POST-TRANSPLANT LYMPHOPROLIFERATIVE DISORDER

Antiviral medications for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

The risk of cytomegalovirus (CMV) infection in solid organ transplant recipients has resulted in the frequent use of prophylaxis to prevent the clinical syndrome associated with CMV infection. This is an update of a review first published in 2005 and updated in 2008 and 2013.

OBJECTIVES

To determine the benefits and harms of antiviral medications to prevent CMV disease and all-cause death in solid organ transplant recipients.

SEARCH METHODS

We contacted the information specialist and searched the Cochrane Kidney and Transplant Register of Studies up to 5 February 2024 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing antiviral medications with placebo or no treatment, comparing different antiviral medications or different regimens of the same antiviral medications for CMV prophylaxis in recipients of any solid organ transplant. Studies examining pre-emptive therapy for CMV infection are studied in a separate review and were excluded from this review.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias and extracted data. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

This 2024 update found four new studies, bringing the total number of included studies to 41 (5054 participants). The risk of bias was high or unclear across most studies, with a low risk of bias for sequence generation (12), allocation concealment (12), blinding (11) and selective outcome reporting (9) in fewer studies. There is high-certainty evidence that prophylaxis with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment is more effective in preventing CMV disease (19 studies: RR 0.42, 95% CI 0.34 to 0.52), all-cause death (17 studies: RR 0.63, 95% CI 0.43 to 0.92), and CMV infection (17 studies: RR 0.61, 95% CI 0.48 to 0.77). There is moderate-certainty evidence that prophylaxis probably reduces death from CMV disease (7 studies: RR 0.26, 95% CI 0.08 to 0.78). Prophylaxis reduces the risk of herpes simplex and herpes zoster disease, bacterial and protozoal infections but probably makes little to no difference to fungal infection, acute rejection or graft loss. No apparent differences in adverse events with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment were found. There is high certainty evidence that ganciclovir, when compared with aciclovir, is more effective in preventing CMV disease (7 studies: RR 0.37, 95% CI 0.23 to 0.60). There may be little to no difference in any outcome between valganciclovir and IV ganciclovir compared with oral ganciclovir (low certainty evidence). The efficacy and adverse effects of valganciclovir or ganciclovir were probably no different to valaciclovir in three studies (moderate certainty evidence). There is moderate certainty evidence that extended duration prophylaxis probably reduces the risk of CMV disease compared with three months of therapy (2 studies: RR 0.20, 95% CI 0.12 to 0.35), with probably little to no difference in rates of adverse events. Low certainty evidence suggests that 450 mg/day valganciclovir compared with 900 mg/day valganciclovir results in little to no difference in all-cause death, CMV infection, acute rejection, and graft loss (no information on adverse events). Maribavir may increase CMV infection compared with ganciclovir (1 study: RR 1.34, 95% CI: 1.10 to 1.65; moderate certainty evidence); however, little to no difference between the two treatments were found for CMV disease, all-cause death, acute rejection, and adverse events at six months (low certainty evidence).

AUTHORS' CONCLUSIONS

Prophylaxis with antiviral medications reduces CMV disease and CMV-associated death, compared with placebo or no treatment, in solid organ transplant recipients. These data support the continued routine use of antiviral prophylaxis in CMV-positive recipients and CMV-negative recipients of CMV-positive organ transplants.

Revisiting the Role of γδ T Cells in Anti-CMV Immune Response after Transplantation

Gamma delta (γδ) T cells form an unconventional subset of T lymphocytes that express a T cell receptor (TCR) consisting of γ and δ chains. Unlike conventional αβ T cells, γδ T cells share the immune signature of both the innate and the adaptive immunity. These features allow γδ T cells to act in front-line defense against infections and tumors, rendering them an attractive target for immunotherapy. The role of γδ T cells in the immune response to cytomegalovirus (CMV) has been the focus of intense research for several years, particularly in the context of transplantation, as CMV reactivation remains a major cause of transplant-related morbidity and mortality. Therefore, a better understanding of the mechanisms that underlie CMV immune responses could enable the design of novel γδ T cell-based therapeutic approaches. In this regard, the advent of next-generation sequencing (NGS) and single-cell TCR sequencing have allowed in-depth characterization of CMV-induced TCR repertoire changes. In this review, we try to shed light on recent findings addressing the adaptive role of γδ T cells in CMV immunosurveillance and revisit CMV-induced TCR reshaping in the era of NGS. Finally, we will demonstrate the favorable and unfavorable effects of CMV reactive γδ T cells post-transplantation.

EBV Latency III-Transformed B Cells Are Inducers of Conventional and Unconventional Regulatory T Cells in a PD-L1-Dependent Manner

EBV infects and immortalizes B cells in vitro and in vivo. It is the causative agent of most immune deficiency-related lymphoproliferative disorders and is associated with various lymphomas. EBV latency III-transformed B cells are known to express two immunosuppressive molecules, IL-10 and PD-L1, two characteristics of regulatory B cells (Bregs). In this study, we show that, in addition to secretion of the Breg immunosuppressive cytokines IL-10, IL-35, and TGF-β1, EBV latency III-transformed B cells were able to repress proliferation of their autologous T cells preactivated by CD2, CD3, and CD28. This inhibitory effect was likely caused by CD4⁺ T cells because EBV latency III-transformed B cells induced a strong proliferation of isolated autologous CD8 T cells. Indeed, EBV was able to promote expansion of autologous FOXP3⁺ CD39^high CTLA4⁺, Helios⁺, GITR⁺, LAG3⁺ CD4 T cells (i.e., regulatory T cells [Tregs]). Two types of Tregs were induced: unconventional CD25^neg and conventional CD25^pos Tregs. These Tregs expressed both the latency-associated peptide (LAP) and the PD-1 receptor, two markers of functional Tregs. Expansion of both Treg subtypes depended on PD-L1, whose expression was under the control of LMP1, the main EBV oncogene. These results demonstrate that, like Bregs, EBV latency III-transformed B cells exhibit strong immunoregulatory properties. These data provide clues to the understanding of how after EBV primo-infection, EBV-proliferating B cells can survive in an aggressive immunological environment and later emerge to give rise to EBV-associated B cell lymphomas such as in elderly patients.

Classical Hodgkin lymphoma-type and monomorphic-type post-transplant lymphoproliferative disorder following liver transplantation: a case report

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is a life-threatening complication that can be difficult to treat; moreover, determination of the pathophysiological type is difficult. We report a rare case of a patient who developed two types of Epstein-Barr virus (EBV)-negative PTLD following living donor liver transplantation (LDLT).

CASE PRESENTATION

A 64-year-old man underwent LDLT for acute fulminant hepatitis B. Sixty-five months later, he developed EBV-negative monomorphic B cell PTLD. Reduction of immunosuppressive therapy and chemotherapy with rituximab resulted in a partial response. He received radioimmunotherapy with yttrium-90-ibritumomab tiuxetan, which was effective for all lesions, except for the splenic hilar lesion, which enlarged and seemed to penetrate the stomach. Therefore, he underwent resection of the pancreatic tail with splenectomy and partial gastrectomy. The pathological diagnosis was EBV-negative classical Hodgkin lymphoma (cHL)-type PTLD.

CONCLUSIONS

This patient showed an unexpected course of PTLD, from both a clinical and pathological perspective. There are no prior reports of an adult case of EBV-negative cHL-type PTLD coexisting with EBV-negative monomorphic B cell PTLD. When a strange and refractory lesion persists despite effective therapy for PTLD, we must consider the possibility of another type of PTLD within the residual lesion.

American Society of Nephrology Quiz and Questionnaire 2013: transplantation

The nephrology quiz and questionnaire remains an extremely popular session for attendees of the Annual Meeting of the American Society of Nephrology. As in past years, the conference hall was overflowing with interested audience members. Topics covered by expert discussants included electrolyte and acid-base disorders, glomerular disease, ESRD/dialysis, and transplantation. Complex cases representing each of these categories along with single best answer questions were prepared by a panel of experts. Before the meeting, program directors of United States nephrology training programs answered questions through an Internet-based questionnaire. A new addition to the nephrology quiz and questionnaire was participation in the questionnaire by nephrology fellows. To review the process, members of the audience test their knowledge and judgment on a series of case-oriented questions prepared and discussed by experts. Their answers are compared in real time using audience response devices with the answers of nephrology fellows and training program directors. The correct and incorrect answers are then briefly discussed after the audience responds, and the results of the questionnaire are displayed. This article recapitulates the session and reproduces its educational value for the readers of CJASN. Enjoy the clinical cases and expert discussions.

Antiviral medications for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

The risk of cytomegalovirus (CMV) infection in solid organ transplant recipients has resulted in the frequent use of prophylaxis with the aim of preventing the clinical syndrome associated with CMV infection. This is an update of a review first published in 2005 and updated in 2008.

OBJECTIVES

To determine the benefits and harms of antiviral medications to prevent CMV disease and all-cause mortality in solid organ transplant recipients.

SEARCH METHODS

We searched MEDLINE, EMBASE and the Cochrane Central Registry of Controlled Trials (CENTRAL) in The Cochrane Library to February 2004 for the first version of this review. The Cochrane Renal Group's specialised register was searched to February 2007 and to July 2011 for the first and current updates of the review without language restriction.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing antiviral medications with placebo or no treatment, comparing different antiviral medications and comparing different regimens of the same antiviral medications in recipients of any solid organ transplant. Studies examining pre-emptive therapy were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias and extracted data. Results were reported as risk ratios (RR) or risk differences (RD) with 95% confidence intervals (CI) for dichotomous outcomes and by mean difference (MD) with 95% CI for continuous outcomes. Statistical analyses were performed using the random-effects model. Subgroup analysis and univariate meta-regression were performed using restricted maximum-likelihood to estimate the between study variance. Multivariate meta-regression was performed to investigate whether the results were altered after allowing for differences in drugs used, organ transplanted, and recipient CMV serostatus at the time of transplantation.

MAIN RESULTS

We identified 37 studies (4342 participants). Risk of bias attributes were poorly performed or reported with low risk of bias reported for sequence generation, allocation concealment, blinding and selective outcome reporting in 25% or fewer studies.Prophylaxis with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment significantly reduced the risk for CMV disease (19 studies; RR 0.42, 95% CI 0.34 to 0.52), CMV infection (17 studies; RR 0.61, 95% CI 0.48 to 0.77), and all-cause mortality (17 studies; RR 0.63, 95% CI 0.43 to 0.92) primarily due to reduced mortality from CMV disease (7 studies; RR 0.26, 95% CI 0.08 to 0.78). Prophylaxis reduced the risk of herpes simplex and herpes zoster disease, bacterial and protozoal infections but not fungal infection, acute rejection or graft loss.Meta-regression showed no significant difference in the relative benefit of treatment (risk of CMV disease or all-cause mortality) by organ transplanted or CMV serostatus; no conclusions were possible for CMV negative recipients of negative organs.Neurological dysfunction was more common with ganciclovir and valaciclovir compared with placebo/no treatment. In direct comparison studies, ganciclovir was more effective than aciclovir in preventing CMV disease (7 studies; RR 0.37, 95% CI 0.23 to 0.60) and leucopenia was more common with aciclovir. Valganciclovir and IV ganciclovir were as effective as oral ganciclovir. The efficacy and adverse effects of valganciclovir/ganciclovir did not differ from valaciclovir in three small studies. Extended duration prophylaxis significantly reduced the risk of CMV disease compared with three months therapy (2 studies; RR 0.20, 95% CI 0.12 to 0.35). Leucopenia was more common with extended duration prophylaxis but severe treatment associated adverse effects did not differ between extended and three month durations of treatment.

AUTHORS' CONCLUSIONS

Prophylaxis with antiviral medications reduces CMV disease and CMV-associated mortality in solid organ transplant recipients. These data suggest that antiviral prophylaxis should be used routinely in CMV positive recipients and in CMV negative recipients of CMV positive organ transplants.

Adult post-transplant lymphoproliferative disease in the liver graft in patients with recurrent hepatitis C

AIM

The aim of this study is to clarify the association between hepatitis C virus (HCV) infection and post-transplant lymphoproliferative disease (PTLD) in the liver allograft.

METHODS

Of the 933 adults who underwent liver transplantation (LT) between 1990 and 2005, 10 patients developed PTLD. Seven of the 10 patients that were HCV(+) (group 1) were compared with three HCV-negative recipients (group 2).

RESULTS

The mean time between LT and PTLD was 24.5 months. There were no differences between in Epstein-Barr virus antibody status or tumor lymphocyte subsets. In five of the seven HCV-positive recipients who developed PTLD, PTLD recurred preferentially in the liver allograft, whereas none of the three HCV-negative patients who developed PTLD did so in the liver (71.4 vs. 0%, respectively, P=0.038). In all five patients with graft PTLD, HCV recurred within 12 months followed by PTLD. There were significant differences between groups 1 and 2 in mean lymphocyte infiltrate scores (6.0±2.1 vs. 2.0±0.7, P=0.037), fibrosis stage (2.4±0.5 vs. 0.7±0.5, P=0.029), and frequency of lymphoid follicles in portal areas (33.6±14.8% vs. 1.1±2.3%, P=0.0002).

CONCLUSION

When PTLD occurs in patients with HCV recurrence after LT, it does so preferentially in the liver allograft.

Epstein-Barr virus load in whole blood is associated with immunosuppression, but not with post-transplant lymphoproliferative disease in stable adult heart transplant patients

Development of Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) is a serious complication following heart transplantation (HTX). This study investigates EBV DNA load in adult heart transplant recipients, its association with immunosuppression, and its potential as a marker for development of PTLD. EBV DNA load was measured prospectively by quantitative real-time polymerase chain reaction (PCR) in 172 stable HTX patients. Sixty-seven patients (39.0% of total) had a positive EBV PCR at initial examination [median 4.9 (range 1.1-16.9) years post-HTX]. In follow-up testing of 67 positive patients 6 months later, 36 patients continued to have a positive EBV PCR. Overall incidence of EBV DNA was significantly associated with calcineurin inihibitors, azathioprine medication, and with the absence of mycophenolate mofetil (MMF) treatment. In patients with positive EBV DNA levels at initial examination and negative levels at retesting, cyclosporine A levels were found to be significantly higher at initial examination (148.4 +/- 70.2 vs. 119.6 +/- 53.5 ng/ml, P < 0.05). Three patients (1.7%, 3/172) were diagnosed with PTLD during the course of the study (mean follow up 4.0 years). EBV DNA viral load determination does not appear to be useful for risk prediction or early diagnosis of PTLD in adults after HTX, but an association of EBV DNA load with qualitative and quantitative immunosuppression is demonstrated.

Antiviral medications for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

The risk of cytomegalovirus (CMV) infection in solid organ transplant recipients has resulted in the frequent use of prophylaxis with the aim of preventing the clinical syndrome associated with CMV infection.

OBJECTIVES

To determine the benefits and harms of antiviral medications to prevent CMV disease and all-cause mortality in solid organ transplant recipients.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, reference lists and abstracts from conference proceedings without language restriction. Date of last search: February 2007

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing antiviral medications with placebo or no treatment, comparing different antiviral medications and comparing different regimens of the same antiviral medications in recipients of any solid organ transplant.

DATA COLLECTION AND ANALYSIS

Statistical analyses were performed using the random effects model and results expressed as relative risk (RR) for dichotomous outcomes with 95% confidence intervals (CI). Subgroup analysis and univariate meta-regression were performed using restricted maximum-likelihood to estimate the between study variance. Multivariate meta-regression was performed to investigate whether the results were altered after allowing for differences in drugs used, organ transplanted and recipient CMV serostatus at the time of transplantation.

MAIN RESULTS

Thirty four studies (3850 participants) were identified. Prophylaxis with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment significantly reduced the risk for CMV disease (19 studies; RR 0.42, 95% CI 0.34 to 0.52), CMV infection (17 studies; RR 0.61, 95% CI 0.48 to 0.77), and all-cause mortality (17 studies; RR 0.63, 95% CI 0.43 to 0.92) primarily due to reduced mortality from CMV disease (7 studies; RR 0.26, 95% CI 0.08 to 0.78). Prophylaxis reduced the risk of herpes simplex and herpes zoster disease, bacterial and protozoal infections but not fungal infection, acute rejection or graft loss. Meta-regression showed no significant difference in the relative benefit of treatment (risk of CMV disease or all-cause mortality) by organ transplanted or CMV serostatus; no conclusions were possible for CMV negative recipients of negative organs. In direct comparison studies, ganciclovir was more effective than aciclovir in preventing CMV disease (7 studies; RR 0.37, 95% CI 0.23 to 0.60). Valganciclovir and IV ganciclovir were as effective as oral ganciclovir.

AUTHORS' CONCLUSIONS

Prophylaxis with antiviral medications reduces CMV disease and CMV-associated mortality in solid organ transplant recipients. They should be used routinely in CMV positive recipients and in CMV negative recipients of CMV positive organ transplants.

Immunoglobulins, vaccines or interferon for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is the most common virus causing disease and death in solid organ transplant recipients during the first six months post-transplant. Previous systematic reviews have demonstrated the efficacy of antiviral medications used prophylactically or pre-emptively in preventing CMV disease. In this review the efficacy of older agents (immunoglobulins (IgG), anti CMV vaccines and interferon) are examined.

OBJECTIVES

To assess the benefits and harms of IgG, anti CMV vaccines or interferon for preventing symptomatic CMV disease in solid organ transplant recipients.

SEARCH STRATEGY

We searched the Cochrane Renal Group's Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL, in The Cochrane Library), MEDLINE, EMBASE, reference lists and abstracts from conference proceedings without language restriction. Date of last search: December 2005

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing IgG, anti CMV vaccine or interferon with placebo or no treatment, IgG alone or combined with antiviral medications with antiviral medications or IgG alone in recipients of any solid organ transplant.

DATA COLLECTION AND ANALYSIS

Two of four authors independently assessed trial quality and extracted data from each trial. Statistical analyses were performed using the random effects model and results expressed as relative risk (RR) for dichotomous outcomes with 95% confidence intervals (CI).

MAIN RESULTS

Thirty seven trials (2185 participants) were included in this review. There was no significant difference in the risk for CMV disease (16 trials, 770 patients: RR 0.80, 95% CI 0.61 to 1.05), CMV infection (14 trials, 775 patients: RR 0.94, 95% CI 0.80 to 1.10) or all-cause mortality (8 trials, 502 patients: RR 0.57, 95% CI 0.32 to 1.03) with IgG compared with placebo/no treatment. However IgG significantly reduced the risk of death from CMV disease (6 trials, 346 patients: RR 0.33, 95% CI 0.14 to 0.80). There was no difference in the risk for CMV disease (4 trials, 298 patients: RR 1.17, 95% CI 0.74 to 1.86), CMV infection (4 trials, 298 patients: RR 1.16, 95% CI 0.89 to 1.52) or all-cause mortality (2 trials, 217 patients: RR 0.92, 95% CI 0.37 to 2.29) between antiviral medication combined with IgG and antiviral medication alone. There was no significant difference in the risk of CMV disease with anti CMV vaccine or interferon compared with placebo or no treatment.

AUTHORS' CONCLUSIONS

Currently there are no indications for IgG in the prophylaxis of CMV disease in recipients of solid organ transplants.

Cytomegalovirus in transplantation ? challenging the status quo

BACKGROUND

Cytomegalovirus (CMV) infection of solid organ transplant (SOT) recipients causes both ''direct'' and ''indirect'' effects including allograft rejection, decreased graft and patient survival, and predisposition to opportunistic infections and malignancies. Options for CMV prevention include pre-emptive therapy, whereby anti-CMV agents are administered based on sensitive viral assays, or universal prophylaxis of all at-risk patients. Each approach has advantages and disadvantages in terms of efficacy, costs, and side effects. Standards of care for prophylaxis have not been established.

METHODS

A committee of international experts was convened to review the available data regarding CMV prophylaxis and to compare preventative strategies for CMV after transplantation from seropositive donors or in seropositive recipients.

RESULTS

Pre-emptive therapy requires frequent monitoring with subsequent treatment of disease and associated costs, while universal prophylaxis results in greater exposure to potential toxicities and costs of drugs. The advantages of prophylaxis include suppressing asymptomatic viremia and prevention of both direct and indirect effects of CMV infection. Meta analyses reveal decreased in mortality for patients receiving CMV prophylaxis. Costs associated with prophylaxis are less than for routine monitoring and pre-emptive therapy. The optimal duration of antiviral prophylaxis remains undefined. Extended prophylaxis may improve clinical outcomes in the highest-risk patient populations including donor-seropositive/recipient-seronegative renal transplants and in CMV-infected lung and heart transplantation.

CONCLUSIONS

Prophylaxis is beneficial in preventing direct and indirect effects of CMV infection in transplant recipients, affecting both allograft and patient survival. More studies are necessary to define optimal prophylaxis regimens.

Post-transplant multiple myeloma in a pediatric renal transplant patient

Post-transplant lymphoproliferative disease (PTLD) is a well-recognized complication of the intense immunosuppression required in solid organ and bone marrow transplant recipients. The clinical presentation is varied and can range from a benign infectious mononucleosis-like syndrome to malignant lymphoma. PTLD manifesting as multiple myeloma occurs rarely. We report the unique occurrence of Epstein-Barr virus (EBV)-associated post-transplant multiple myeloma in a 16-year-old male. In contrast to previously described cases of PTLD-myeloma type, this patient was very young, had a clear association with EBV, and an indolent clinical course.

Reactivation of Viruses in Solid Organ Transplant Patients Receiving Cytomegalovirus Prophylaxis

A series of substudies of a large international cytomegalovirus (CMV) prophylaxis trial investigated the incidence and clinical relevance of reactivation of human herpesviruses 6, 7, and 8, varicella zoster virus, Epstein-Barr virus, polyomavirus, and adenovirus, and the effect of CMV prophylaxis on clinical and subclinical non-CMV viral infections, in adult solid organ transplant (SOT) patients. Results of the substudy analyses showed that viremia caused by a number of viruses is surprisingly common posttransplantation; most of these infections likely represent reactivation of endogenous latent virus. In addition, although infection or active viral replication was common in this cohort of SOT patients, symptomatic disease due to these viruses was uncommon and the clinical sequelae of viremia were unclear or not apparent. CMV prophylaxis may have modified the natural history of some of these non-CMV viral infections.

Post-transplant lymphoproliferative disorder following pediatric heart transplantation

Immunosuppression after heart transplantation is implicated in development of post-transplant lymphoproliferative disorder (PTLD). Despite a higher prevalence of PTLD in children, there is scarce knowledge about incidence, pathophysiologic mechanisms and risk factors for PTLD in pediatric recipients of cardiac allografts. We examined retrospectively the medical records of all 143 pediatric patients (mean age 9.2 +/- 6.1 yr) who received donor allografts between 1984 and 2002 and survived over 30 days. Five children (3.5%) developed PTLD over a mean follow-up period of 41.1 +/- 46.0 months. Time from transplant to diagnosis of PTLD ranged from 3.9 to 112 months (mean 48.0 +/- 41.9 months). Excluding PTLD, no other malignancies were found in this population. Actuarial freedom from PTLD was 99.2%, 99.2% and 96.2% at 1, 2, and 5 yr, respectively. Children who developed PTLD were more likely (by univariate analysis) to have been Rh negative (p = 0.01), Rh mismatched (p = 0.003), Epstein-Barr virus (EBV) seronegative (p = 0.001) and transplanted for congenital heart disease (p < 0.02). PTLD was associated with significant morbidity and mortality with a mean survival following diagnosis of 21.2 months. PTLD is a serious complicating outcome of cardiac transplantation that occurs in approximately 3.5% of children. Aside of immunosuppression, risk factors in this series for developing PTLD include EBV seronegativity and Rh negative status and mismatch. Non-hematogenous malignancies are rare in light of short allograft half-life.

Antiviral medications for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

The risk of cytomegalovirus (CMV) infection in solid organ transplant recipients has resulted in the frequent use of prophylaxis with the aim of preventing the clinical syndrome associated with CMV infection.

OBJECTIVES

To determine the benefits and harms of antiviral medications to prevent CMV disease and all-cause mortality in solid organ transplant recipients.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, reference lists and abstracts from conference proceedings without language restriction.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing antiviral medications with placebo or no treatment, trials comparing different antiviral medications and trials comparing different regimens of the same antiviral medications in recipients of any solid organ transplant.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data from each trial. Statistical analyses were performed using the random effects model and results expressed as relative risk (RR) for dichotomous outcomes with 95% confidence intervals (CI). Subgroup analysis and univariate meta-regression were performed using restricted maximum-likelihood to estimate the between study variance. Multivariate meta-regression was performed to investigate whether the results were altered after allowing for differences in drugs used, organ transplanted and recipient CMV serostatus at the time of transplantation.

MAIN RESULTS

Thirty two trials (3737 participants) were identified. Prophylaxis with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment significantly reduced the risk for CMV disease (19 trials; RR 0.42, 95% CI 0.34 to 0.52), CMV infection (17 trials; RR 0.61, 95% CI 0.48 to 0.77), and all-cause mortality (17 trials; RR 0.63, 95% CI 0.43 to 0.92) primarily due to reduced mortality from CMV disease (seven trials; RR 0.26, 95% CI 0.08 to 0.78). Prophylaxis reduced the risk of herpes simplex and herpes zoster disease, bacterial and protozoal infections but not fungal infection, acute rejection or graft loss. Meta-regression showed no significant difference in the risk of CMV disease or all-cause mortality by organ transplanted or CMV serostatus; no conclusions were possible for CMV negative recipients of negative organs. In direct comparison trials, ganciclovir was more effective than aciclovir in preventing CMV disease (seven trials; RR 0.37, 95% Cl 0.23 to 0.60). Valganciclovir and intravenous ganciclovir were as effective as oral ganciclovir.

AUTHORS' CONCLUSIONS

Prophylaxis with antiviral medications reduces CMV disease and CMV-associated mortality in solid organ transplant recipients. They should be used routinely in CMV positive recipients and in CMV negative recipients of CMV positive organ transplants.

Monitoring of Epstein-Barr viral load in pediatric heart and lung transplant recipients by real-time polymerase chain reaction

BACKGROUND

Elevation in Epstein-Barr virus (EBV) load measured in peripheral blood has been proposed as a marker for development of post-transplant lymphoproliferative disease (PTLD), but there are few published data examining this relationship. We report the longitudinal surveillance of EBV for all recipients of heart (HTx), heart-lung (HLTx) and lung (LTx) transplants at our institution.

METHODS

The study population included all patients transplanted between January 2003 and July 2004. EBV load was serially measured in peripheral blood by real-time polymerase chain reaction (PCR). Results were correlated with recipient pre-transplant EBV status and development of PTLD.

RESULTS

Forty-four transplant operations were performed, including 33 HTx, 6 HLTx and 5 LTx. Thirty-two (73%) of the patients were EBV seropositive pre-transplant. Nineteen (44%) pediatric recipients developed EB viremia, including 17 HTx, 1 HLTx and 1 LTx. Eleven (58%) of these patients were EBV seropositive pre-transplant. EBV was first detected at a median of 30.5 days (range 2 to 81) post-transplant. The median peak EBV load in that group was 10,099 copies/ml (range 5,935 to 255,466) whole blood. One patient with cystic fibrosis post-LTx developed PTLD localized in the colon. This patient was EBV seronegative pre-transplant; peak EBV load was 14,513 copies/ml. Acute infectious mononucleosis was seen in 1 case. Positive pre-transplant EBV status did not predict post-transplant EB viremia (positive predictive value 0.03).

CONCLUSIONS

Contrary to earlier reports, our data demonstrate that a high EBV load does not lead to PTLD early post-transplant. These results do not support the practice of pre-emptively reducing immunosuppression in patients with raised EBV load.

The validity of the OSA-18 among three groups of pediatric patients

OBJECTIVE

To compare the signs and symptoms of obstructive sleep apnea syndrome in three groups of pediatric patients; solid organ transplant recipients, healthy children, and children with leukemia; in order to examine the effects of chronic illness on the obstructive sleep apnea-18-item questionnaire and to investigate its validity as a screening tool for obstructive sleep apnea in the pediatric solid organ transplant population.

METHODS

In this cross-sectional study, there were two hundred and six subjects; 46 kidney transplant recipients, 59 liver transplant recipients, 34 patients with leukemia, and 67 healthy children. Adenotonsillar enlargement was assessed by using the obstructive sleep apnea-18-item questionnaire and by performing a focused physical examination of the oral and nasal cavity at the time of the child's routine visit in either the transplant clinic, outpatient oncology center, or general pediatric clinic.

RESULTS

Comparison of questionnaire scores amongst the three groups showed significant differences between the healthy children and liver transplant recipients as well as those with leukemia. There was a significant difference in the physical examination scores of the children with leukemia as compared to the other groups.

CONCLUSIONS

Adenotonsillar enlargement in pediatric transplant recipients can be an early indication of post-transplantation lymphoproliferative disorder. However, the prevalence of adenotonsillar enlargement in the transplant population does not appear to differ from that of the healthy population. Additionally, scores on the OSA-18 in the transplant population were confounded by chronic illness. Further prospective studies need to be performed to develop a screening tool to identify transplant recipients at risk for post-transplantation adenotonsillar lymphoma.

Pre-emptive treatment with oral valganciclovir in management of CMV infection after cardiac transplantation

BACKGROUND

Cytomegalovirus (CMV) has long been recognized as the most common opportunistic pathogen in transplant recipients. The use of post-detection antiviral treatment of CMV as a strategy to prevent disease in cardiac recipients is becoming the standard policy. Valganciclovir is an oral pro-drug of ganciclovir, with a 10-fold greater bioavailability than oral gancyclovir.

PATIENTS AND METHODS

We reported our first experience with 8 patients (3 female, 45.0 +/- 10.5 years old, non-CMV mismatched) who underwent cardiac transplantation and had positive results of CMV polymerase chain reaction (PCR) within first 6 weeks after transplantation without concomitant CMV disease. These patients received valganciclovir in dosage 450 to 900 mg daily depending on renal function for 3 weeks. Standard immunosuppressive regimen consisted of cyclosporin A, MMF and corticosteroids, and was not changed after detection of CMV infection. In one patient we used sirolimus with respectively reduced dosage of cyclosporin A. Weekly measurements of CMV-PCR were performed to observe results of therapy.

RESULTS

After 1 week of valganciclovir therapy CMV-PCR plasma concentration in all patients decreased significantly (2,105 copies/ml vs 400 copies/ml; p < 0.0001). No relapse of CMV infection has been detected after completing of valganciclovir therapy with follow up duration of 9.0 +/- 0.92 months. The drug was generally well tolerated, and we did not observe any severe drug related adverse events.

CONCLUSION

Oral valganciclovir as pre-emptive antiviral therapy administrated after detection of CMV infection seems to be an effective and safe treatment in cardiac transplant recipients.

Prevention and treatment of cytomegalovirus infection in solid organ transplant recipients

PURPOSE OF REVIEW

Cytomegalovirus remains the single most important pathogen affecting solid organ transplant recipients. Its importance lies both in its effects and as a model for deciphering the clinical impact and management of other agents such as hepatitis C virus and other herpes viruses such as human herpes virus-6 and 7. The effects of cytomegalovirus infection in these patients can be divided into two categories: the direct causation of a wide variety of infectious disease syndromes; and the indirect effects, which include contributing to the net state of immunosuppression, allograft injury, and potentiating posttransplant lymphoproliferative disease.

RECENT FINDINGS

The advent of valganciclovir, with its excellent oral bioavailability, combined with intravenous ganciclovir have provided powerful tools for controlling the direct effects of cytomegalovirus, particularly with the recognition that the intensity of the antiviral therapy has to be linked to the intensity of the immunosuppression required.Unfortunately, far less is known about the efficacy of antiviral therapy in managing the indirect effects of cytomegalovirus. Preliminary data suggest antiviral prophylaxis protects against acute allograft injury, as well as decreasing the incidence of some opportunistic infection.

SUMMARY

A great deal of progress has been made in the prevention and treatment of the infectious disease syndromes caused by cytomegalovirus, with the development of the concept of the therapeutic prescription. This has two components: an immunosuppressive component to prevent and treat rejection and an antimicrobial component to make it safe. Much more information, however, is required.

INFECTION WITH HUMAN HERPESVIRUS 8 AND TRANSPLANT-ASSOCIATED GAMMOPATHY

BACKGROUND

The role of human herpesvirus (HHV)-8 in the pathogenesis of multiple myeloma and its pre-malignant state of monoclonal gammopathy is unclear. HHV-8 is transmitted by organ transplantation, representing a unique model with which to investigate primary HHV-8 infection.

METHODS

The authors studied the incidence of clonal gammopathy in renal transplant recipients and correlated it with previous and recent HHV-8 infection.

RESULTS

Clonal gammopathy was observed in 31 of 162 (19%) HHV-8-seronegative patients, in 5 of 17 (29%) HHV-8-seropositive patients, and in 9 of 24 (38%) HHV-8 seroconverters within 5 years after transplantation. Gammopathy was often transient, and no progression to myeloma was observed. Two patients with persistent gammopathy developed B-cell lymphoma. In a logistic regression model, HHV-8 serostatus of the graft recipient was significantly associated with subsequent development of gammopathy, with a relative risk (RR) of 1.9 and a 95% confidence interval (CI) of 0.5 to 6.4 for an HHV-8-seropositive recipient and an RR of 2.9 and a 95% CI of 1.01 to 8.0 for seroconverters as compared with baseline (HHV-8 seronegative). Other significant variables were cytomegalovirus (CMV) serostatus and the intensity of immunosuppression (RR of 10.4 and 95% CI of 2.6-41.7 for a CMV-negative recipient with a CMV-positive donor vs. a CMV-negative recipient with a CMV-negative donor and RR of 17.6 and 95% CI of 2.0-150.8 if OKT3 was used vs. no use of antilymphocytic substances).

CONCLUSIONS

Transplant recipients with HHV-8 infection are more likely to develop clonal gammopathy. However, this risk is much lower than the risk conferred by CMV infection and antilymphocytic therapy, arguing against a major role of HHV-8 infection in the pathogenesis of clonal plasma cell proliferation.

Post-transplantation lymphoproliferative disease in heart and heart-lung transplant recipients: 30-year experience at Stanford University

BACKGROUND

Post-transplantation lymphoproliferative disease (PTLD) is an important source of morbidity and mortality in transplant recipients, with a reported incidence of 0.8% to 20%. Risk factors are thought to include immunosuppressive agents and viral infection. This study attempts to evaluate the impact of different immunosuppressive regimens, ganciclovir prophylaxis and other potential risk factors in the development of PTLD.

METHODS

We reviewed the records of 1026 (874 heart, 152 heart-lung) patients who underwent transplantation at Stanford between 1968 and 1997. Of these, 57 heart and 8 heart-lung recipients developed PTLD. During this interval, 4 different immunosuppressive regimens were utilized sequentially. In January 1987, ganciclovir prophylaxis for cytomegalovirus serologic-positive patients was introduced. Other potential risk factors evaluated included age, gender, prior cardiac diagnoses, HLA match, rejection frequency and calcium-channel blockade.

RESULTS

No correlation of development of PTLD was found with different immunosuppression regimens consisting of azathioprine, prednisone, cyclosporine, OKT3 induction, tacrolimus and mycophenolate mofetil. A trend suggesting an influence of ganciclovir on the prevention of PTLD was not statistically significant (p = 0.12). Recipient age and rejection frequency, as well as high-dose cyclosporine immunosuppression, were significantly (p < 0.02) associated with PTLD development. The prevalence of PTLD at 13.3 years was 15%.

CONCLUSIONS

The overall incidence of PTLD was 6.3%. It was not altered by sequential modifications in treatment regimens. Younger recipient age and higher rejection frequency were associated with increased PTLD occurrence. The 15% prevalence of PTLD in 58 long-term survivors was unexpectedly high.

Endobronchial post-transplant lymphoproliferative disorder and its management with photodynamic therapy: a case report

Post-transplant lymphoproliferative disorder (PTLD) is a recognized complication of solid-organ transplantation. We describe a 56-year-old man with end-stage idiopathic pulmonary fibrosis who underwent right-sided single-lung transplantation and who had biopsy-proven PTLD involving the main bronchi 3 months later. The lesions recurred despite endobronchial electrosurgery and systemic therapy with interferon for 3 months. Interferon was deceased and anti-CD20 therapy and photodynamic therapy were performed concurrently using flexible bronchoscopy. The subsequent follow-up endobronchial biopsy specimen results were negative for PTLD. This case is the first reported use of photodynamic therapy combined with anti-CD20 for treating PTLD. Endobronchial PTLD is a rare complication of lung transplantation and can be managed successfully with photodynamic therapy.

Infections in the heart transplant recipient

The overall incidence of infection after transplantation has decreased with improved immunosuppressive agents, increased knowledge and use of prophylaxis, and better detection and treatment of infection. Nevertheless, infection continues to be a major cause of morbidity and mortality in heart transplant recipients. The knowledgeable nurse in any setting who cares for a transplant recipient must be aware of the lifelong susceptibility to common and opportunistic infections. The transplant recipient and his or her family must also be aware of the risks of early opportunistic infection. Infection is a lifelong concern for all persons on immunosuppressant medications, and the individual must learn appropriate precautions to reduce this risk. Hand washing and avoidance of infected individuals are the most important self-care actions that the transplant patient should adopt. Recipients must also learn to monitor for subtle signs of infection. The nurse is responsible for teaching self-care to patients and family members. Ultimately, a team effort by the patient, family, nurses, and physicians can reduce the risk of infection in this vulnerable population.

Risk factors for adenotonsillar hypertrophy in children following solid organ transplantation

OBJECTIVE

Post-transplantation lymphoproliferative disorder (PTLD), or its precursor, Epstein-Barr virus (EBV)-related lymphoid hyperplasia, may first present in the tonsils and adenoids in the pediatric solid organ transplant population. We sought to identify signs and symptoms of and risk factors for adenotonsillar hypertrophy (ATH), a potential precursor to PTLD in children following solid organ transplantation.

METHODS

We performed a cross-sectional study of 132 consecutive pediatric solid organ transplant patients at our institution. Questionnaire, physical examination, and laboratory data collection were obtained. Correlation of signs and symptoms of ATH with objective laboratory data was conducted.

RESULTS

132 pediatric transplant recipients (64 renal, 68 liver) were enrolled. Mean age at transplantation was 7.4 (S.D. 6.0) years with a mean follow-up of 49.0 (S.D. 48.4) months post-transplantation. The mean questionnaire score was 8.4 (S.D. 7.9) out of a maximum 65 and the mean physical examination score was 3.9 (S.D. 1.9) out of a maximum 8, with a statistically significant correlation between the two (Pearson's r=0.352, P<0.001). A multivariate linear regression model found recipient EBV seronegativity and younger age at transplantation to be statistically significant risk factors for development of ATH (P=0.024 and 0.035, respectively).

CONCLUSIONS

Young age and EBV seronegativity confer increased risk for ATH in pediatric patients undergoing solid organ transplantation. As ATH may be the earliest sign of PTLD, long-term surveillance is required to determine the impact of ATH on quality of life and survival in these patients.

Orbital presentation of posttransplantation lymphoproliferative disorder: a small case series

OBJECTIVE

To describe a small series of patients with orbital presentation of posttransplantation lymphoproliferative disorder (PTLD).

DESIGN

Retrospective, interventional case series.

PARTICIPANTS

Three patients with orbital presentation of histologically diagnosed PTLD.

METHODS

Review of medical records.

MAIN OUTCOME MEASURES

Measured parameters included vision, proptosis, and tumor extent.

RESULTS

Three cases of orbital PTLD are described. In two of the cases, the tumor initially demonstrated orbital signs and symptoms, whereas in the third case, orbital and systemic signs were synchronous. Two of three patients had disseminated disease discovered at the time of presentation. One adult patient had synchronous presentation of PTLD in the orbit and prostate. One pediatric patient had tumor dissemination to the liver at the time of presentation. The PTLD tumors were classified histologically as diffuse large cell lymphoma of monomorphic or immunoblastic type in all three cases. Treatment included local irradiation, decreased immunosuppression, and antilymphocyte monoclonal antibodies.

CONCLUSIONS

Orbital presentation is a rare manifestation of PTLD. However, ophthalmologists must consider this diagnosis carefully in organ transplant recipients with subtle orbital signs and symptoms at presentation. Early detection may alter prognosis. In each case presented, the diagnosis was established via lesion biopsy and subsequent histologic or flow cytometric evaluation, or both.

Cytomegalovirus in solid organ transplantation

Despite substantial advances made in controlling the effects of cytomegalovirus (CMV) infection, it remains the single most important pathogen in solid organ transplantation (SOT). Because CMV shares some characteristics with other human herpesviruses, it is also an important model system for understanding the actions of herpesviruses 6 and 7, Epstein-Barr virus (EBV) and, potentially, hepatitis C and B. As the lessons learned from HIV influenced our thinking about other viral infections (e.g. importance of viral load), so too what is learned about CMV will be applied to other herpesviruses. The pervasive nature of CMV and the common problems posed by this virus prompted the convening of a panel of experts in the field of SOT to discuss issues associated with CMV in transplant recipients. This supplement reflects the presentations and discussions at this symposium, including the clinical implications of CMV drug resistance, economic impact of CMV on transplant programs, the rationale for CMV hyperimmune globulin (CMW-IGIV, CytoGam) in SOT, antibody inhibition of CMV, hypogammaglobulinemia, role of CMV in allograft vasculopathy, and the clinical use of CytoGam therapy in a variety of SOT patients. A number of questions during the general discussion prompted the addition of other material to this Supplement, including the development of CMV-IGIV for clinical use in SOT recipients and resource utilization associated with CMV-related hospital readmissions.

Risk factors for lymphoproliferative disorders after liver transplantation in adults: an analysis of 480 patients

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) is a well-known complication of organ transplantation that leads to death in more than 50% of cases. The aim of this work was to identify specific risk factors for lymphoproliferative disorders after liver transplantation in adults.

METHODS

A total of 480 consecutive patients who underwent transplantation between 1986 and 1997 were studied (323 men, 157 women; mean age: 49.8+/-10.4 years). Demographics, the indication for transplantation, the immunosuppressive regimens, the incidence of rejection episodes, and Epstein-Barr virus infection were analyzed. Univariate and multivariate analysis were used to identify factors predictive of PTLD.

RESULTS

Sixteen cases of PTLD (3.3%) occurred at a median of 5.5 (range, 1-39) months after liver transplantation. All 16 cases occurred in patients with evidence of exposure to Epstein-Barr virus before transplantation. In multivariate analysis, the use of antilymphocyte antibodies (P=0.007, relative risk [RR]=4.2, 95% confidence interval [CI]=1.5-11.7), age older than 50 years (P=0.037, RR=3.5, 95% CI=0.95-13.0), liver transplantation for hepatitis C virus cirrhosis (P=0.015, RR=8.7, 95% CI=1-78.3), and liver transplantation for alcoholic cirrhosis (P=0.015, RR=9.6, 95% CI=1.2-77.2) were independently associated with the onset of PTLD.

CONCLUSION

Liver transplantation for hepatitis C virus-related and alcoholic cirrhosis and age older than 50 years are three additional risk factors for lymphoproliferative disorder independent of the use of antilymphocyte antibodies. The use of antilymphocyte antibodies after liver transplantation should be avoided in these categories of patients, especially those older than 50 years.

Infectious disease prophylaxis in renal transplant patients: a survey of US transplant centers

Definitive approaches to most infectious diseases following renal transplantation have not been established, leading to different approaches at different transplant centers. To study the extent of these differences, we conducted a survey of the practices surrounding specific infectious diseases at US renal transplant centers. A survey containing 103 questions covering viral, bacterial, mycobacterial and protozoal infections was developed. Surveys were sent to program directors at all U.S. renal transplant centers. Responses were received from 147 of 245 (60%) transplant centers and were proportionately represented all centers with respect to program size and geographical location. Pre-transplant donor and recipient screening for hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV) and cytomegalovirus (CMV) is uniform, but great discrepancy exists in the testing for other agents. HCV seropositive donors are used in 49% of centers. HIV seropositivity remains a contraindication to transplantation, although 13% of centers indicated they have experience with such patients. Post-transplant, there is wide variety in approach to CMV and Pneumocystis carinii (PCP) prophylaxis. Similarly divergent practices affect post-transplant vaccinations, with 54% of centers routinely vaccinating all patients according to customary guidelines in non-transplant populations. In contrast, 22% of centers indicated they do not recommend vaccination in any patients. We believe an appreciation of the differences in approaches to post-transplant infectious complications may encourage individual centers to analyse the results of their own practices. Such analysis may assist in the design of studies to answer widespread and important questions regarding the care of patients following renal transplantation.

Central nervous system infection during immunosuppression

Suppression of the immune system by human immunodeficiency virus (HIV) infection or immunosuppressive therapy following transplantation increases susceptibility to CNS infection. Examination of the level and type of immunosuppression, in addition to the clinical and radiologic findings at the time of diagnosis can aid the clinician in determining the most likely etiology of infection. This article discusses how suppression of the host immune status modifies the presentation and diagnosis of selected CNS infections and the recommended treatment for these infections.

Adenotonsillar histopathology after organ transplantation

OBJECTIVES

The increasing number of surviving pediatric organ transplant recipients has resulted in a new clinical controversy surrounding the significance of adenotonsillar hypertrophy. The objective of this study is to evaluate adenotonsillar specimens, understand characteristic histopathology, and to examine the frequency and significance of this finding in this population.

METHODS

Twenty-one cases of pediatric transplant recipients with adenoidal and/or tonsillar hypertrophy were reviewed retrospectively in a tertiary-care setting. Particular attention was given to the histopathology of their surgical specimens, including any evidence of posttransplantation lymphoproliferative disorders (PTLD).

RESULTS

Using morphologic, immunohistochemical, and molecular genetic analyses, 15 (71%) of 21 patients were noted to have Epstein-Barr virus (EBV)-related lymphoid hyperplasia, including 1 case (4.7%) of PTLD. Six (29%) of 21 had evidence of reactive follicular hyperplasia not related to EBV. B-cell and T-cell markers were nearly uniformly positive when tested for, except in the single patient with PTLD, who exhibited polymorphic, polyclonal B-cell morphology. Kappa and lambda light-chain clonality markers were positive in 11 (92%) of 12 patients.

CONCLUSIONS

EBV-related lymphoid hyperplasia is frequently associated with adenotonsillar hypertrophy in pediatric organ transplant patients (71% of our cases); 92% of those cases tested exhibit polyclonal B-cell populations. PTLD, an important cause of morbidity and mortality in this population, represented approximately 5% of our cases. The remainder of cases represent follicular hyperplasia unrelated to EBV or lymphoproliferative abnormalities. Characteristic histopathologic findings are presented.

Post-transplant lymphoproliferative disease in children

Epstein-Barr virus (EBV)-driven post-transplant lymphoproliferative disease (PTLD) is an important cause of morbidity and mortality following transplantation, and it occurs more frequently in children than in adults. Of 22 (5%) children at our institution who developed tissue-proven PTLD 1-60 months (mean 16.5 months) following organ transplant, 11 died: nine of these 22 patients developed PTLD between 1989 and 1993, and seven (78%) died; the remaining 13 developed PTLD between 1994 and 1998, and four (31%) died (p = 0.08). All nine patients who developed PTLD < 6 months after transplant died, but 11 of 13 patients who manifested disease > or = 6 months after transplant survived (p = 0.0002). Ten of 11 (91%) survivors, but only two of eight (25%) children who died, had serologic evidence of EBV infection at the time of PTLD diagnosis (p = 0.04). EBV seroconversion identified patients at risk for developing PTLD, but also characterized patients with sufficient immune function to survive EBV-related lymphoid proliferation. In situ hybridization for EBER1 mRNA was diagnostically helpful because it detected EBV in tissue sections of all 20 patients with B-cell PTLD, including those with negative serology.

Utility of semiquantitative polymerase chain reaction for Epstein-Barr virus to measure virus load in pediatric organ transplant recipients with and without posttransplant lymphoproliferative disease

We examined the utility of Epstein-Barr virus (EBV) load as a test for the presence of posttransplant lymphoproliferative disease (PTLD). A semiquantitative (SQ) EBV polymerase chain reaction (PCR) on peripheral blood mononuclear cells (PBMC) was used to determine virus load. We compared the values from pediatric patients, both with and without PTLD, with those from healthy pediatric and adult subjects. The virus loads for asymptomatic healthy subjects had a range of 0-1 log10 cells/10(6) PBMCs. Among transplant recipients (n=135), the mean virus load (+/- standard deviation) at the time of diagnosis of PTLD was 3.1+/-1.2 log(10) cells/10(6) PBMCs versus a baseline value of 1.3+/-1.4 log(10) cells/10(6) PBMCs in children without PTLD (P<.0001). A cutoff of > or =3 log10 cells/10(6) peripheral blood leukocytes resulted in the following values for use of virus load as a test for PTLD: sensitivity, 69%; specificity, 76%; positive predictive value, 28%; and negative predictive value, 95%. We conclude that determination of EBV load by use of SQ PCR is more useful in ruling out than in indicating the presence of PTLD.

Introduction to the Immunocompromised Host Society consensus conference on epidemiology, prevention, diagnosis, and management of infections in solid-organ transplant patients

Infectious complications are still a significant cause of morbidity and death in solid-organ transplant patients, with significant infection being found in up to two-thirds of these individuals. The risk of infection in the organ transplant patient, particularly of opportunistic infection, is largely determined by 3 factors: the net state of immunosuppression, the epidemiologic exposures the patient encounters, and the consequences of the invasive procedures to which the patient is subjected. The most important principles of patient treatment are prevention, early diagnosis, and specific therapy. This issue is designed as a position paper by a group of experts on epidemiology, prevention, diagnosis, and management of infections in solid-organ transplant patients. We feel that our efforts may serve as an important first step in the development of guidelines in this area.

Diagnosis and management of posttransplant lymphoproliferative disorder in solid-organ transplant recipients

The Epstein-Barr virus (EBV) has a pivotal pathophysiologic role in the development of most lymphoproliferative disorders that occur after solid-organ transplantation. The term "EBV-associated posttransplant lymphoproliferative disorder" (PTLD) includes all clinical syndromes of EBV-associated lymphoproliferation, ranging from uncomplicated posttransplant infectious mononucleosis to true malignancies that contain clonal chromosomal abnormalities. PTLDs are historically associated with a high mortality rate in patients who have a monoclonal form of the disorder. Recently described approaches to pathology, diagnosis, treatment, and preventive strategies of PTLD, however, have the potential to improve outcome.

Interferon and cytotoxic chemotherapy for the treatment of post-transplant lymphoproliferative disorder

Interferon-alpha and cytotoxic chemotherapy may be effective treatment modalities for the post-transplant lymphoproliferative disorder. Interferon-alpha may result in a complete response in up to 40% of patients, while chemotherapy may be effective in 75% of those failing local surgical excision, a reduction in immunosuppression, and an antiviral agent. Interferon may be used early after diagnosis in patients with relatively slowly growing tumors. Chemotherapy should be selected for patients with bulky, rapidly growing malignancies. The toxicity of chemotherapy may be minimized by discontinuing maintenance immunosuppression during chemotherapy, administering GCSF, and providing antimicrobial prophylaxis. Rejection is minimized by the reintroduction of maintenance immunosuppression when the patient is no longer neutropenic.

Epstein-Barr virus-related post-transplant lymphoproliferative disease in solid organ transplant recipients, 1988-97: a Canadian multi-centre experience

The aim of this work was to obtain information on the magnitude of the problem, disease characteristics, and clinical practices relating to post-transplant lymphoproliferative disease (PTLD) in Canadian institutions. Adult and pediatric Canadian solid organ transplant groups were sent a questionnaire between July and October 1998. Analyzable data were obtained from 33 transplant groups. For the period 1988-97, 90 cases of PTLD were seen among 4283 solid organ transplant recipients. The incidence of PTLD varied from 0 to 14.6%, with the highest rates in children. Lymph nodes were the sites most frequently affected. Among the classifiable lesions, the majority were monoclonal. The lesions were of B-cell origin in 42.2% and of T-cell in 15.6%. The lesions were classified as monomorphic in 31.1%, polymorphic 18.9%, and hyperplastic in 1.1%. Tumors were reported as low grade in 26.7% and high grade in 10%. The majority of patients (71.1%) received reduced immunosuppression. Anti-viral agents were used in 52.2%. Chemotherapy was used in 27.8%, while immune globulin was used in 22.2%. Surgical resection was used in 20.0%, radiotherapy in 14.4%, and interferon-alpha therapy in 12.2%. The results showed that 48.9% of the patients had died, while 25.6% and 8.9% were regarded as having complete remission and partial remission, respectively. In conclusion, the incidence of PTLD varies widely across Canadian centres. Children are disproportionately affected and the mortality rate is high. Management practices vary significantly, and the need for information sharing was identified as one way of optimizing management.

Adenotonsillar hypertrophy and Epstein-Barr virus in pediatric organ transplant recipients

OBJECTIVES/HYPOTHESIS

Epstein-Barr virus-related (EBV-related) lymphoid hyperplasia of the tonsils and adenoids is a precursor to post-transplantation lymphoproliferative disorder (PTLD). The incidence of post-transplantation adenotonsillar hypertrophy, a potential early sign of PTLD or EBV-related lymphoid hyperplasia, is not known. We sought to identify potential risk factors for adenotonsillar hypertrophy manifested as EBV-related hyperplasia and early PTLD in the pediatric solid organ transplant population.

STUDY DESIGN

Cross-sectional analysis.

METHODS

We developed a 65-point questionnaire concerning obstructive sleep disorder and upper respiratory tract infections and an 8-point focused physical examination, to identify prevalence of and risk factors for adenotonsillar hypertrophy in the pediatric transplant population. We evaluated 120 pediatric solid organ transplant recipients by parental questionnaire and focused adenotonsillar physical examination.

RESULTS

Of the 120 patients, 62 had undergone liver transplantation and 58 had undergone kidney transplantation. Overall, the mean questionnaire score was 8.36 (range, 0-40) and the mean physical examination score was 3.86 (range, 1-8). Patients whose EBV serological test result was negative at the time of transplant had higher scores for both the questionnaire (mean score, 10.24) and the physical examination (mean score, 4.56) than those whose EBV serological test result was positive at the time of transplantation (scores of 7.38 and 3.30 for questionnaire and physical examination, respectively). The difference in examination scores was statistically significant (P <.003).

CONCLUSIONS

Epstein-Barr virus seronegativity at the time of organ transplantation is a known risk factor for PTLD, with associated risk of developing EBV-related lymphoid hyperplasia. Our results indicate a higher incidence of symptoms and signs consistent with adenotonsillar hypertrophy in the EBV seronegative population. Adenotonsillar hypertrophy may be a precursor to EBV-related lymphoid hyperplasia and PTLD and must be identified in this patient population.

Ethical considerations in composite tissue allotransplantation

Ethical issues posed by the hand transplant program conducted by hand and plastic surgeons at Jewish and University Hospitals, Louisville, Kentucky, are examined in this essay. Because a composite tissue allotransplantation (CTA) is an experimental procedure, it raises issues as to the protection of human subjects. The background for the emergence of medical ethics as a discipline is indicated and the processes employed by the CTA team in order to address ethical concerns are discussed. Questions are posed as to the justifications for certain procedures and those pertaining to the goals of medicine, informed consent, and patient quality of life. Other issues include benefits versus risks, patient autonomy and medical paternalism or non-maleficence. The Louisville team seems to have dealt conscientiously with all ethical questions that have been posed and has treated the hand recipient with competence and continuity of care. No reasons based in ethical concerns have surfaced that would in any way discredit the program.

Posttransplantation lymphoproliferative disorders in pediatric patients undergoing liver transplantation

OBJECTIVES

To study the clinicopathologic and molecular genetic findings in posttransplantation lymphoproliferative disorders (PTLDs) following pediatric liver transplantation and to determine the applicability of a recently proposed consensus classification system.

DESIGN

The clinical, pathologic, and molecular genetic findings of 11 PTLDs that occurred in 10 patients are presented. These 10 patients were derived from a group of 121 pediatric patients who underwent liver transplantation at the University of California, San Francisco. The PTLDs were classified using the proposed Society for Hematopathology scheme. Clonality was determined by immunohistochemical detection of monotypic immunoglobulin or by using polymerase chain reaction-based methods to detect monoclonal immunoglobulin heavy-chain gene rearrangements. Epstein-Barr virus (EBV) was detected by immunohistochemistry, in situ hybridization, or polymerase chain reaction. Epstein-Barr virus typing and the presence of LMP1 gene deletions were also analyzed by polymerase chain reaction.

RESULTS

There were 3 early lesions, 4 polymorphic PTLDs, and 4 monomorphic PTLDs. Monoclonality was demonstrated in 8 of 9 cases assessed. Epstein-Barr virus was present in all cases; of 9 cases assessed by polymerase chain reaction, the virus was type A in 8 and type B in 1. No EBV LMP1 gene deletions were identified. The corresponding liver explants were negative for EBV in 8 cases and positive in 1 case. Greater than 3 foci of disease and monomorphic PTLD were associated with decreased actuarial survival (P <.05).

CONCLUSIONS

The prognosis of pediatric patients with PTLD is favorable for early lesions and polymorphous PTLD, particularly in patients with localized disease. Multifocal disease and monomorphic PTLD are associated with an unfavorable prognosis.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.