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.     

Posttransplant Lymphoproliferative Disorder Following Pancreas Transplantation

The incidence, risk factors and impact on patient and graft survival were evaluated for posttransplant lymphoproliferative disorder (PTLD) among 212 pancreas transplant recipients. Thirteen (6.1%) developed PTLD during 71 ± 27 months follow-up. Cumulative incidences of PTLD at 1, 3, 5 and 10 years posttransplant were 4.2%, 5.3%, 6.0% and 7.0%, respectively. Incidence of PTLD was lower for recipients of simultaneous pancreas kidney compared to pancreas after kidney transplant or pancreas transplant alone, though not significantly so. Recipient Epstein–Barr virus (EBV) seronegativity and number of doses of depleting antibody therapy administered at transplant were associated with increased risk of PTLD, while recipient age, gender, transplant type, cytomegalovirus mismatch maintenance immunosuppression type and treated acute rejection were not. All 13 cases underwent immunosuppression reduction, and 10 received anti-CD20 monoclonal antibody. During follow-up, 10/13 (77%) responded to treatment with complete remission, while 3 (23%) died as a result of PTLD. Patient and graft survivals did not differ for recipients with and without PTLD. The strong association of PTLD with EBV-seronegativity requires considering this risk factor when evaluating and monitoring pancreas transplant recipients. With reduction of immunosuppression and anti-CD20 therapy, survival for pancreas transplant recipients with PTLD was substantially better than previously reported.     

Epstein-Barr virus seronegativity is a risk factor for late-onset posttransplant lymphoroliferative disorder in adult renal allograft recipients

BACKGROUND: Posttransplant lymphoproliferative disorder (PTLD) remains a difficult management issue; therefore, many studies focus on the identification of risk factors to allow for preventive strategies. We investigated risk factors for PTLD in the adult renal transplant setting. METHODS: A single-center, matched case-control study design was used. Cases were identified from patients who underwent a first renal transplant between January 1, 1985, and December 1, 2001. Two controls were chosen per case, matched (+/-1 year) by date of transplant and graft survival. Clinical and demographic data were ascertained from medical records. Pretransplant serology for Epstein-Barr virus (EBV) and cytomegalovirus was confirmed on frozen, stored sera. Statistical analysis included univariate and multivariable examination of putative risk factors using conditional logistic regression. RESULTS: Twenty cases of PTLD were identified, an incidence of 2.4%. Median time from transplant to diagnosis was 55 months (range, 3-168 months), with 16 cases of late-onset PTLD (>1 year posttransplant). The only significant risk in univariate analysis was EBV-negative status at transplant (risk ratio 6.0, P=0.03). In multivariable analysis, EBV-negative status remained significant (adjusted risk ratio 8.9, P=0.01). The risk related to EBV status held true when late cases were analyzed separately (adjusted risk ratio 7.1, P=0.03). CONCLUSIONS: Pretransplant EBV-seronegative status is a strong risk for development of PTLD in adult renal allograft recipients, even in late disease. These results indicate that primary infection with EBV may have a pathogenic role in some cases of late PTLD.     

Use of mycophenolate mofetil as rescue therapy after pediatric liver transplantation

BACKGROUND: Mycophenolate mofetil (MMF) has been increasingly used after liver transplantation (LT) in adults. We report our preliminary experience with MMF as rescue therapy after pediatric LT. METHODS: A total of 19 children received MMF for 21 indications. Median age at LT was 30 months (range 7-149). The median initial oral dose of MMF was 23 mg/kg/day (range 12-43) orally. Median follow-up after initiation of MMF therapy was 642 days (range 229-1606). RESULTS: 1) Efficacy: MMF was indicated for rejection or insufficient immunosuppression in 16 cases, with normalization of both liver function tests and liver histology in 10 (62%). MMF was successfully used in one patient with post-LT immmune hepatitis and one patient with corticodependence. In three patients with renal function impairment, MMF allowed reduction of cyclosporine A or tacrolimus blood levels, without subsequent rejection. 2) Tolerance: Six patients (32%) experienced eight side effects, mainly gastrointestinal and hematological, which resolved after cessation of MMF in five cases and dose reduction in three. One case of posttransplant lymphoproliferative disease (PTLD) occurred under MMF therapy (5.2%). Four patients had EBV primary infection, while under MMF therapy, without subsequent PTLD. Three patients had CMV primary infection, and five CMV reactivation, under MMF therapy. Seven remained asymptomatic, and one presented with CMV enteritis. CONCLUSIONS: These preliminary results suggest that MMF is an effective and safe immunosuppressant in pediatric LT recipients. Its use is hampered by frequent gastrointestinal and hematological side-effects. MMF does not seem to increase the risk of PTLD nor CMV disease.     

Analysis of risk factors for the development of posttransplant lymphoprolipherative disorder among 119 children who received primary intestinal transplants at a single center

Posttransplant lymphoproliferative disorder (PTLD) is a well-known complication after pediatric transplantation. We analyzed all potential risk factors to assess patient and graft outcomes of 119 children who received intestinal transplantations. MATERIALS AND METHODS: Between August 1994 and March 2005, 119 patients underwent cadaveric intestinal transplantation. Their median age at transplant was 1.4 years (range: 0.6-17), median weight was 9.5 kg (range: 4.7-67), and 57% were boys. The median follow-up among 49 ongoing survivors was 41 months (range: 4-121). All PTLD cases were biopsy proven. In the past 5 years, treatment included antiviral therapy, immunosuppression withdrawal, and use of rituximab. RESULTS: The incidence of PTLD was 11.8% (14/119). No patient experienced graft failure secondary to PTLD, while two patients died from PTLD (14.2%). The PTLD group was divided into an early onset group (<4 months, 6 of 14; 42.8%) and a late onset group (>2 years, 8 of 14; 57.2%). No patient experienced PTLD between 4 months and 2 years after transplantation. The use of OKT3 was the only significant risk factor for the development of PTLD. No factor was specifically associated with the early versus late development of PTLD. CONCLUSIONS: The only factor associated with a significantly higher risk of PTLD was the use of OKT3 to treat a rejection episode. Finally, since the the introduction of anti-CD20 antibodies as part of the treatment protocol for PTLD, the risk of death due to PTLD appears to have become manageably low.     

Polyomavirus nephropathy after renal transplantation: a single centre experience

BACKGROUND: Polyomavirus associated nephropathy (PVN) in renal transplant recipients has been observed with increasing frequency recently and has emerged as a cause of allograft failure linked to highly potent new immunosuppressive regimens containing tacrolimus or mycophenolate mofetil (MMF). METHODS: Polyomavirus associated nephropathy was identified in nine out of 182 patients who received renal transplantation between October 1998 and July 2003. PVN was confirmed by allograft biopsy. The clinical records of these nine patients were reviewed, as were all of the allograft biopsies. Electron microscopy was performed in all nine cases. After the diagnosis of PVN, maintenance immunosuppression was reduced. The clinical course and outcome of the PVN patients were reviewed in relation to manipulation of immunosuppressive agents. RESULTS: There were nine cases of PVN in renal transplant recipients and the incidence of PVN was 4.9%. All patients with PVN were under triple immunosuppression comprising tacrolimus and MMF. The mean time to a diagnosis of PVN was 7.8 months after transplantation. Three of the nine patients received antirejection therapy prior to PVN. Seven out of nine PVN patients presenting acute allograft dysfunction were initially treated with high-dose intravenous steroid pulse or OKT3 before reduction of the immunosuppression. After reduction of the immunosuppression, seven patients stabilized their renal function. Two (22%) lost their grafts due to persistent PVN and chronic rejection. Two (22%) patients later developed acute rejection after reduction of the immunosuppression. CONCLUSION: PVN can cause allograft dysfunction and graft loss. Renal allograft recipients who are at risk of PVN should be routinely screened with urine cytology and quantitative measurements of viral load in the blood, particularly patients who had graft dysfunction. Early diagnosis and judicious alteration of immunosuppressive agents might permit a superior prognosis and reduce the graft loss from PVN in renal transplant recipients.     

Impact of mycophenolate mofetil on recurrent rejection in kidney transplant patients

PURPOSE: Mycophenolate mofetil (MMF) has emerged as a valuable adjunctive agent in renal transplantation. However, due to intolerable adverse effects associated with MMF use in our transplant population, we have used MMF selectively in patients at high risk for recurrent graft rejection, since these patients are known to be at risk for poor long-term graft outcomes. The purpose of this study was to assess the efficacy of MMF in preventing the recurrence of acute rejection following an initial rejection episode in kidney transplant patients in the first year following transplantation. METHODS: Forty-four kidney transplant recipients were given MMF prospectively following treatment of their initial rejection episode to prevent recurrent rejection. MMF 1-2 g/d was given. Doses were adjusted based on tolerance; MMF therapy was to be continued for at least 6 months. The control group consisted of 124 consecutive kidney transplant recipients who had received standard anti-rejection therapy without the addition of MMF. Maintenance immunosuppression consisted predominantly of cyclosporine, prednisone+/-azathioprine. Anti-rejection therapy for both groups consisted of either corticosteroids (methylprednisolone 500 mg i.v. for 3 d or oral prednisone 2 mg/kg/d with rapid taper over 3 wk), OKT3 5 mg/d for 10 d or ATG 15 mg/kg/d for 10 d. All rejection episodes were confirmed by biopsy. RESULTS: The majority of rejection episodes were characterized histologically as mild or moderate. Most patients (76%) received corticosteroids for treatment of their first rejection episode. There was a 68% reduction in the incidence of recurrent rejection episodes within the first year of transplant in patients receiving MMF; only 14% of recipients receiving MMF developed recurrent rejection compared to 44% of patients in the control group (p<0.05). Approximately 50% of patients developed MMF-associated adverse effects (leukopenia, GI toxicity). Only 52% of patients remained on MMF at 6 months. One-yr graft survival was 86% in the MMF group and 89% in the control group (p>0.05). One-year patient survival was 93 and 100%, respectively (p>0.05). CONCLUSIONS: The addition of MMF to maintenance therapy for patients experiencing acute renal allograft rejection may prevent recurrent rejection episodes in the subsequent follow-up year.     

Posttransplant lymphoproliferative disorder in pediatric renal transplantation

Of 84 renal transplants performed in our center since 1986, six recipients (7.1%) developed posttransplant lymphoproliferative disorder (PTLD). All received quadruple immunosuppression with Minnesota anti-lymphoblastic globulin or anti-thymocyte globulin, methylprednisolone, cyclosporine, and azathioprine or mycophenolate mofetil. Five were seronegative for Epstein-Barr virus (EBV) when they received their renal transplant. All patients received prophylactic acyclovir treatment postrenal transplant and none developed a cytomegalovirus (CMV) infection. All patients were positive for EBV by serology and polymerase chain reaction at the time of diagnosis of PTLD. Clinical features at presentation included fever (6/6), adenopathy (4/6), hypertrophied adenoids (4/6), liver involvement (2/6), and allograft involvement (2/6), 2–78 months (4/6<6 months) postrenal transplant. Histopathology of PTLD tissue revealed T cell rich/ Hodgkin disease-like B cell PTLD in one patient, polymorphic PTLD in four, and monomorphic (large B cell lymphoma) PTLD in one. Immunophenotyping of the PTLD biopsy specimen revealed predominant T cells in three, mixed B and T cells in two patients, and B cell in one. No aneuploid populations were identified by flow cytometric DNA ploidy assay. DNA from the PTLD tissue revealed weak to moderate IgH gene rearrangement in four of six patients but no T cell receptor β-chain or c-myc gene rearrangement on Southern blot analysis. The child with monomorphic (large B cell lymphoma) PTLD was clonal with λ light chain restriction on immunophenotyping. Treatment consisted of reduced immunosuppression and ganciclovir/ acyclovir in all patients. CMV hyperimmune globulin was used as an adjunctive therapy in two patients. Chemotherapy was needed in only one patient. A single rejection episode occurred in two children following reduction in immunosuppression, which reversed following intravenous methylprednisolone therapy. PTLD resolved in all patients and at present all patients are alive with functional grafts 2–54 months post diagnosis. Our experience suggests that reduced immunosuppression and anti-viral treatment is adequate in most cases of PTLD, but chemotherapy and hyperimmune globulin therapy may be beneficial in cases resistant to first-line therapy. Since all but one of our patients were EBV seronegative at the time of transplant, vigilance is especially important for early detection of PTLD in this group of the pediatric renal transplant population. Received: 17 November 1998 / Revised: 4 February 1999 / Accepted: 4 February 1999     

肾移植术后停用环孢素的安全性研究（附42例报告）

目的 探讨肾移植受者术后停用环孢素（CsA）的安全性及停用的时机.方法 42例首次接受尸体供肾肾移植患者,术后早期曾采用含CsA的三联免疫抑制方案治疗,停用CsA后改用泼尼松＋硫唑嘌呤二联免疫抑制方案4例,改用泼尼松＋MMF二联免疫抑制方案38例.根据停药原因分为两组,A组20例患者,包括因移植肾功能减退、蛋白尿停用CsA 患者14例、严重肝损害保守治疗无效停用CsA患者 4例、不能耐受CsA其他不良反应停用CsA患者 2例;B组22例患者肾功能稳定、正常,无CsA导致的不良反应,主动要求或因经济原因停用CsA.另按术后不同时间停用CsA分为两组,术后1年内停用CsA组（16例）与术后1年后停用CsA组（26例）.所有患者均采用逐步停药方法,每周或每2周减少CsA 25 mg/d,直至完全停药;同时,MMF在原剂量基础上增加0.25 ～0.50 g/d.所有患者均随访超过1年,比较A、B两组患者停用CsA前后的血清肌酐（Scr）变化,并了解肝损害及其他不良反应的发生情况;比较术后不同时间停用CsA患者的排斥反应发生率.结果 A组20例患者在随访期间均未恢复应用CsA,其因CsA导致的肝损害及其他不良反应均有所好转.B组22例患者中,9例在随访期间恢复CsA应用,其中因Scr缓慢上升 6例、发生排斥反应1例,患者要求恢复使用2例.A组患者停用CsA前的Scr为（124±30）μmol/L,停用CsA 1年后的Scr为（108±12）μmol/L;B组相应为（ 81±5）μmol/L、（68±4）μmol/L.术后1年内停用CsA组患者的排斥反应发生率明显高于术后1年后停用CsA组的排斥反应发生率（19 %比8 %,P＜0.05）.结论 对因使用CsA出现移植肾功能减退、蛋白尿或严重不良反应的患者,在排除移植物排斥的前提下,可逐步停用CsA和（或）相应增加其他免疫抑制药.对于肾功能稳定,未出现CsA不良反应的患者,还是以小剂量CsA维持治疗为妥.CsA的停用时机以肾移植术后1年以上为宜,过早停用CsA会增加排斥反应发生率.     

Review of immunosuppressive usage in pancreas transplantation

Throughout 1997, nearly 10 000 pancreas transplants have been performed worldwide, with 88% being simultaneous kidney transplants (SKPT). The current 1 yr patient survival rate exceeds 90% and pancreas graft survival (complete insulin independence) rate exceeds 80% for SKPT, 70% for sequential pancreas after kidney transplant (PAKT), and 65% for pancreas transplant alone (PTA). According to registry data, rejection accounts for 32% of graft failures in the first year after pancreas transplantation. However, improvements are expected to continue with the evolution of treatment protocols. Most pancreas transplant centers employ quadruple drug immunosuppression with anti-lymphocyte induction with either a monoclonal or polyclonal antibody agent. In recent years, there has been an overall decline in the use of antibody induction therapy from 90% during the period 1987–1993 to 83% of pancreas transplants performed during 1994–1997. Maintenance immunosuppression is triple therapy consisting of a calcineurin inhibitor (cyclosporine or tacrolimus), corticosteroids, and an anti-metabolite (AZA or MMF). Prior to 1995, nearly all pancreas transplant recipients were managed with Sandimmune. In the last 2 yr, tacrolimus-based therapy has been used in approximately 20% of cases and a new microemulsion formulation of cyclosporine (Neoral) has replaced Sandimmune in contemporary post-transplant immunosuppression. In addition, MMF is replacing AZA as part of the standard immunosuppressive regimen after pancreas transplantation. At present, a number of centers are conducting various trials with new drug combinations including either Neoral or tacrolimus in combination with steroids and MMF with or without antibody induction therapy. From 1994 to 1997, the 1 yr rates of immunologic graft loss have decreased to 2% after SKPT, 9% after PAKT, and 16% after PTA. The current array of new immunosuppressive agents are providing more effective control of rejection and permitting solitary pancreas transplantation to become an accepted treatment option in diabetic patients without advanced complications. The apparent potency of new drug combinations has also resulted in a resurgence of interest in steroid withdrawal. Immunosuppressive strategies will continue to evolve in order to achieve effective control of rejection while minimizing injury to the allograft and risk to the patient. In addition, new regimens must not only address the issue of specific drug toxicities but also long-term economic, metabolic, and quality of life outcomes. Pancreas transplantation will remain an important alternative in the treatment of diabetic patients until other strategies are developed that can provide equal glycemic control with less immunosuppression and overall morbidity.     

New immunosuppressive treatment in kidney transplantation

BACKGROUND: Mycophenolate mofetil (MMF) has been successfully introduced into clinical practice with evident benefits for renal transplant recipients. SUBJECTS AND METHODS: To evaluate some clinical results of MMF introduction, two groups of subjects underwent cadaveric renal transplants over the last 3 years and were retrospectively investigated. The first group (AZA group) contained 40 subjects (26 males and 14 females) on triple-drug therapy with steroids, cyclosporine and azathioprine (AZA). The second group (MMF group) contained 25 patients ( 19 males and 6 females) on the same regime with steroids and cyclosporine but MMF was administered as a third drug instead of AZA. The AZA group received renal transplant after a mean dialytic time of 32 +/- 19 months and the AZA group's dialytic time was 39.9 +/- 17 months. Clinical data, collected after a minimum 12 months observational period included a crude mortality rate and survival analysis recognized by Kaplan-Meyer curve, creatinine, creatinine clearance, rejection episodes and major clinical events such as infections and acute tubular necrosis. RESULTS: One subject died in each group. For kidney graft survival, Kaplan Meyer survival analysis showed a mean survival time of 1170.04 days in the AZA group vs 845 in the MMF group without statistical significance. Graft survival demonstrated 5:40 (12.5%) graft losses in the AZA group vs no kidney transplant loss in the MMF group (the only deceased patient had a well functioning kidney). The curve of graft cumulative proportion survival analysis demonstrated a more improved survival in the MMF group, but this difference did not reach a statistical significance (p = 0.07). Acute rejection episodes in the AZA group were 37.5% vs. 20% in the MMF group. In both groups, CMV infection was successfully treated with specific antiviral agents. CONCLUSIONS: MMF represents an important step towards induction and maintenance of immunosuppression. Our experience in a relatively small cohort investigated in a single center, demonstrates encouraging results regarding graft survival in comparison to those detected in conventional triple drug therapy. Surprisingly, in spite of stronger immunosuppressive treatment, the prevalence of CMV infections was not statistically different in the MMF versus the AZA group.     

Successful treatment of central nervous system PTLD with rituximab and cranial radiotherapy

Background

Primary central nervous system (PCNS) post-transplant lymphoproliferative disorder (PTLD) is a rare complication of solid organ transplantation and is typically an Epstein–Barr virus (EBV)-induced B-cell CD20+ lymphoma. The modalities of treatment include reduction in immunosuppression, cranial radiotherapy (CRT), intravenous and intrathecal rituximab when CD20 is expressed on B-lymphocytes and PTLD cells, and chemotherapy.

Case-Diagnosis/Treatment

We report the successful treatment of EBV-driven PCNS PTLD by reduction in immunosuppression (RI), CRT, and intravenous rituximab. Our patient was an 11-year-old boy with a living-related renal transplant for end-stage renal failure (ESRF) secondary to posterior urethral valves (PUV) and bilateral renal dysplasia (BRD) and on triple immunosuppression with prednisolone, tacrolimus, and azathioprine who had a rising EBV load, which was managed with reduction in tacrolimus dose, withdrawal of azathioprine, and introduction of mycophenolate mofetil (MMF).

Conclusions

The patient presented 7 years post-transplant with a seizure and abnormal neurology secondary to polymorphous hyperplastic lesions in the brain, which responded to rituximab and CRT.     

Pediatric renal transplantation without steroids

Pediatric renal transplant patients present a number of challenges and problems, especially the inhibited post-transplant growth seen in children receiving standard immunosuppressive triple therapy that includes steroids. We report the successful use of steroid-free immunosuppression since 1990 in 14 pediatric renal allograft recipients who received a 10-day initial course of antilymphocyte globulin and surface area-adjusted doses of cyclosporine, 7 of whom also received mycophenolate mofetil (MMF) as maintenance immunosuppression. Only 1 patient died (3 months after transplantation as a result of a primary Epstein-Barr virus infection-induced lymphoproliferative disorder), 1 patient’s graft never functioned, and another patient lost his graft after 3 years because of chronic rejection. Three patients experienced early acute cellular rejection, which resolved in 2 cases with OKT3, and in the 3rd with MMF. There were no late acute rejections. All patients evidenced growth and a growth spurt under this regimen. We conclude that all the pediatric patients benefited from our steroid-free protocol and that this protocol is superior to conventional triple therapies, which entail the eventual reduction and discontinuation of steroids, a procedure that not only inhibits growth but also carries an additional risk of acute rejection due to a steroid-adapted immune response. Received April 16, 1997; received in revised form September 8, 1997; accepted September 10, 1997     

Steroid-free immunosuppression after renal transplantation-long-term experience from a single centre.

BACKGROUND: A steroid-free immunosuppressive protocol may improve the general well-being of patients, but long-term renal graft survival has been a concern. METHODS: In a retrospective clinical study, 329 consecutive transplantations with renal grafts at our centre during the period 1995-2004, were followed for up to 9.3 years. Patients mainly received steroid-free immunosuppression with an initial induction with antithymocyte globulin or basiliximab and maintenance therapy with ciclosporin and mycophenolate mofetil (MMF). Steroids were given after rejection, or if the physician judged it necessary, for instance because of primary kidney disease or when calcineurin inhibitor toxicity was suspected. RESULTS: About 71% of the patients did not take steroids at all. Nevertheless, graft survival rates at 1, 5 and 7 years were 95, 77 and 72% for all grafts, including 27% living donor transplants and 27% second or subsequent grafts. Ten patients (3.2%) died with functioning grafts. Within the first year of transplantation there were 69 acute rejections in 63 patients (19%). Four cases (1.3%) of post-transplant lymphoproliferative disorder (PTLD) occurred with one graft loss and no deaths. Owing to a high PTLD rate in a previous patient cohort, total immunosuppression was lessened after 1998. CONCLUSIONS: Steroid avoidance is possible with good results with respect to acute rejection and long-term graft survival. After introducing MMF, largely avoiding muromonab-CD3 mouse raised monoclonal antibody against CD (OKT3), and reducing doses of calcineurin inhibitor, the rates of PTLD did not differ from what is usually found. For the present, induction and use of MMF, together with a calcineurin inhibitor, is probably to be preferred.     

The Impact of EBV Status on Characteristics and Outcomes of Posttransplantation Lymphoproliferative Disorder

We examined the associations of Epstein–Barr virus (EBV) status with characteristics and outcomes of posttransplantation lymphoproliferative disorder (PTLD) by studying 176 adult solid organ transplant recipients diagnosed with PTLD between 1990 and 2013 (58 [33%] EBV‐negative; 118 [67%] EBV‐positive). The proportion of EBV‐negative cases increased over time from 10% (1990–1995) to 48% (2008–2013) (p < 0.001). EBV‐negative PTLD had distinct characteristics (monomorphic histology, longer latency) though high‐risk features (advanced stage, older age, high lactate dehydrogenase, central nervous system involvement) were not more common compared to EBV‐positive PTLD. In multivariable analysis, EBV negativity was not significantly associated with worse response to initial therapy (adjusted odds ratio, 0.84; p = 0.75). The likelihood of achieving a complete remission (CR) was not significantly different for EBV‐negative versus EBV‐positive PTLD including when therapy was reduction of immunosuppression alone (35% vs. 43%, respectively, p = 0.60) or rituximab (43% vs. 47%, p = 1.0). EBV negativity was also not associated with worse overall survival (adjusted hazard ratio, 0.91; p = 0.71). Our findings indicate that EBV status is not prognostic or predictive of treatment response in adults with PTLD. The high proportion of EBV‐negative disease diagnosed in recent years highlights the need for new strategies for prevention and management of EBV‐negative PTLD.     

Humanized anti-CD20 monoclonal antibody (Rituximab) treatment for post-transplant lymphoproliferative disorder

INTRODUCTION: Post-transplant lymphoproliferative disorders (PTLD) is a consequence of Epstein-Barr virus (EBV) infection and is a B-cell hyperplasia with CD-20 positive lymphocytes. The treatment of PTLD includes reduction/withdrawal of immunosuppression and chemotherapy. This study reports our center experience with humanized monoclonal antibody against CD-20 (Rituximab) for the treatment of PTLD. MATERIAL AND METHODS: Eight cases of PTLD after solid organ transplantation [six kidney, one kidney/pancreas (KP) and one liver] occurred between September 1998 and October 2001. The mean time between transplant and the diagnosis of PTLD was 57.3 months (range 3 months to 10 yr). Five patients underwent cadaveric transplant, five males and six were Caucasians with mean age of 48 yr (range 20-67 yr). RESULTS: The clinical presentation was as follows: lymphadenopathy--5, gastrointestinal bleeding--2 and tonsillar enlargement--1. The diagnosis was made by a lymph node biopsy in five, a gastric ulcer biopsy in two and a tonsillar biopsy in one case. Six of them had polymorphous, two had monoclonal B-cell lymphoma, and all were positive for CD-20. Six were related to EBV, documented by latent membrane protein (LMP) or Epstein-Barr encoded RNA (EBER) staining. Immunosuppression at the time of PTLD diagnosis consisted of tacrolimus in six cases and cyclosporine A (CsA) in two with mycophenolate mofetil (MMF) and azathioprine--3 each and sirolimus--1. Rituximab was administered at a dose of 375 mg/m2 once a week for 4 wk. There were no side effects seen with this therapy. Immunosuppression was reduced in all patients. Complete remission was observed in seven cases (one required two courses). One patient who did not respond received chemotherapy. Patients were followed for a mean period of 22.5 months (range 10-45 months post-PTLD diagnosis. At the last follow-up all eight patients were alive, seven with a functioning graft and one on maintenance dialysis. Three of these patients had been in remission for more than 2.5 yr. CONCLUSION: Rituximab is an effective agent in the treatment of PTLD without the morbidity characteristic of chemotherapy. Chemotherapy should be reserved only for those refractory to Rituximab therapy.     

Two corticosteroid-free regimens-tacrolimus monotherapy after basiliximab administration and tacrolimus/mycophenolate mofetil-in comparison with a standard triple regimen in renal transplantation: results of the Atlas study

BACKGROUND: The side effects associated with corticosteroids have led to efforts to minimize their use in renal transplant patients. In this study we compared two corticosteroid-free tacrolimus-based regimens with a standard triple therapy. METHODS: This was a 6-month, phase III, open-label, parallel-group, multicenter study. The total analysis set comprised 451 patients, randomized (1:1:1) to receive tacrolimus (Tac) monotherapy following basiliximab (Bas) administration (n=153), Tac/mycophenolate mofetil (MMF) (n=151), or, Tac/MMF/corticosteroids triple therapy as a control (n=147). RESULTS: The study was completed by 91.2% (triple therapy), 94.7% (Tac/MMF), and 82.4% (Bas/Tac) of patients. Patient baseline characteristics were similar in all groups. The incidences of biopsy-proven acute rejection were 8.2% (triple therapy), 30.5% (Tac/MMF), and 26.1% (Bas/Tac), p<0.001 (multiple test for comparison with triple therapy); Bas/Tac vs. Tac/MMF, p=ns. The incidences of corticosteroid-resistant acute rejection were 2.0%, 4.0%, and 5.2%, p=ns. Graft survival (95.9%, 96.7%, and 94.7%, p=ns) and patient survival (100%, 99.3%, and 99.3%, p=ns) were similar in all groups. Median serum creatinine at month 6 was 123.0 micromol/L (triple therapy), 134.7 micromol/L (Tac/MMF) and 135.8 micromol/L (Bas/Tac). The overall safety profiles were similar; differences (p<0.05) were reported for anaemia (24.5% vs. 12.6% vs. 14.5%), diarrhoea (12.9% vs. 17.9% vs. 5.9%), and leukopenia (7.5% vs. 18.5% vs. 5.9%) for the triple therapy, Tac/MMF, and Bas/Tac group, respectively. The incidences of new-onset diabetes mellitus were 4.6%, 7.1%, and 1.4%, respectively. CONCLUSION: Corticosteroid-free immunosuppression was feasible with the Bas/Tac and the Tac/MMF regimens. Both corticosteroid-free regimens were equally effective in preventing acute rejection, with the Bas/Tac therapy offering some safety benefits.     

Circulating Antibody Free Light Chains and Risk of Posttransplant Lymphoproliferative Disorder

Posttransplant lymphoproliferative disorder (PTLD) is a major complication of solid‐organ transplantation. With human immunodeficiency virus infection (an analogous immunosuppressive state), elevated kappa and lambda immunoglobulin free light chains (FLCs) in peripheral blood are associated with increased risk of lymphoma. To assess the role of B‐cell dysfunction in PTLD, we measured circulating FLCs among Canadian transplant recipients, including 29 individuals with PTLD and 57 matched transplant recipients who were PTLD‐free. Compared with controls, PTLD cases had higher kappa FLCs (median 1.53 vs. 1.07 times upper limit of normal) and lambda FLCs (1.03 vs. 0.68). Using samples obtained on average 3.5 months before PTLD diagnosis, cases were more likely to have polyclonal FLC elevations (i.e. elevated kappa and/or lambda with normal kappa/lambda ratio: odds ratio [OR] 4.2, 95%CI 1.1–15) or monoclonal elevations (elevated kappa and/or lambda with abnormal ratio: OR 3.0, 95%CI 0.5–18). Strong FLC‐PTLD associations were also observed at diagnosis/selection. Among recipients with Epstein–Barr virus (EBV) DNA measured in blood, EBV DNAemia was associated with FLC abnormalities (ORs 6.2 and 3.2 for monoclonal and polyclonal elevations). FLC elevations are common in transplant recipients and associated with heightened PTLD risk. FLCs likely reflect B‐cell dysfunction, perhaps related to EBV‐driven lymphoproliferation.     

Anthracycline-based chemotherapy as first-line treatment in adults with malignant posttransplant lymphoproliferative disorder after solid organ transplantation

BACKGROUND: Recommended first-line treatment for posttransplant lymphoproliferative disorder (PTLD) is reduction in immunosuppressive therapy, irrespective of histopathological type. Second-line treatment with chemotherapy is generally reserved for tumors that fail to respond to reduced immunosuppression. In view of the similarities between monomorphic PTLD and non-Hodgkin's lymphoma in the general population, our policy is to treat monomorphic PTLD with anthracycline-based chemotherapy as first-line treatment. METHODS: A retrospective single-center analysis of 18 adults who developed PTLD following liver or kidney transplantation was undertaken, with particular emphasis on tumor histology, treatment received, and clinical outcome. RESULTS: Of the 18 patients with PTLD, 13 had high-grade malignant lymphoma on diagnostic biopsy and received anthracycline-based chemotherapy and reduction in immunosuppression as first-line therapy. Nine (69%) of the 13 patients achieved complete remission and eight (62%) remained in complete remission five years after diagnosis. There was no graft loss from rejection or drug toxicity. Four (22%) patients had polymorphic PTLD on diagnostic biopsy (of which two were re-classified as monomorphic) and one had a low-grade malignant lymphoma. All five patients were treated by reduction in immunosuppression without chemotherapy and were in complete remission at a median of two years after diagnosis. Overall, complete remission was seen in 14 out of 18 patients (78%) at one year following diagnosis. CONCLUSION: The use of anthracycline-based chemotherapy and reduction of immunosuppression as first-line treatment in adults with monomorphic PTLD is well tolerated and achieves sustained complete remission in around 70% of patients with a low risk of graft loss.