An International Survey of Cytomegalovirus Management Practices in Lung Transplantation

Predictors of Cytomegalovirus Recurrence Following Cessation of Posttransplant Prophylaxis

INTRODUCTION

Cytomegalovirus (CMV) infection is associated with a poor prognosis after lung transplantation, and donor and recipient CMV serostatus is a risk factor for reactivation. CMV prophylaxis is commonly administered in the first year following transplantation to reduce CMV infection; however, the risk factors for long-term reactivation remain unclear. We investigated the timing and risk factors of CMV infection after prophylactic administration.

METHODS

This study was a retrospective review of the institutional lung transplantation database from June 2014 to June 2022. Data on patient characteristics, pretransplantation laboratory values, postoperative outcomes, and CMV infection were collected. Donor CMV-IgG-positive and recipient CMV-IgG-negative groups were defined as the CMV mismatch group.

RESULTS

During the study period, 257 patients underwent lung transplantation and received a prophylactic dose of valganciclovir hydrochloride for up to 1 y. CMV infection was detected in 69 patients (26.8%): 40 of 203 (19.7%) in the non-CMV mismatch group and 29 of 54 (53.7%) in the CMV mismatch group (P < 0.001). CMV infection after prophylaxis occurred at a median of 425 and 455 d in the CMV mismatch and non-CMV mismatch groups, respectively (P = 0.07). Multivariate logistic regression analysis revealed that preoperative albumin level (odds ratio [OR] = 0.39, P = 0.04), CMV mismatch (OR = 15.7, P < 0.001), and donor age (OR = 1.05, P = 0.009) were significantly associated with CMV infection.

CONCLUSIONS

CMV mismatch may have increased the risk of CMV infection after lung transplantation, which decreased after prophylaxis. In addition to CMV mismatch, low preoperative albumin level and donor age were independent predictors of CMV infection.

Survival Tree Provides Individualized Estimates of Survival After Lung Transplant

INTRODUCTION

Identifying contributors to lung transplant survival is vital in mitigating mortality. To enhance individualized mortality estimation and determine variable interaction, we employed a survival tree algorithm utilizing recipient and donor data.

METHODS

United Network Organ Sharing data (2000-2021) were queried for single and double lung transplants in adult patients. Graft survival time <7 d was excluded. Sixty preoperative and immediate postoperative factors were evaluated with stepwise logistic regression on mortality; final model variables were included in survival tree modeling. Data were split into training and testing sets and additionally validated with 10-fold cross validation. Survival tree pruning and model selection was based on Akaike information criteria and log-likelihood values. Estimated survival probabilities and log-rank pairwise comparisons between subgroups were calculated.

RESULTS

A total of 27,296 lung transplant patients (8175 single; 19,121 double lung) were included. Stepwise logistic regression yielded 47 significant variables associated with mortality. Survival tree modeling returned six significant factors: recipient age, length of stay from transplant to discharge, recipient ventilator duration post-transplant, double lung transplant, recipient reintubation post-transplant, and donor cytomegalovirus status. Eight subgroups consisting of combinations of these factors were identified with distinct Kaplan-Meier survival curves.

CONCLUSIONS

Survival trees provide the ability to understand the effects and interactions of covariates on survival after lung transplantation. Individualized survival probability with this technique found that preoperative and postoperative factors influence survival after lung transplantation. Thus, preoperative patient counseling should acknowledge a degree of uncertainty given the influence of postoperative factors.

Advances in lung transplantation: 60 years on

Lung transplantation is a well-established treatment for advanced lung disease, improving survival and quality of life. Over the last 60 years all aspects of lung transplantation have evolved significantly and exponential growth in transplant volume. This has been particularly evident over the last decade with a substantial increase in lung transplant numbers as a result of innovations in donor utilization procurement, including the use donation after circulatory death and ex-vivo lung perfusion organs. Donor lungs have proved to be surprisingly robust, and therefore the donor pool is actually larger than previously thought. Parallel to this, lung transplant outcomes have continued to improve with improved acute management as well as microbiological and immunological insights and innovations. The management of lung transplant recipients continues to be complex and heavily dependent on a tertiary care multidisciplinary paradigm. Whilst long term outcomes continue to be limited by chronic lung allograft dysfunction improvements in diagnostics, mechanistic understanding and evolutions in treatment paradigms have all contributed to a median survival that in some centres approaches 10 years. As ongoing studies build on developing novel approaches to diagnosis and treatment of transplant complications and improvements in donor utilization more individuals will have the opportunity to benefit from lung transplantation. As has always been the case, early referral for transplant consideration is important to achieve best results.

Evaluating the efficacy and safety of letermovir compared to valganciclovir for the prevention of human cytomegalovirus disease in adult lung transplant recipients

BACKGROUND

Lung transplant recipients are at high risk for severe cytomegalovirus (CMV) disease. Off-label use of letermovir (LET) may avert myelotoxicity associated with valganciclovir (VGCV), but data in lung transplantation are limited. This study aims to evaluate the outcomes of LET prophylaxis among lung transplant recipients.

METHODS

This retrospective, matched cohort study included lung transplant recipients who received LET for primary CMV prophylaxis following VGCV intolerance. Patients were matched 1:1 to historical VGCV controls based on age, serostatus group, and time from transplant. The primary outcome was CMV breakthrough within 1 year post-LET initiation; secondary outcomes included hematologic changes.

RESULTS

A total of 124 lung transplant recipients were included per group (32% CMV mismatch, D+R-), with LET initiated a median of 9.6 months post-transplantation. One CMV breakthrough event (0.8%) was observed in the LET group versus four (3.2%) in the VGCV group (p = .370). The median (interquartile range) white blood cell (WBC) count was 3.1 (2.1-5.6) at LET initiation which increased to 5.1 (3.9-7.2) at the end of follow-up (p <.001). For VGCV controls, WBC was 4.8 (3.4-7.2) at baseline and 5.4 (3.6-7.2) at the end of follow-up; this difference was not statistically significant (p = .395). Additionally, 98.4% of LET patients experienced ≥1 leukopenia episode in the year prior to LET compared to 71.8% the year after initiation (p <.001). Similar results were observed for neutropenia (48.4% and 17.7%, p <.001).

CONCLUSION

LET prophylaxis was associated with a low rate of CMV reactivation and leukopenia recovery. LET may represent a reasonable prophylaxis option for lung transplant recipients unable to tolerate VGCV.

Infections in lung transplanted patients: A review

Lung transplantation can improve the survival of patients with severe chronic pulmonary disorders. However, the short- and long-term risk of infections can increase morbidity and mortality rates. A non-systematic review was performed to provide the most updated information on pathogen, host, and environment-related factors associated with the occurrence of bacterial, fungal, and viral infections as well as the most appropriate therapeutic options. Bacterial infections account for about 50% of all infectious diseases in lung transplanted patients, while viruses represent the second cause of infection accounting for one third of all infections. Almost 10% of patients develop invasive fungal infections during the first year after lung transplant. Pre-transplantation comorbidities, disruption of physical barriers during the surgery, and exposure to nosocomial pathogens during the hospital stay are directly associated with the occurrence of life-threatening infections. Empiric antimicrobial treatment after the assessment of individual risk factors, local epidemiology of drug-resistant pathogens and possible drug-drug interactions can improve the clinical outcomes.

Prevention of Cytomegalovirus Infection in Solid Organ Transplant Recipients: Guidelines by the Korean Society of Infectious Diseases and the Korean Society for Transplantation

Cytomegalovirus (CMV) is the most important opportunistic viral pathogen in solid organ transplant (SOT) recipients. The Korean guideline for the prevention of CMV infection in SOT recipients was developed jointly by the Korean Society for Infectious Diseases and the Korean Society of Transplantation. CMV serostatus of both donors and recipients should be screened before transplantation to best assess the risk of CMV infection after SOT. Seronegative recipients receiving organs from seropositive donors face the highest risk, followed by seropositive recipients. Either antiviral prophylaxis or preemptive therapy can be used to prevent CMV infection. While both strategies have been demonstrated to prevent CMV infection post-transplant, each has its own advantages and disadvantages. CMV serostatus, transplant organ, other risk factors, and practical issues should be considered for the selection of preventive measures. There is no universal viral load threshold to guide treatment in preemptive therapy. Each institution should define and validate its own threshold. Valganciclovir is the favored agent for both prophylaxis and preemptive therapy. The evaluation of CMV-specific cell-mediated immunity and the monitoring of viral load kinetics are gaining interest, but there was insufficient evidence to issue recommendations. Specific considerations on pediatric transplant recipients are included.

Herpes Virus Infection in Lung Transplantation: Diagnosis, Treatment and Prevention Strategies

Lung transplantation is an ultimate treatment option for some end-stage lung diseases; due to the intense immunosuppression needed to reduce the risk of developing acute and chronic allograft failure, infectious complications are highly incident. Viral infections represent nearly 30% of all infectious complications, with herpes viruses playing an important role in the development of acute and chronic diseases. Among them, cytomegalovirus (CMV) is a major cause of morbidity and mortality, being associated with an increased risk of chronic lung allograft failure. Epstein-Barr virus (EBV) is associated with transformation of infected B cells with the development of post-transplantation lymphoproliferative disorders (PTLDs). Similarly, herpes simplex virus (HSV), varicella zoster virus and human herpesviruses 6 and 7 can also be responsible for acute manifestations in lung transplant patients. During these last years, new, highly sensitive and specific diagnostic tests have been developed, and preventive and prophylactic strategies have been studied aiming to reduce and prevent the incidence of these viral infections. In this narrative review, we explore epidemiology, diagnosis and treatment options for more frequent herpes virus infections in lung transplant patients.

Evaluation of Two Different CMV-Immunoglobulin Regimens for Combined CMV Prophylaxis in High-Risk Patients following Lung Transplant

BACKGROUND

The clinical benefits of the common off-label use of cytomegalovirus (CMV)-specific immunoglobulin (CMV-Ig) combined with antivirals in organ transplantation have not been previously assessed. The objective was to compare the risk of CMV infection and other post-transplantation outcomes between two CMV-Ig prophylaxis regimens in lung transplant recipients; Methods: Retrospective study of 124 donor CMV positive/recipient negative (D+/R-) patients receiving preventive ganciclovir/valganciclovir for 12 months, of whom 62 received adjunctive CMV-Ig as per label indication (short regimen [SR-Ig]; i.e., 7 doses over 2.5 months) and were compared to 62 who received an extended off-label regimen (ER-Ig) consisting of 17 doses over one year after transplantation.

RESULTS

The incidence of CMV infection or disease, acute rejection, chronic lung allograft dysfunction, and survival did not differ between the two CMV-Ig schedules. Although the time to the first CMV infection after transplantation was shorter in the ER-Ig than in the SR-Ig adjunctive group (log-rank: p = 0.002), the risk was independently predicted by antiviral cessation (odds ratio = 3.74; 95% confidence interval = 1.04-13.51; p = 0.030), whereas the CMV-Ig schedule had no effect.

CONCLUSIONS

Extending the adjunctive CMV-Ig prophylaxis beyond the manufacturer's recommendations up to one year does not confer additional clinical benefits regarding lung post-transplantation outcomes.

Infectious Complications in Lung Transplant Recipients

Infection remains a common cause of death throughout the lifespan of a lung transplant recipient. The increased susceptibility of lung transplant recipients is multifactorial including exposure of the graft to the external environment, impaired mucociliary clearance, and high levels of immunosuppression. Long-term outcomes in lung transplant recipients remain poor compared with other solid organ transplants largely due to deaths from infections and chronic allograft dysfunction. Antibacterial, antifungal, and antiviral prophylaxis may be used after lung transplantation to target a number of different opportunistic infections for varying durations of time. The first-month posttransplant is most commonly characterized by nosocomial infections and donor-derived infections. Following the first month to the first 6 months after transplant-a period of intense immunosuppression-is associated with opportunistic infections. While immunosuppression is reduced after the first year posttransplant, infection remains a risk with community-acquired and rarer infectious agents. Clinicians should be vigilant for infection at all time points after transplant. The use of patient-tailored prophylaxis and treatments help ensure graft and patient survival.

Early Postoperative Management of Lung Transplant Recipients

The early postoperative period after lung transplantation is a critical time. Prompt recognition and treatment of primary graft dysfunction can alter long-term allograft function. Cardiovascular, gastrointestinal, renal, and hematologic derangements are common and require close management to limit their negative sequelae.

Wnt activation promotes memory T cell polyfunctionality via epigenetic regulator PRMT1

T cell polyfunctionality is a hallmark of protective immunity against pathogens and cancer, yet the molecular mechanism governing it remains mostly elusive. We found that canonical Wnt agonists inhibited human memory CD8+ T cell differentiation while simultaneously promoting the generation of highly polyfunctional cells. Downstream effects of Wnt activation persisted after removal of the drug, and T cells remained polyfunctional following subsequent cell division, indicating the effect is epigenetically regulated. Wnt activation induced a gene expression pattern that is enriched with stem cell-specific gene signatures and upregulation of protein arginine methyltransferase 1 (PRMT1), a known epigenetic regulator. PRMT1+CD8+ T cells are associated with enhanced polyfunctionality, especially the ability to produce IL-2. In contrast, inhibition of PRMT1 ameliorated the effects of Wnt on polyfunctionality. Chromatin immunoprecipitation revealed that H4R3me2a, a permissive transcription marker mediated by PRMT1, increased at the IL-2 promoter loci following Wnt activation. In vivo, Wnt-treated T cells exhibited superior polyfunctionality and persistence. When applied to cytomegalovirus (CMV) donor-seropositive, recipient-seronegative patients (D+/R-) lung transplant patient samples, Wnt activation enhanced CMV-specific T cell polyfunctionality, which is important in controlling CMV diseases. These findings reveal a molecular mechanism governing T cell polyfunctionality and identify PRMT1 as a potential target for T cell immunotherapy.

National survey of prevention and management of CMV infection in pediatric kidney transplantation in comparison to clinical practice guidelines

BACKGROUND

Cytomegalovirus (CMV) is one of the most frequent opportunistic infections in kidney transplant (KT) recipients and is a risk factor for patient and graft survival after KT. Center-to-center variation, optimal prevention and treatment strategies in pediatric KT are currently unknown. This survey aimed to assess current CMV prevention and treatment strategies used among French pediatric KT centers.

METHODS

A web-based survey was sent to all 13 French pediatric kidney transplantation centers.

RESULTS

Twelve (92%) centers responded to the survey. All centers used prophylaxis for the donor-positive/recipient-negative (D+/R-) group. For R + patients, 54% used prophylaxis, 37% used a pre-emptive strategy. In the low-risk group, D-/R-, 50% used a pre-emptive approach and 50% had no specific prevention strategy. The antiviral used by all centers for prophylaxis was valganciclovir (VGCV). The duration of prophylaxis varied from 3 to 7 months and the duration of viral load monitoring varied from 6 months to indefinitely. No center used a hybrid/sequential approach. For the treatment of CMV DNAemia, VGCV or intravenous GCV were used. Therapeutic drug monitoring of VGCV was performed in 5 centers (42%). Five centers reported drug resistance. Eight centers (67%) administered VGCV during the treatment of acute graft rejection.

CONCLUSIONS

There is uniformity in CMV management in some areas among pediatric KT centers in France but not in others which remain diverse and are not up to date with current guidelines, suggesting unnecessary variation which could be reduced with better evidence to inform practice.

A Randomized Study of Quantiferon CMV-directed Versus Fixed-duration Valganciclovir Prophylaxis to Reduce Late CMV After Lung Transplantation

BACKGROUND

We provide the results of the first interventional study of cytomegalovirus (CMV)-specific immune monitoring to direct the length of antiviral prophylaxis in lung transplantation (LTx).

METHODS

Patients (n = 118) at risk of CMV infection were randomized 1:2 to either 5 months or variable length valganciclovir prophylaxis (5-11 mo post-LTx), as determined by the QuantiFERON (QFN)-CMV assay. Patients with a negative QFN-CMV assay (< 0.2 IU/mL) received prolonged valganciclovir prophylaxis.

RESULTS

The primary endpoint that was the incidence of CMV infection in the lung allograft within 18 months of LTx was significantly reduced in the QFN-CMV directed arm (37% versus 58%, P = 0.03). Secondary endpoints that included blood viremia, acute rejection, and chronic lung allograft dysfunction did not differ between the 2 arms. Of the 80/118 patients who ceased antiviral prophylaxis at 5 months, the incidence of viremia (> 600 copies/mL) within the blood was significantly reduced in patients with a positive QFN-CMV assay compared with those without protective immunity (13% versus 67%, P = 0.0003), as was the incidence of severe viremia (> 10 000 copies/mL) (3% versus 50%, P < 0.001). Ceasing antiviral prophylaxis at 11 months in patients with a negative assay was associated with a 25% incidence of late CMV viremia.

CONCLUSIONS

Cytomegalovirus immune monitoring allows an individualized approach to CMV prophylaxis and reduces late CMV infection within the lung allograft.

Use of Viral Load as a Surrogate Marker in Clinical Studies of Cytomegalovirus in Solid Organ Transplantation: A Systematic Review and Meta-analysis

Symptomatic cytomegalovirus (CMV) disease has been the standard endpoint for clinical trials in organ transplant recipients. Viral load may be a more relevant endpoint due to low frequency of disease. We performed a meta-analysis and systematic review of the literature. We found several lines of evidence to support the validity of viral load as an appropriate surrogate end-point, including the following: (1) viral loads in CMV disease are significantly greater than in asymptomatic viremia (odds ratio, 9.3 95% confidence interval, 4.6-19.3); (2) kinetics of viral replication are strongly associated with progression to disease; (3) pooled incidence of CMV viremia and disease is significantly lower during prophylaxis compared with the full patient follow-up period (viremia incidence: 3.2% vs 34.3%; P < .001) (disease incidence: 1.1% vs 13.0%; P < .001); (4) treatment of viremia prevented disease; and (5) viral load decline correlated with symptom resolution. Based on the analysis, we conclude that CMV load is an appropriate surrogate endpoint for CMV trials in organ transplant recipients.

Indefinite cytomegalovirus prophylaxis with valganciclovir after lung transplantation

Human cytomegalovirus (HCMV) infections and reactivations are common after lung transplantation and are associated with the development of bronchiolitis obliterans syndrome. Against this background, temporary HCMV prophylaxis is an established standard regimen after lung transplantation in most centers. However, the optimal duration of prophylaxis is unclear. We conducted a retrospective two-center study to determine the efficacy of indefinite lifelong HCMV prophylaxis with oral valganciclovir in a cohort of 133 lung transplant recipients with a mean follow-up time of approximately 5 years. During the follow-up period, HCMV DNA was detected in 22 recipients (16.5%). In one case, HCMV pneumonitis developed after prophylaxis had been terminated. We observed a beneficial safety profile and tolerability in our cohort, as the majority of patients still received valganciclovir after a 1- and 3-year observation period, respectively. Compared to the literature, these data indicate a beneficial effect of extended valganciclovir prophylaxis with an acceptable safety profile.

High incidence of clinically significant cytomegalovirus infection in CMV D+/R+ lung transplant recipients receiving 3 months of antiviral prophylaxis

BACKGROUND

Universal antiviral prophylaxis is the preferred preventive strategy for lung transplant recipients (LTRs) at risk of CMV infection. We compared the risk of CMV infection between CMV D+/R + and D-/R + LTRs after 3 months of prophylaxis.

METHODS

This was a retrospective review of CMV R + LTRs transplanted between 2005 and 2013. Patients dying before completing 3 months, or receiving >180 days of prophylaxis were excluded. The primary outcome was proportion of LTRs who developed CMV infection and clinically significant CMV infection defined as CMV infection leading to preemptive therapy or CMV disease.

RESULTS

We analyzed 90 D+/R + and 72 D-/R + with a median follow up of 730 days. CMV infection and disease was more common in D+/R + compared to D-/R+ (CMV infection 66% vs 40%; P = 0.001; CMV disease 13% vs 4% P = 0.045). Fifty-nine patients developed at least one episode of clinically significant CMV infection (41/90 [46%] D+/R + and 18/72 [25%] D-/R + P=0.007) with recurrence occurring in 29 LTRs (49% of patients with previous CMV infection), of which 22 (76%) were CMV D+/R+. Thirty percent had side effects related to CMV therapy.

CONCLUSION

Three months prophylaxis in D+/R + LTRs was associated with high rates of clinically significant CMV infection and recurrences.

The Third International Consensus Guidelines on the Management of Cytomegalovirus in Solid-organ Transplantation

Despite recent advances, cytomegalovirus (CMV) infections remain one of the most common complications affecting solid organ transplant recipients, conveying higher risks of complications, graft loss, morbidity, and mortality. Research in the field and development of prior consensus guidelines supported by The Transplantation Society has allowed a more standardized approach to CMV management. An international multidisciplinary panel of experts was convened to expand and revise evidence and expert opinion-based consensus guidelines on CMV management including prevention, treatment, diagnostics, immunology, drug resistance, and pediatric issues. Highlights include advances in molecular and immunologic diagnostics, improved understanding of diagnostic thresholds, optimized methods of prevention, advances in the use of novel antiviral therapies and certain immunosuppressive agents, and more savvy approaches to treatment resistant/refractory disease. The following report summarizes the updated recommendations.

Long-Term Impact of Cytomegalovirus Serologic Status on Lung Transplantation in the United States

BACKGROUND

Cytomegalovirus (CMV) infection has been associated with poor outcomes after solid organ transplantation. The long-term impact of donor and recipient CMV serological status on lung transplant outcomes remains unclear. Accordingly, we evaluated the impact of donor and recipient CMV status on long-term patients as well as allograft survival after single (SLT) and double lung transplantation (BLT).

METHODS

The Scientific Registry of Transplant Recipients was used to track all adult lung transplants in United States from May 2005 to June 2016. Patient mortality and bronchiolitis obliterans syndrome were determined up to 5 years using Cox proportional hazards modeling. Additionally, landmark analysis was performed conditional on survival at 1 year.

RESULTS

Compared with donor negative-recipient CMV-IgG negative (D-R-), donor positive-recipient negative (D+R-) and donor positive-recipient positive (D+R+) groups had increased mortality at 1 and 5 years after BLT, with the former demonstrating highest risk. Although mortality was not increased with CMV seropositive donors after SLT at 1 year, both D+R- and D+R+ groups demonstrated greater mortality at 5 years. Risk of bronchiolitis obliterans syndrome was not affected by CMV serological status. Conditional landmark analysis confirmed that lungs from CMV seropositive donors conferred highest risk for long-term mortality.

CONCLUSIONS

CMV seronegative recipients undergoing either BLT or SLT from CMV seropositive donors have the highest risk of long-term mortality that extends beyond the first year. Further studies are needed to determine the causes of higher mortality observed in the CMV seronegative recipients and risks and benefits of extension of CMV prophylaxis, particularly in the high-risk group.

Respiratory Viruses and Other Relevant Viral Infections in the Lung Transplant Recipient

As advances occur in surgical technique, postoperative care, and immunosuppressive therapy, the rate of mortality in the early postoperative period following lung transplantation continues to decline. With the improvements in immediate and early posttransplant mortality, infections and their sequel as well as rejection and chronic allograft dysfunction are increasingly a major cause of posttransplant mortality. This chapter will focus on infections by respiratory viruses and other viral infections relevant to lung transplantation, including data regarding the link between viral infections and allograft dysfunction.

Risk factors, survival, and impact of prophylaxis length in cytomegalovirus-seropositive lung transplant recipients: A prospective, observational, multicenter study

BACKGROUND

The optimal length of cytomegalovirus (CMV) prophylaxis in lung transplantation according to CMV serostatus is not well established.

METHODS

We have performed a prospective, observational, multicenter study to determine the incidence of CMV infection and disease in 92 CMV-seropositive lung transplant recipients (LTR), their related outcomes and risk factors, and the impact of prophylaxis length.

RESULTS

At 18 months post transplantation, 37 patients (40%) developed CMV infection (23 [25%]) or disease (14 [15.2%]). Overall mortality was higher in patients with CMV disease (64.3% vs 10.2%; P<.001), but only one patient died from CMV disease. In the multivariate analysis, CMV disease was an independent death risk factor (odds ratio [OR] 18.214, 95% confidence interval [CI] 4.120-80.527; P<.001). CMV disease incidence was higher in patients with 90-day prophylaxis than in those with 180-day prophylaxis (31.3% vs 11.8%; P=.049). Prophylaxis length was an independent risk factor for CMV disease (OR 4.974, 95% CI 1.231-20.094; P=.024). Sixteen patients withdrew from prophylaxis because of adverse events.

CONCLUSION

CMV infection and disease in CMV-seropositive LTR remain frequent despite current prophylaxis. CMV disease increases mortality, whereas 180-day prophylaxis reduces the incidence of CMV disease.

Cytomegalovirus Immunoglobulin After Thoracic Transplantation: An Overview

Cytomegalovirus (CMV) is a highly complex pathogen which, despite modern prophylactic regimens, continues to affect a high proportion of thoracic organ transplant recipients. The symptomatic manifestations of CMV infection are compounded by adverse indirect effects induced by the multiple immunomodulatory actions of CMV. These include a higher risk of acute rejection, cardiac allograft vasculopathy after heart transplantation, and potentially bronchiolitis obliterans syndrome in lung transplant recipients, with a greater propensity for opportunistic secondary infections. Prophylaxis for CMV using antiviral agents (typically oral valganciclovir or intravenous ganciclovir) is now almost universal, at least in high-risk transplants (D+/R-). Even with extended prophylactic regimens, however, challenges remain. The CMV events can still occur despite antiviral prophylaxis, including late-onset infection or recurrent disease, and patients with ganciclovir-resistant CMV infection or who are intolerant to antiviral therapy require alternative strategies. The CMV immunoglobulin (CMVIG) and antiviral agents have complementary modes of action. High-titer CMVIG preparations provide passive CMV-specific immunity but also exert complex immunomodulatory properties which augment the antiviral effect of antiviral agents and offer the potential to suppress the indirect effects of CMV infection. This supplement discusses the available data concerning the immunological and clinical effects of CMVIG after heart or lung transplantation.

Long term complications following 54 consecutive lung transplants

BACKGROUND

Due to the complex therapy and the required high level of immunosuppression, lung recipients are at high risk to develop many different long term complications.

METHODS

From 1993-2000, a total of 54 lung transplantation (LuTx) were performed at our center. Complications, graft and patient survival of this cohort was retrospectively analyzed.

RESULTS

One/five and ten-year patient survival was 71.4%, 41.2% and 25.4%; at last follow up (4/2010), twelve patients were alive. Of the 39 deceased patients, 26 died from infectious complications. Other causes of death were myocardial infarction (n=1), progressive graft failure (n=1), intracerebral bleeding (n=2), basilary vein thrombosis (n=1), pulmonary emboli (n=1), others (n=7). Surgical complication rate was 27.7% during the first year and 25% for the 12 long term survivors. Perioperative rejection rate was 35%, and 91.6% for the 12 patients currently alive. Infection incidence during first hospitalization was 79.6% (1.3 episodes per transplant) and 100% for long term survivors. Commonly isolated pathogens were cytomegalovirus (56.8%), Aspergillus (29.4%), RSV (13.7%). Other common complications were renal failure (56.8%), osteoporosis (54.9%), hypertension (45%), diabetes mellitus (19.6%).

CONCLUSIONS

Infection and rejection remain the most common complications following LuTx with many other events to be considered.

Polyfunctional T-Cell Signatures to Predict Protection from Cytomegalovirus after Lung Transplantation

RATIONALE

Cytomegalovirus (CMV), which is one of the most common infections after lung transplantation, is associated with chronic lung allograft dysfunction and worse post-transplantation survival. Current approaches for at-risk patients include a fixed duration of antiviral prophylaxis despite the associated cost and side effects.

OBJECTIVES

We sought to identify a specific immunologic signature that predicted protection from subsequent CMV.

METHODS

CMV-seropositive lung transplantation recipients were included in the discovery (n = 43) and validation (n = 28) cohorts. Polyfunctional CMV-specific immunity was assessed by stimulating peripheral blood mononuclear cells with CMV pp65 or IE-1 peptide pools and then by measuring T-cell expression of CD107a, IFN-γ, tumor necrosis factor-α (TNF-α), and IL-2. Recipients were prospectively monitored for subsequent viremia. A Cox proportional hazards regression model that considered cytokine responses individually and in combination was used to create a predictive model for protection from CMV reactivation. This model was then applied to the validation cohort.

MEASUREMENTS AND MAIN RESULTS

Using the discovery cohort, we identified a specific combination of polyfunctional T-cell subsets to pp65 that predicted protection from subsequent CMV viremia (concordance index 0.88 [SE, 0.087]). The model included both protective (CD107a(-)/IFN-γ(+)/IL-2(+)/TNF-α(+) CD4(+) T cells, CD107a(-)/IFN-γ(+)/IL-2(+)/TNF-α(+) CD8(+) T cells) and detrimental (CD107a(+)/IFN-γ(+)/IL-2(-)/TNF-α(-) CD8(+) T cells) subsets. The model was robust in the validation cohort (concordance index 0.81 [SE, 0.103]).

CONCLUSIONS

We identified and validated a specific T-cell polyfunctional response to CMV antigen stimulation that provides a clinically useful prediction of subsequent cytomegalovirus risk. This novel diagnostic approach could inform the optimal duration of individual prophylaxis.

Pharmacoepidemiology of cytomegalovirus prophylaxis in a large retrospective cohort of kidney transplant recipients with Medicare Part D coverage

We assembled a cohort of 21 117 kidney transplant patients from July 2006 to June 2011 with Medicare Part D coverage using US Renal Database System data to determine real-world use of cytomegalovirus (CMV) prophylaxis. CMV prophylaxis was defined as filled prescriptions for daily oral valganciclovir (≤900 mg), ganciclovir (≤3 g), or valacyclovir (6-8 g) within 28 d of transplant. Multilevel logistic regression analyses were performed to determine factors associated with CMV prophylaxis. CMV prophylaxis (97% valganciclovir) was identified in 61% of kidney transplant recipients (median duration, 64 d); 71% of seronegative recipients of kidneys from seropositive donors (D+/R-); 63% of R+ patients; 60% of patients with unknown serostatus; and 34% of D-/R- patients. Variability in usage of prophylaxis among transplant centers was greater than variability within transplant centers. One in four transplant centers prescribed CMV prophylaxis to >60% of their D-/R- patients. CMV donor/recipient serostatus, lymphocyte-depleting agents for induction and mycophenolate for maintenance were associated with CMV prophylaxis. CMV prophylaxis was commonly used among kidney transplant recipients. Routine prescription of CMV prophylaxis to D-/R- patients may have occurred in some transplant centers. Limiting unnecessary use of CMV prophylaxis may decrease healthcare costs and drug-related harms.

Cytomegalovirus disease is associated with higher all-cause mortality after lung transplantation despite extended antiviral prophylaxis

BACKGROUND

The duration of anticytomegalovirus (CMV) prophylaxis after lung transplantation (LT) varies among transplant centers.

METHODS

A retrospective review of CMV donor-seropositive/recipient-seronegative (D+/R-) and CMV recipient-seropositive (R+) LT patients between January 2005 and September 2012 was performed. Starting January 2007, valganciclovir prophylaxis was given for at least 12 months (often lifelong) for CMV D+/R- and extended from three to six months for R+ LT patients. Risks of CMV infection and CMV disease, and mortality after LT, were assessed.

RESULTS

A total of 88 LT patients were studied, including 32 CMV D+/R-, and 56 R+ patients. During the follow-up period, 11 (12.5%) patients had asymptomatic CMV infection, and nine (10.3%) developed CMV disease. CMV disease (HR, 4.189; 95% CI: 1.672-10.495; p = 0.002) and CMV infection and disease (HR, 3.775; 95% CI: 1.729-8.240; p = 0.001) were significant risk factors for mortality. Overall, no significant difference was observed in rates of CMV infection or disease among LT recipients who received shorter vs. extended CMV prophylaxis.

CONCLUSIONS

Despite extended prophylaxis, LT patients remain at risk of CMV infection and disease. CMV remains associated with increased mortality after transplantation.

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.

Treatment of Cytomegalovirus Infection with Cidofovir and CMV Immune Globulin in a Lung Transplant Recipient

Cytomegalovirus (CMV) infection after lung transplantation is associated with increased risk for pneumonitis and bronchiolitis obliterans as well as allograft rejection and opportunistic infections. Ganciclovir is the mainstay of prophylaxis and treatment but CMV infections can be unresponsive. Apart from direct antiviral drugs, CMV immunoglobulin (CMVIG) preparations may be considered but are only licensed for prophylaxis. A CMV-seronegative 42-year-old man with cystic fibrosis received a lung from a CMV-seropositive donor. Intravenous ganciclovir prophylaxis was delayed until day 12 due to acute postoperative renal failure and was accompanied by five doses of CMVIG (10 g). By day 16, CMV-DNA was detectable and rising; CMV-specific T-cells were undetectable. Switch from ganciclovir to foscarnet prompted a transient decrease in CMV viral load, but after increasing again to reach 3600 copies/mL foscarnet was changed to intravenous cidofovir and CMVIG was restarted. CMV load continued to fluctuate and declined slowly, whereas CMV-specific T-cells were detected five months later and increased thereafter. At last follow-up, the patient was in very good clinical condition with no evidence of bronchiolitis obliterans. No side effects of this treatment were observed. In this hard-to-treat case, the combination of cidofovir with off-label use of CMVIG contributed to a successful outcome.

Risks and Epidemiology of Infections After Lung or Heart–Lung Transplantation

Nowadays, lung transplantation is an established treatment option of end-stage pulmonary parenchymal and vascular disease. Post-transplant infections are a significant contributor to overall morbidity and mortality in the lung transplant recipient that, in turn, are higher than in other solid organ transplant recipients. This is likely due to several specific factors such as the constant exposure to the outside environment and the colonized native airway, and the disruption of usual mechanisms of defense including the cough reflex, bronchial circulation, and lymphatic drainage. This chapter will review the common infections that develop in the lung or heart–lung transplant recipient, including the general risk factors for infection in this population, and specific features of prophylaxis and treatment for the most frequent bacterial, viral, and fungal infections. The effects of infection on lung transplant rejection will also be discussed.

Incidence, Risk Factors and Outcomes of Delayed-onset Cytomegalovirus Disease in a Large Retrospective Cohort of Lung Transplant Recipients

BACKGROUND

Cytomegalovirus (CMV) replication and disease commonly occur in lung transplant recipients after stopping anti-CMV prophylaxis. The epidemiology of CMV disease is not well studied, given the difficulties in assembling representative study populations with prolonged follow-up. We hypothesized that delayed-onset CMV disease (>100 days after transplantation) occurs more commonly than early-onset CMV disease in lung transplant recipients, and is associated with an increased risk of death.

METHODS

We assembled a large cohort of lung transplant recipients using 2004 to 2010 International Classification of Diseases, Ninth Revision, Clinical Modification billing data from 3 Agency for Healthcare Research and Quality State Inpatient Databases, and identified demographics, comorbidities, CMV disease coded during hospital readmission and inpatient death. We used Cox proportional hazard multivariate analyses to assess for an independent association between delayed-onset CMV disease and death.

RESULTS

In the cohort of 1528 lung transplant recipients from 12 transplant centers, delayed-onset CMV disease occurred in 13.7% (n = 210) and early-onset CMV disease occurred in 3.3% (n = 51). Delayed-onset CMV pneumonitis was associated with inpatient death longer than 100 days after transplantation (adjusted hazard ratio, 1.6; 95% confidence interval [95% CI], 1.1-2.5), after adjusting for transplant failure/rejection (aHR, 2.5; 95% CI, 1.5-4.1), bacterial pneumonia (aHR, 2.8; 95% CI, 2.0-3.9), viral pneumonia (aHR, 1.5; 95% CI, 1.1-2.1), fungal pneumonia (aHR, 1.8; 95% CI, 1.3-2.3), single lung transplant (aHR, 1.3; 95% CI, 1.0-1.7), and idiopathic pulmonary fibrosis (aHR, 1.4; 95% CI, 1.0-1.8).

CONCLUSIONS

Delayed-onset CMV disease occurred more commonly than early-onset CMV disease among lung transplant recipients. These results suggest that delayed-onset CMV pneumonitis was independently associated with an increased risk of death.

Therapeutic approach to respiratory infections in lung transplantation

Lung transplant recipients (LTRs) are at life-long risk for infections and disseminated diseases owing to their immunocompromised state. Besides organ failure and sepsis, infection can trigger acute and chronic graft rejection which increases mortality. Medical prophylaxis and treatment are based on comprehensive diagnostic work-up including previous history of infection and airway colonisation to reduce long-term complications and mortality. Common bacterial pathogens include Pseudomonas and Staphylococcus, whilst Aspergillus and Cytomegalovirus (CMV) are respectively the commonest fungal and viral pathogens. Clinical symptoms can be various in lung transplant recipients presenting an asymptomatic to severe progress. Regular control of infection parameters, daily lung function testing and lifelong follow-up in a specialist transplant centre are mandatory for early detection of bacterial, viral and fungal infections.

After transplantation each patient receives intensive training with rules of conduct concerning preventive behaviour and to recognize early signs of post transplant complications. Early detection of infection and complications are important goals to reduce major complications after lung transplantation.

Lower incidence of CMV infection and acute rejections with valganciclovir prophylaxis in lung transplant recipients

Background

Cytomegalovirus (CMV) is the most common opportunistic infection following lung transplantation. CMV replication in the lung allograft is described as accelerating the development of bronchiolitis obliterans syndrome (BOS). Finding a strategy to prevent CMV infection is an important issue.

Methods

We performed a retrospective, single-centre study of 114 lung transplant recipients (LTRs) who underwent lung transplantation from January 2001 to December 2006. In a smaller cohort of 88 CMV seropositive (R+) LTRs, three months of valganciclovir prophylaxis (2004-2006) was compared to three months of oral ganciclovir (2001-2003) with respect to the incidence of CMV infection/disease, the severity of CMV disease, acute rejection, BOS-free 4 year survival and 4 year survival. In the whole group of 114 LTRs the impact of CMV infection on long-term survival (BOS free 4 year survival and 6 year survival) was assessed.

Results

For the cohort of 88 CMV seropositive LTRs, the incidence of CMV infection/disease at one year was lower in the valganciclovir group compared to the ganciclovir group (24% vs. 54%, p = 0.003). There was a tendency towards reduced CMV disease, from 33% to 20% and a significant lower incidence of asymptomatic CMV infection (22% vs. 4%, p = 0.005). A lower incidence of acute rejection was observed in the valganciclovir group. However, there was no significant difference between the two groups in BOS free 4 year survival and 4 year survival.

For the entire group of 114 LTRs, BOS-free 4 year survival for recipients with CMV disease was (32%, p = 0.005) and among those with asymptomatic CMV infection (36%, p = 0.061) as compared with patients without CMV infection (69%). Six year survival was lower among patients with CMV disease, (64%, p = 0.042) and asymptomatic CMV infection (55%, p = 0.018) than patients without CMV infection (84%).

Conclusions

A lower incidence of CMV infection/disease and acute rejections was observed with valganciclovir (3 months) when compared to oral ganciclovir (3 months). The long-term impact of CMV infection/disease was significant for BOS-free survival and survival.

Cytomegalovirus infections in solid organ transplantation: a review

Cytomegalovirus (CMV) continues to have a tremendous impact in solid organ transplantation despite remarkable advances in its diagnosis, prevention and treatment. It can affect allograft function and increase patient morbidity and mortality through a number of direct and indirect effects. Patients may develop asymptomatic viremia, CMV syndrome or tissue-invasive disease. Late-onset CMV disease continues to be a major problem in high-risk patients after completion of antiviral prophylaxis. Emerging data suggests that immunologic monitoring may be useful in predicting the risk of late onset CMV disease. There is now increasing interest in the development of an effective vaccine for prevention. Novel antiviral drugs with unique mechanisms of action and lesser toxicity are being developed. Viral load quantification is now undergoing standardization, and this will permit the generation of clinically relevant viral thresholds for the management of patients. This article provides a brief overview of the contemporary epidemiology, clinical presentation, diagnosis, prevention and treatment of CMV infection in solid organ transplant recipients.

Updated international consensus guidelines on the management of cytomegalovirus in solid-organ transplantation

Cytomegalovirus (CMV) continues to be one of the most common infections after solid-organ transplantation, resulting in significant morbidity, graft loss, and adverse outcomes. Management of CMV varies considerably among transplant centers but has been become more standardized by publication of consensus guidelines by the Infectious Diseases Section of The Transplantation Society. An international panel of experts was reconvened in October 2012 to revise and expand evidence and expert opinion-based consensus guidelines on CMV management, including diagnostics, immunology, prevention, treatment, drug resistance, and pediatric issues. The following report summarizes the recommendations.

Lung transplant infection

Lung transplantation has become an accepted therapeutic procedure for the treatment of end‐stage pulmonary parenchymal and vascular disease. Despite improved survival rates over the decades, lung transplant recipients have lower survival rates than other solid organ transplant recipients. The morbidity and mortality following lung transplantation is largely due to infection‐ and rejection‐related complications. This article will review the common infections that develop in the lung transplant recipient, including the general risk factors for infection in this population, and the most frequent bacterial, viral, fungal and other less frequent opportunistic infections. The epidemiology, diagnosis, prophylaxis, treatment and outcomes for the different microbial pathogens will be reviewed. The effects of infection on lung transplant rejection will also be discussed.

Late respiratory infection after lung transplantation

BACKGROUND

Aiming to improve outcome of lung transplantation (LTx) patients, we reviewed risk factors and treatment practices for the LTx recipients who experienced respiratory infection in the late post-LTx period (>1 month after LTx).

METHODS

We analyzed the clinical data of 48 recipients and donors from 61 LTx, who experienced late respiratory infections. Late respiratory infections were classified according to the etiology, time of occurrence, and frequency of donor-to-host transmission or colonization of the recipient prior to transplantation.

RESULTS

During the period of observation, 42 episodes of respiratory infections occurred. The organisms most frequently involved were gram (-) bacteria: Acinetobacter baumannii (n=13, 31.0%), Pseudomonas aeruginosa (n=7, 16.7%), and Klebsiella pneumoniae (n=4, 10.0%). Among the 42 episodes recorded, 14 occurred in the late post-LTx period. These were bacterial (n=6, 42.9%), fungal (n=2, 14.3%), viral (n=4, 28.5%), and mycobacterial (n=2, 14.3%) infections. Of 6 bacterial infections, 2 were from multidrug-resistant (MDR) A. baumannii and one from each of MDR P. aeruginosa, extended spectrum β-lactamase (+) K. pneumoniae, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae. Infection-related death occurred in 6 of the 14 episodes (43%).

CONCLUSION

Although the frequency of respiratory infection decreased sharply in the late post-LTx period, respiratory infection was still a major cause of mortality. Gram (-) MDR bacteria were the agents most commonly identified in these infections.

[Prevention of cytomegalovirus disease in lung transplantation]

Lung transplant recipients, more than other organ transplant recipients, are at particular risk for cytomegalovirus (CMV) infection and disease. CMV prevention avoids the indirect effects of this virus, such as opportunistic fungal infections and obliterative bronchiolitis, the latter being the major limiting factor in the long-term success of lung-transplantation. CMV prevention strategies have significantly reduced CMV disease and CMV-related mortality. Two major strategies are commonly used for CMV prevention: universal prophylaxis and preemptive therapy. In lung transplant recipients, the efficacy and safety of preemptive treatment have not been studied and therefore, cannot be recommended. Universal prophylaxis is the best strategy for preventing CMV disease in lung transplant recipients. There is no consensus on the optimal duration of prophylaxis, but the recently published GESITRA-SEIMC/REIPI 2011 Guidelines for the management of CMV infection in solid-organ transplant patients recommend 6 months posttransplantation. In D+/R- recipients, this period can be prolonged to 12 months if there are difficulties in monitoring at 6 months posttransplantation. The future of prevention will probably depend on immunoguided strategies.

Is prevention the best treatment? CMV after lung transplantation

Cytomegalovirus (CMV) is the most prevalent opportunistic infection that occurs in lung-transplant recipients. In addition to its direct morbidity, multiple studies have demonstrated that CMV, in particular CMV pneumonia, is associated with an increased risk for chronic graft dysfunction manifested as bronchiolitis obliterans syndrome (BOS) and worse posttransplant survival. Therefore, prevention of CMV remains an important goal to improve long-term lung-transplant outcomes. Although centers often employed 3 months of prophylaxis in at-risk patients after lung transplantation, a significant proportion of patients still developed infection or disease after the discontinuation of prophylaxis, highlighting the need for more effective approaches to CMV prevention. A number of early single-center reports suggested benefit to extending prophylaxis to longer durations, but concerns regarding cost, late-onset CMV disease, viral resistance and bone marrow toxicity limited enthusiasm for longer durations. However, several recent studies including a multicenter, prospective, randomized, double-blinded clinical trial have demonstrated significant benefits to extending CMV prophylaxis beyond 3 months. Although some areas of controversy remain, the clinical implications of these recent studies suggest that extending prophylaxis with valganciclovir up to 12 months is clearly beneficial for CMV prevention after lung transplantation.