a severe shortage of cadaveric organ donors, it may be possible to select ABOi candidate donors with positive DSA and crossmatch.

Chronic Rejection After Intestinal Transplant: Where Are We in Order to Avert It?

Chronic rejection affects the long-term survival of all solid organ transplants and, among intestinal allografts, occurs in up to 10% of the recipients. The insidious clinical evolution of the chronic allograft enteropathy, the absence of noninvasive biomarkers, and the late endoscopic findings delay its diagnosis. No pharmacological approach has been proven effective, and allograft removal nowadays still represents the only available therapy. The inclusion of the liver in the visceral allograft appears to be the only intervention affecting the development of chronic rejection, as revealed by large-center studies and registry reports. A significant body of evidence emerged from the experimental setting and provided essential knowledge on the complex mechanisms behind the development of chronic allograft enteropathy. More recently, donor-specific antibodies have been suggested as an early, key element in the natural history of chronic allograft enteropathy and several novel approaches, tackling the antibody-mediated graft injury, have gained acceptance in clinical settings and are believed to impact on chronic rejection. The inclusion of a liver allograft is advocated when re-transplanting a sensitized recipient, due to its protective effect against humoral immunity. Multicenter trials are required to understand and tackle chronic rejection, and find the therapeutic answer to this clinical dilemma.

Combined Kidney Transplantation and Splenic Fossa Auxiliary Heterotopic Liver Transplantation in a Highly Sensitized Recipient: A Case Report

BACKGROUND

Combined kidney and auxiliary orthotopic liver transplantation from the same donor is used to treat highly sensitized renal transplant recipients. Auxiliary liver can protect the transplanted kidney against hyperacute rejection.

METHODS

In the current case, combined kidney and splenic fossa auxiliary heterotopic liver transplantation was performed from the same donor for a highly sensitized recipient without preoperative preconditioning. No postoperative hyperacute rejection occurred.

RESULTS

Seven days after surgery, preexisting antibody levels rose and decreased after treatment; meanwhile, the function of transplanted kidney returned to normal. During 24 months of follow-up, the grafts showed good blood perfusion and functioned well. The levels of preexisting antibodies, donor-specific antibodies (DSA) and C1q-fixing human leukocyte antigen (C1q-HLA) antibodies, all decreased.

CONCLUSIONS

Combined kidney and splenic fossa auxiliary heterotopic liver transplantation can be used in renal transplantation for highly sensitized recipients.

Protecting the Kidney in Liver Transplant Recipients: Practice-Based Recommendations From the American Society of Transplantation Liver and Intestine Community of Practice

Both acute and chronic kidney disease are common after liver transplantation and result in significant morbidity and mortality. The introduction of the Model for End-stage Liver Disease score has directly correlated with an increased prevalence of perioperative renal dysfunction and the number of simultaneous liver-kidney transplantations performed. Kidney dysfunction in this population is typically multifactorial and related to preexisting conditions, pretransplantation renal injury, perioperative events, and posttransplantation nephrotoxic immunosuppressive therapies. The management of kidney disease after liver transplantation is challenging, as by the time the serum creatinine level is significantly elevated, few interventions affect the course of progression. Also, immunological factors such as antibody-mediated kidney rejection have become of greater interest given the rising liver-kidney transplant population. Therefore, this review, assembled by experts in the field and endorsed by the American Society of Transplantation Liver and Intestine Community of Practice, provides a critical assessment of measures of renal function and interventions aimed at preserving renal function early and late after liver and simultaneous liver-kidney transplantation. Key points and practice-based recommendations for the prevention and management of kidney injury in this population are provided to offer guidance for clinicians and identify gaps in knowledge for future investigations.

Long-term Clinical Relevance of De Novo Donor-Specific Antibodies After Pediatric Liver Transplantation

BACKGROUND

Anti-HLA antibodies and especially donor-specific antibodies (DSA) play a significant role in graft survival after solid organ transplantation. Their impact on long-term survival in adult liver transplantation (LT) is controversial, but they may be a risk factor. The effects of DSA after pediatric LT are still unclear.

METHODS

We performed a retrospective evaluation of DSA in sera from 43 children who had received transplants at our tertiary center. Twenty-four patients had good long-term clinical and laboratory graft function (group 1), whereas 19 LT recipients suffered from histologically confirmed and clinically relevant chronic allograft rejection (group 2); 16 of these have already undergone retransplantation due to graft dysfunction. Inclusion criteria were availability of sera before the first LT to identify preformed antibodies in case of DSA positivity after LT and long-term follow-up at our institution. Sera were analyzed for anti-HLA antibodies using Luminex single antigen beads, where a mean fluorescence intensity value of more than 1500 was considered positive.

RESULTS

The prevalence of DSA was 33% for group 1 and 68% for group 2. Antibodies were predominantly HLA class II. Values of mean fluorescence intensity were comparable in both groups. Only one of the DSA+ ve patients from group 1 exhibited preformed antibodies. In conclusion, pediatric patients with chronic rejection revealed a higher rate of de novo DSA, especially of HLA-class II DSA. Further studies are necessary to confirm these data with a larger pediatric cohort.

Influence of preformed donor-specific antibodies and C4d on early liver allograft function

INTRODUCTION. The impact of preformed donor-specific antibodies (DSA) is incompletely understood in liver transplantation. The incidence and impact of preformed DSA on early post liver transplant were assessed and these were correlated with compliment fragment C4d on allograft biopsy. METHODS. Pretransplant serum from 41 consecutive liver transplant recipients (brain dead donors; DBD = 27 and cardiac death donors; DCD = 14) were tested for class-specific anti-human leukocyte antigen (HLA) and compared against donor HLA types. Liver biopsies were taken during cold storage (t-1) and post-reperfusion (t0) stained with C4d and graded for preservation-reperfusion injury (PRI). RESULTS. Of the 41 recipients, 8 (20%) had anti-HLA class I/II antibodies pretransplant, 3 (7%) were confirmed preformed DSA; classes I and II (n=1) and class I only (n=2). No biopsies showed definite evidence of antibody-mediated rejection. Graft biopsies in overall showed only mild PRI with ischemic hepatocyte C4d pattern similar in both positive and negative DSA patients. One DSA-positive (33%) compared with four DSA-negative patients (10%) had significant early graft dysfunction; severe PRI causing graft loss from primary nonfunction was seen only in DSA-negative group. Allograft biopsy of preformed DSA-positive patient demonstrated only minimal PRI; however, no identifiable cause could be attributed to graft dysfunction other than preformed DSA. CONCLUSION. Preformed DSA are present in 5-10% liver transplant recipients. There is no association between anti-HLA DSA and PRI and C4d, but preformed DSA may cause early morbidity. Larger studies on the impact of DSA with optimization of C4d techniques are required.

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.

Significance of true-positive and false-positive pretransplantation lymphocytotoxic crossmatch in primary liver allograft outcomes

BACKGROUND

At the time of transplantation, a recipient's serum is tested against the prospective donor's lymphocytes to identify specific reactivity and to look for a donor-specific crossmatch (CXM). Here, we investigated the relationship between the pretransplantation lymphocytotoxic CXM results and the long-term outcome of liver transplantation at a single center.

METHODS

From October 1998 to April 2011, medical records, laboratory data, and pretransplantation lymphocytotoxic CXM results were collected from 1133 consecutive liver transplant recipients.

RESULTS

We performed liver transplantations on 80 (7.1%) patients after a true-positive CXM (t+CXM). The t+CXM group exhibited higher initial aminotransferase levels immediately after transplantation compared with a negative CXM group. However, no significant differences in rejection, biliary or vascular complications, viral disease recurrence, or de novo malignancies were found. Although overall graft and patient survival did not differ between the groups, liver-specific graft survival was inferior in the t+CXM group. It was also found that, in 42 (3.7%) recipients, initially positive results converted to final negative results after the elimination of immunoglobulin M autoantibodies. We defined this subpopulation as a false-positive CXM. Significantly decreased posttransplantation aminotransferase levels with a higher incidence of de novo malignancies were observed in this group compared with negative controls.

CONCLUSION

Our findings demonstrate that t+CXM transplants show increased aspartate aminotransferase and alanine aminotransferase peak immediately after transplantation, which influences liver-specific graft outcomes. Additionally, the presence of circulating immunoglobulin M autoantibodies against recipients' own antigens may be protective in liver grafts. However, this may be a predisposing factor for de novo malignancies.

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.

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.

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.

Lymphocytotoxic crossmatch in pediatric living donor liver transplantation

To investigate the relationship between the pretransplant LCT results and the outcome after pediatric LDLT in a single center. The clinical data of 76 children undergoing 79 LDLTs including three retransplantations from May 2001 to January 2006 were retrospectively analyzed. All of the children had end-stage liver disease, and their median age was 1.4 yr (range, six months to 16.5 yr). Immunosuppressive therapy consisted of cyclosporine- or FK-based regimens with steroids. The children were classified into two groups (positive or negative) according to the pretransplant LCT results. The incidences of post-transplant surgical complications and of rejection episodes were compared. The relationship between the pretransplant LCT results and patient and graft survival rates was also analyzed. Seventy-nine pretransplant crossmatch tests were done; 13 (16.5%) were positive, and 66 (83.5%) were negative. No significant difference was found in the pretransplant clinical factors between two crossmatch groups. There was no significant difference between the groups in the incidence of vascular and biliary tract complications, in the rate of early or steroid-resistant cellular rejections, or in one- and three-yr patient (91.7%, 91.7%, respectively, in the positive group, 93.5%, 93.5%, respectively, in the negative group, p = 0.80) and graft (92.3%, 92.3%, respectively, in the positive group, 88.8%, 86.4%, respectively, in the negative group, p = 0.63) survival. The present study demonstrates that there is no reason to do pretransplant LCT to select the living donor for pediatric LDLT.

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.

ABO antigen expression in graft tissue: is titration against donor erythrocytes relevant?

ABO-incompatible living donor renal transplantation has become an accepted treatment for end-stage renal disease. Two main factors appear to be important when crossing the ABO barrier, the donor organ A/B antigen expression and the amount of recipient anti-A/B antibody. Antigen expression depends on the ABO blood group and subgroup and may vary in different tissues and cells. The amount of recipient anti-A/B antibody, determined by titration, is very variable. One major drawback with titration is the lack of conformity between different laboratories, making comparisons difficult. For clinical use, the anti-A/B antibody titration technique has to be simple, rapid, and cheap, in addition to being accurate. Although there is a need for more standardized procedures for determination of ABO antibodies, existing techniques are sufficient in the clinical care of patients. To illustrate the variation in susceptibility of different graft tissues to ABO antibodies, in this paper we describe a case of an ABO-incompatible combined liver and kidney transplantation.

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

Combined liver and renal transplantations can be performed against a positive cross-match, indicating that the liver protects the kidney from the harmful HLA antibodies. This led us to the hypothesis that a partial auxiliary liver graft may have a similar protective effect when performed together with the kidney in highly sensitized patients. Seven patients, with broadly reacting HLA antibodies and positive crossmatches, were transplanted with a partial liver and a kidney from the same donor. In one of the cases a living donor was used. We performed lymphocytotoxic and flow cross-matches before and after the transplantation. Cross-matches turned negative after grafting in five of seven cases. The kidney function was excellent, without rejections, during the follow-up (24-60 months) in these patients. In two cases the cross-match remained positive after transplantation, one with a never-functioning renal graft and the other with an early graft failure, probably due to humoral rejection. A simultaneous transplantation of a partial auxiliary liver graft from the same donor, with the sole purpose of protecting the kidney from harmful lymphocytotoxic antibodies, can be performed successfully despite a positive cross-match and may thus be a new option of treatment for highly sensitized patients waiting for a kidney transplant.

IVIg attenuates T cell-mediated killing of human neurons

Beneficial effects of intravenous immunoglobulin (IVIg) in relapsing-remitting multiple sclerosis (MS) have been described, including a decrease of brain atrophy. We have previously shown that activated T cells kill neurons in culture. In this manuscript, we show that the pretreatment of activated T cells with IVIg attenuates T cell neurotoxicity. This is attributed to the ability of IVIg to decrease the adhesion of T cells onto neurons, possibly through an effect on LFA-1, and by lowering the levels of Fas and FasL on T cells. Our results are relevant to understanding how therapies affect the MS disease process.

Combined Liver-Kidney Transplantation With Preformed Anti-HLA Antibodies: A Case Report

A pretransplant positive cross-match is a contraindication for kidney transplantation, unlike in liver transplantation (OLT). In combined liver kidney transplantation (LKT) it is hypothesized that liver can protect kidney from rejection. We report the case of a 35-year-old woman on renal replacement therapy with gastrointestinal tract compression due to a hematoma following spontaneous liver rupture (May 2004). She was affected by amyloidosis, treated with a bone marrow autotransplantation (2001). The liver rupture was surgically untreatable, so an LKT was proposed. Panel-reactive antibody was 80% to 100% (complement dependent cytotoxicity) with specific anti-HLA antibodies (enzyme-linked immunosorbent assay). A compatible donor was found (July 2004). The cross-match before LKT was positive for B and T cells (score 8): an emergency OLT was performed. Immediately after liver reperfusion the cross-match result was less positive (6) for T cells. After 6 hours it was negative for T and slightly positive for B cells (4): the kidney was transplanted. The immunosuppressive therapy was: alemtuzumab, steroids, and tacrolimus. Renal function immediately recovered. On day 7 a rejection episode was successfully treated by increasing steroids (intravenous bolus). At discharge hepatic and renal function were normal (creatinine 1 mg/dL). They are stable after 1 year. This case showed LKT efficacy even in complex immunological situations. Many immunological mechanisms, still not defined, are hypothesized about the protective role of the liver. This case confirmed experimental data that highlighted that in vivo in humans a cross-match can change from positive to negative after OLT giving highly sensitized patients the possibility for LKT.

Influence of HLA compatibility and lymphocyte cross-matching on acute cellular rejection following living donor adult liver transplantation

BACKGROUND

Reports on the relevance of immunogenetic factors in living donor adult liver transplantation (LDALT) are often conflicting or inconclusive. We therefore investigated the human leukocyte antigen (HLA) mismatches, lymphocyte crossmatch positivity, and the reactivity in mixed lymphocyte culture (MLC) in a series of LDALT.

METHODS

A total of 104 LDALT patients were studied. The minimum follow-up was 12 months, and the graft survival rates were assessed. The incidence of the most common complications was analyzed. And the influence of HLA, the flow cytometric analysis findings, enhanced cytotoxic cross-matching and MLC on graft survival, and acute rejection was also investigated.

RESULTS

As a result, 96 negative cross-matching and eight positive cross-matching cases were identified. Positive cytotoxic cross-matching had a significant effect on graft survival (P<0.05), while flow cytometric cross-matching also had an additional effect on acute rejection (P<0.05). The MLC of the patients with three HLA mismatches was significantly higher than the MLC of patients with zero HLA mismatches. The incidence of acute cellular rejection (ACR) was higher in the patients with three mismatches than in the other patients, and moderate rejection only occurred in the patients with three mismatches.

CONCLUSION

HLA mismatching was not statistically associated with the overall graft survival after LDALT. The graft failure rates were higher in the positive cross-matching cases and therefore a strong immuosuppressant might be needed for positive cross-matching cases.

Immunoglobulin-G subclass antidonor reactivity in transplant recipients

Outcomes may differ after kidney transplantation compared to combined liver-kidney transplantation. In animal models, distinct patterns of antidonor immunoglobulin (Ig) G subclasses are associated with either rejection or transplant tolerance. Flow cytometry has increased the sensitivity of antidonor immunoglobulin detection. We compared antidonor IgG subclass responses in kidney transplant recipients to those in recipients of liver or multiorgan grafts. In this study of 19 organ (kidney, liver, pancreas) transplantations, recipient serum incubated with donor splenocytes was tested by flow cytometry for the presence of IgM, IgG, or IgG subclass 1-4. Sera before transplantation and 10 days and 100 days after transplantation were used. No differences were seen in antidonor IgM, IgG, or IgG subclass antibodies among recipients of kidney transplants and liver grafts or combination grafts, either before or after transplantation. IgG4 gradually but significantly increased after transplantation in all groups. High levels of antidonor IgG3 either before transplantation or produced after it were found in 3 kidney recipients who experienced acute rejection. No other patients experienced rejection, and no other increase in IgG3 was seen. In conclusion, antidonor IgG subclass profiles may be useful to distinguish populations at risk of rejection but they do not differentiate the immunological response after kidney transplantation from that after liver or combined transplantation. A late rise in antidonor IgG4 is consistent with decreased antidonor reactivity thought to occur late after transplantation.

Protective anti-donor IgM production after crossmatch positive liver-kidney transplantation

The mechanism by which a liver transplantation might protect a simultaneous kidney transplant in a crossmatch-positive recipient is unknown. Flow cytometry crossmatch (FCXM) has increased the sensitivity of donor-specific antibody (DSA) detection compared with complement-dependant cytotoxicity (CDC). Here we compare the outcome of a liver-kidney transplantation (LKT), which was CDC and FCXM positive, to the mate-isolated kidney transplantation (KT), which was CDC negative but FCXM positive, from the same donor. Immunoglobulin G (IgG) and immunoglobulin M (IgM) DSAs were measured by FCXM using splenocytes and purified T cells. The KT graft was hyperacutely rejected and removed, but the LKT graft survived without episodes of rejection. Both the KT and the LKT recipients had high levels of circulating antidonor IgG, but not IgM, before transplantation. By day 3, antidonor IgG and IgM in the LKT recipient increased 2 and 7 fold respectively, whereas the KT recipient maintained the high IgG level but did not increase IgM. Histology of the KT graft showed IgG and complement (C1q) deposition, but in the LKT grafts, IgM was deposited without IgG or C1q. Circulating IgG and IgM DSAs returned to background by day 10 and were still at background on day 100. We report a crossmatch-positive LKT where posttransplantation production of IgM DSA, which failed to fix complement, appeared to protect the grafts.

Results of combined and sequential liver-kidney transplantation

Experience with combined liver-kidney transplantation (L-KTx) has increased, but controversy regarding this procedure continues because the indications are not clearly defined yet. Between 1984 and 2000, 38 patients underwent simultaneous L-KTx and 9 patients underwent sequential transplantation, receiving either a liver before a kidney or a kidney before a liver. Main indications for a simultaneous procedure were polycystic liver-kidney disease with cirrhosis and coincidental renal failure. The main indications for sequential procedure were cirrhosis caused by viral infection for the liver and glomerulonephritis for the kidneys. Outcomes in these patients were evaluated retrospectively. Regarding simultaneous transplantation, 28 (73.7%) long-term survivors were followed up for 0.7 to 12.5 years. Currently, 24 (63.2%) patients are alive with good liver function. Fourteen patients died; 10 patients died in the early postoperative phase because of septic complications, and most of them were cirrhotic with a poor preoperative clinical status. Currently, 2 of the surviving patients (8%) have returned to dialysis, 4 (17%) have reduced renal function, and 18 (75%) have good renal function. Five liver and 2 kidney retransplantations were performed during the follow-up. In cases of sequential grafting, patients undergoing kidney transplantation in the presence of a previously transplanted stable liver did better than those who underwent liver transplantation after kidney transplantation. When liver transplantation was performed early and electively before substantial worsening, combined L-KTx is a safe procedure offering excellent long-term palliation.

Outcome of simultaneous liver-kidney transplantation in highly sensitized, crossmatch-positive patients

BACKGROUND

In simultaneous liver-kidney transplantation (SLKT), the liver has been described to protect the kidney from rejection, and acceptable results are possible despite a pretransplant positive crossmatch. At our center, 21 SLKT have been performed since 1993, 2 of them against a positive crossmatch.

OBJECTIVES

In this study we retrospectively analyzed two cases of SLKT after positive pretransplant crossmatch.

METHODS

Two highly sensitized women (30 and 52 years) with hepatic cirrhosis VHC on hemodialysis after a first KT failure were assessed. Pretransplant panel reactive antibodies (PRA) by complement dependent cytotoxicity NIH (CDC) were 81% and 99% respectively. Both patients received a SLKT. CM was performed at pretransplant and 24 and 48 hours posttransplant by CDC and by flow cytometry with double labeling with CD3-PE and antihuman IgG-FITC. Patients received ATG, cyclosporine, and prednisone therapy.

RESULTS

CM was positive pretransplant by CDC and flow cytometry. At 48 hours, CDC became almost negative (10%-20% mortality) and flow cytometry became negative. One of the patients experienced an episode of acute rejection at 10 days posttransplant that resolved with steroid pulses. Both patients presently have working grafts 26 and 24 months posttransplant (Cr, 1.1 and 1.5 mg/dL; GOT, 34 and 14 IU/L; GTP, 29 and 12 IU/L; GGT, 9 and 66 IU/L).

CONCLUSIONS

Our experience suggests that a positive crossmatch is not an absolute contraindication for SLKT. Good graft and patient survival rates are possible even among highly sensitized patients.

Impact of human leukocyte antigen matching in liver transplantation

BACKGROUND

Human leukocyte antigen (HLA) compatibilities are beneficial in the setting of kidney transplantation but have demonstrated inconclusive results after liver transplantation. On the basis of recent controversial reports, the authors analyzed the impact of HLA matching in their patients after liver transplantation under modern immunosuppressive drug regimens and new HLA typing techniques with respect to outcome and adverse immunologic events.

METHODS

Data from 924 transplants with complete donor-recipient HLA typing were retrospectively analyzed. Immunosuppression was commenced as either cyclosporine A- or tacrolimus-based therapy in different protocols. The follow-up period ranged from 1 to 144.8 months (median, 66 months).

RESULTS

The actuarial graft survival was 88% after 1 year and 78.7% after 5 years and was similar in tacrolimus- and cyclosporine A-treated patients. However, cyclosporine A-treated patients underwent significantly more rejection episodes. The number of HLA compatibilities had no influence on graft survival, whereas the number of acute rejections was significantly less in transplants with more HLA compatibilities (P<0.05). Graft survival tended to be improved in patients with chronic hepatitis B and more HLA compatibilities (P=0.05). In contrast, graft survival in transplants for primary sclerosing cholangitis was significantly impaired in the presence of one or two HLA-DR compatibilities (P<0.05). In addition, in autoimmune hepatitis, survival tended to be lower in the presence of more HLA compatibilities (P=0.1). Overall graft survival or frequency of adverse immunologic events was not influenced by any specific donor-recipient HLA allele.

CONCLUSION

This study demonstrated fewer acute rejections in transplants with more HLA compatibilities. However, in liver transplantation, a more specific investigation of HLA typing may be necessary, because in some indications HLA antigens play a role in the nature of the disease. Therefore, recurrence of autoimmune disease may be more severe in patients sharing HLA antigens.

ABO-incompatible liver transplantation with no immunological graft losses using total plasma exchange, splenectomy, and quadruple immunosuppression: evidence for accommodation

ABO-incompatible liver transplants (LTX) have been associated with a high risk of antibody-mediated rejection, poor patient and graft survival, and a high risk of vascular thrombosis and ischemic bile duct complications. We used pretransplantation and posttransplantation double-volume total plasma exchange (TPE), splenectomy, and quadruple immunosuppression (cyclophosphamide or mycophenolate mofetil, prednisone, cyclosporine or tacrolimus, and OKT3 induction) in 14 patients receiving ABO-incompatible LTX between June 1992 and February 2001: A(1) to O (seven), B to O (two), B to A (two), A to B (one), AB to A (one), and AB to O (one). Actuarial 1- and 5-year patient and graft survival rates are 71.4% and 61.2 % and 71.4% and 61.2%, respectively, with a mean follow-up of 62.9 +/- 39.4 months. Ten acute cellular rejections occurred, and the mean time to the first episode was 62 +/- 33 days. All were steroid sensitive. No antibody-mediated rejection or vascular thromboses occurred. Pretransplantation pre-TPE immunoglobulin (Ig) G mean isohemagglutinin titers were 262 +/- 326, compared with pretransplantation post-TPE titers of 65 +/- 103 (P =.04). Eight of nine patients with measurable titers before and after TPE achieved a reduction in titers. The mean number of posttransplantation TPE was 5.5 +/- 4.1 (range, 0 to 12), and the last TPE was on postoperative day 9.4 +/- 5.3. IgG isohemagglutinin titers 2 weeks posttransplantation had increased to 153 +/- 309 (P =.03 compared with pretransplantation pre-TPE IgG). ABO-incompatible liver transplantations can be performed with acceptable patient and graft survival rates with a low risk of antibody-mediated rejection with a combination of TPE, splenectomy, and quadruple immunosuppression. Recovery of isohemagglutinin antibody levels without humoral rejection suggests that accommodation may be the protective mechanism preventing late antibody-mediated rejection.

Identification of patients best suited for combined liver-kidney transplantation: part II

Liver-kidney transplantation (LKT) should be reserved for those recipients with primary disease affecting both organs. However, increasing transplant list waiting times have increased the development and duration of acute renal failure before liver transplantation. Furthermore, the need for posttransplant calcineurin inhibitors can render healing from acute renal failure difficult. Because of the increasing requests for and controversy over the topic of a kidney with a liver transplant (OLT) when complete failure of the kidney is not known, the following article will review the impact of renal failure on liver transplant outcome, treatment of peri-OLT renal failure, rejection rates after LKT, survival after LKT, and information on renal histology and progression of disease into the beginnings of an algorithm for making a decision about combined LKT.