Clinical and virologic outcomes in high-risk adult Epstein-Barr virus mismatched organ transplant recipients

Incidence and Timing of Epstein-Barr Virus Whole Blood DNAemia in Epstein-Barr Virus-Mismatched Adult and Pediatric Solid Organ Transplant Recipients

BACKGROUND

Epstein-Barr virus (EBV) viral load (VL) monitoring is recommended post-transplant for EBV-mismatched (donor EBV seropositive/recipient EBV seronegative) solid organ transplant (SOT) recipients as a component of post-transplant lymphoproliferative disorder (PTLD) prevention, but the optimal frequency and timing of EBV VL monitoring remains unknown.

METHODS

In this retrospective cohort study, we investigated the incidence and timing of whole blood EBV DNAemia in EBV-mismatched adult and pediatric SOT recipients, who had EBV VL monitoring as part of a pre-emptive approach to PTLD prevention to optimize monitoring algorithms. We explored associations between donor-acquired EBV DNAemia (DA-EBV), defined as EBV DNAemia within 1 year post-transplant, and donor and recipient characteristics, and determined the proportion who developed PTLD.

RESULTS

We analyzed 257 D+/R- recipients (kidney n = 64, heart n = 75, liver n = 93, lung n = 25); 126/257 (49.0%) developed DA-EBV at a median of 83 days (Q1-Q3: 50-130 days) post-transplant. Incidence of DA-EBV varied by organ and was highest in liver (62.4%) and lowest in heart recipients (28.0%). PTLD was diagnosed in 38/257 (14.8%) EBV-mismatched recipients, 25/162 (15.4%) children, and 13/95 (13.7%) adults. DA-EBV was uncommon in recipients less than 6 months old (3/29, 10.3%) and among recipients less than 12 months with donors less than 12 months (2/29, 6.9%); possible mechanisms of protection other than recipient passive maternal antibody and false-positive donor serostatus are discussed.

CONCLUSION

Monitoring for DA-EBV should be focused on months 2-6 post-transplant. Less frequent whole blood EBV VL monitoring is likely a safe option in recipients less than 6 months old and recipients 6-12 months old with donors less than 12 months old.

Feasibility and Safety of Ex Vivo Delivery of Rituximab to Lung Allografts in Transplant Recipients at High Risk for Epstein-Barr Virus-associated Posttransplant Lymphoproliferative Disorder

Background

Ex vivo lung perfusion (EVLP) offers a novel platform for delivering targeted therapies directly to donor lungs before transplantation, potentially reducing systemic side effects. Our study evaluated the feasibility and safety of rituximab delivery to donor lungs from Epstein-Barr virus (EBV)-seropositive donors for transplantation into EBV-seronegative recipients (D+/R-) to reduce the risk of EBV-associated posttransplant lymphoproliferative disorder (PTLD), which remains a major obstacle in the transplant setting.

Methods

A pilot study was conducted involving 5 EBV-seronegative lung transplant recipients. Donor lungs were perfused with 500 mg rituximab during EVLP for 3-4 h. Primary outcomes included safety and feasibility, assessed by monitoring lung function during perfusion, posttransplant complications, and graft dysfunction. Secondary outcomes included EBV DNAemia, PTLD incidence, peripheral B-cell frequencies, EBV blood transcripts, and rituximab serum levels.

Results

Rituximab delivery via EVLP was feasible and safe, with no significant deviations in lung function or adverse events linked to treatment. One patient experienced primary graft dysfunction. Peripheral B-cell counts were reduced immediately posttransplant and remained low in some patients, whereas others rebounded over the weeks posttransplant, and serum rituximab levels were undetectable after 2 wk. Three patients developed EBV DNAemia and 2 developed PTLD within 2 y, although PTLD lesions were not observed in transplanted lungs.

Conclusions

EVLP-based rituximab delivery is a feasible and promising strategy for targeting donor-transmitted EBV with minimal systemic exposure. Although the findings suggest potential clinical benefit, the development of PTLD in extrathoracic sites underscores the need for further optimization and larger studies to evaluate efficacy and refine the intervention.

Limited utility of Epstein-Barr virus (EBV) surveillance for predicting post-transplant lymphoproliferative disorders in adult EBV seropositive lung transplant recipients

BACKGROUND

EBV DNAemia surveillance, with reduction of immunosuppression at certain viral load (VL) thresholds, is a common practice for mitigating progression from EBV DNAemia to post-transplant lymphoproliferative disorder (PTLD) in lung transplant recipients (LTRs). The utility of EBV surveillance in adult EBV seropositive LTRs is unknown.

METHODS

We performed a retrospective cohort study of EBV seropositive adult LTRs who underwent lung transplant between 1/1/19 and 12/31/20 and received whole blood (WB) EBV PCR surveillance. We compared peak WB EBV VLs among 3 groups: 1) asymptomatic LTRs who developed PTLD, before PTLD was clinically suspected, 2) LTRs who developed PTLD, after PTLD was clinically suspected, and 3) LTRs who did not develop PTLD. We calculated the positive predictive value (PPV) of moderate-grade DNAemia (2840 to 11,360 IU/mL) and high-grade DNAemia (≥ 11,360 IU/mL) for identifying active or future PTLD.

RESULTS

Six (2.6 %) of 229 LTRs developed PTLD. Among LTRs who developed PTLD, median peak EBV VL was significantly higher after PTLD was suspected than before clinical signs of PTLD were present (16,004 IU/mL vs. ≤568 IU/mL, p = 0.016). Median peak EBV VLs were similar between asymptomatic LTRs who later developed PTLD and LTRs who did not develop PTLD (median peak EBV VL ≤568 IU/mL vs. ≤568 IU/mL, p = 0.62). The PPVs for moderate- and high-grade DNAemia were 14.7 % and 33.3 %, respectively.

CONCLUSIONS

EBV surveillance did not accurately identify EBV seropositive LTRs at risk for progressing to PTLD. EBV PCR testing in asymptomatic EBV seropositive transplant recipients may represent an opportunity for diagnostic stewardship.

Risk and prognosis of posttransplant lymphoproliferative disease in Epstein-Barr virus-seronegative kidney transplant recipients - an observational cohort study from Norway and western Denmark

Posttransplant lymphoproliferative disorder (PTLD) poses a serious challenge in kidney transplant recipients. Epstein-Barr virus (EBV)-seronegative recipients have a significantly increased risk of PTLD, but few studies have investigated risk factors for PTLD in EBV-seronegative recipients in the current era of immunosuppression. This cohort study from Norway and western Denmark included first-time kidney transplant recipients between 2007 and 2021 and estimated the cumulative incidence, risk, and prognosis of PTLD. In total, 80 of 5084 recipients developed biopsy-proven PTLD (median follow-up of 6.8 years). Two-year cumulative incidence of PTLD was 7.3% in EBV-seronegative adults and 14.1% in EBV-seronegative children. The age-adjusted hazard ratio (HR) for PTLD was 30.7 (95% CI, 13.9-67.9) in EBV-seronegative vs EBV-seropositive adults and 5.4 (95% CI, 1.1-26.9) in children. Recipients receiving induction therapy with antithymocyte globulin had an increased risk of PTLD (HR, 4.4; 95% CI, 1.8-10.6), while rituximab induction was associated with a lower risk of PTLD (HR, 0.20; 95% CI, 0.03-1.49). The age-adjusted mortality rate was higher in EBV-seronegative recipients with vs without PTLD (HR, 3.3; 95% CI, 1.3-8.3). In conclusion, the risk of PTLD in EBV-seronegative kidney transplant recipients is high in the contemporary era of immunosuppression. Induction therapy should be carefully considered in this high-risk population.

Nutrition and Epstein-Barr viremia in children underwent liver transplantation: A retrospective, cross-sectional study

BACKGROUND AND AIMS

We aimed to examine the association between nutritional status, assessed by height/length and body weight for age and sex, and Epstein-Barr virus (EBV) viremia in children underwent liver transplantation.

METHODS

Nutritional status was determined by total score of age- and sex-specific height/length and body weight: < (-2 SD) as "2 points", (-2 SD to -1 SD) as "1 point", and ≥ (-1SD) as "0 point". Children were further classified into three groups: malnutrition (4 points), risk of malnutrition (1-3 points), and normal (0 point). EBV viremia were confirmed by real time quantitative PCR method if EBV burden was ≥400 copies/ml.

RESULTS

A total number of 896 children (414 boys and 482 girls, medium age 8 months) were included in the study. The medium height was 65.0 cm while medium body weight was 7.0 kg. The prevalence of EBV viremia was 54.6% during follow up. Comparing with children with normal nutritional status, the adjusted odds ratios for the risk of EBV viremia was 2.14 (95% CI: 1.44, 3.19) in children with risk of malnutrition, and 2.29 (95% CI: 1.54, 3.40) in children with malnutrition. Each point increase of nutritional score was associated with a 21% higher risk of EBV viremia (odd ratios = 1.21; 95% CI: 1.10, 1.34) in fully adjusted model.

CONCLUSIONS

Nutritional score was associated with EBV viremia in children underwent liver transplantation.

The IPTA Nashville Consensus Conference on Post-Transplant lymphoproliferative disorders after solid organ transplantation in children: III - Consensus guidelines for Epstein-Barr virus load and other biomarker monitoring

The International Pediatric Transplant Association convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorders after solid organ transplantation in children. In this report from the Viral Load and Biomarker Monitoring Working Group, we reviewed the existing literature regarding the role of Epstein-Barr viral load and other biomarkers in peripheral blood for predicting the development of PTLD, for PTLD diagnosis, and for monitoring of response to treatment. Key recommendations from the group highlighted the strong recommendation for use of the term EBV DNAemia instead of "viremia" to describe EBV DNA levels in peripheral blood as well as concerns with comparison of EBV DNAemia measurement results performed at different institutions even when tests are calibrated using the WHO international standard. The working group concluded that either whole blood or plasma could be used as matrices for EBV DNA measurement; optimal specimen type may be clinical context dependent. Whole blood testing has some advantages for surveillance to inform pre-emptive interventions while plasma testing may be preferred in the setting of clinical symptoms and treatment monitoring. However, EBV DNAemia testing alone was not recommended for PTLD diagnosis. Quantitative EBV DNAemia surveillance to identify patients at risk for PTLD and to inform pre-emptive interventions in patients who are EBV seronegative pre-transplant was recommended. In contrast, with the exception of intestinal transplant recipients or those with recent primary EBV infection prior to SOT, surveillance was not recommended in pediatric SOT recipients EBV seropositive pre-transplant. Implications of viral load kinetic parameters including peak load and viral set point on pre-emptive PTLD prevention monitoring algorithms were discussed. Use of additional markers, including measurements of EBV specific cell mediated immunity was discussed but not recommended though the importance of obtaining additional data from prospective multicenter studies was highlighted as a key research priority.

Growth Transformation of B Cells by Epstein-Barr Virus Requires IMPDH2 Induction and Nucleolar Hypertrophy

The in vitro growth transformation of primary B cells by Epstein-Barr virus (EBV) is the initial step in the development of posttransplant lymphoproliferative disorder (PTLD). We performed electron microscopic analysis and immunostaining of primary B cells infected with wild-type EBV. Interestingly, the nucleolar size was increased by two days after infection. A recent study found that nucleolar hypertrophy, which is caused by the induction of the IMPDH2 gene, is required for the efficient promotion of growth in cancers. In the present study, RNA-seq revealed that the IMPDH2 gene was significantly induced by EBV and that its level peaked at day 2. Even without EBV infection, the activation of primary B cells by the CD40 ligand and interleukin-4 increased IMPDH2 expression and nucleolar hypertrophy. Using EBNA2 or LMP1 knockout viruses, we found that EBNA2 and MYC, but not LMP1, induced the IMPDH2 gene during primary infections. IMPDH2 inhibition by mycophenolic acid (MPA) blocked the growth transformation of primary B cells by EBV, leading to smaller nucleoli, nuclei, and cells. Mycophenolate mofetil (MMF), which is a prodrug of MPA that is approved for use as an immunosuppressant, was tested in a mouse xenograft model. Oral MMF significantly improved the survival of mice and reduced splenomegaly. Taken together, these results indicate that EBV induces IMPDH2 expression through EBNA2-dependent and MYC-dependent mechanisms, leading to the hypertrophy of the nucleoli, nuclei, and cells as well as efficient cell proliferation. Our results provide basic evidence that IMPDH2 induction and nucleolar enlargement are crucial for B cell transformation by EBV. In addition, the use of MMF suppresses PTLD. IMPORTANCE EBV infections cause nucleolar enlargement via the induction of IMPDH2, which are essential for B cell growth transformation by EBV. Although the significance of IMPDH2 induction and nuclear hypertrophy in the tumorigenesis of glioblastoma has been reported, EBV infection brings about the change quickly by using its transcriptional cofactor, EBNA2, and MYC. Moreover, we present here, for the novel, basic evidence that an IMPDH2 inhibitor, namely, MPA or MMF, can be used for EBV-positive posttransplant lymphoproliferative disorder (PTLD).

Combined assessment of Epstein-Barr virus viral capsid antigen and Epstein-Barr virus nuclear antigen-1 serology for post-transplant lymphoproliferative disorder risk stratification in adult solid organ transplant recipients

BACKGROUND

Epstein-Barr virus (EBV) seronegative solid organ transplant recipients (SOTRs) are at increased risk for post-transplant lymphoproliferative disorder (PTLD). Assays for EBV serostatus assess antibody to both EBV viral capsid antigen (VCA) and Epstein-Barr nuclear antigen-1 (EBNA-1), but PTLD risk among SOT recipients with discordant VCA and EBNA-1 results is unknown.

METHODS

We performed a retrospective, single-center cohort study to determine the risk of PTLD among adult (≥ 18 years) SOTRs with discordant pre-transplant VCA and EBNA-1 IgG compared to that of SOTRs with concordantly negative or concordantly positive serology using univariable and multivariable Cox-proportional hazards models.

RESULTS

Of 4106 SOTRs, the number (%) who were concordantly positive, concordantly negative, and discordant was 3787 (92.2%), 149 (3.6%), and 170 (4.2%), respectively. The adjusted hazard of PTLD was significantly higher among discordant SOTRs compared to concordantly positive SOTRs (aHR 2.6, 95% CI 1.04-6.6, p =.04) and lower compared to concordantly negative SOTRs (aHR 0.27, 95% CI 0.10-0.76, p <.001). The adjusted hazard of EBV+ PTLD among those with discordant serology was also significantly higher compared to the concordantly positive cohort (aHR 3.53, 95% CI 1.04-12.0, p =.04) and significantly lower compared to the concordantly negative cohort (aHR 0.23, 95% CI 0.06-0.82, p =.02).

CONCLUSIONS

Risk of PTLD among SOTRs with discordant VCA and EBNA-1 may be intermediate between those with concordantly positive and negative serology. If confirmed in future studies, revision of national EBV serology reporting to include both VCA and EBNA results may be needed to optimize PTLD risk stratification.

Editorial: testing for Epstein Barr virus and treating autoimmune hepatitis-still a long way to go! Authors' reply

This article is linked to Nayagam et al papers. To view these articles, visit https://doi.org/10.1111/apt.16708 and https://doi.org/10.1111/apt.16751

Epstein-Barr virus status and immunosuppression use in paediatric autoimmune liver disease

BACKGROUND

Since azathioprine is associated with lymphoproliferative disorders in Epstein-Barr virus (EBV)-naïve patients with inflammatory bowel disease, guidelines advise avoidance. No recommendations exist for autoimmune liver disease (AILD).

AIMS

To evaluate EBV status and EBV-related complications in paediatric AILD.

METHODS

Single-centre, retrospective, observational study of paediatric AILD.

RESULTS

In 245 paediatric patients with AILD, azathioprine was used in 168 (68.6%) and mycophenolate mofetil in 69 (28.2%). EBV status was assessed in 18 (10.7%) prior to azathioprine and 6 (8.7%) MMF. Acute EBV infection was diagnosed in five patients while on immunosuppression, resulting in one transient hepatitis and one persistent hepatitis. There were no cases of lymphoproliferative disorder in native livers. Liver transplantation (LT) was performed in 39 (15.9%) patients, with 8 EBV IgG-negative at LT. Post-LT EBV viraemia developed in 29 (74.4%), first detected at median 26 days (IQR, 13-86). EBV IgG-negative recipients had higher peak viraemia (266 984 IU/mL [IQR, 41108-2429050] v 5333 [IQR, 2036-38770], P = .004) and longer time to peak viraemia (375 days [IQR, 251-884] v 70 [IQR, 21-604], P = .04). Early EBV-associated post-transplant lymphoproliferative disorder (PTLD) was diagnosed in two patients, both EBV-IgG negative with prior azathioprine.

CONCLUSIONS

Real-world data demonstrate that EBV serostatus is not routinely checked before immunosuppression for paediatric AILD. Lymphoproliferative disorder was not diagnosed in those with native livers; however, EBV IgG-negative LT recipients receiving EBV IgG-positive donor organs are at risk of early PTLD. Large multicentre studies with longer follow-up are required to further evaluate the risk.

Association of antiviral prophylaxis and rituximab use with posttransplant lymphoproliferative disorders (PTLDs): A nationwide cohort study

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication of solid organ transplantation (SOT). Most PTLD cases are associated with Epstein-Barr virus (EBV) infection. The role of antiviral prophylaxis or rituximab therapy for prevention of PTLD in SOT recipients is controversial. In a nationwide cohort, we assessed the incidence, presentation, and outcome of histologically proven PTLD. We included 4765 patients with a follow-up duration of 23 807 person-years (py). Fifty-seven PTLD cases were identified; 39 (68%) were EBV positive (EBV+ PTLD). Incidence rates for EBV+ PTLD at 1, 2, and 3 years posttransplant were 3.51, 2.24, and 1.75/1000 py and 0.44, 0.25, and 0.29/1000 py for EBV- PTLD. We did not find an effect of antiviral prophylaxis on early and late EBV+ PTLD occurrence (early EBV+ PTLD: SHR 0.535 [95% CI 0.199-1.436], p = .264; late EBV+ PTLD: SHR 2.213, [95% CI 0.751-6.521], p = .150). However, none of the patients (0/191) who received a rituximab-containing induction treatment experienced PTLD, but 57 of 4574 patients without rituximab induction developed PTLD. In an adjusted restricted mean survival time model, PTLD-free survival was significantly longer (0.104 years [95% CI 0.077-0.131]) in patients receiving rituximab as induction treatment. This study provides novel data on the association of rituximab induction and reduced risk for PTLD.

Innate and Adaptive Immune Correlates of Chronic and Self-limiting EBV DNAemia in Solid-organ Transplant Recipients

BACKGROUND

Epstein-Barr virus (EBV) DNAemia is a major risk factor for posttransplant lymphoproliferative disorder; however, immune correlates of EBV DNAemia in the transplant setting are limited.

METHODS

Peripheral blood mononuclear cells were collected from 30 transplant recipients with self-limiting EBV DNAemia (SLD; n = 11) or chronic EBV DNAemia (CD; n = 19) at enrollment and 4-8 weeks later. Mass cytometry was used to characterize innate and T-cell immune correlates of EBV DNAemia. Furthermore, flow cytometry was used to measure the frequency of EBV-specific T-cell responses between groups following stimulation with an EBV-infected cell lysate.

RESULTS

Unsupervised analysis of the innate compartment (CD3CD19 cells) identified 5 CD11c clusters at higher abundance in the SLD group (false discovery rate ≤ 1%). These clusters expressed CD11b, CD45RO, CD14, CD123, CD127, and CD38, among others. Unsupervised profiling of the T-cell compartment (CD3CD19) revealed 2 CD4 T-cell clusters at higher frequency among those with SLD (false discovery rate ≤ 1%), which expressed CD45RA, CCR7, CD27, CD28, and CD40L-suggestive of a naive T cell (TN). Manual biaxial gating confirmed increased frequencies of conventional dendritic cells (3.1% versus 2.1%; P = 0.023) and CD4 TN (4.4% versus 1.9%; P = 0.018) among those with SLD. Last, frequencies of interferon-γ-producing EBV-specific CD4 T cells were significantly lower in the CD group relative to those with SLD (4243 versus 250 cells/10 cells; P = 0.015).

CONCLUSIONS

CD is associated with a reduction of CD11c cells, CD4 TN, and interferon-γ-producing EBV-specific CD4 T cells, suggesting an interplay between innate and adaptive immune compartments may be important for regulating EBV DNAemia.

Post-transplant lymphoproliferative disorders, Epstein-Barr virus infection, and disease in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

PTLD with the response-dependent sequential use of RIS, rituximab, and cytotoxic chemotherapy is recommended. Evidence gaps requiring future research and alternate treatment strategies including immunotherapy are highlighted.