Effect of Cytomegalovirus Immunoglobulin on the Incidence of Lymphoproliferative Disease After Lung Transplantation: Single-Center Experience With 1157 Patients

Slaying the "Troll of Transplantation"-new frontiers in cytomegalovirus management: A report from the CMV International Symposium 2023

The 2023 International CMV Symposium took place in Barcelona in May 2023. During the 2-day meeting, delegates and faculty discussed the ongoing challenge of managing the risk of cytomegalovirus infection (the Troll of Transplantation) after solid organ or hematopoietic cell transplantation. Opportunities to improve outcomes of transplant recipients by applying advances in antiviral prophylaxis or pre-emptive therapy, immunotherapy, and monitoring of cell-mediated immunity to routine clinical practice were debated and relevant educational clinical cases presented. This review summarizes the presentations, cases, and discussions from the meeting and describes how further advances are needed before the Troll of Transplantation is slain.

Lymphoproliferative disorders after renal transplantation along 2 decades: a large longitudinal study of 21.546 recipients

INTRODUCTION

Post transplant lymphoproliferative disorders (PTLD) are heterogeneous lymphoid proliferations in recipients of solid organs which seem to be related to Epstein Barr Virus (EBV). The use of antilymphocyte antibodies, EBV seronegativity in the recipient,acute rejection and CMV infection have been identified as classical risk factors.

MATERIAL Y METHODS

We have studied in a retrospective observational study, the incidence of PTLD in a period of 22 years, its relationship with EBV, presence of classical risk factors and outcome in 21546 simple adult renal transplant recipients from cadaveric and living donors, transplanted in 21 hospitals from 1990 to 2009.

RESULTS

A total of 275 recipients developed PTLD (1,2%),195 males (70,9%), 80 females (29,1%) aged 59.2 (p25 44.7 p75 68)years. Two hundred forty-five (89.0%) were 1st transplant recipients and 269 (97,8%) from cadaveric donors. EBV in the tissue was reported in 94 out of the 155 studied recipients (60.6%) and 86.0% of the proliferations were due to B lymphocytes. PTLD median appearance after transplant were 42.months (p25, 75, 12, 77, 5). One hundred eighty-eight recipients out of 275 patients (68.3%) had any classical risk factor and the use of antilymphocyte antibodies was the most frequent. During the follow-up, 172 patients died (62,5%) and 103 (37,5%) had a complete remission. The main cause of death was PTLD progression (n = 91, 52,9%), followed by sepsis (n = 24, 13,9%). The follow-up period post-transplant of the recipients was between 3 and 22 years. The incidence was 0,14% during the first year post-trasplant and 0.98% the cumulative incidence at 10 years. Patient survival after diagnosis was 51%, 44% and 39% after 1, 2 and 5 years, respectively. Finally, overall graft survival was 48%, 39% and 33% at the same periods.

CONCLUSION

PTLD has a low incidence in renal transplant recipients. Most of the proliferations are due to B lymphocytes and seem to have a close relationship with EBV. PTLD can develop in the absence of classical risk factors. The prognosis is poor, mainly due to PTLD progression, but the survivors can even maintain their grafts.

Role of Cytomegalovirus in the Development of Posttransplant Lymphoproliferative Disorders With or Without Epstein-Barr Virus Infection

OBJECTIVES

Many studies have revealed the role of Epstein-Barr virus infection, in combination with chronic immunosuppression, as the main factor in the development of posttransplant lymphoproliferative disorder malignancy. Although many studies have been published on other confounding factors involved in posttransplant lymphoproliferative disorders, the role of coinfection with both cytomegalovirus and Epstein-Barr virus has not been investigated. We evaluated the role of cytomegalovirus infection as a risk factor in transplant recipients who were simultaneously infected with Epstein-Barr virus.

MATERIALS AND METHODS

In the current retrospective study, 143 recipients of various solid-organ transplants at Namazi Hospital from April 2018 to March 2019 were assessed for coinfection with cytomegalovirus and Epstein-Barr virus with the TaqMan real-time polymerase chain reaction assay. We collected clinical and pathology details from their medical records.

RESULTS

Of the 143 patients, 81 (57%) were male. Children under 5 years old were the largest group with 32% prevalence, and the most common organ transplant in this study was liver transplant. The prevalence of cytomegalovirus and Epstein-Barr virus coinfection was 12.6% (18/143 patients), of whom 50% experienced posttransplant lymphoproliferative disorder (9/18 patients) during 18 months after transplant. The incidence of posttransplant lymphoproliferative disorder was significantly higher among patients coinfected with cytomegalovirus and Epstein-Barr virus than among patients without coinfection. We observed a significant correlation between cytomegalovirus viral loads, as well as Epstein-Barr virus genome load, in posttransplant lymphoproliferative disorder development.

CONCLUSIONS

Coinfection with cytomegalovirus and Epstein-Barr virus, as well as the genome load of each virus, can serve as a strong predictive factor of posttransplant lymphoproliferative disorder in solidorgan transplant recipients.

Posttransplant Lymphoproliferative Disorder Following Kidney Transplantation: A Review

Posttransplant lymphoproliferative disorder (PTLD) is one of the most feared complications following kidney transplantation. Over a 10-year period, the risk of PTLD in kidney transplant recipients (KTRs) is 12-fold higher than in a matched nontransplanted population. Given the number of kidney transplants performed, KTRs who experience PTLD outnumber other organ transplant recipients who experience PTLD. Epstein-Barr virus infection is one of the most important risk factors for PTLD, even though 40% of PTLD cases in contemporary series are not Epstein-Barr virus-associated. The overall level of immunosuppression seems to be the most important driver of the increased occurrence of PTLD in solid organ transplant recipients. Reduction in immunosuppression is commonly accepted to prevent and treat PTLD. Although the cornerstone of PTLD treatment had been chemotherapy (typically cyclophosphamide-doxorubicin-vincristinr-prednisone), the availability of rituximab has changed the treatment landscape in the past 2 decades. The outcome of PTLD in KTRs has clearly improved as a result of the introduction of more uniform treatment protocols, improved supportive care, and increased awareness and use of positron emission tomography combined with computed tomography in staging and response monitoring. In this review, we will focus on the most recent data on epidemiology, presentation, risk factors, and management of PTLD in KTRs.

Association between infectious event and de novo malignancy after heart transplantation

The aim of the study was to investigate the incidence of and risk factors for de novo malignancy after heart transplantation (HTx) in a single center. We assessed 102 consecutive patients who received HTx and were followed-up in our center regularly for > 1 year from June 2006 to May 2018. We investigated the incidence of and risk factors for de novo malignancy. The cumulative incidence of each malignancy type during the follow-up period was one (0.98%) for skin cancer, four (3.92%) for nonskin solid organ cancer, and six (5.88%) for posttransplant lymphoproliferative disorder (PTLD). The percentage of patients with more than one infectious event ≤ 1 year after HTx was higher in the malignancy group than in the non-malignancy group. Furthermore, Kaplan-Meier analysis revealed that the incidence rate of infectious events was higher in patients with malignancies than in those without (log-rank P < 0.001). After dividing malignancies into a PTLD group and a solid organ malignancy group, we found that negative Epstein-Barr virus serostatus, cytomegalovirus-positive antigenemia, and the occurrence of any viral or gastrointestinal infectious event at ≤ 1 year were more frequent in patients with PTLD than in patients without it. The survival rate was significantly lower for patients with solid organ malignancy than for patients without malignancy. In conclusion, there was a correlation between infectious events and de novo malignancy, particularly in patients with PTLD. We should confirm this finding by conducting a larger cohort study.

Increased risk of PTLD in lung transplant recipients with cystic fibrosis

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) is an important cause of morbidity and mortality following lung transplantation. Recipients with cystic fibrosis (CF) may have an increased risk of PTLD although the literature is limited to single center cohorts. Our primary aim is to examine PTLD in an adult lung transplant population by utilizing the International Society for Heart and Lung Transplantation Registry.

METHODS

We studied 30,598 adult recipients of lung transplants performed between 1999 and 2011. The primary outcome was development of and time to PTLD. In addition to indication for transplant, other predictors examined included Epstein-Barr virus (EBV) and cytomegalovirus (CMV) serostatus, gender, and age. Outcomes were assessed with univariable and multivariable Cox proportional hazard models to obtain hazard ratios (HR).

RESULTS

17% of the cohort had a diagnosis of CF. PTLD developed in 2% of CF recipients compared to 1% for non-CF recipients (p<0.001). Compared to non-CF recipients, CF recipients had higher prevalence of EBV and CMV seronegativity and higher prevalences of high risk EBV and CMV mismatch (D+/R-). There is a significant association between CF and the development of PTLD [HR 1.66 (95% CI 1.30-2.12)]. Stratified multivariable analysis controlling for age revealed EBV negative non-CF recipients have an almost 2 fold increased risk of developing PTLD, whereas EBV negative CF recipients had an almost 6.5 fold increased risk.

CONCLUSIONS

CF recipients have a higher risk for PTLD compared to non-CF recipients. Further studies are needed to account for additional risk factors and management in this population post-transplant.

The Role of Antiviral Prophylaxis for the Prevention of Epstein-Barr Virus-Associated Posttransplant Lymphoproliferative Disease in Solid Organ Transplant Recipients: A Systematic Review

The role of antiviral prophylaxis for the prevention of posttransplant lymphoproliferative disease (PTLD) remains controversial for solid organ transplantation (SOT) recipients who are seronegative for Epstein-Barr virus (EBV) but who received organs from seropositive donors. We performed a systematic review and meta-analysis to address this issue. Two independent assessors extracted data from studies after determining patient eligibility and completing quality assessments. Overall, 31 studies were identified and included in the quantitative synthesis. Nine studies were included in the direct comparisons (total 2366 participants), and 22 were included in the indirect analysis. There was no significant difference in the rate of EBV-associated PTLD in SOT recipients among those who received prophylaxis (acyclovir, valacyclovir, ganciclovir, valganciclovir) compared with those who did not receive prophylaxis (nine studies; risk ratio 0.95, 95% confidence interval 0.58-1.54). No significant differences were noted across all types of organ transplants, age groups, or antiviral use as prophylaxis or preemptive therapy. There was no significant heterogeneity in the effect of antiviral prophylaxis on the incidence of PTLD. In conclusion, the use of antiviral prophylaxis in high-risk EBV-naive patients has no effect on the incidence of PTLD in SOT recipients.

Immunomodulation by hyperimmunoglobulins after solid organ transplantation: Beyond prevention of viral infection

Hyperimmunoglobulins are pharmaceutical formulations of human IgG which contain high titers of antibodies against specific viruses. They have been successfully used in solid organ transplantation (SOT) to prevent Cytomegalovirus (CMV) and Hepatitis B Virus (HBV) infection. The introduction of effective and cheaper antiviral drugs has resulted in decreasing usage of hyperimmunoglobulins in SOT. However, it may still be attractive to combine antiviral drug therapy with hyperimmunoglobulins after SOT, as there is some evidence that hyperimmunoglobulins, similar to high doses of intravenous immunoglobulins (IVIgs), might exert anti-inflammatory activity and thereby prevent immunological graft damage and improve graft and patient survival. In this review we discuss the existing clinical evidence for beneficial anti-inflammatory effects of hyperimmunoglobulins after cardiac, lung, kidney, and liver transplantation. Only a limited number of studies have addressed this issue, and these studies often included small patient cohorts and showed considerable variations in the type, intensity and duration of treatment regimens. Due to these limitations, it is difficult to draw firm conclusions. Retrospective studies consistently demonstrated that addition of CMV hyperimmunoglobulin (CMV-Ig) to antiviral drug prophylaxis after lung transplantation is associated with reduced rates of CMV disease and bronchiolitis obliterans syndrome (BOS), and improved patient survival. The doses of CMV-Ig administered after SOT are much lower than the minimal effective dose of IVIg used for anti-inflammatory therapy in auto-immune diseases. Therefore, it is questionable whether the reduced incidence of BOS is the result of 'direct' anti-inflammatory effects of CMV-Ig or is caused by a reduction of CMV infection, which is a risk factor for BOS. No or very limited evidence for better prevention of immunological graft damage by anti-CMV combination therapy is available for heart, kidney and liver transplant patients. In liver transplantation published evidence suggests that the high-doses of Hepatitis B virus hyperimmunoglobulin (HBIg) administered to prevent HBV-infection may reduce the risk of acute rejection, while combination therapy of HBIg and antiviral drugs in HBV-infected patients is consistently associated with better graft and patient survival compared to antiviral monotherapy. Well-designed prospective randomized studies with larger patient cohorts are needed to substantiate the current limited evidence for anti-inflammatory benefits of hyperimmunoglobulins besides prevention of CMV and HBV infection after SOT.

Cytomegalovirus Hyper Immunoglobulin for CMV Prophylaxis in Thoracic Transplantation

Cytomegalovirus (CMV) infection negatively influences both short- and long-term outcomes after cardiothoracic transplantation. In heart transplantation, registry analyses have shown that CMV immunoglobulin (CMVIG) with or without virostatic prophylaxis is associated with a significant reduction in mortality and graft loss versus no prophylaxis, particularly in high-risk donor (D)+/recipient (R)- transplants. Randomized comparative trials are lacking but retrospective data suggest that addition of CMVIG to antiviral prophylaxis may reduce rates of CMV-related events after heart transplantation, including the incidence of acute rejection or chronic allograft vasculopathy. However, available data consistently indicate that when CMVIG is used, it should be administered with concomitant antiviral therapy, and that evidence concerning preemptive management with CMVIG is limited, but promising. In lung transplantation, CMVIG should again only be used with concomitant antiviral therapy. Retrospective studies have shown convincing evidence that addition of CMVIG to antiviral prophylaxis lowers CMV endpoints and mortality. The current balance of evidence suggests that CMVIG prophylaxis reduces the risk of bronchiolitis obliterans syndrome, but a controlled trial is awaited. Overall, the relatively limited current data set suggests that prophylaxis with CMVIG in combination with antiviral therapy appears effective in D+/R- heart transplant patients, whereas in lung transplantation, addition of CMVIG in recipients of a CMV-positive graft may offer an advantage in terms of CMV infection and disease.

Lymphoproliferative Disorders after Lung Transplantation: Clinicopathological Characterization of 16 Cases with Identification of Very-Late-Onset Forms

BACKGROUND

The incidence of posttransplant lymphoproliferative disorders (PTLD) has recently declined, but late cases are increasingly reported in lung transplant recipients.

OBJECTIVES

We present our experience with PTLD after lung transplantation, attempting to examine the distinguishing characteristics of early versus late cases.

METHODS

We have reviewed clinical and pathological data of all cases occurring in our institution between 2001 and 2014.

RESULTS

Patients, aged 15-63 years, were mostly (12/16) Epstein-Barr virus (EBV) seropositive at the time of transplantation. Eleven early cases, occurring 9.4 ± 5.2 months after transplantation and mostly (9/11) prior to 2010, had EBV+ diffuse large B-cell lymphomas. Lungs and/or thoracic lymph nodes were often involved (n = 8). Treatments included reduction of immune suppression (n = 11), rituximab (n = 8) and chemotherapy (n = 7). Two patients are in complete remission at 26 and 216 months. Nine patients died 8.0 ± 6.5 months after PTLD diagnosis. Of the 5 cases with late PTLD occurring 4-23 years (mean ± SD: 10.4 ± 7.7) after transplantation (and 3/5 after 2009), 1 had pulmonary lymphomatoid granulomatosis (only endothoracic case), 1 cutaneous large T-cell lymphoma, 2 had anaplastic large cell lymphomas, and 1 Hodgkin's disease. Two of the 5 cases were EBV-, including one followed by a second EBV+ PTLD after 8 years of complete remission. Two patients were alive and well (follow-up: 44 and 151 months), one having suffered from EBV-related cholestatic hepatitis 6 years after the PTLD.

CONCLUSION

Our small experience shows a trend toward (very) late occurrence, associated with more unusual clinicopathologic features, but not with a worse prognosis.

Rabbit antithymocyte globulin induction and risk of post-transplant lymphoproliferative disease in adult and pediatric solid organ transplantation: An update

The most modifiable risk factor for post-transplant lymphoproliferative disease (PTLD) is the type and dose of induction and maintenance immunosuppressive therapy. It is challenging to identify the contribution of a single agent such as rabbit antithymocyte globulin (rATG) in the setting of multidrug therapy. Registry analyses can be helpful but are limited by methodological restrictions and inclusion of historical patient cohorts. These are typically from eras when rATG dosing was markedly higher than current dosing (e.g. total dose 14 mg/kg versus 6 mg/kg now), accompanied by higher exposure to maintenance therapies, and often an absence of antiviral prophylaxis. The largest registry analysis to assess rATG specifically found no risk of PTLD after kidney transplantation, but conflicting results have been reported, highlighting the difficulty of interpreting this type of analysis. The relative rarity of PTLD means that individually controlled trials are underpowered to assess its occurrence, but the available data do not suggest an effect of rATG. A pooled analysis of data from studies of rATG induction in kidney and heart transplantation found the incidence of PTLD to be comparable to published reports in the overall transplant population. Data on the effect of rATG dose are inconclusive, but in patients receiving antiviral prophylaxis it does not appear to be influential. Nevertheless, it would seem reasonable to employ the lowest dose of rATG compatible with effective induction, particularly in EBV-seronegative recipients and other high-risk groups such as heart-lung transplant recipients. Overall, the risk of PTLD following rATG induction therapy with modern dosing regimens and under current management conditions appears unlikely to make an important contribution to the risk:benefit balance.

Epstein-Barr Virus-Specific Humoral Immune Responses in Health and Disease

Epstein-Barr virus (EBV) is widely distributed in the world and associated with a still increasing number of acute, chronic, malignant and autoimmune disease syndromes. Humoral immune responses to EBV have been studied for diagnostic, pathogenic and protective (vaccine) purposes. These studies use a range of methodologies, from cell-based immunofluorescence testing to antibody-diversity analysis using immunoblot and epitope analysis using recombinant or synthetic peptide-scanning. First, the individual EBV antigen complexes (VCA , MA, EA(D), EA(R) and EBNA) are defined at cellular and molecular levels, providing a historic overview. The characteristic antibody responses to these complexes in health and disease are described, and differences are highlighted by clinical examples. Options for EBV vaccination are briefly addressed. For a selected number of immunodominant proteins, in particular EBNA1, the interaction with human antibodies is further detailed at the epitope level, revealing interesting insights for structure, function and immunological aspects, not considered previously. Humoral immune responses against EBV-encoded tumour antigens LMP1, LMP2 and BARF1 are addressed, which provide novel options for targeted immunotherapy. Finally, some considerations on EBV-linked autoimmune diseases are given, and mechanisms of antigen mimicry are briefly discussed. Further analysis of humoral immune responses against EBV in health and disease in carefully selected patient cohorts will open new options for understanding pathogenesis of individual EBV-linked diseases and developing targeted diagnostic and therapeutic approaches.

Alemtuzumab in lung transplantation: an open-label, randomized, prospective single center study

Induction therapy with alemtuzumab followed by lower maintenance immunosuppression (IS) has been associated with reduced morbidity and mortality in abdominal and heart transplantation (TX). In the current study, alemtuzumab, in combination with reduced levels of maintenance IS, was compared to thymoglobulin in combination with standard IS. Sixty consecutive patients who underwent lung transplantation (LUTX) at a single center were prospectively randomized in two groups: group A received alemtuzumab in conjunction with reduced doses of tacrolimus, steroids and mycophenolate mofetil. Group B received thymoglobulin in association with standard dose IS. Patient and graft survival, freedom from acute cellular rejection (ACR), lymphocytic bronchiolitis, bronchiolitis obliterans syndrome, kidney function, infectious complications and posttransplant lymphoproliferative disorder were analyzed. Alemtuzumab induction therapy resulted in complete the absence of ACR episodes ≥ A2 within the first year post-TX. The difference to thymoglobulin was significant (alemtuzumab 0 vs. ATG 0.33; p = 0.019). All other factors studied did not show any differences between the two groups. Alemtuzumab induction therapy after LUTX in combination with reduced maintenance IS significantly reduces higher-grade rejection rates. This novel therapeutic agent had no impact on survival, infections rates, kidney function and incidence of malignancies.