Posttransplant lymphoproliferative disorders and Epstein-Barr virus prophylaxis

Oral pathology in inflammatory bowel disease

The incidence of inflammatory bowel diseases (IBD) - Crohn’s disease (CD) and ulcerative colitis (UC) - has been increasing on a global scale, and progressively, more gastroenterologists will be included in the diagnosis and treatment of IBD. Although IBD primarily affects the intestinal tract, extraintestinal manifestations of the disease are often apparent, including in the oral cavity, especially in CD. Specific oral manifestations in patients with CD are as follows: indurate mucosal tags, cobblestoning and mucogingivitis, deep linear ulcerations and lip swelling with vertical fissures. The most common non-specific manifestations, such as aphthous stomatitis and angular cheilitis, occur in both diseases, while pyostomatitis vegetans is more pronounced in patients with UC. Non-specific lesions in the oral cavity can also be the result of malnutrition and drugs. Malnutrition, followed by anemia and mineral and vitamin deficiency, affects the oral cavity and teeth. Furthermore, all of the drug classes that are applied to the treatment of inflammatory bowel diseases can lead to alterations in the oral cavity due to the direct toxic effects of the drugs on oral tissues, as well as indirect immunosuppressive effects with a risk of developing opportunistic infections or bone marrow suppression. There is a higher occurrence of malignant diseases in patients with IBD, which is related to the disease itself and to the IBD-related therapy with a possible oral pathology. Treatment of oral lesions includes treatment of the alterations in the oral cavity according to the etiology together with treatment of the primary intestinal disease, which requires adequate knowledge and a strong cooperation between gastroenterologists and specialists in oral medicine.

In vivo intratumoral Epstein-Barr virus replication is associated with XBP1 activation and early-onset post-transplant lymphoproliferative disorders with prognostic implications

Post-transplant lymphoproliferative disorders are life-threatening complications following hematopoietic or solid organ transplantation. They represent a spectrum of mostly EBV-driven lymphoplasmacytic proliferations. While the oncogenic effect of EBV is related to latent infection, lytic infection also has a role in lymphomagenesis. In vitro, EBV replication is linked to plasma cell differentiation and XBP1 activation, although this phenomenon has never been addressed in vivo. We analyzed for the first time latent and lytic intratumoral EBV infection in a series of 35 adult patients with a diagnosis of post-transplant lymphoproliferative disorder (26M/9F, median age 54 years). A complete EBV study was performed including the analysis of the latent EBER, latent membrane protein-11, and EBV nuclear antigens as well as the immediate-early BZLF1/ZEBRA and early BMRF1/EADE31 lytic genes. XBP1 activation was assessed by nuclear protein expression. EBV infection was observed in 28 (80%) cases being latency II and III the most frequently observed 22 (79%). Intratumoral EBV replication was detected in 17 (60%) cases. Among these, XBP1 activation was observed in 11/12 evaluable cases associated with strong cytoplasmic immunoglobulin expression consistent with plasma cell differentiation. Intriguingly, the combination of latency III infection and EBV replication identified a high-risk subgroup of patients with significantly shorter survival (overall survival at 1 year 18% vs 48%) and early-onset (median of 7 vs 26 months) post-transplant lymphoproliferative disorder. Moreover, these patients appear to be more heavily immunosuppressed, so they exhibit lower rates of rejection and graft vs host disease but higher rates of cytomegalovirus reactivation. In conclusion, EBV replication is associated with plasma cell differentiation and XBP1 activation with prognostic implications. Both latency III and lytic EBV infection are related to aggressive and early-onset post-transplant lymphoproliferative disorder. These results suggest that immunohistochemical study of latent and lytic EBV genes in the clinical practice may help to select higher-risk patients to new therapies including antiviral treatments.

Epstein-Barr virus infection in transplant recipients: Summary of a workshop on surveillance, prevention and treatment

Diseases caused by the Epstein-Barr virus are of great significance among organ transplant recipients. One of these diseases, post-transplant lymphoproliferative disease, is a major complication among organ transplant recipients. Management of this entity is problematic due to the difficulties with laboratory surveillance, diagnosis, prevention and treatment. A group of Canadian and American experts was assembled to discuss these aspects of Epstein-Barr virus diseases in Canadian organ transplant recipients. This report summarizes the relevant background literature and levels of evidence in relation to the outcomes of the deliberations and recommendations by the expert panel.

Second malignancies after allogeneic hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (allo-HCT) may prolong life and cure patients suffering from otherwise fatal diseases. However, the growing population of long-term survivors has led to the realization of multiple long-term complications, including the risk of second malignancies. Compared to the autologous setting, allo-HCT carries a much higher risk of posttransplant lymphoproliferative disorder (PTLD), which usually occurs within the first year after allo-HCT and is strongly associated with the Epstein-Barr virus (EBV). Treatment-related myelodysplastic syndromes (tMDS) and second leukemias are extremely rare. Both autologous and allo-HCT carry increased risks for second solid malignancies (SSM). The cumulative incidence of SSM continues to increase in each of the largest studies with as much as 20 years of follow-up, likely related to the long latency of radiation-related SSM. Systematic, prospective monitoring, vigilant screening processes, and well-maintained survivorship clinics and databases are absolute necessities, and should be included in the infrastructure of individual transplant centers and networks, with mandatory periodic reporting of second malignancy incidences. Primary care and transplant physicians alike must be aware of the risk of second malignancies after allo-HCT. Most importantly, guidelines should be developed in regard to screening and prevention of second malignancies, so that physicians can provide state-of-the-art counsel and care for the benefit of our patients.

Non-Hodgkin's lymphoma manifest as gingival hyperplasia in a renal transplant recipient

Gingival hyperplasia is a frequent complication in transplant patients who receive cyclosporine or calcium channel blockers. We studied an unusual case involving a renal transplant recipient with post-transplant non-Hodgkin's lymphoma that manifested as gingival hyperplasia. We initially consider that it was a side effect of cyclosporine and nifedipine. The lesion did not respond to dose reductions or the withdrawal of cyclosporine and nifedipine, and the gingival hyperplasia progressed in a localized fashion, becoming ulcerated and bleeding easily. Histological examination revealed the presence of malignant lymphoma.

Ganciclovir and acyclovir reduce the risk of post-transplant lymphoproliferative disorder in renal transplant recipients

Given its association with Epstein-Barr virus (EBV), there is considerable interest in assessing the impact of prophylactic anti-viral therapy on post-transplant lymphoproliferative disorder (PTLD). A recently completed multi center case-control study assessed the impact of immunosuppressive therapy on PTLD risk among renal transplant patients and collected information on the use of anti-viral therapy. Biopsy-confirmed PTLD cases (n = 100) were matched to 375 controls by center, date of transplant, and age. Data were collected on immunosuppression and rejection therapies, demographics, pre-transplant viral status, number of rejections, and anti-viral use. With adjustment for known risk factors, prophylactic anti-viral use was associated with up to 83% reduction in the risk of PTLD, depending on the anti-viral agent. These results were stronger for the first year post-transplant. For every 30 days of ganciclovir treatment, risk of PTLD during the first year was lower by 38% (Odds Ratio [OR]= 0.62; 95% confidence interval [CI]= 0.38-1.0); acyclovir effects were less striking (OR = 0.83; 95% CI = 0.59-1.16). Anti-viral therapy appears to play a role in reducing the risk of PTLD in renal transplant patients. Ganciclovir may be more potent than acyclovir.

Viral prophylaxis in organ transplant patients

Viral pathogens have emerged as the most important microbial agents having deleterious effects on solid organ transplant (SOT) recipients. Antiviral chemoprophylaxis involves the administration of medications to abort transmission of, avoid reactivation of, or prevent progression to disease from, active viral infection. Cytomegalovirus (CMV) is the major microbial pathogen having a negative effect on SOT recipients. CMV causes infectious disease syndromes, augments iatrogenic immunosuppression and is commonly associated with opportunistic superinfection. CMV has also been implicated in the pathogenesis of rejection. Chemoprophylactic regimens for CMV have included oral aciclovir (acyclovir) at medium and high doses, intravenous and oral ganciclovir, and the prodrugs valaciclovir (valacyclovir) and valganciclovir. CMV prophylactic strategies should be stratified, with the highest-risk patients receiving the most 'potent' prophylactic regimens. Herpes simplex virus (HSV) reactivation in SOT recipients is more frequent, may become more invasive, takes longer to heal, and has greater potential for dissemination to visceral organs than it does in the immunocompetent host. Prophylactic regimens for CMV are also effective chemoprophylaxis against HSV; in the absence of CMV prophylaxis, aciclovir, valaciclovir or famciclovir should be used as HSV prophylaxis in seropositive recipients. Primary varicella-zoster virus (VZV) after SOT is rare and most commonly seen in the paediatric transplant population because of VZV epidemiology. Zoster occurs in 5-15% of patients, usually after the sixth post-transplant month. Prophylactic regimens for zoster are neither practical nor cost effective after SOT because of the late onset of disease and low proportion of affected individuals. All SOT recipients should receive VZV immune globulin after contact with either varicella or zoster. Epstein-Barr virus has its most significant effect in SOT as the precipitating factor in the development of post-transplant lymphoproliferative disorders. Antiviral agents that could be effective are the same as those used for CMV, but indications for and effectiveness of prophylaxis are poorly established. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are important pathogens in the SOT population as indications for transplantation. So-called 'prophylaxis' for recurrent HBV and HCV after liver transplantation is controversial, suppressive rather than preventive, and potentially lifelong. Influenza infection after SOT is acquired by person-to-person contact. During epidemic periods of influenza, transplant populations experience a relatively high frequency of infection, and influenza may affect immunosuppressed SOT recipients more adversely than immunocompetent individuals. Antiviral medications for prevention of influenza are administered as post-exposure prophylaxis to SOT recipients, in addition to yearly vaccine, in circumstances such as influenza epidemics and nosocomial outbreaks, and after exposure to a symptomatic individual during 'flu season'.

Posttransplant lymphoproliferative disease: treatment and outcome in renal transplant recipients

Posttransplant lymphoproliferative disorders (PTLD) are a heterogeneous group of lymphoid diseases that occur after solid organ and bone marrow transplantation. We performed a retrospective study to assess the incidence, response to treatment, and patient and graft survival after PTLD.

PATIENTS

Between January 1980 and December 2002, 1.96% (n=10) of 509 renal transplant recipients developed PTLD. Seventy percent were men. Mean age was 40 years (range 21-65). They were classified into four groups based upon the type of PTLD: group I, early lesion (n=1); group II, polymorphic PTLD (n=1); group III, monomorphic PTLD (n=7) including five non-Hodgkin lymphoma [NHL] and two Burkitt (BL); and group IV, Hodgkin lymphoma (HL) (n=1). The mean time from transplantation to diagnosis was 77 months (range 4-138). Although only 20% of cases were early presentation, Epstein-Barr virus (EBV) was found in the tumor cells of seven cases. Treatment was individualized according to PTLD type: for group I, immunosuppression reduction (IR); group II, IR plus acyclovir; group III, withdrawal or IR plus chemotherapy and/or surgery in all but one patient who was also treated with anti-CD20 monoclonal antibody and radiotherapy. Interferon was also used in one patient. For group IV, treatment was IR plus radiotherapy.

RESULTS

A complete response was achieved in nine cases (90%) with one recurrence. Three patients returned to dialysis. One patient with BL died.

CONCLUSIONS

The incidence of PTLD in our center was 1.96%. Patient survival after PTLD was 90%, with 60% maintaining allograft function. Individualized treatment according to extension, histology, and location is mandatory to obtain a high survival rate.

Epstein-Barr virus (EBV) reactivation is a frequent event after allogeneic stem cell transplantation (SCT) and quantitatively predicts EBV-lymphoproliferative disease following T-cell--depleted SCT

Reactivation of the Epstein-Barr virus (EBV) after allogeneic stem cell transplantation (allo-SCT) may evoke a protective cellular immune response or may be complicated by the development of EBV-lymphoproliferative disease (EBV-LPD). So far, very little is known about the incidence, recurrence, and sequelae of EBV reactivation following allo-SCT. EBV reactivation was retrospectively monitored in 85 EBV-seropositive recipients of a T-cell--depleted (TCD) allo-SCT and 65 EBV-seropositive recipients of an unmanipulated allo-SCT. Viral reactivation (more than 50 EBV genome equivalents [gEq]/mL) was monitored frequently by quantitative real-time plasma polymerase chain reaction until day 180 after SCT. Probabilities of developing viral reactivation were high after both unmanipulated and TCD-allogeneic SCT (31% +/- 6% versus 65% +/- 7%, respectively). A high CD34(+) cell number of the graft appeared as a novel significant predictor (P =.001) for EBV reactivation. Recurrent reactivation was observed more frequently in recipients of a TCD graft, and EBV-LPD occurred only after TCD-SCT. High-risk status, TCD, and use of antithymocyte globulin were predictive for developing EBV-LPD. Plasma EBV DNA quantitatively predicted EBV-LPD. The positive and negative predictive values of a viral load of 1000 gEq/mL were, respectively, 39% and 100% after TCD. Treatment-related mortality did not differ significantly between TCD and non-TCD transplants, but the incidence of chronic graft-versus-host disease was significantly less in TCD patients. It is concluded that EBV reactivation occurs frequently after TCD and unmanipulated allo-SCT, especially in recipients of grafts with high CD34(+) cell counts. EBV-LPD, however, occurred only after TCD, and EBV load quantitatively predicted EBV-LPD in recipients of a TCD graft. (Blood. 2001;98:972-978)

The role of antiviral and immunoglobulin therapy in the prevention of Epstein-Barr virus infection and post-transplant lymphoproliferative disease following solid organ transplantation

The recognition of the importance of Epstein-Barr virus (EBV) infection, including EBV-associated post-transplant lymphoproliferative disease (PTLD), has led to a new focus on the prevention of this problem. This paper reviews the scientific rationale behind, and clinical experience with, the use of chemoprophylaxis (using acyclovir or ganciclovir) and immunoprophylaxis (using intravenous immunoglobulin) in the prevention of EBV/PTLD. While some centers have already introduced the use of one or both of these agents as standard prophylaxis against the development of this complication, published data in support of these protocols are currently lacking. Well designed clinical trials are necessary to evaluate the potential role of both antiviral and immunoglobulin agents in the prevention of EBV/PTLD in organ transplant recipients.

Unusual gingival presentation of post-transplantation lymphoproliferative disorder: a case report and review of the literature

Post-transplantation lymphoproliferative disorder is a well-documented complication of solid organ or bone marrow transplantation. Histologically, it is characterized by an abnormal proliferation of lymphocytes, which can range from benign B-cell hyperplasia to malignant lymphoma. Non-Hodgkin's lymphoma (NHL) is associated with several risk factors, such as congenital or acquired immunodeficiency states, autoimmune disorders, and infectious agents (eg, Epstein-Barr virus). Primary sites of presentation in the head and neck are Waldeyer's ring, paranasal sinuses, salivary glands, the oral cavity, and the larynx. Clinical appearance of gingival NHL varies but is usually found to be an asymptomatic gingival enlargement or mass resembling a pyogenic granuloma. We present a patient with a gingival ulceration that was subsequently diagnosed as Epstein-Barr virus malignant lymphoma resulting from the immunosuppression needed to prevent graft-versus-host disease after bone marrow transplantation.

Post-transplant malignancy: the role of immunosuppression

Immunosuppressed organ allograft recipients have a 3- to 4-fold increased risk of developing tumours, but the risk of developing certain cancers is increased several hundredfold. With the exception of skin and lip cancers, most of the common malignancies seen in the general population are not increased in incidence. Instead, there is a higher frequency of some relatively rare tumours, including post-transplant lymphomas and lymphoproliferative disorders (PTLD), Kaposi's sarcoma (KS), renal carcinomas, in situ carcinomas of the uterine cervix, hepatobiliary carcinomas, anogenital carcinomas and various sarcomas (excluding KS). Skin and lip cancers present some unusual features: a remarkable frequency of KS, reversal of the ratio of basal to squamous cell carcinomas seen in the general population, the young age of the patients, and the high incidence of multiple tumours (in 43% of the patients). Anogenital cancers occur at a much younger age than in the general population. Salient features of PTLD are the high frequency of Epstein-Barr virus-related lesions, frequent involvement of extranodal sites, a marked predilection for the brain and frequent allograft involvement. As the immunosuppressed state per se and various potentially oncogenic viruses play a major role in causing these cancers, preventative measures include reducing immunosuppression to the lowest level compatible with good allograft function and prophylactic measures against certain virus infections. Reduction of exposure to sunlight may also decrease the incidence of skin cancer. In addition to conventional treatments (resection, radiation therapy, chemotherapy) patients may receive antiviral drugs, interferon-alpha and various other manipulations of the immune system. A significant percentage of cases of PTLD and KS respond to reduction or cessation of immunosuppressive therapy.

Inhibitory effect of cycloSaligenyl-nucleoside monophosphates (cycloSal-NMP) of acyclic nucleoside analogues on HSV-1 and EBV

The in vitro antiviral activity of a new series of cycloSal-pro-nucleotides derived from the acyclic nucleoside analogues aciclovir and penciclovir against herpes simplex virus type 1 (HSV-1), thymidine kinase deficient (TK-) HSV-1, and Epstein-Barr virus (EBV) was evaluated. Using the XTT-based tetrazolium reduction assay EZ4U, the cycloSal derivatives were examined for their antiviral and cytotoxic effects in HSV-1 as well as HSV-1-TK--infected Vero cells. The anti-EBV activity was assessed by means of an EBV DNA hybridization assay using a digoxigenin-labeled probe specific for the Bam H1-W-fragment of the EBV genome and by measuring viral capsid antigen (VCA) expression in P3HR-1 cells by indirect immunofluorescence. Among the new cycloSal-phosphotriesters the three aciclovir monophosphates proved to be potent and selective inhibitors of HSV-1 replication, EBV DNA synthesis and EB-VCA expression. Of interest is the retention of activity of the aciclovir monophosphates in HSV-1-TK--infected cells. Particularly 3-methyl-cycloSal-aciclovir monophosphate retained the same effectiveness, as compared to the wild type virus strain. In contrast to the aciclovir pro-nucleotides the penciclovir cycloSal-phosphotriesters exhibited at best only a marginal antiviral effect on HSV and EBV replication.

Epstein-Barr virus-related disorders in children undergoing renal transplantation with tacrolimus-based immunosuppression

In children undergoing renal transplantation, Epstein-Barr virus- (EBV) related disorders, including posttransplant lymphoproliferative disorder, constitute a major complication associated with tacrolimus-based immunosuppression. In this study, we reviewed the EBV complications in 81 children, all of whom had EBV serological studies before renal transplantation. We also highlight the data in a subgroup of 30 children transplanted more recently who were monitored sequentially for EBV symptoms and signs and with immunological studies, and in whom the donor EBV serology was also determined. During a mean follow-up time of 3.9+/-2.3 years, 19 children developed symptomatic Epstein-Barr virus (EBV*) infection. This consisted of the clinical syndrome of infectious mononucleosis in 7 children; in addition, 10 children developed posttransplant lymphoproliferative disorder (PTLD), which was histologically confirmed in 8, and 2 others developed malignant lymphoma. Recipient seronegativity (EBV-) and donor EBV seropositivity (EBV+) predicted a high probability for seroconversion (P=0.0072) and for developing PTLD or malignancy (P<0.01). In the subgroup of 30 children studied prospectively, seroconversion occurred in 15 of 19 seronegative recipients of EBV seropositive grafts at 6.6+/-2.6 months (mean+/-SD) after transplantation. Seven children developed symptomatic EBV infection (including three with PTLD) in association with seroconversion and a rise in EBV viral load in the peripheral blood, demonstrated by an EBV-specific polymerase chain reaction (EBV-PCR). Of 15 seroconverters, 7 who developed symptomatic infection had received EBV+ grafts; 8 others with EBV+ grafts seroconverted but did not become symptomatic. These two subgroups did not differ in age, rejection rate, antiviral prophylaxis, or level of immunosuppression. In the overall group of 81 children, only the two with malignant lymphoma who were managed with chemotherapy had substantial morbidity. The 10 individuals with PTLD received a regimen combining i.v. ganciclovir and CytoGam, and stopping or reducing the tacrolimus. Four children with associated marked tonsilar growth underwent tonsillectomy. All 19 individuals with EBV disorders resolved their symptoms and signs, and all have maintained good allograft function during a follow-up time of 3.0+/-2.5 years (mean+/-SD) after the development of symptomatic EBV infection, PTLD, or malignancy. We conclude that seronegative recipients of EBV+ grafts are at high risk for developing EBV-related disorders after renal transplantation under tacrolimus-based immunosuppression, although the ultimate clinical outcomes have been remarkably good. These data form the basis for formulating strategies for early identification of children at risk for EBV complications, and for instituting preventive and treatment strategies that permit these children to realize the substantial benefits offered by tacrolimus-based immunosuppression.

Preventing acute rejection, Epstein-Barr virus infection, and posttransplant lymphoproliferative disorders after kidney transplantation: use of aciclovir and mycophenolate mofetil in a steroid-free immunosuppressive protocol

BACKGROUND

A widely held view is that any increase in the potency of an immunosuppressive agent will lead to an increase in infection and malignancy, such as life-threatening Epstein-Barr virus (EBV) induced posttransplant lymphoproliferative disorders (PTLD). We tested this paradigm by studying the effect of adding mofetil to a steroid-free protocol under cover of high-dose aciclovir prophylaxis on the number of acute rejections, EBV infections and PTLDs after kidney transplantation.

METHODS

EBV serology was performed in 267 consecutive renal transplantations (1990-1997). All were treated with cyclosporine with an initial 10-day antilymphocyte globulin course, supplemented from September 1995 with MMF. In 208 consecutive transplantations after June 1992 aciclovir 3200 mg/day was given for 3 months posttransplantation.

RESULTS

After an observation period of up to 7 years we found that: (1) primary or reactivated EBV infection (PREBV) was correlated to acute rejection (treated with OKT3; P<0.00005) and to the incidence of PTLD (P=0.03; P=0.01, if Hodgkin's disease is included); (2) aciclovir protected against PREBV (P<0.00005) and (3) adding mofetil to the immunosuppressive protocol reduced PREBV further (P=0.0001), (4) in 78 transplantations treated with cyclosporine/antilymphocyte globulin/mofetil we observed only 10 acute rejections (P=0.0001), 10 PREBVs (P<0.00005), and no PTLDs compared with the cyclosporine/antilymphocyte globulin group (P=0.04).

CONCLUSIONS

Supplemental immunosuppression with mofetil protects against acute rejection. In combination with aciclovir, there is also a reduction in the number of PREBVs, apparently as a result of both direct viral prophylaxis and better rejection control, and in the incidence of EBV-induced PTLD.

Prevention and preemptive therapy of postransplant lymphoproliferative disease in pediatric liver recipients

BACKGROUND

We have previously reported a 10% incidence of posttransplant lymphoproliferative disease (PTLD) in pediatric patients receiving first liver grafts and primarily immunosuppressed with tacrolimus. To decrease the incidence of PTLD, we developed a protocol utilizing preemptive intravenous ganciclovir in high-risk recipients (i.e., donor (D)+, recipient (R)-), combined with serial monitoring of peripheral blood for Epstein Barr virus (EBV) by polymerase chain reaction (PCR).

METHODS

Consecutive pediatric recipients of a first liver graft were immunosuppressed with oral tacrolimus (both induction and maintenance), and low-dose prednisone. EBV serologies were obtained at the time of orthotopic liver transplant in recipients and donors. Recipients were divided into groups: group 1, high-risk (D+R-), and group 2, low-risk (D+R+; D-R-; D-R+). In group 1 (high-risk), all patients received a minimum of 100 days of intravenous ganciclovir (6-10 mg/kg/day), while, in group 2 (low-risk), patients received intravenous ganciclovir during their initial hospitalization and then were converted to oral acyclovir (40 mg/kg/day) at discharge. Semiquantitative EBV-PCR determinations were made at 1-2-month intervals. In both groups, patients with an increasing viral copy number by EBV-PCR had tacrolimus levels decreased to 2-5 ng/ml. Tacrolimus was stopped, and intravenous ganciclovir reinstituted for PTLD. A positive EBV-PCR with symptoms, but negative histology, was defined as EBV disease; PTLD was defined as histologic evidence of polyclonal or monoclonal B cell proliferation.

RESULTS

Forty children who had survived greater than 2 months were enrolled. There were 18 children in group 1 (high-risk; mean age of 14+/-15 months and mean follow-up time of 243+/-149 days) and 22 children in group 2 (low-risk; mean age of 64+/-65 months and follow-up time of 275+/-130 days). In group 1 (high-risk), there was no PTLD and one case of EBV disease (mononucleosis-like syndrome), which resolved. In group 2 (low-risk), there were two cases of PTLD; both resolved when tacrolimus was stopped. Both children were 8 months old at time of transplant. Neither received OKT3, and they had one and two episodes of steroid-sensitive rejection, respectively. One child had EBV disease (mild hepatitis), which resolved.

CONCLUSIONS

Since instituting this protocol, the overall incidence of PTLD has fallen from 10% to 5% for children receiving primary tacrolimus therapy after OLT. No high-risk pediatric liver recipient treated preemptively with intravenous ganciclovir developed PTLD. Both children with PTLD were less than 1 year at OLT and considered low-risk. However, their positive EBV antibody titers may have been maternal in origin and not have offered long-term protection. Serial monitoring of EBV-PCR after pediatric OLT is recommended to decrease the risk of PTLD by allowing early detection of EBV infection, which is then managed by decreasing immunosuppression and continuing intravenous ganciclovir.

Arginine butyrate-induced susceptibility to ganciclovir in an Epstein-Barr-virus-associated lymphoma

Lymphoproliferative disorders associated with Epstein-Barr virus (EBV) infections can occur in the setting of immunosuppression. In some patients, the lymphoproliferative disorder can resemble an aggressive monoclonal non-Hodgkins lymphoma (NHL). These NHL are poorly responsive to conventional therapy. Similarly, antiviral therapy with synthetic nucleosides such as ganciclovir are ineffective because the genes that render the virus susceptible to therapy are not expressed in EBV+ lymphomas. Using a cell line derived from a lung transplant recipient with an EBV+ immunoblastic NHL, we studied the ability of arginine butyrate to induce the expression of EBV thymidine kinase. Arginine butyrate was not only effective in inducing EBV thymidine kinase transcription, but also acted synergistically with the antiviral agent ganciclovir to inhibit cell proliferation and decrease cell viability. Based on these findings, the patient from whom the cell line was derived was treated with arginine butyrate/ganciclovir as well as conventional cytotoxic chemotherapy. No additional toxicity was observed with the arginine butyrate/ganciclovir therapy. Histologic examination of the tumor showed substantial necrosis. These observations suggest the feasibility of arginine butyrate induction of ganciclovir susceptibility in patients with EBV-associated lymphomas.

Inhibitory effects of novel nucleoside and nucleotide analogues on Epstein-Barr virus replication

The anti-Epstein-Barr virus (EBV) activity of different classes of compounds was assessed by means of an EBV DNA hybridization assay using a digoxigenin-labelled probe specific for the BamHI W fragment of the EBV genome, as well as by measuring viral capsid antigen (VCA) expression after a 7 day incubation period of P3HR-1 producer cells with the test substances. Acyclovir, ganciclovir, cidofovir and zidovudine were included as reference compounds. Several compounds proved to be potent and selective inhibitors of EBV DNA synthesis and VCA expression. Of the new compounds that were evaluated for their anti-EBV activity, the highest efficacy (lowest EC50) and highest selectivity index (SI) were shown by the purine nucleoside analogue 2-amino-7-[(1,3-dihydroxy-2-propoxy)methyl]purine (S2242) (EC50 0.6 ng/ml; SI 600), the acyclic nucleoside phosphonate analogues 9-(2-phosphono -methoxyethyl)-6-dimethylaminopurine (EC50 1.1 micrograms/ml; SI 91), 9-(2-phosphonomethoxyethyl)-2- amino-6-benzhydrylaminopurine (EC50 1.3 micrograms/ml; SI 29), 7-(2-phosphonomethoxyethyl)-6-dimethyl-aminopurine (EC50 0.8 microgram/ml; SI 56), 9-(R)-(2-phosphonomethoxypropyl)-6-(2-dimethylaminoethyl)-aminopur ine (EC50 0.5 microgram/ml; SI 42), the 2',3'-dideoxythymidine derivative 3'-oximino-2',3'-dideoxythymidine (EC50 1.5 micrograms/ml; SI 65), and 1-(2,3- dideoxy-3-N-hydroxyamino-beta-D-threo-pentafuranyl)pentafuranos yl)thymine (EC50 4.1 micrograms/ml; SI > 24).

Infectious complications following renal transplantation

Despite significant advancements in renal transplantation, infectious disease complications remain an important cause of morbidity and mortality in the transplant recipient. The prevention and treatment of these infections remain a major challenge.

Preoperative and postoperative imaging in the surgical management of pulmonary emphysema

For patients with emphysema, imaging studies have been useful for diagnostic purposes and for preoperative patient selection for surgical intervention, such as bullectomy, lung transplantation, and LVRS. Chest radiography is useful in evaluating hyperinflation. Inspiratory and expiratory films are used to estimate diaphragmatic excursion and air-trapping. CT scan is used to evaluate the anatomy and distribution of emphysema throughout the lungs, providing information clinically unobtainable by other means. Both imaging techniques are useful for detecting other disease processes. Radionuclide lung scanning also provides an estimate of target areas, volume occupying but nonfunctioning lung. Cohort studies utilizing these imaging techniques have demonstrated associations between preoperative characteristics and postoperative outcome. The imaging studies, especially the chest radiograph, have also played an important role in postoperative management. Many other imaging options are available, such as HRCT scan, quantitative CT scan, and single photon emission CT scan. Other techniques, such as MR imaging, may play a future role as well.

Reduced incidence of Epstein-Barr virus-associated posttransplant lymphoproliferative disorder using preemptive antiviral therapy

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) has been observed with increasing frequency consequent to the availability of more effective and potent immunosuppression. Prior work suggested that a peripheral blood monitoring strategy detecting peripheral B lymphoproliferation was effective in the early diagnosis of PTLD among 7 of 179 (3.9%) consecutive transplant recipients. Each of those seven patients received at least one course of antithymocyte globulin, Minnesota antilymphocyte globulin, or OKT3 before developing PTLD.

METHODS

To determine whether antiviral prophylaxis might reduce the incidence of PTLD, a subsequent group of 198 consecutive recipients received either ganciclovir or acyclovir during antilymphocyte antibody administration. When the donor or recipient were cytomegalovirus-seropositive, ganciclovir was given; acyclovir was used when both were cytomegalovirus-seronegative. Baseline and protocol posttransplant cell surface profiles were obtained using immunofluorescence and flow cytometry to detect T cells, lymphocyte activation markers, and the CD19 B cell antigen.

RESULTS

Demographic factors, including the incidence of recipients more than 50 years of age, non-Caucasians, previous transplantation, and diabetes mellitus, were similar in both groups. Additionally, the number of patients receiving antilymphocyte preparations was similar. However, only one patient (0.5%) from the latter group who received preemptive antiviral therapy developed PTLD. Although elevations in CD19+ B cells preceded clinical PTLD among each of the seven earlier patients, evidence of peripheral B cell proliferation was not demonstrated for the sole patient from the latter group, which suggests a possible effect of antiviral therapy.

CONCLUSIONS

Prophylactic antiviral therapy may reduce the sensitivity of peripheral monitoring for B lymphoproliferation, but the dramatic reduction in PTLD incidence strongly supports its use among transplant recipients at risk.

Analysis of hospital charges after simultaneous pancreas-kidney transplantation in the era of managed care

BACKGROUND

The purpose of this study was to analyze and compare hospital charges in simultaneous pancreas-kidney transplant (SPKT) recipients before and after implementation of managed care principles.

METHODS

Two groups were compared: 14 consecutive SPKT patients transplanted in 1991 vs. 15 consecutive SPKT patients transplanted in 1995. All patients underwent whole organ pancreas transplantation with bladder drainage and received quadruple immunosuppression with OKT3 induction. The two groups were well-matched; outliers were excluded (four in 1991 and five in 1995), and no attempt was made to convert 1991 to 1995 dollars. Patient and graft survival rates were 100%, and no major early complications occurred. All SPKTs were performed in a single hospital setting, and all inpatient charges for the initial hospitalization were analyzed retrospectively and itemized by service.

RESULTS

Pharmacy, organ acquisition, and clinical laboratory services accounted for nearly 80% of charges in each group. For the initial transplant hospitalization, the 1995 group experienced significant reductions in: (1) length of stay (16.3+/-1.4-135+/-3.5 days, P=0.03); (2) total number of laboratory tests (392+/-15-224+/-60, P<10(-3)); (3) clinical laboratory charges ($23,623+/-$1,780-$11,165+/-$3,091, P<10(-6)); and (4) total inpatient charges with organ acquisition charges excluded ($87,815+/-$8,678-$75,152+/-$16,871, P=0.049). However, these potential savings were offset by a nearly 47% increase in organ acquisition charges and a 38% increase in medical/surgical supplies. Consequently, total hospital charges for SPKT were no different in 1991 and 1995.

CONCLUSIONS

Despite the rising costs of medical care, we have implemented managed care principles after SPKT that were successful in stabilizing hospital charges by decreasing length of stay and clinical laboratory tests during the study period. However, escalating charges related to organ acquisition and medical/surgical supplies remain a problem.

Clinical use of tacrolimus (FK-506) in infants and children with renal transplants

Although cyclosporine (CsA)-based immunosuppressive regimens have been highly successful in renal transplantation in infants and children, their adverse influence on somatic growth, general appearance, and blood pressure are of particular importance in this population. Over the past 4 years, we have utilized tacrolimus (formerly FK-506) as the primary immunosuppressive agent in 43 unselected children and achieved 1-year and 3-year allograft survival rates of 96% and 85%, respectively. We have also used tacrolimus to rescue 14 of 19 (74%) renal allografts from CsA-resistant rejection. Corticosteroids were discontinued in 62% of non-rescue patients without increasing the risk of rejection or renal dysfunction over a mean follow-up time of 25 months. Tacrolimus monotherapy has been associated with improved body growth and less obesity, while tacrolimus alone or in combination with prednisone was virtually free of hirsutism or gingival hypertrophy, and posed a low risk for hypertension. A major disadvantage of this regimen may be an increased risk for viral infections and a benign form of posttransplant lymphoproliferative disease. This article describes the tacrolimus protocol utilized in our center and focuses on practical clinical issues including therapeutic monitoring, benefits, and major toxicity in children with renal allografts.