What's New—What's Hot in Clinical Science: American Transplant Congress 2004
Abstract
The American Transplant Congress 2004, held in Boston last May, was the biggest conference in the history of the event, with over 4000 attendees. A wide variety of clinical topics were presented and discussed, all advancing the field of solid organ transplantation. This manuscript will attempt to summarize the presentations at the meeting. Particularly ‘hot’ clinical topics included the recent passage of a law to increase organ recovery, the use of expanded criteria kidney donors, a new model for the allocation of deceased donor lungs, survival following liver transplantation and its potential effect on liver allocation and the use of novel immunosuppressive drugs.
Introduction
A year had passed since the American Transplant Congress (ATC) 2003 in Washington, D.C. ATC 2004 was marked by a new venue, the Hynes Convention Center, Boston, the city in which Dr Joseph Murray and colleagues performed the first kidney transplant in 1954. The Congress was a landmark event due to the largest number of submitted abstracts and the largest attendance in the history of the event, with over 4000 registrants. A wide variety of presentations on a number of topics in solid organ transplantation were discussed, debated and devoured. This manuscript attempts to summarize the ‘hottest’ topics at ATC 2004.
Public Policy
On April 5, 2004, President Bush signed into law the Organ Donation and Recovery Improvement Act (P.L. 108–216), paving the way for federal funding of projects related to organ donation. If funds are appropriated, the bill will provide up to $50 million for living donor travel and living expenses, public education programs and grants for hospitals and organ procurement organizations for organ donation coordinators.
Secretary of the Department of Health and Human Services, Tommy Thompson, has recently announced the Organ Donation Breakthrough Collaborative, a project that will study centers with high conversion rates for organ donors, with the hope of establishing ‘best practices’ for hospitals and organ procurement organizations. Secretary Thompson has also established a donor awareness program for high school students.
Deceased donor lungs have previously been allocated based on waiting time. In an attempt to prioritize patients on the waiting list, investigators have developed a model in order to prioritize patients based on the benefit derived from a lung transplant (1).1 Investigators used data from the Scientific Registry of Transplant Recipients (SRTR) and Organ Procurement and Transplantation Network (OPTN) to identify factors through a Cox regression analysis that influence pre- and post-lung transplant survival. By subtracting twice the expected mortality on the waiting list in the year to come without a transplant from the expected 1-year survival following a transplant, patients are prioritized based on a score reflecting their severity of illness and post-transplant outcome. The model is currently being considered by the United Network for Organ Sharing (UNOS) and, potentially, could be in place sometime in 2005.
Deceased donor livers have been allocated based on the predicted mortality on the waiting list since late February, 2002. The Model for End-stage Liver Disease (MELD) uses a mathematical formula with the most recent values of total serum bilirubin, serum creatinine and INR to calculate a score that serves as a measure of predicted 3-month mortality without a liver transplant. This model was derived from cirrhotic patients undergoing a transjugular intrahepatic portosystemic shunt for complications related to portal hypertension. Ideally, this prioritization system was designed to place deceased donor organs in the sickest patients first. However, a study showed that local use of donor organs frequently leads to the use of organs in patients with relatively low MELD scores, i.e., scores <12 (2). Furthermore, the 1-year survival rate for patients transplanted with scores <18 was actually worse than the 1-year survival for these patients if they remained on the waiting list, suggesting a need for a ‘minimum’ MELD score for transplantation. This study also examined the survival of patients transplanted with MELD scores over 40, the ‘highest’ MELD score attainable and at which the score is frozen. Many in the field of liver transplantation thought transplantation in this group of critically ill patients, frequently on dialysis or with hepatorenal syndrome, would lead to poorer rates of survival. However, the 1-year survival rates were not significantly different from patients transplanted with lower MELD scores. Thus, transplants in such patients should be considered on a case-by-case basis.
Access to solid organ transplantation is a frequently debated issue in the field. Investigators found an overwhelmingly majority of deceased donor pancreata went to Caucasian patients (Table 1), in spite of comparable 5-year survival figures in Caucasian, Hispanic and African American recipients for pancreas after kidney and pancreas transplant alone (3). Although the breakdown of pancreatic transplant recipients by race is similar to that seen in deceased donor liver transplantation (4), the transplant community needs to intensify its efforts to educate physicians and patients regarding the availability and efficacy of pancreatic transplantation, as it does for all solid organ transplants. Funding opportunities for transplants in minority populations should be optimized as well.
| 1990–1995 | 1996–2002 | |||||
|---|---|---|---|---|---|---|
| PAK (%) | PTA (%) | SPK (%) | PAK (%) | PTA (%) | SPK (%) | |
| Caucasian | 96 | 94 | 89 | 89 | 93 | 82 |
| African American | 2 | 1 | 7 | 6 | 4 | 10 |
| Hispanic | 1 | 4 | 3 | 4 | 2 | 5 |
| Others | 1 | 1 | 1 | 1 | 1 | 3 |
- PAK = pancreas after kidney transplant; PTA = pancreas transplant alone; SPK = simultaneous pancreas/kidney transplant.
Kidney Transplantation
Expanded criteria donors
The use of donors with the potential for worse outcomes and expansion of the donor pool continues to be a hot topic in the field of solid organ transplantation. Three abstracts examining the use of expanded criteria kidney donors (ECD) deserve mention. A study using the SRTR data found the use of expanded criteria donor kidneys had led to a 14.3% increase in recovered organs and a 7.7% increase in the number of transplants over the previous year (5). As a group, ECD donors were older, with 53.5% greater than 60 years, and the remainder older than 50 years. Another study examined waiting time and mortality risk by race and age (6). Use of an ECD in patients older than 40 years, African Americans, or Asians only led to an increased survival in patients with a wait time greater than 1350 days. Patients with waiting times less than 1350 days derived no survival benefit, suggesting the need for ECD kidneys may not be as urgent in areas with short to medium wait times. The number of patients on standard versus ECD wait lists was the topic of a study from the SRTR/OPTN database (7). Interestingly, 43% of patients on the standard list were also on the list for an ECD kidney. These patients tended to be older, African American, diabetic or highly sensitized. However, over 70% of these patients ultimately received a deceased donor kidney from the standard list, in spite of ECD listing. In part, this likely reflected points assigned by their existing wait list position.
Immunosuppression
Alemtuzumab was the topic of a clinical symposium devoted to its origins and use in solid organ transplantation. A monoclonal antibody that binds to CD52, a cell surface glycoprotein on a number of different cells and originally licensed in the United States for use in lymphoreticular malignancies, alemtuzumab depletes lymphocytes. A 5-year follow-up study of kidney transplant recipients in the United Kingdom treated with alemtuzumab followed by low-dose cyclosporine monotherapy showed patient and graft survival rates and rejection rates similar to two cohorts of patients, one treated with conventional cyclosporine-based triple therapy or sirolimus, cyclosporine and prednisone. These cohorts were transplanted in the same period and at the same center (8). A single case of post-transplant lymphoproliferative disease and another case of autoimmune hemolytic anemia were seen. A group of 41 patients treated with alemtuzumab, tacrolimus and mycophenolate mofetil, in the absence of maintenance corticosteroids, had both patient and allograft survival rates of 100% and a 10% incidence of biopsy proven rejection with a mean follow-up of 8 months (9). A series of patients treated with alemtuzumab with delayed graft function had a significantly decreased risk of allograft rejection when compared to patients treated with other immunosuppressive regimens (10). Finally, a study of 15 patients without evidence of rejection showed a decreased expression of mRNA of factors associated with chronic allograft nephropathy (TGF-β, Smad3, type I collagen and VGEF) in patients treated with alemtuzumab versus those treated with other agents (11).
Initial data on the use of LEA29Y, a blocker of the B7/CD28 costimulatory pathway, were presented. With relatively short-term follow-up (6 months), improved GFR, lower cholesterol levels, lower systolic blood pressure and a lower incidence of acute rejection were seen, as compared to cyclosporine (12,13). Longer follow-up is needed and will likely be presented at future meetings.
Corticosteroids, once considered the backbone of immunosuppression, may not be necessary in all kidney transplant recipients. Extended follow-up of series of patients withdrawn from corticosteroids showed excellent patient and allograft survival rates, as well as improvement in adverse events commonly associated with corticosteroids. The timing of the withdrawal has been in question. However, three studies suggest it may never be too late to stop corticosteroids. Four-year follow-up of a group of 4012 patients treated with thymoglobulin, calcineurin inhibitors, mycophenolate mofetil or sirolimus and corticosteroid withdrawal on post-operative day 6 showed a 95/92% patient/allograft survival, with 89/95% free of acute cellular or chronic rejection (14). A European multicenter trial of 833 patients randomized to tacrolimus/mycophenolate mofetil/corticosteroids, tacrolimus/mycophenolate mofetil with corticosteroid withdrawal at 3 months or tacrolimus/corticosteroids with mycophenolate mofetil withdrawal, revealed similar rates of acute cellular rejection, chronic rejection and calculated creatinine clearance in all groups with 3-year follow-up (15). Slightly lower systolic blood pressure, cholesterol levels and incidence of new onset diabetes mellitus were seen in the corticosteroid withdrawal group. Finally, a group of 56 patients maintained on mycophenolate mofetil and cyclosporine after corticosteroid withdrawal at least 6 months following the transplant, showed similar levels of serum creatinine at each annual follow-up for 5 years when compared to a group of 58 patients on corticosteroid maintenance (16). Lower body weight and improved bone mineral density were seen in the corticosteroid withdrawal group. Thus, excellent rates of allograft and patient survival are seen with long-term follow-up, regardless of whether corticosteroids are withdrawn early, at 3 months, or 6 months following the transplant.
Highly sensitized patients
Previous strategies in the management of highly sensitized patients have focused on the use of specific immunosuppressive regimens in combination with intravenous immunoglobulin (IVIG) infusions, in an effort to reduce allograft rejection. Four-year follow-up of 57 patients treated with IVIG, daclizumab or thymoglobulin, in combination with mycophenolate mofetil and tacrolimus showed acute cellular rejection in 38.5% of patients, most of which were C4d+ (17). Excellent patient and allograft survival rates were seen at 96.5% and 82.5%, respectively. Another study examined low level donor reactive HLA class I alloantibody patients, with humoral rejection seen in 11% of 18 patients treated with the combination of IVIG, thymoglobulin, tacrolimus, mycophenolate mofetil and corticosteroids (18). Longer follow-up will be needed to gauge long-term success.
The definition of long-term success is usually based on allograft/patient survival and creatinine clearance. Protocol kidney allograft biopsies in highly sensitized patients may define subclinical damage. Patients with a positive cross-match had a trend toward more moderate fibrosis in biopsies obtained at baseline, 4, and 12 months following transplantation (19). Whether a change in immunotherapy triggered by histologic findings will improve the long-term outcomes is unclear.
ABO incompatible donors
Another method of overcoming the organ shortage has been the use of ABO incompatible kidneys. Routinely, these transplants have been performed with combination immunosuppression, plasmapheresis and splenectomy. Three presentations examined various aspects of ABO incompatible transplants and offered new approaches. A study of 77 recipients of ABO incompatible living donor transplants found donor blood type antibody suppression the key to protection from hyperacute or humoral rejection (20). Although donor blood type antigens were strongly expressed on vascular endothelium as much as 7 years following the transplant, suppression of blood type antibody prevented allograft rejection.
The use of ABO incompatible donors is often discouraged due to the need for a splenectomy. Rituximab, a monoclonal antibody that binds to CD20 surface antigens on the surface of B-lymphocytes, may make splenectomy unnecessary. One group used pre-transplant plasmapheresis and IVIG, post-transplant thymoglobulin, tacrolimus, mycophenolate mofetil and corticosteroids in non-A2 blood group donors (21). Prior to May 2003, splenectomy was performed. Since May 2003, rituximab has been given to four patients instead of splenectomy 1 week prior to the transplant. While 31% of splenectomized patients developed humoral rejection, 25% of the rituximab group developed subclinical humoral rejection. Another study used a 10-day pre-transplant conditioning period, using a single dose of rituximab followed by full-dose tacrolimus, mycophenolate mofetil and corticosteroids. Immunoadsorption was followed by IVIG. Splenectomy was not performed. Although only eight patients have entered the protocol, patient and allograft survival have been excellent with normal renal allograft function (22). Whether studies with additional patients and longer follow-up show similar findings remains to be seen.
Outcomes
The increasing use of older donors continues to raise concerns about the short- and long-term outcomes. A multicenter group using the United States Renal Data System (USRDS) information on 36 417 recipients showed a significantly improved allograft half-life for 1 year if the donor was younger than 55 years old (23). Lest one think the deterioration in donor renal function begins in ‘gray hairs’ alone, another study showed a decline in glomerular filtration rate after the age of 21 years at a rate of 0.51 mL/min/1.73 m2/year in donor age (24).
Transplantation in elderly patients has also become common practice. In patients over the age of 60, a review of over 120 000 patients listed or transplanted over a 10-year period showed similar survival benefits between live and deceased donor transplants (25). However, any dialysis exposure led to a lower relative risk of death in living donor recipients, suggesting the need for an emphasis on live donor transplantation in the elderly patient on dialysis. Another study of risks of death within 90 days of the transplant also showed dialysis as a risk for patients over the age of 60 years, if they received an expanded criteria donor kidney or had delayed graft function (26). Thus, dialysis in the elderly patient awaiting kidney transplantation increases the risk of adverse events postoperatively.
The issue of histologic injury prior to functional allograft decline led one group to perform protocol biopsies. Kidney biopsies in 506 (410 live donor and 115 deceased donor) transplants at 4, 12 and 24 months following transplantation showed histologic abnormalities in 66.8% of patients. Specifically, subclinical rejection was seen in 6% of patients at 24 months, while BK virus nephropathy and chronic fibrosis increased in frequency between 4 and 24 months. (27). Whether earlier intervention (particularly for subclinical polyoma virus infection) based on histologic data would affect the outcomes is unclear.
Another relatively unexpected predictor of outcome was identified in a European study. Seven hundred twenty six patients from the Austrian dialysis and transplant registry had lower rates of patient and allograft survival in the presence of elevated homocysteine levels (28).
Obesity, one of the greatest effectors of overall health, appears to affect post-kidney transplant outcome, as well. Defined as a body mass index (BMI) > 30, obesity led to a worse patient and allograft survival than patients with a BMI < 25, according to investigators who studied 500 patients (29).
Complications
Polyoma virus nephropathy is a significant complication following kidney transplantation. A study of renal allograft histology in patients with polyoma virus nephropathy revealed a more vigorous T-cell response, as measured by expression of CD8, interferon gamma and perforin, and a greater inflammatory response (TNF-α and LT-β) when compared to patients with acute cellular rejection (30). This may allow these two processes to be differentiated.
The bioavailability of immunosuppressive medications may have a profound effect on steady-state levels and the potential for allograft rejection. Diarrhea decreases the oral availability of tacrolimus due to diminished levels of intestinal P-glycoprotein (PGP) (31). Additional intestinal enzyme levels are affected by commonly used medications. Cimetidine, a blocker of the histamine 2 receptor, inhibits intestinal cytochrome P450 3A4 (CYP3A4), while intestinal CYP3A4 activity is increased by both omeprazole and simvastatin (32). Thus, the bioavailability of immunosuppressive medications could be decreased in patients on cimetidine and increased in patients on omeprazole and simvastatin.
Pediatric kidney transplantation
Studies from two centers showed more complications following laparoscopic nephrectomy than open nephrectomy in pediatric recipients. Higher rates of delayed graft function and acute cellular rejection were seen in 478 recipients of laparoscopic donor kidneys compared to 512 open nephrectomy donor recipients, using the UNOS data (33). Higher serum creatinines were seen in a smaller study of 30 laparoscopic donors versus 45 open nephrectomy donors (34).
A ‘hot’ topic of discussion was the transition of the pediatric patient from the pediatric nephrologist to the adult nephrologist. The transition can be emotional for the patient, parents and the entire transplant team on the pediatric and adult side. Better ways to ease this transition are needed to optimize patient care and minimize the emotional distress for all involved.
Pancreas transplantation
The impact of solitary pancreas transplantation on wait list deaths and transplant mortality was the topic of a large study. A review of the UNOS/IPTR data between 1995 and 2003 showed the relative risk of death after solitary pancreas transplant was lower than the risk of death on the wait list for both non-uremic and post-uremic diabetic patients (35). The relative mortality risk after transplantation was similar for pancreas after kidney transplant and pancreas transplant alone. Thus, in this study having a pancreas transplant did improve survival versus staying on the waiting list. Furthermore, the survival rates are similar regardless of whether the transplant occurs after a kidney transplant or as a pancreas transplant alone.
Pancreatic biopsies following transplantation appear to be changing. A comparison of the first 100 biopsies to the most recent 100 biopsies at a single center showed an increased amount of graft sclerosis and less acute cellular rejection (36). This finding may be related to the effects of aging on pancreatic allografts.
Steroid-free transplantation may also be possible in the field of pancreatic transplantation. A study of 65 patients, previously on calcineurin inhibitors and corticosteroids, used a single dose of alemtuzumab (following calcineurin inhibitor and corticosteroid withdrawal) given a mean of 32 months after either a simultaneous pancreas/kidney transplant or a pancreas transplant alone. Patients were then placed on maintenance therapy with either mycophenolate mofetil or sirolimus (37). No patient deaths have occurred, though four allografts have been lost. Reversible acute rejection occurred in five cases. Although additional study is needed, alemtuzumab may be an alternative maintenance strategy with the potential for prolonged renal function in either native or transplanted kidneys.
Heart transplantation
Allograft vasculopathy, a common complication following cardiac transplantation, may be less problematic in patients treated with specific immunosuppressive medications. A study of 136 patients followed for 2 years revealed protection from vasculopathy in patients on sirolimus, cyclosporine and corticosteroids, as compared to a group on azathioprine, cyclosporine and corticosteroids (38). A multicenter trial of 117 patients on everolimus, in combination with cyclosporine and corticosteroids, showed similar findings at 2 years, when compared to a group on azathioprine, cyclosporine and corticosteroids (39).
Ventricular-assist devices (VAD) prolong the lives of patients awaiting heart transplantation. However, one study showed patients bridged to transplantation with a VAD have higher short- and long-term mortality, in a review of over 10 000 patients, 2500 of which had VAD (40). The higher mortality rates are likely due to a higher severity of illness and the potential for infection and complications related to placement and maintenance of the VAD.
Lung transplantation
Bronchiolitis obliterans syndrome is a constant threat to lung transplant recipients. A multicenter study of lung transplant recipients randomized to everolimus or azathioprine (both in combination with cyclosporine and corticosteroids), showed an inhibition of the decline in pulmonary function in patients treated with everolimus at 12 months (41). Unfortunately, similar changes were not seen at 24 and 36 months of follow-up, likely due to the high number of dropouts from the study and a higher rate of serious infections and serum cholesterols in the everolimus group.
The use of alemtuzumab in lung transplant recipients was presented in a single center study (42). In a group of 42 patients with a relatively short follow-up of 4 months, 93% of patients were on tacrolimus monotherapy after induction with alemtuzumab, with comparable rates of patient and allograft survival as compared to patients treated with standard therapies.
Renal failure, the proverbial albatross in non-renal solid organ transplantation, appears to have a similar effect on lung transplant recipients. A study of 296 patients showed that acute renal failure with dialysis increased the risk of death with a hazard ratio of 5.2 (43). Risks for acute renal failure with dialysis included a low baseline glomerular filtration rate, a diagnosis other than chronic obstructive pulmonary disease, the use of amphotericin B and ventilator use for more than 1 day.
Liver transplantation
Transplantation in patients with hepatocellular carcinoma constitutes 20–25% of all liver transplants. Many centers, due to the fear of tumor spread beyond the limits of transplantation, frequently use adjunctive local therapy with either transarterial chemoembolization (TACE) or radiofrequency ablation (RFA) in patients on the wait list. One retrospective study compared survival and disease-free survival at 1 and 4 years in 29 patients treated with TACE, percutaneous ethanol injection, liver resection or RFA to 33 patients who received no adjunctive therapy (44). There was no difference in tumor extent by standard criteria between the two groups. No difference was seen in post-transplant survival rates or disease-free survival, raising the question of whether pre-transplant adjunctive therapy is necessary. These results could lead to a randomized trial, previously not thought appropriate, due to the perception that intervention was better than no intervention. Additional study is obviously required.
Outcomes
The outcome of liver transplants in subpopulations of patients previously not thought appropriate for transplantation continue to improve with adjunctive therapies. A series of patients transplanted with HIV and hepatitis B coinfection were presented with excellent patient and allograft survival (45). Furthermore, HIV and resistant strains of hepatitis B were well controlled with the use of antiviral agents. Cholangiocarcinoma, seen as a contraindication to liver transplantation at many centers due to poor historical survival and disease-free survival rates, may be an indication for transplant in cases with limited tumor burden. A series of 28 patients transplanted with cholangiocarcinoma with pre-transplant external beam radiation, transcatheter iridium-192 bachytherapy and chemotherapy with 5-FU or capecitabine showed a 5-year survival of 82%, similar to survival rates for other indications for liver transplantation (46).
The use of living donors has increased the number of annual liver transplants by 5–10%. Review of one center's experience of 75 live donor transplants revealed lower rates of acute cellular rejection, less severe hepatitis C infection and an increased rate of biliary complications (47). The lack of severity of recurrent hepatitis C was intriguing due to previous studies suggesting more severe recurrence of hepatitis C in recipients of living donor transplants.
A study combining the experiences of two European centers showed an improvement in 5-year survival rates in patients transplanted for hepatitis C in recent years (48), in spite of the increasing use of older donors, a known risk factor for severe recurrence of hepatitis C in the allograft (49,50). A change in immunosuppressive regimens in hepatitis C recipients, particularly with regard to lower doses of corticosteroids, may have led to the results.
MELD, a marker for a 3-month mortality used to prioritize patients on the waiting list, may predict the outcome following a living donor transplant. One study showed that the MELD score was a determinant of short-term mortality following adult-to-adult living donor transplantation (51). Whether MELD should be used as a means of living donor recipient selection remains to be seen.
The use of non-heart beating donors for liver transplantation has led to mixed results. A review of the UNOS data on 355 non-heart beating donors used over a 10-year period showed that low-risk non-heart beating donors (donor warm ischemic time less than 30 min and cold ischemic time less than 10 h), had comparable patient and allograft survival rates to recipients of living donor liver transplants at 1 and 3 years (52). Thus, ideal conditions with relatively brief warm and cold ischemic times may allow the use of these expanded criteria donors.
Immunosuppression
Data on the use of novel immunosuppressive agents in liver transplantation and an update on previously used agents were the hot topics of discussion. A multicenter study comparing everolimus to placebo in cyclosporine-treated patients revealed an acceptability and tolerability profile for everolimus but increased creatinine, cholesterol and triglycerides (53). A trend toward fewer episodes of acute cellular rejection was seen in those patients treated with everolimus.
A study of 56 patients randomized to alemtuzumab and low-dose tacrolimus versus tacrolimus and corticosteroids showed the alemtuzumab group had comparable rates of patient and allograft survival, though three cases of herpes zoster were seen in the alemtuzumab group (54). Whether alemtuzumab leads to improved glomerular filtration rates due to lower calcineurin inhibitor levels, more frequent opportunistic infections, higher rates of post-transplant malignancy, or has any effect on the severity of post-transplant hepatitis C will need to be the focus of additional studies with longer-term follow-up.
A review of a large registry database of over 11 600 patients showed liver transplant recipients treated with the combination of mycophenolate mofetil, tacrolimus and corticosteroids had a reduced risk of graft loss, death censored graft loss and patient death than a comparable group treated with tacrolimus and corticosteroids alone (55). Of particular importance was a significantly lower risk of death from bacterial infections in the patients treated with mycophenolate mofetil.
Complications
Osteopenia and osteoporosis, common complications seen in patients with chronic liver disease or liver transplants, can lead to painful atraumatic fractures. A placebo-controlled trial of zolendronate in patients following liver transplantation showed improvement in bone density measurements in as little as 3 months (56). This finding is of particular significance as liver transplant recipients routinely have a marked decrease in bone mineral density within the first 3–6 post-transplant months. Additional follow-up data to document further improvement are anxiously awaited.
Pediatric liver transplantation
While MELD scores have served as the means of prioritizing patients for the adult wait list, pediatric patients are prioritized using the PELD score. One study suggested PELD may not be helping patients with decompensated cirrhosis (57). Since PELD was instituted in February 2002, no change has been seen in the number of ICU patients transplanted. Furthermore, the calculated PELD score was used in only 57% of cases. No difference has been seen in either patient or allograft survival. Thus, in spite of the hope that listing practices would become more standardized, regional variation, largely through the use of letters of exception, continues to hamper the use of PELD in the pediatric liver transplant community.
Biliary atresia, the most common indication for liver transplantation, has seen relatively unchanged practices and outcomes over a period of 8 years (58). Using the SRTR data, the mean age of death has declined, suggesting infants may be underserved. Higher mortality rates have been seen in split liver transplants than deceased donor whole allograft transplants and living donor transplants, though the latter did not reach statistical significance.
Renal function, commonly decreased in adult liver transplant recipients, appears to be reasonably well preserved in pediatric patients. At 3 years following the transplant, only 8% of recipients have a glomerular filtration rate less than 80 mL/min (59). Treatment with cyclosporine was associated with a higher risk of renal insufficiency, based on a univariate analysis.
Summary
The ATC 2004 marked a move to Boston and the spacious Hynes Convention Center. The high quality scientific presentations of this year's meeting will be difficult to beat. However, the ongoing efforts of investigators worldwide will undoubtedly make the meeting in Seattle as exciting and thought provoking as ever.
