The role of quantitative Epstein-Barr virus polymerase chain reaction and preemptive immunosuppression reduction in pediatric liver transplantation: a preliminary experience

The IPTA Nashville consensus conference on Post-Transplant lymphoproliferative disorders after solid organ transplantation in children: II-consensus guidelines for prevention

The International Pediatric Transplant Association (IPTA) convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorder after solid organ transplantation in children. In this report from the Prevention Working Group, we reviewed the existing literature regarding immunoprophylaxis and chemoprophylaxis, and pre-emptive strategies. While the group made a strong recommendation for pre-emptive reduction of immunosuppression at the time of EBV DNAemia (low to moderate evidence), no recommendations for use could be made for any prophylactic strategy or alternate pre-emptive strategy, largely due to insufficient or conflicting evidence. Current gaps and future research priorities are highlighted.

Epstein-Barr Viral Load Monitoring Strategy and the Risk for Posttransplant Lymphoproliferative Disease in Adult Liver Transplantation : A Cohort Study

BACKGROUND

Primary infection with or reactivation of Epstein-Barr virus (EBV) can occur after liver transplant (LT) and can lead to posttransplant lymphoproliferative disease (PTLD). In pediatric LT, an EBV-DNA viral load (EBV VL) monitoring strategy, including the reduction of immunosuppression, has led to a lower incidence of PTLD. For adult LT recipients with less primary infection and more EBV reactivation, it is unknown whether this strategy is effective.

OBJECTIVE

To examine the effect of an EBV VL monitoring strategy on the incidence of PTLD after LT in adults.

DESIGN

Cohort study.

SETTING

Two university medical centers in the Netherlands.

PATIENTS

Adult recipients of first LT in Leiden between September 2003 and January 2017 with an EBV VL monitoring strategy formed the monitoring group (M1), recipients of first LT in Rotterdam between January 2003 and January 2017 without such a strategy formed the contemporary control group (C1), and those who had transplants in Leiden between September 1992 and September 2003 or Rotterdam between 1986 and January 2003 formed the historical control groups (M0 and C0, respectively).

MEASUREMENTS

Influence of EBV VL monitoring on incidence of PTLD.

RESULTS

After inverse probability of treatment weighting of the 4 groups to achieve a balance among the groups for important patient characteristics, differences within hospitals between the historical and recent era in cumulative incidences-expressed as the number of events per 1000 patients measured at 5-, 10-, and 15-year follow-up-showed fewer events in the contemporary era in both centers. This difference was considerably larger in the monitoring center, whereas the 95% CI included the null value of 0 for point estimates.

LIMITATION

Retrospective, low statistical power, and incompletely balanced groups, and non-EBV PTLD cannot be prevented.

CONCLUSION

Monitoring EBV VL may reduce PTLD incidence after LT in adults; larger studies are warranted.

PRIMARY FUNDING SOURCE

None.

Viral infections in acute graft-versus-host disease: a review of diagnostic and therapeutic approaches

BACKGROUND

While immunosuppressive therapy for acute graft-versus-host disease (aGVHD) advances, viral reactivation has been found to be an increasingly common complication in these patients. Dermatologists may often be consulted on inpatient services for evaluation.

OBJECTIVE

We investigated the literature for the role of viral infections in aGVHD and review the current evidence regarding management.

METHODS

Articles in the public domain regarding aGVHD, cytomegalovirus, Epstein-Barr virus, varicella zoster virus, hepatitis viruses, parvovirus B19, and respiratory viruses were included.

RESULTS

Dermatologic findings vary between different viral antigens, and some infections may be a marker for the development of aGVHD or worsen prognosis.

LIMITATIONS

The heterogeneous cohorts of the studies reviewed often preclude direct comparison between results.

CONCLUSION

The relationship between viral reactivation and aGVHD may be bidirectional and is worthy of further exploration. Additional studies are needed to determine appropriate prophylaxis and treatment.

More benign lymphoproliferative disease after liver transplant in infants

CONTEXT-Despite the high frequency of liver transplants in infants, few data are available on the characteristics of posttransplant lymphoproliferative disorders in liver transplant patients (PTLD). OBJECTIVE-To analyze special features and behavior of PTLD arising after liver transplant in infants. METHODS-A comprehensive search of the literature was conducted for the available data on PTLD in infant liver transplant recipients through PubMed and Google scholar. An infant was defined as a liver recipient who was less than 2 years old at the time of transplant. Overall, 205 cases of PTLD were found in 24 reports, and the 100 infants with PTLD were compared with children and adults with PTLD. RESULTS-PTLD lesions in infants were more likely to be polymorphic whereas monomorphic lesions were more prevalent among older patients (P= .05). Remission rates, metastasis frequency, and organ involvement did not differ significantly between the groups. Survival analysis showed that the infants had a significantly better outcome than did older patients (P= .05). CONCLUSION-PTLD is more benign and may have a better outcome in infant liver transplant recipients than in older recipients. A prospective multicenter approach is needed for future research studies.

Effect of maintenance immunosuppressive drugs on virus pathobiology: evidence and potential mechanisms

Recent evidence suggesting a potential anti-CMV effect of mTORis is of great interest to the transplant community. However, the concept of an immunosuppressant with antiviral properties is not new, with many accounts of the antiviral properties of several agents over the years. Despite these reports, to date, there has been little effort to collate the evidence into a fuller picture. This manuscript was developed to gather the evidence of antiviral activity of the agents that comprise a typical immunosuppressive regimen against viruses that commonly reactivate following transplant (HHV1 and 2, VZV, EBV, CMV and HHV6, 7, and 8, HCV, HBV, BKV, HIV, HPV, and parvovirus). Appropriate immunosuppressive regimens posttransplant that avoid acute rejection while reducing risk of viral reactivation are also reviewed. The existing literature was disparate in nature, although indicating a possible stimulatory effect of tacrolimus on BKV, potentiation of viral reactivation by steroids, and a potential advantage of mammalian target of rapamycin (mTOR) inhibition in several viral infections, including BKV, HPV, and several herpesviruses.

Burden of de novo malignancy in the liver transplant recipient

Recipients of liver transplantation (LT) have a higher overall risk (2-3 times on average) of developing de novo malignancies than the general population, with standardized incidence ratios ranging from 1.0 for breast and prostate cancers to 3-4 for colon cancer and up to 12 for esophageal and oropharyngeal cancers. Aside from immunosuppression, other identified risk factors for de novo malignancies include the patient's age, a history of alcoholic liver disease or primary sclerosing cholangitis, smoking, and viral infections with oncogenic potential. Despite outcome studies showing that de novo malignancies are major causes of mortality and morbidity after LT, there are no guidelines for cancer surveillance protocols or immunosuppression protocols to lower the incidence of de novo cancers. Patient education, particularly for smoking cessation and excess sun avoidance, and regular clinical follow-up remain the standard of care. Further research in epidemiology, risk factors, and the effectiveness of screening and management protocols is needed to develop evidence-based guidelines for the prevention and treatment of de novo malignancies.

Impact of immunosuppression on the development of Epstein-Barr virus (EBV) viremia after pediatric liver transplantation

OBJECTIVES

Pediatric liver transplant (OLT) patients are at risk of posttransplant lymphoproliferative disease (PTLD) from Epstein-Barr virus (EBV). This study examined the impact of induction and immunosuppression on EBV viremia.

METHODS

A retrospective chart review was performed on 197 pediatric patients and induction regimen, immunosuppression levels, and EBV viremia were documented for 1 year post-OLT. Logistic regression models determined associations between induction, immunosuppression, and EBV.

RESULTS

Fifty six percent of patients developed EBV viremia. Incidence of EBV viremia was 73% with antithymocyte globulin (ATG), 63% with daclizumab, and 39% for neither, though the trend was not significant [ATG: odds ratio (OR) 0.19; 95% confidence interval (CI) 0.024-1.58; P = .125; daclizumab OR; 1.07; 95% CI 0.270-4.23; P = .925]. Tacrolimus immunosuppression levels were supratherapeutic 28.7% of the time; however, only supratherapeutic tacrolimus levels between 0 and 2 weeks increased EBV viremia at 2 to 4 weeks post-OLT (OR 1.80; 95% CI 1.10-2.94; P = .02). Three patients developed PTLD.

CONCLUSIONS

The use of ATG and daclizumab induction likely does not play a role in the development of EBV viremia. Supratherapeutic tacrolimus levels 0 to 2 weeks post-OLT impact the development of EBV viremia at 2 to 4 weeks. The incidence of PTLD was low, suggesting better EBV and immunosuppression monitoring plays an important role in reducing PTLD.

Current concepts in pediatric liver transplantation

Liver transplantation is the definitive treatment for end-stage liver disease in both children and adults. Advances over the last 2 decades have resulted in excellent patient and graft survival rates in what were previously cases of fatal disorders. These developments have been due to innovations in surgical technique, increased surgical experience, refinements in immunosuppressive regimens, quality improvements in intraoperative anesthetic management, better understanding of the pathophysiology of the liver diseases, and better preoperative and postoperative care. Remarkably, the use of split-liver and living-related liver transplantation surgical techniques has helped mitigate the well-recognized national organ shortage. This review will discuss the major aspects of pediatric liver transplantation as it pertains to indication for transplantation, recipient selection and listing for orthotopic liver transplantation, pre-orthotopic liver transplantation care of children, optimal timing of orthotopic liver transplantation, surgical technical considerations, postoperative care and complications, and patient and graft survival outcomes.

Baseline evaluation of serum markers of inflammation and their utility in clinical practice in paediatric liver transplant recipients

BACKGROUND

Several biomarkers of penetrating infections vs. rejection in liver transplant (LT) have been suggested; however, baseline values in paediatric LT recipients have not been studied.

AIM

We evaluated the baseline concentration of procalcitonin (PCT), C-reactive protein (CRP) and interleukin-6 (IL-6) in a post-LT paediatric group.

METHODS

We measured serum PCT, CRP and IL-6 in 58 consecutive paediatric LT recipients. Specimens were collected for group 1 (n=22) at day 1, group 2 (n=12) at day 7 post-LT and group 3 (n=24) at onset of febrile episode. Day 7 samples were obtained from patients who had no graft dysfunction or signs/symptoms of sepsis.

RESULTS

Median values for PCT were: group 1 was 5.16 μg/L (95% CI, 2.18-21.13); group 2: 0.170 μg/L (95% CI, 0.15-0.36) and, group 3: 1.93 μg/L (95% CI, 1.36-2.66) for bacterial and fungal infection, 0.19 μg/L (95% CI, 0.10-0.48) for rejection, and 0.31 μg/L (95% CI, 0.15-0.44) for viral infection. The area under the ROC (AUROC) for PCT, CRP and IL-6 in bacterial infection vs. rejection was 1.0 (P<0.0001), 0.842 (95% CI 0.686-0.998; P<0.0001) and 0.739 (95% CI 0.559-0.919; P 0.0046), respectively.

CONCLUSION

PCT levels were significantly higher in bacterial and fungal infection in comparison to other inflammatory markers. PCT proved to be the most specific parameter in differentiating bacterial infection from viral infection and allograft rejection.

The changing face of post-transplant lymphoproliferative disease in the era of molecular EBV monitoring

Pediatric PTLD is often associated with primary EBV infection and immunosuppression. The aim was to retrospectively review the spectrum of histologically documented PTLD for two time intervals differentiated by changes in use of molecular EBV monitoring. Eleven of 146 patients (7.5%) in 2001-2005 (Era A) and 10 of 92 (10.9%) in 1993-1997 (Era B) were diagnosed with PTLD. The median age at liver transplantation (0.8 and 0.9 yr, respectively) and the median duration between liver transplant and diagnosis of PTLD (0.6 and 0.7 yr, respectively) were similar in both eras. However, patients in Era A presented with significantly less advanced histological disease compared to patients in Era B (p=0.03). Specifically, nine patients (82%) in Era A had Pl hyperplasia/polymorphic PTLD, whereas in Era B, six had advanced histological disease (five monomorphic and one unclassified). Three transplant recipients in Era B died secondary to PTLD, whereas there were no PTLD-related deaths in Era A (p=0.03). Heightened awareness of risk for PTLD, alterations in baseline immunosuppression regimens, implementation of molecular EBV monitoring, pre-emptive reduction in immunosuppression and improved therapeutic options may have all contributed to a milder PTLD phenotype and improved clinical outcomes.

Efficacy and safety of valganciclovir in liver-transplanted children infected with Epstein-Barr virus

Epstein-Barr virus (EBV) infection after liver transplantation (LT) is associated with increased risk of posttransplant lymphoproliferative disorder (PTLD). Lowering immunosuppression is the current method to prevent PTLD in LT children with a high viral load. The aim of this study was to assess the efficacy and safety of valganciclovir (VGCV) in children with EBV infection after LT. Forty-seven children showing detectable EBV-DNA (72% asymptomatic) were treated with VGCV (520 mg/sqm twice daily) with no immunosuppression decrease (except in 4 cases). VGCV treatment started 17 months (median) after the onset of EBV infection. A 30-day treatment applied to 26 patients led to undetectable EBV-DNA in 11/32 courses (34.3%), with 82% relapsing. A long VGCV treatment (median: 8 months) achieved undetectable EBV-DNA in 20/42 (47.6%), 60% of whom maintained response off therapy. There were no new PTLD cases. Symptoms worsened in 1 (2.1%) in whom PTLD was suspected but not confirmed in liver and jejunum biopsies. Factors associated with achievement of undetectable EBV-DNA were a longer time from LT and a lower rate of intervening infections in comparison with nonresponders. The safety profile for VGCV was excellent. Graft rejection occurred in 6%. In conclusion, in 47 LT children with a sustained increased EBV load treated with VGCV and unchanged immunosuppression, PTLD was suspected in 1 child (2.1%). A viral load decrease could be achieved as EBV-DNA was undetectable in 47% of patients under prolonged treatment.

Present status and future perspectives of intestinal transplantation

Intestinal transplantation (ITx) is the only definitive therapy for irreversible intestinal failure. Owing to the limited short- and long-term graft survival over the years, ITx has been a complementary treatment to home parenteral nutrition. However, the development of intestinal and multivisceral transplantation has been significant over the past 15-20 years owing to the progress in immunosuppressive therapy, refinement of surgical techniques, post-transplant care, intestinal immunology, and immunological as well as anti-infectious monitoring. The improvement of patient- and graft survival over the last few years together with data on the cost effectiveness of ITx, following 2 years after transplantation, may require a redefinition of the indication for ITx.

Relationship of immunosuppression to Epstein-Barr viral load and lymphoproliferative disease in pediatric heart transplant patients

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) is a severe complication in transplant recipients. Detection of increased Epstein-Barr viral (EBV) load in the peripheral blood acts as a surrogate marker for increased risk of PTLD development. We prospectively monitored EBV load, immunosuppression and PTLD in pediatric heart transplant (HTx) patients to determine risk factors for an increased EBV load and risk of PTLD.

METHODS

Forty-one pediatric heart transplant recipients were included and underwent prospective monitoring of their immunosuppression and ethylene-diamine tetraacetic acid (EDTA) blood sampling for EBV load (copies/microg DNA) measurement using quantitative real-time polymerase chain reaction (PCR; TaqMan) during January 2001 to December 2006.

RESULTS

EBV load was measurable in 70% and was significantly increased (>2,000 copies/microg DNA) in 35% of the patients, with a median EBV load of 5,100 (range 0 to 50,665 copies/microg DNA). Increased EBV load was detected in patients receiving CsA-azathioprine or more than two doses of anti-thymocyte globulin (ATG) and in those <10 years of age, without any significant differences in CsA blood levels. Lowest or negative EBV load was measured in patients receiving CsA-mycophenolate mofetil (MMF) or CsA only. CsA blood levels were not predictable for increased EBV load or PTLD. Six patients developed a EBV-associated B-cell lymphoma (PTLD), among whom 4 (67%) were receiving CsA-azathioprine.

CONCLUSIONS

Frequent EBV load monitoring identifies patients at high risk for PTLD development. Azathioprine and ATG are major risk factors for increased EBV load and PTLD and patients may benefit from a change of immunosuppression in addition to pre-emptive anti-viral or anti-tumor strategies.

Bioartificial Pancreas for the Treatment of Diabetes

Recent advances in islet transplantation using highly purified islets and effective immunosuppression strategies have resulted in substantial improvement in achieving insulin independence in type 1 diabetes patients. However, there are side effects from long-term immunosuppression, and transplant rejection and/or the recurrence of autoimmune attack of the transplanted islets cannot be completely prevented, even with immunosuppressive treatment. Therefore, construction of a safe and functional bioartificial pancreas (BAP) that provides an adequate environment for islet cells may be an important approach to treat diabetic patients. Various types of BAP devices have been developed and examined in animals. In this review, I introduce the previous BAP studies and our approach of BAP development.

Posttransplant lymphoproliferative disorder in adult liver transplant recipients: a report of seventeen cases

Posttransplant lymphoproliferative disorder (PTLD) is a major complication of liver transplantation, but previous descriptions have been limited to case reports and small case series. We report a retrospective analysis of 17 consecutive cases of PTLD associated with liver transplantation. The median age at PTLD diagnosis was 47 years (range 19 - 63) with a median time of 25 months from liver transplantation to PTLD diagnosis (range 3 - 75). PTLD location was frequently extranodal (71%) and involved the transplanted liver (41%). PTLD histology consisted of nine (53%) monomorphic and eight (47%) polymorphic disease. EBV was present by in situ hybridization in 11 (79%) of 14 cases evaluated. Initial therapy included reduction in immunosuppression (RI) alone in 13 (76%) of 17 patients, resulting in 6 (46%) complete responses (CR) and 7 (54%) progressive disease (PD). Monoclonal CD20 antibody (rituximab) and CHOP chemotherapy were used as initial therapy or as second line after RI failure. Currently, five patients (29%) are alive in CR. Although detection and treatment of PTLD in liver transplant recipients remains problematic and upfront mortality is still high, long-term survival is possible. Further studies are necessary to better define treatment strategies.

Epstein–Barr virus infection as a complication of transplantation of a nerve allograft from a living related donor

✓Reconstruction of extensive nerve defects is hampered by the amount of autogenous nerve tissue available for transplantation and by donor site morbidity. Nerve allografts, being of foreign origin and potentially unlimited in supply, provide a solution to these problems. Studies have shown that nerve allotransplants require immunosuppression only until end-organ connections are made and that immunosuppressant therapy may be subsequently discontinued with no negative effect on functional outcome. Also, recent experimental and clinical focus has been on shorter periods of immunosuppression in order to reduce risk, even stopping immunosuppression after regeneration has reached the distal suture line rather than before recovery of end-organ connections. In the pediatric population, the increased disease burden and increased potential for nerve regeneration as well as the frequent availability of a living related donor make allografts all the more attractive as solutions to nerve reconstructive problems. Nevertheless, the risks of immunosuppression must not be underemphasized, and they deserve more attention in the current nerve transplantation literature.

The authors report on a child who, at the age of 1 year, received a nerve allograft from a living related donor who was positive for Epstein–Barr virus (EBV). The child quickly developed a symptomatic EBV infection concurrent with immunosuppressant drug therapy. The immunosuppression regimen was stopped prematurely, and the patient suffered only a short illness, but the EBV infection could have developed into a life-threatening posttransplant lymphoproliferative disorder (PTLD). The patient is consequently predisposed to develop PTLD and will have to be monitored for the rest of his life. This case highlights the importance of considering the potentially fatal risks associated with this elective procedure. Future studies are needed to quantify and minimize this complication. Nevertheless, it should be weighed against the potential functional benefit from using nerve allografts.

Sustained Epstein-Barr virus detection in paediatric liver transplantation. Insights into the occurrence of late PTLD

Epstein-Barr virus (EBV) infection is the main cause of post-transplant lymphoproliferative disease (PTLD). Little is known on chronic carrier state and its relation with late PTLD. We aimed to study EBV infection in the long-term after paediatric liver transplantation (OLT). We conducted a retrospective review of 34 children monitored for a median of 5.8 years (range 1.5-17.7). 21 were IgG seronegative (group A) and 13 seropositive (group B) before OLT. Primary infection was the appearance of VCA-IgM or VCA-IgG or Real-Time Polymerase Chain Reaction (RT-PCR) in patients previously IgG seronegative; positive VCA-IgM or EA-IgG or RT-PCR lasting longer than 6 months was defined sustained viral detection (SVD). 18/21 patients of group A had a primary infection at a median time of 3 months after transplant (0.5-60). 14/18 of group A and 0/13 of group B had a SVD (P < 0.0001). Viral loads greater than 500 copies/10(5) mononuclear cells occurred in 12/18 patients in group A and 0/13 patients in group B (P < 0.0001). The 3 patients who developed late PTLD (median time after OLT 47 months, range 15-121) were from group A, and presented with SVD before developing PTLD. In conclusion, EBV infection in seronegative patients at OLT is associated with greater viral loads and sustained viral detection. Late PTLD occurred only in naïve patients with markers of SVD. Three to 4 monthly long-term monitoring of EBV in pre-OLT naïve patients might help preventing the occurrence of late PTLD.

CMV-IVIG for prevention of Epstein Barr virus disease and posttransplant lymphoproliferative disease in pediatric liver transplant recipients

A randomized controlled trial of CMV-IVIG (cytomegalovirus-intravenous immunoglobulin) for prevention of Epstein Barr virus (EBV) posttransplant lymphoproliferative disease (PTLD) in pediatric liver transplantation (PLTx) recipients was begun in Pittsburgh and subsequently expanded to four additional sites. Protocol EB viral loads were obtained in a blinded fashion; additional loads could be obtained for clinical indications. Patients were followed for 2 years post-LTx. Eighty-two evaluable patients (39 CMV-IVIG, 43 placebo) developed 18 episodes of EBV disease (7 CMV-IVIG, 11 placebo) including nine cases of PTLD (three CMV-IVIG, six placebo). No significant differences were seen in the adjusted 2-year EBV disease-free rate (CMV-IVIG 79%, placebo 71%) and PTLD-free rate (CMV-IVIG 91%, placebo 84%) between treatment and placebo groups at 2 years (p > 0.20). The absence of significant effect of CMV-IVIG may be explained by a lack of efficacy of the drug or limitations of sample size.

Marked increased risk of Epstein-Barr virus-related complications with the addition of antithymocyte globulin to a nonmyeloablative conditioning prior to unrelated umbilical cord blood transplantation

Umbilical cord blood (UCB) is increasingly used as an alternative source of hematopoietic stem cells for transplantation for patients who lack a suitable sibling donor. Despite concerns about a possible increased risk of Epstein-Barr virus (EBV) posttransplantation lymphoproliferative disorder (PTLD) after UCB transplantation, early reports documented rates of PTLD comparable to those reported after HLA-matched unrelated marrow myeloablative (MA) transplantations. To further investigate the incidence of EBV PTLD after UCB transplantation and potential risk factors, we evaluated the incidence of EBV-related complications in 335 patients undergoing UCB transplantation with an MA or nonmyeloablative (NMA) preparative regimen. The incidence of EBV-related complications was a 4.5% overall, 3.3% for MA transplantations, and 7% for NMA transplantations. However, the incidence of EBV-related complications was significantly higher in a subset of patients treated with an NMA preparative regimen that included antithymocyte globulin (ATG) versus those that did not (21% vs 2%; P < .01). Nine of 11 patients who developed EBV PTLD were treated with rituximab (anti-CD20 antibody), with the 5 responders being alive and disease free at a median of 26 months. Use of ATG in recipients of an NMA preparative regimen warrants close monitoring for evidence of EBV reactivation and potentially preemptive therapy with rituximab.

Epstein-Barr viremia levels after pediatric liver transplantation as measured by real-time polymerase chain reaction

Effective immunosuppression has improved the results following liver transplantation, but also increased the risk for opportunistic infections. Epstein-Barr virus (EBV) infection in transplant patients can cause various symptoms including the life-threatening premalignant condition, post-transplantation lymphoproliferative disorder (PTLD). Serum specimens from 24 consecutive children (mean 7.6 specimens/patient), who had undergone liver transplantation in Göteborg from January 1995 to May 2002, were analyzed retrospectively for EBV DNA by real-time TaqMan polymerase chain reaction (PCR). The results were related to clinical picture, immunosuppression, graft rejection and infections with other agents. Eleven patients (46%) developed primary EBV infection at a mean time of 4.8 months after transplantation, and six (25%) reactivated EBV infection at a mean of 4.0 months after transplantation. Four of the 11 patients with primary infection had symptomatic EBV infection: two had PTLD and two hepatitis. One patient in the group with reactivated infection developed PTLD. EBV DNA levels were significantly higher in the group with primary symptomatic infection compared with the patients with primary asymptomatic infection (mean 65 500 copies/mL; range 14 200-194 300 vs. 3700 copies/mL; range 100-9780). In patients with symptomatic infection EBV DNA levels did not differ between PTLD and hepatitis patients. The data suggest that quantitative analysis of EBV DNA in serum by real-time PCR is useful for identification of EBV-related disease.

Optimal management of the post-intestinal transplant patient

The lack of controlled interventional studies limits the ability to assess optimal management of intestine transplant recipients. This report aims to examine factors that probably impact on the quality of patient care in the setting of intestine transplantation. The specific practice in the most experienced intestine transplant programs in the United States was surveyed with regard to immunosuppressive regimens, treatment of acute allograft rejection, feeding, and viral surveillance and treatment. The most striking finding was in the level of agreement between the centers, particularly with regard to use of tacrolimus for maintenance immunosuppression, methylprednisone boluses for treatment of acute rejection, early postoperative enteral feeding, and ganciclovir prophylaxis.

Tacrolimus and steroids versus ciclosporin microemulsion, steroids, and azathioprine in children undergoing liver transplantation: randomised European multicentre trial

BACKGROUND

Results of studies in adult recipients of liver allograft suggest that tacrolimus is more efficacious than ciclosporin microemulsion in the prevention of acute rejection. We aimed to compare these drugs in children undergoing liver transplantation.

METHODS

This 12-month multicentre, open-label, parallel-group, randomised study compared a dual tacrolimus regimen (tacrolimus/corticosteroids, n=93) with a triple ciclosporin microemulsion regimen (ciclosporin microemulsion/corticosteroids/azathioprine, n=92) in children who had had liver transplants (age < or =16 years, bodyweight < or =40 kg). Initial oral daily doses were 0.30 mg/kg for tacrolimus and 10 mg/kg for ciclosporin microemulsion. Primary endpoint was the incidence of and time to first histologically proven acute rejection. We excluded patients from analysis if they did not receive the study drug, or were given incorrect medication. Otherwise patients were analysed in accordance with their random treatment allocation, irrespective of whether they switched medication during the trial.

FINDINGS

Median age was 22 months (IQR 9-56) in the tacrolimus group and 17 months (9-54) in the ciclosporin microemulsion group. We noted no difference between treatment groups with respect to patient survival (93.4% vs 92.2%; p=0.77) or graft survival (92.3% vs 85.4%; p=0.16) at month 12 after transplant. The acute rejection free rate at study end (Kaplan-Meier method) was 55.5% for patients on tacrolimus and 40.2% for patients on ciclosporin microemulsion (p=0.0288). The Kaplan-Meier estimate of patients free from corticosteroid-resistant acute rejection at study end was 94.0% for tacrolimus-treated patients and 70.4% for ciclosporin-microemulsion-treated patients (p<0.0001). Overall, incidence of adverse events did not differ between groups.

INTERPRETATION

Tacrolimus is a safe and effective treatment for the prevention of rejection after liver transplantation in children.

Complete immunosuppressive withdrawal as a uniform approach to post-transplant lymphoproliferative disease in pediatric liver transplantation

Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) in pediatric liver transplant recipients is associated with a high mortality (up to 60%) and the younger age groups, who are predominantly EBV-naïve, are at highest risk for development of this disease. The aim of this study is to assess, in this high-risk group, patient outcome and graft loss to rejection when complete withdrawal of immunosuppressive agents (IMS) is instituted as the mainstay of treatment in addition to the use of standard therapy. A retrospective analysis of 335 pediatric patients whose liver transplants were performed by our team between September 1988 and September 2002, was carried out through review of computer records, database and patient charts. Fifty patients developed either EBV or PTLD; 80% were < or =2 yr of age. Of these 50 patients, 19 had a positive tissue diagnosis for PTLD and 31 were diagnosed with EBV infection, 14 of whom had positive tissue for EBV. Fifty-eight percent of patients who developed PTLD and 51.6% of patients with EBV received antibody for induction or treatment of rejection prior to onset of disease. Forty-six patients (92%) received post-transplant antiviral prophylaxis with ganciclovir or acyclovir. Antiviral treatment included ganciclovir in 76%, acyclovir in 20% and Cytogam (in addition to one of the former agents) in 44%. In those with PTLD, treatment included chemotherapy (n = 1), Rituximab (n = 2), and ocular radiation (n = 1). IMS was stopped in all patients with PTLD and in 19 with EBV infection and was held as long as there was no allograft rejection. Eight patients have remained off IMS for a mean of 1535.5 +/- 623 days. Of the 21 patients who were restarted on IMS for acute rejection, 18 responded to steroids and/or reinstitution of low-dose calcineurin inhibitors. The mean time to rejection while off IMS in this group was 107.43 +/- 140 days (range: 7-476). Two patients were re-transplanted for chronic rejection; one had chronic rejection that existed prior to discontinuing IMS. The mortality rate in our series was 31.6% in those with PTLD and 6% in those with EBV disease. The cause of death was related to PTLD or sepsis in all cases; no deaths were due to graft loss from acute or chronic rejection. PTLD is associated with high mortality in the pediatric population. Based on this report, we advocate aggressive management of PTLD that is composed of early cessation of IMS, the use of antiviral therapy, and chemotherapy when indicated. Episodes of rejection that occur after stopping IMS can be successfully treated with standard therapy without graft loss to acute rejection.

Sirolimus for pediatric liver transplant recipients with post-transplant lymphoproliferative disease and hepatoblastoma

Sirolimus is a promising immune suppressive agent, with the potential to reduce calcineurin inhibitor associated nephrotoxicity, halt progression of chronic rejection and prevent tumor proliferation. The aim of this study was to review the experience using sirolimus in pediatric liver transplant recipients at a single center. Database and medical charts of all pediatric liver transplant recipients receiving sirolimus at the Hospital for Sick Children in Toronto were reviewed. Eight patients received sirolimus between October, 2000 and September, 2002. Indications for using sirolimus were post-transplant lymphoproliferative disease (PTLD) (n = 6) and hepatoblastoma (n = 2). Two patients with PTLD concurrently had renal impairment and chronic rejection. Sirolimus dosages ranged between 1.5 and 5 mg once daily. Median duration of follow-up was 17 months. Persistently elevated liver transaminase levels in the two children with chronic rejection decreased during sirolimus therapy. Recurrence of PTLD occurred in one patient. Two patients were diagnosed with acute cellular rejection after transition to maintenance sirolimus monotherapy. Resolution of adverse effects including mouth sores (n = 3), leg swelling (n = 2) and hyperlipidemia (n = 3) occurred either spontaneously or with dose reduction. Sirolimus was discontinued in four patients because of persisting bone marrow suppression, interstitial pneumonitis, life-threatening sepsis and refractory diarrhea. Children with PTLD or hepatoblastoma may benefit from immune suppression with sirolimus after liver transplantation. Further multi-center, prospective, randomized controlled trials will be instrumental to further the knowledge of long-term efficacy, safety and tolerability of sirolimus for selected children following liver transplantation.

EBV kidney allograft infection: possible relationship with a peri-graft localization of PTLD

Post-transplant lymphoproliferative disorder (PTLD) is a grave complication of transplantation and the result of uncontrolled proliferation of B lymphocytes infected with Epstein-Barr virus (EBV). Herein we assess whether EBV infects renal grafts and whether there is a relationship between EBV kidney infection and PTLD. Allograft biopsies from 23 patients with PTLD were studied for the presence of EBV DNA and RNA (EBER-1, -2) by in situ hybridization and for CD21 by immunohistochemistry. Results were compared to 43 transplants from people without PTLD. EBV DNA and RNA were detected in 11/43 patients without PTLD (26%), and in 15/23 (65%) patients with PTLD (p = 0.004). EBV DNA and RNA localized to proximal tubular cells and these cells showed up-regulation of the EBV receptor CD21. EBV-infected allografts were noted in 12/12 patients with PTLD located near the allograft and in 3/11 (27%) of patients with PTLD distant from the graft. Multiple biopsies in eight patients showed that graft EBV infection can precede the diagnosis of PTLD by as long as 42 months. It is concluded that EBV can infect kidney allografts, and there appears to be a relationship between this infection and the presence of PTLD near the graft.