Guidance on novel influenza A/H1N1 in solid organ transplant recipients

Impact of Respiratory Viral Infections in Transplant Recipients

Respiratory viral infections (RVIs) are among the leading cause of morbidity and mortality in pediatric hematopoietic stem cell transplant (HCT) and solid organ transplant (SOT) recipients. Transplant recipients remain at high risk for super imposed bacterial and fungal pneumonia, chronic graft dysfunction, and graft failure as a result of RVIs. Recent multicenter retrospective studies and prospective studies utilizing contemporary molecular diagnostic techniques have better delineated the epidemiology and outcomes of RVIs in pediatric transplant recipients and have advanced the development of preventative vaccines and treatment interventions in this population. In this review, we will define the epidemiology and outcomes of RVIs in SOT and HSCT recipients, describe the available assays for diagnosing a suspected RVI, highlight evolving management and vaccination strategies, review the risk of donor derived RVI in SOT recipients, and discuss considerations for delaying transplantation in the presence of an RVI.

Recipient With Influenza A Infection: Contraindication to Transplant? A Case Report

Active infections in recipients are considered an absolute contraindication to liver transplantation due to the risk of severe disease caused by the required immunosuppression. Even though viral infections, such as Influenza A, have been treated in liver transplant patients both in the immediate and late postoperative period with favorable outcomes, no cases of prediagnosed Influenza A have been described in which the decision to proceed with the indication had to be made. In certain viral infections, like Influenza A, the paucisymptomatic state and the availability of appropriate treatment could open the door to performing liver transplants with positive results.

Approach to suspected donor-derived infections

Prevention of donor-derived disease among pediatric solid organ transplant recipients requires judicious risk-benefit assessment. Comprehensive guidelines outline specific donor risk factors and post-transplant monitoring strategies to prevent and mitigate transmission of HIV, hepatitis B, and hepatitis C. However, elimination of unanticipated donor-derived infections remains challenging. The objectives of this review are to (1) define risk of anticipated vs. unanticipated disease transmission events in pediatric solid organ transplant recipients; (2) discuss donor presentations that confer greater risk of unanticipated disease transmission; (3) develop a matrix for consideration of donor acceptance; and (4) discuss limitations and future directions for donor screening. Although solid organ transplant confers inherent risk of infection transmission, the risk of significant disease transmission events may be mitigated by a comprehensive approach including donor assessment, consideration of recipient need, post-transplant monitoring, and early intervention.

Impact of SARS-CoV-2-Related Hygiene Measures on Community-Acquired Respiratory Virus Infections in Lung Transplant Recipients in Switzerland

Background and Objectives: Community-acquired respiratory virus (CARV) infections pose a serious risk for lung transplant recipients (LTR) as they are prone to severe complications. When the COVID-19 pandemic hit Switzerland in 2020, the government implemented hygiene measures for the general population. We investigated the impact of these measures on the transmission of CARV in lung transplant recipients in Switzerland. Materials and Methods: In this multicenter, retrospective study of lung transplant recipients, we investigated two time periods: the year before the COVID-19 pandemic (1 March 2019-29 February 2020) and the first year of the pandemic (1 March 2020-28 February 2021). Data were mainly collected from the Swiss Transplant Cohort Study (STCS) database. Descriptive statistics were used to analyze the results. Results: Data from 221 Swiss lung transplant cohort patients were evaluated. In the year before the COVID-19 pandemic, 157 infections were diagnosed compared to 71 infections in the first year of the pandemic (decline of 54%, p < 0.001). Influenza virus infections alone showed a remarkable decrease from 17 infections before COVID-19 to 2 infections after the beginning of the pandemic. No significant difference was found in testing behavior; 803 vs. 925 tests were obtained by two of the three centers during the respective periods. Conclusions: We observed a significant decline in CARV infections in the Swiss lung transplant cohort during the first year of the COVID-19 pandemic. These results suggest a relevant impact of hygiene measures when implemented in the population due to the COVID-19 pandemic on the incidence of CARV infections.

Clinical characteristics, risk factors and antiviral treatments of influenza in immunosuppressed inpatients in Beijing during the 2015-2020 influenza seasons

BACKGROUND

Compared with immunocompetent patients, immunosuppressed patients have higher morbidity and mortality, a longer duration of viral shedding, more frequent complications, and more antiviral resistance during influenza infections. However, few data on this population in China have been reported. We analysed the clinical characteristics, effects of antiviral therapy, and risk factors for admission to the intensive care unit (ICU) and death in this population after influenza infections and explored the influenza vaccination situation for this population.

METHODS

We analysed 111 immunosuppressed inpatients who were infected with influenza virus during the 2015-2020 influenza seasons. Medical data were collected through the electronic medical record system and analysed. Univariate analysis and multivariate logistics analysis were used to identify risk factors.

RESULTS

The most common cause of immunosuppression was malignancies being treated with chemotherapy (64.0%, 71/111), followed by haematopoietic stem cell transplantation (HSCT) (23.4%, 26/111). The most common presenting symptoms were fever and cough. Dyspnoea, gastrointestinal symptoms and altered mental status were more common in HSCT patients than in patients with immunosuppression due to other causes. Approximately 14.4% (16/111) of patients were admitted to the ICU, and 9.9% (11/111) of patients died. Combined and double doses of neuraminidase inhibitors did not significantly reduce the risk of admission to the ICU or death. Risk factors for admission to the ICU were dyspnoea, coinfection with other pathogens and no antiviral treatment within 48 h. The presence of dyspnoea and altered mental status were independently associated with death. Only 2.7% (3/111) of patients less than 12 months old had received a seasonal influenza vaccine.

CONCLUSION

Fever and other classic symptoms of influenza may be absent in immunosuppressed recipients, especially in HSCT patients. Conducting influenza virus detection at the first presentation seems to be a good choice for early diagnosis. Clinicians should pay extra attention to immunosuppressed patients with dyspnoea, altered mental status, coinfection with other pathogens and no antiviral treatment within 48 h because these patients have a high risk of severe illness. Inactivated influenza vaccines are recommended for immunosuppressed patients.

Early success transplanting kidneys from donors with new SARS-CoV-2 RNA positivity: A report of 10 cases

Transplantation of solid organs from donors with active SARS-CoV-2 infection has been advised against due to the possibility of disease transmission to the recipient. However, with the exception of lungs, conclusive data for productive infection of transplantable organs do not exist. While such data are awaited, the organ shortage continues to claim thousands of lives each year. In this setting, we put forth a strategy to transplant otherwise healthy extrapulmonary organs from SARS-CoV-2-infected donors. We transplanted 10 kidneys from five deceased donors with new detection of SARS-CoV-2 RNA during donor evaluation in early 2021. Kidney donor profile index ranged from 3% to 56%. All organs had been turned down by multiple other centers. Without clear signs or symptoms, the veracity of timing of SARS-CoV-2 infection could not be confirmed. With 8-16 weeks of follow-up, outcomes for all 10 patients and allografts have been excellent. All have been free of signs or symptoms of donor-derived SARS-CoV-2 infection. Our findings raise important questions about the nature of SARS-CoV-2 RNA detection in potential organ donors and suggest underutilization of exceptionally good extrapulmonary organs with low risk for disease transmission.

Influenza Virus Infection and Transplantation

Influenza infection poses significant risk for solid organ transplant recipients who often experience more severe infection with increased rates of complications, including those relating to the allograft. Although symptoms of influenza experienced by transplant recipients are similar to that of the general population, fever is not a ubiquitous symptom and lymphopenia is common. Annual inactivated influenza vaccine is recommended for all transplant recipients. Newer strategies such as using a higher dose vaccine or multiple doses in the same season appear to provide greater immunogenicity. Neuraminidase inhibitors are the mainstay of treatment and chemoprophylaxis although resistance may occur in the transplant setting. Influenza therapeutics are advancing, including the recent licensure of baloxavir; however, many remain to be evaluated in transplant recipients and are not yet in routine clinical use. Further population-based studies spanning multiple influenza seasons are needed to enhance our understanding of influenza epidemiology in solid organ transplant recipients. Specific assessment of newer influenza therapeutics in transplant recipients and refinement of prevention strategies are vital to reducing morbidity and mortality.

Respiratory viruses

Respiratory viruses are commonly detected in both healthy and immunocompromised children. In most healthy children, respiratory viruses are associated with self-limited upper respiratory tract infections and are not accompanied by significant morbidity. In immunocompromised hosts, including hematopoietic cell transplant recipients, solid organ transplant recipients, and oncology patients, respiratory viruses can be associated with significant clinical manifestations, including prolonged viral shedding, lower respiratory tract disease, the need for supplemental oxygen, late airflow obstruction, and even death. This chapter reviews the major respiratory viruses, including respiratory syncytial virus, human metapneumovirus, influenza, parainfluenza viruses, human rhinoviruses, and human coronaviruses. Other viruses can manifest as pulmonary infection; however, these viruses are discussed elsewhere (see Chapter 17 for discussion of cytomegalovirus and Chapter 22 for discussion of adenoviruses).

SARS-CoV-2 Infection and the Liver

A novel strain of coronoviridae (SARS-CoV-2) was reported in Wuhan China in December 2019. Initially, infection presented with a broad spectrum of symptoms which typically included muscle aches, fever, dry cough, and shortness of breath. SARS-CoV-2 enters cells via ACE2 receptors which are abundant throughout the respiratory tract. However, there is evidence that these receptors are abundant throughout the body, and just as abundant in cholangiocytes as alveolar cells, posing the question of possible direct liver injury. While liver enzymes and function tests do seem to be deranged in some patients, it is questionable if the injury is due to direct viral damage, drug-induced liver injury, hypoxia, or microthromboses. Likely, the injury is multifactoral, and management of infected patients with pre-existing liver disease should be taken into consideration. Ultimately, a vaccine is needed to aid in reducing cases of SARS-CoV-2 and providing immunity to the general population. However, while considering the types of vaccines available, safety concerns, particularly of RNA- or DNA-based vaccines, need to be addressed.

Coronavirus Disease 2019 Pneumonia in Immunosuppressed Renal Transplant Recipients: A Summary of 10 Confirmed Cases in Wuhan, China

Background

Previous studies on coronavirus disease 2019 (COVID-19) have focused on populations with normal immunity, but lack data on immunocompromised populations.

Objective

To evaluate the clinical features and outcomes of COVID-19 pneumonia in kidney transplant recipients.

Design, setting, and participants

A total of 10 renal transplant recipients with laboratory-confirmed COVID-19 pneumonia were enrolled in this retrospective study. In addition, 10 of their family members diagnosed with COVID-19 pneumonia were included in the control group.

Intervention

Immunosuppressant reduction and low-dose methylprednisolone therapy.

Outcome measurements and statistical analysis

The clinical outcomes (the severity of pneumonia, recovery rate, time of virus shedding, and length of illness) were compared with the control group by statistical analysis.

Results and limitations

The clinical symptomatic, laboratory, and radiological characteristics of COVID-19 pneumonia in the renal transplant recipients were similar to those of severe COVID-19 pneumonia in the general population. The severity of COVID-19 pneumonia was greater in the transplant recipients than in the control group (five severe/three critical cases vs one severe case). Five patients developed transient renal allograft damage. After a longer time of virus shedding (28.4 ± 9.3 vs 12.2 ± 4.6 d in the control group) and a longer course of illness (35.3 ± 8.3 vs 18.8 ± 10.5 d in the control group), nine of the 10 transplant patients recovered successfully after treatment. One patient developed acute renal graft failure and died of progressive respiratory failure.

Conclusions

Kidney transplant recipients had more severe COVID-19 pneumonia than the general population, but most of them recovered after a prolonged clinical course and virus shedding. Findings from this small group of cases may have important implications for the treatment of COVID-19 pneumonia in immunosuppressed populations.

Patient summary

Immunosuppressed transplant recipients with coronavirus disease 2019 infection had more severe pneumonia, but most of them still achieved a good prognosis after appropriate treatment.

Pediatric heart transplant from an incompletely treated influenza A-positive donor

There is a shortage of pediatric donor hearts for waitlisted children, and yet nearly 50% of organs offered are not transplanted. Donor quality is often cited as a reason for declining organs offered from donors infected with influenza, presumably due to concern about disease transmission at transplant leading to severe disease. We previously described an excellent outcome after heart transplant from a donor infected with influenza B that had been treated with a complete course of oseltamivir. In this report, we describe a similar outcome after transplantation of an organ from an influenza A-positive donor with symptomatic disease incompletely treated with oseltamivir. Due to the availability of effective antiviral treatment, we suggest that influenza A is also a manageable donor infection that need not preclude heart placement.

Safety, Resistance, and Efficacy Results from a Phase IIIb Study of Conventional- and Double-Dose Oseltamivir Regimens for Treatment of Influenza in Immunocompromised Patients

INTRODUCTION

Immunocompromised patients infected with influenza exhibit prolonged viral shedding and higher risk of resistance. Optimized treatment strategies are needed to reduce the risk of antiviral resistance. This phase IIIb, randomized, double-blind study (NCT00545532) evaluated conventional-dose or double-dose oseltamivir for the treatment of influenza in immunocompromised patients.

METHODS

Patients with primary or secondary immunodeficiency and influenza infection were randomized 1:1 to receive conventional-dose oseltamivir (75 mg adolescents/adults [≥ 13 years]; 30-75 mg by body weight in children [1-12 years]) or double-dose oseltamivir (150 or 60-150 mg, respectively), twice daily for an extended period of 10 days. Nasal/throat swabs were taken for virology assessments at all study visits. Co-primary endpoints were safety/tolerability and viral resistance. Secondary endpoints included time to symptom alleviation (TTSA) and time to cessation of viral shedding (TTCVS).

RESULTS

Of 228 patients enrolled between February 2008 and May 2017, 215 (199 adults) were evaluable for safety, 167 (151 adults) for efficacy, and 152 (138 adults) for resistance. Fewer patients experienced an adverse event (AE) in the conventional-dose group (50.5%) versus the double-dose group (59.1%). The most frequently reported AEs were nausea, diarrhea, vomiting, and headache. Fifteen patients had post-baseline resistance, more commonly in the conventional-dose group (n  = 12) than in the double-dose group (n  = 3). In adults, median TTSA was similar between arms, while median TTCVS was longer with conventional dosing.

CONCLUSIONS

Oseltamivir was well tolerated, with a trend toward better safety/tolerability for conventional dosing versus double dosing. Resistance rates were higher with conventional dosing in this immunocompromised patient population.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00545532.

FUNDING

F. Hoffmann-La Roche Ltd.

Community-Acquired Respiratory Viruses in Transplant Patients: Diversity, Impact, Unmet Clinical Needs

Patients undergoing solid-organ transplantation (SOT) or allogeneic hematopoietic cell transplantation (HCT) are at increased risk for infectious complications. Community-acquired respiratory viruses (CARVs) pose a particular challenge due to the frequent exposure pre-, peri-, and posttransplantation. Although influenza A and B viruses have a top priority regarding prevention and treatment, recent molecular diagnostic tests detecting an array of other CARVs in real time have dramatically expanded our knowledge about the epidemiology, diversity, and impact of CARV infections in the general population and in allogeneic HCT and SOT patients. These data have demonstrated that non-influenza CARVs independently contribute to morbidity and mortality of transplant patients. However, effective vaccination and antiviral treatment is only emerging for non-influenza CARVs, placing emphasis on infection control and supportive measures. Here, we review the current knowledge about CARVs in SOT and allogeneic HCT patients to better define the magnitude of this unmet clinical need and to discuss some of the lessons learned from human influenza virus, respiratory syncytial virus, parainfluenzavirus, rhinovirus, coronavirus, adenovirus, and bocavirus regarding diagnosis, prevention, and treatment.

Community-acquired respiratory viruses in solid organ transplant

PURPOSE OF REVIEW

Respiratory viruses are common in solid organ transplant (SOT) recipients and recognized as a significant cause of mortality and morbidity. This review examines the literature on influenza and noninfluenza viruses in the SOT recipient.

RECENT FINDINGS

Advances in immunosuppression and antimicrobial prophylaxis have led to improved patient and graft survival, yet respiratory viruses continue to be a common cause of disease in this population. Influenza viruses have received top priority regarding prevention and treatment, whereas advances in molecular diagnostic tests detecting an array of other respiratory viruses have expanded our knowledge about the epidemiology and impact of these viruses in both the general population and SOT patients. Effective treatment and prevention for noninfluenza respiratory viruses are only emerging.

SUMMARY

Respiratory viruses can contribute to a wide array of symptoms in SOT, particularly in lung transplant recipients. The clinical manifestations, diagnosis, and treatment options for influenza and noninfluenza viruses in SOT patients are reviewed. PCR and related molecular techniques represent the most sensitive diagnostic modalities for detection of respiratory viruses. Early therapy is associated with improved outcomes. Newer classes of antivirals and antibodies are under continuous development for many of these community acquired respiratory viruses.

Pediatric heart transplantation from an influenza B-positive donor

As heart transplantation demand is increasing without subsequent growth of the donor pool, need for expansion of acceptance criteria is paramount, particularly when considering critically ill, highly sensitized patients. We present a case report of a pediatric heart transplant recipient of an organ refused by 197 prior potential recipients due to the donor being infected with influenza virus. We perform a literature review of recent solid organ transplant cases from influenza-positive donors and conclude that the donor pool may be expandable by allowing donors with treatable infections to be included.

Respiratory Viral Infections in Transplant Recipients

Respiratory viral infections (RVIs) are common among the general population; however, these often mild viral illnesses can lead to serious morbidity and mortality among recipients of hematopoietic stem cell and solid organ transplantation. The disease spectrum ranges from asymptomatic or mild infections to life-threatening lower respiratory tract infection or long-term airflow obstruction syndromes. Progression to lower respiratory tract infection or to respiratory failure is determined by the intrinsic virulence of the specific viral pathogen as well as various host factors, including the type of transplantation, status of the host’s immune dysfunction, the underlying disease, and other comorbidities. This chapter focuses on the epidemiology, clinical manifestations, diagnosis, and management of RVIs in this susceptible population and includes respiratory syncytial virus, parainfluenza virus, human metapneumovirus, influenza virus, human coronavirus, and human rhinovirus. The optimal management of these infections is limited by the overall paucity of available treatment, highlighting the need for new antiviral drug or immunotherapies.

Infectious Disease Transmission in Solid Organ Transplantation: Donor Evaluation, Recipient Risk, and Outcomes of Transmission

In 2016, the Transplantation Society of Australia and New Zealand, with the support of the Australian Government Organ and Tissue authority, commissioned a literature review on the topic of infectious disease transmission from deceased donors to recipients of solid organ transplants. The purpose of this review was to synthesize evidence on transmission risks, diagnostic test characteristics, and recipient management to inform best-practice clinical guidelines. The final review, presented as a special supplement in Transplantation Direct, collates case reports of transmission events and other peer-reviewed literature, and summarizes current (as of June 2017) international guidelines on donor screening and recipient management. Of particular interest at the time of writing was how to maximize utilization of donors at increased risk for transmission of human immunodeficiency virus, hepatitis C virus, and hepatitis B virus, given the recent developments, including the availability of direct-acting antivirals for hepatitis C virus and improvements in donor screening technologies. The review also covers emerging risks associated with recent epidemics (eg, Zika virus) and the risk of transmission of nonendemic pathogens related to donor travel history or country of origin. Lastly, the implications for recipient consent of expanded utilization of donors at increased risk of blood-borne viral disease transmission are considered.

Clinical Vignettes: Donor-Derived Infections

Patients undergoing solid organ transplantation (SOT) may acquire infections from the transplanted organ. Routine screening for common infections are an established part of the pretransplant evaluation of donors and recipients. Likewise, strategies exist for prophylaxis and surveillance for common donorassociated infections including hepatitis B, CMV and EBV. However, despite advances in diagnostic testing to evaluate the infectious risk of donors, unanticipated transmission of pathogens occurs, particularly when donors are asymptomatic or have subtle or unusual manifestations of a transmissible Infection. Infectious diseases (ID) providers play an integral role in donor and recipient risk assessment and can advise transplant centers on organ utilization and guide evaluation and management of the SOT recipient. Consideration of the donor cause of death and preceding clinical syndromes are important for characterizing the potential risk for recipient infection. This allows a more accurate analysis of the risk: benefit of accepting a life-saving organ and risk of infection. ID providers and transplant teams should work closely with organ procurement organizations (OPOs) to solicit additional donor information when a donor-derived infection is suspected so that reporting can be facilitated to ensure communication with the care-teams of other organ recipients from the same donors. National advisory committees work closely with federal agencies to provide oversight, guide policy development, and assess outcomes to assist with the prevention and management of donor-transmitted disease through organ transplantation. The clinical vignettes in this review highlight some of the complexities in the evaluation of potential donor transmission.

Respiratory Viruses: Influenza, RSV, and Adenovirus in Kidney Transplantation

Although advances in immunosuppression and antimicrobial prophylaxis have led to improved patient and graft survival, respiratory viruses continue to be a common cause of morbidity and mortality in immunocompromised populations. We describe the clinical manifestations, diagnosis and treatment options for influenza, respiratory syncytial virus and adenovirus infection in the kidney transplant population.

Clinical Characteristics and Outcomes of Influenza A Infection in Kidney Transplant Recipients: A Single-Center Experience

BACKGROUND

Influenza virus infection can cause severe illness in certain high-risk groups. Solid organ and hematopoietic stem cell transplant recipients have been shown to present a greater risk for severe influenza and complications than the general population.

METHODS

Retrospective descriptive cohort study of the features and outcomes of influenza infection in renal transplant recipients from July 2009 to May 2014.

RESULTS

Thirty-one patients were diagnosed with influenza A infection within the specified period. The incidence of influenza A was 26.5 cases/1,000 person-years. Hospital admission (68%), secondary bacterial pneumonia (68%), intensive care unit admission (14%), and mortality rate (14%) were higher than reported for immunocompetent patients.

CONCLUSIONS

Influenza diagnosis and treatment should be prompt in immunocompromised patients to reduce the risk of complications. Patients who require intensive care owing to respiratory and hemodynamic complications present high mortality rates.

Immunizations in solid organ and hematopoeitic stem cell transplant patients: A comprehensive review

The Solid Organ Transplantation (SOT) and Haematopoietic Stem Cell Transplantation (HSCT) population is continuously increasing as a result of broader indications for transplant and improved survival. Infectious diseases, including vaccine-preventable diseases, are a significant threat for this population, primarily after but also prior to transplantation. As a consequence, clinicians must ensure that patients are optimally immunized before transplantation, to provide the best protection during the early post-transplantation period, when immunosuppression is the strongest and vaccine responses are poor. After 3-6 months, inactivated vaccines immunization can be resumed. By contrast, live-attenuated vaccines are lifelong contraindicated in SOT patients, but can be considered in HSCT patients at least 2 years after transplantation, if there is no immunosuppression or graft-versus-host-disease. However, because of the advantages of live-attenuated over inactivated vaccines--and also sometimes the absence of an inactivated alternative--an increasing number of prospective studies on live vaccine immunization after transplantation are performed and give new insights about safety and immunogenicity in this population.

Impact of HIV on the severity of influenza

Despite current antiretroviral therapy, HIV/AIDS is one of the most prelevant problems in healthcare worldwide. Similarly, influenza viruses are causes of epidemics outbreaks. HIV-infected patients are considered a high risk group for severe influenza infection, although several recent observational studies suggest that not all HIV-infected patients are equally susceptible to complications and that these patients should be stratified by their immunodeficiency status and other factors (such as smoking or comorbidities). Here, we have compiled the most recent data on the impact that HIV has on influenza infection.

Prophylactic vaccinations in chronic kidney disease: Current status

In this review, recent data on results concerning prophylactic vaccinations against hepatitis B virus, influenza viruses, and pneumococci are presented. Effects of active immunization in chronic kidney disease depend on category of glomerular filtration rate (GFR). The lower GFR category the better results of response to vaccination. Abnormalities in toll-like receptors and down-regulation of B-cell activating factor receptor in transitional B cells were recently included into uremia-associated deficits in immunocompetence. Development of novel, more potent vaccines containing toll-like receptor agonists as adjuvants may help to achieve more effective immunization against hepatitis B virus in immunocompromised patients. Experimental studies announce further vaccine adjuvants. A vaccine against hepatitis C virus is not available yet, but promising results were already obtained in the experimental and preliminary clinical studies. Prophylactic vaccinations against influenza viruses and pneumococci become increasingly popular in dialysis facilities due to their proved benefits.

Live virus vaccines in transplantation: friend or foe?

Solid organ and hematopoietic stem cell transplant recipients may be exposed to diseases which may be prevented through live attenuated virus vaccines (LAVV). Because of their immunosuppression, these diseases can lead to severe complications in transplant recipients. Despite increasing evidence regarding the safety and effectiveness of certain LAVV, these vaccines are still contraindicated for immunocompromised patients, such as transplant recipients. We review the available studies on LAVV, such as varicella zoster, measles-mumps-rubella, influenza, yellow fever, polio, and Japanese encephalitis vaccines in transplant patients. We discuss the current recommendations and the potential risks, as well as the expected benefits of LAVV immunization in this population.

Immunization after kidney transplantation-what is necessary and what is safe?

Many transplant recipients are not protected against vaccine-preventable illnesses, primarily because vaccination is still an underutilized tool both before and after transplantation. This missed opportunity for protection can result in substantial morbidity, graft loss and mortality. Immunization strategies should be formulated early in the course of renal disease to maximize the likelihood of vaccine-induced immunity, particularly as booster or secondary antibody responses are less affected by immune compromise than are primary or de novo antibody responses in naive vaccine recipients. However, live vaccines should be avoided in immunocompromised hosts. Although some concern has been raised regarding increased HLA sensitization after vaccination, no clinical data to suggest harm currently exists; overall, non-live vaccines seem to be immunogenic, protective and safe. In organ transplant recipients, some vaccines are indicated based on specific risk factors and certain vaccines, such as hepatitis B, can protect against donor-derived infection. Vaccines given to close contacts of renal transplant recipients can provide an additional layer of protection against infectious diseases. In this article, optimal vaccination of adult transplant recipients, including safety, efficacy, indication and timing, is reviewed.

Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections

Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor.

Influenza prevention and treatment in transplant recipients and immunocompromised hosts

The host immune response is critical for the control and clearance of influenza virus after initial infection. Unfortunately, key components of the innate and adaptive responses to influenza are compromised in solid organ and hematopoietic stem cell transplant recipients. As a result, influenza in these key patient populations is associated with prolonged viral shedding, more frequent complications, including bacterial and fungal superinfections and rejection, and increased mortality. While vaccine is the critical prophylaxis strategy in other populations, response rates are diminished, particularly early post-transplant, among immunocompromised patients. Prospective data suggest that antiviral prophylaxis represents an effective and safe alternative to vaccine in patients who would be predicted to have poor responses to influenza vaccine. While there have not been randomized, controlled studies of antiviral therapy completed in solid organ or hematopoietic stem cell patient populations, observational data suggest that early therapy is associated with reduced rates of progression to lower airway involvement, morbidity, and mortality. Further studies are needed to define the optimal regimen, dose, duration, and endpoint to define successful treatment.

Live viral vaccines in immunocompromised patients

ABSTRACT: 

Live-attenuated viral vaccines (LAV) have been used safely for several decades in healthy individuals to protect against diseases with great success. In immunocompromised hosts their use is usually not recommended. We explore the use of currently available LAV, such as live-attenuated influenza, varicella–zoster virus, measles, mumps and rubella, oral polio, rotavirus, yellow fever virus vaccines, especially in patients with cancer, solid organ or hematopoietic stem cell transplant, HIV, and with acquired or congenital immunodeficiencies. Although evidence-based recommendations cannot currently be made, it is possible that LAV will be recommended in specific, well-defined situations in these immunocompromised patients in the future.

Respiratory distress syndrome caused by influenza H1N1 in a patient with a simultaneous pancreas-kidney transplantation

Adult respiratory distress syndrome is a severe respiratory failure due to noncardiogenic pulmonary edema with high mortality rates (50-70%). The most common etiology of respiratory distress is sepsis, but it may also be caused by several of the immunosuppressants prescribed in transplantation. In the last year, influenza H1N1 virus infection has become more relevant. It has shown a greater incidence among immunosuppressed patients as well as those with chronic kidney disease or diabetes mellitus. We present the case of a patient with simultaneous pancreas-kidney transplantation who presented respiratory distress after the second dose of thymoglobulin. Initially, we interpreted that the thymoglobulin was the cause, so it was replaced with basiliximab. Empirical treatment was started with 3 doses of 6-methylprednisolone (250 mg), with a favorable response. After 7 days, we received the results of the reverse-transcriptase polymerase chain reaction of a nasal smear and blood culture, which were positive for H1N1 virus. In our knowledge, this is the first reported case of a patient with simultaneous pancreas-kidney transplantation and respiratory distress secondary to H1N1 virus infection who showed a favorable response to corticosteroid therapy.

A multicenter evaluation of pandemic influenza A/H1N1 in hematopoietic stem cell transplant recipients

BACKGROUND

Hematopoietic stem cell transplant (HSCT) recipients have increased morbidity from respiratory viral infections. Pandemic influenza A - A(H1N1)/pdm09 - in 2009-2010 was associated with increased severity of illness in patients with underlying co-morbidities including HSCT, but the factors that contribute to severe disease in HSCT patients are not well characterized.

METHODS

We conducted a multicenter review of microbiologically proven influenza A(H1N1)pdm09 in the HSCT population between April 2009 and April 2010 to determine factors that are associated with severe disease.

RESULTS

We identified 37 adult patients (26 allogeneic and 11 autologous HSCT recipients). Median time from transplant to diagnosis was 411 days (range 4 days-14.9 years). Three cases were hospital acquired. Twenty-eight of 37 (75.7%) had confirmed A(H1N1)pdm09. Presumed viral lower respiratory tract infection was present in 12/37 (32.4%) patients. Antiviral therapy was given to 33/37 (89%) patients, primarily oseltamivir (n = 24) and oseltamivir before or after another antiviral (n = 8). Excluding those with nosocomial A(H1N1)pdm09, 18/34 (52.9%) were hospitalized and 6 (33%) required admission to an intensive care unit. Mortality within 30 and 60 days of symptom onset was 7/37 (18.9%) and 11/37 (29.7%), respectively. Factors associated with mortality included nosocomial acquisition (P = 0.023), receipt of mycophenolate mofetil (P = 0.001), or antilymphocyte antibody (P = 0.005) within the past 6 months, reduced-intensity conditioning (P = 0.027), and bacteremia (P = 0.021).

CONCLUSIONS

A(H1N1)pdm09 infection was particularly severe in HSCT recipients, specifically among those receiving augmented immunosuppression for graft-versus-host disease. The high mortality of the nosocomial cases highlights the need for strict infection-control measures in hospitals during influenza outbreaks.

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.

Prolonged influenza virus shedding and emergence of antiviral resistance in immunocompromised patients and ferrets

Immunocompromised individuals tend to suffer from influenza longer with more serious complications than otherwise healthy patients. Little is known about the impact of prolonged infection and the efficacy of antiviral therapy in these patients. Among all 189 influenza A virus infected immunocompromised patients admitted to ErasmusMC, 71 were hospitalized, since the start of the 2009 H1N1 pandemic. We identified 11 (15%) cases with prolonged 2009 pandemic virus replication (longer than 14 days), despite antiviral therapy. In 5 out of these 11 (45%) cases oseltamivir resistant H275Y viruses emerged. Given the inherent difficulties in studying antiviral efficacy in immunocompromised patients, we have infected immunocompromised ferrets with either wild-type, or oseltamivir-resistant (H275Y) 2009 pandemic virus. All ferrets showed prolonged virus shedding. In wild-type virus infected animals treated with oseltamivir, H275Y resistant variants emerged within a week after infection. Unexpectedly, oseltamivir therapy still proved to be partially protective in animals infected with resistant virus. Immunocompromised ferrets offer an attractive alternative to study efficacy of novel antiviral therapies.

Immunocompromised patients, such as transplant recipients on immune suppressive therapy, are a substantial and gradually expanding patient group. Upon influenza virus infection, these patients clear the virus less efficiently and are more likely to develop severe pneumonia than immunocompetent individuals. Existing antiviral strategies are far from satisfactory for this patient group, as they show limited effectiveness with frequent emergence of antiviral resistance. For ethical and practical reasons antiviral efficacy studies are hard to conduct in these patients. Therefore, we developed an immunocompromised ferret, mimicking an immune suppressive regimen used for solid organ transplant recipients. Upon infection with 2009 pandemic influenza A/H1N1 virus these animals, like immunocompromised patients, develop severe respiratory disease with prolonged virus excretion. Interestingly, all immunocompromised ferrets on oseltamivir therapy excreted oseltamivir resistant viruses (H275Y) within one week after start of treatment. Furthermore, high dose oseltamivir therapy still proved to be partially effective against these oseltamivir resistant viruses. These immunocompromised ferrets provide a useful tool in the development of novel antiviral approaches for immunocompromised patients suffering from influenza.

Management of influenza infection in solid-organ transplant recipients: consensus statement of the Group for the Study of Infection in Transplant Recipients (GESITRA) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Network for Research in Infectious Diseases (REIPI)

BACKGROUND

Solid organ transplant (SOT) recipients are at greater risk than the general population for complications and mortality from influenza infection.

METHODS

Researchers and clinicians with experience in SOT infections have developed this consensus document in collaboration with several Spanish scientific societies and study networks related to transplant management. We conducted a systematic review to assess the management and prevention of influenza infection in SOT recipients. Evidence levels based on the available literature are given for each recommendation. This article was written in accordance with international recommendations on consensus statements and the recommendations of the Appraisal of Guidelines for Research and Evaluation II (AGREE II).

RESULTS

Recommendations are provided on the procurement of organs from donors with suspected or confirmed influenza infection. We highlight the importance of the possibility of influenza infection in any SOT recipient presenting upper or lower respiratory symptoms, including pneumonia. The importance of early antiviral treatment of SOT recipients with suspected or confirmed influenza infection and the necessity of annual influenza vaccination are emphasized. The microbiological techniques for diagnosis of influenza infection are reviewed. Guidelines for the use of antiviral prophylaxis in inpatients and outpatients are provided. Recommendations for household contacts of SOT recipients with influenza infection and health care workers in close contact with transplant patients are also included. Finally antiviral dose adjustment guidelines are presented for cases of impaired renal function and for pediatric populations.

CONCLUSIONS

The latest scientific information available regarding influenza infection in the context of SOT is incorporated into this document.

Humoral Immune Response following Seasonal Influenza Vaccine in Islet Transplant Recipients

Annual influenza vaccine is recommended for organ transplant recipients, but immunogenicity is known to be suboptimal. Islet transplant recipients receive immunosuppressive therapy, but there are no data on the immunogenicity of influenza vaccine in this population. In this prospective cohort study, adult islet transplant recipients at least 3 months posttransplant were enrolled. All patients received the 2010–2011 seasonal influenza vaccine. Serum was obtained pre- and postvaccination to determine humoral response to each of the three influenza strains included in the vaccine. Adverse effects of vaccine were also noted. A total of 61 islet transplant recipients were enrolled and completed the study protocol. The median time from last transplant was 1.9 years (range 0.26–11.4 years), and most patients had undergone multiple prior islet transplant procedures (90.2%). Overall immunogenicity of the vaccine was poor. Seroconversion rates to H1N1, H3N2, and B antigens were 34.4%, 29.5%, and 9.8%, respectively. In the subset not seroprotected at baseline, a protective antibody titer postvaccination was achieved in 58.6%, 41.9%, and 34.5% of patients, respectively. Patients within the first year of transplant were significantly less likely to seroconvert to at least one antigen (23.5% vs. 54.5%; p = 0.029). Alemtuzumab recipients trended toward lower seroconversion rates (25% vs. 51%; p = 0.11). No vaccine-related safety concerns were identified. Seasonal influenza vaccine had suboptimal immunogenicity in islet transplant recipients especially those who were less than 1 year posttransplant or had received alemtuzumab induction. Novel strategies for protection in this group of patients need further study.

Low seroconversion after one dose of AS03-adjuvanted H1N1 pandemic influenza vaccine in solid-organ transplant recipients

BACKGROUND

Immunocompromised individuals are more susceptible to complications produced by influenza infection. As a result, solid-organ transplant (SOT) recipients were targeted as a priority group to receive AS03-adjuvanted H1N1 influenza vaccine during 2009.

OBJECTIVE

To evaluate seroconversion after one dose of adjuvanted pandemic influenza H1N1 (pH1N1) vaccine in SOT recipients.

METHODS

Adult SOT recipients were enrolled to receive one 3.75 μg dose of adjuvanted pH1N1 vaccine. Serological status was tested using a hemagglutination inhibition assay before and two and four weeks postvaccination.

RESULTS

The five SOT recipients (one liver, two kidney and two lung transplants) had a median age of 50 years (range 36 to 53 years), and three were male, who were a median time of three years (range two months to 15 years) post-transplant. All patients were on a double or triple immunosuppressive regimen. The prevaccination pH1N1 titre was 1:10 in four patients and 1:40 in one patient. Seroprotection was observed only in one patient, with a rise in titre from 1:40 at baseline to 1:320 at both two and four weeks after vaccination. This lung transplant recipient had documented previous infection with pH1N1.

CONCLUSION

Results of the present small study call into question whether one dose of adjuvanted pH1N1 vaccine can provide seroprotection in SOT recipients.

Emerging viral diseases in kidney transplant recipients

Viruses are the most important cause of infections and a major source of mortality in Kidney Transplant Recipients (KTRs). These patients may acquire viral infections through exogenous routes including community exposure, donor organs, and blood products or by endogenous reactivation of latent viruses. Beside major opportunistic infections due to CMV and EBV and viral hepatitis B and C, several viral diseases have recently emerged in KTRs. New medical practices or technologies, implementation of new diagnostic tools, and improved medical information have contributed to the emergence of these viral diseases in this special population. The purpose of this review is to summarize the current knowledge on emerging viral diseases and newly discovered viruses in KTRs over the last two decades. We identified viruses in the field of KT that had shown the greatest increase in numbers of citations in the NCBI PubMed database. BKV was the most cited in the literature and linked to an emerging disease that represents a great clinical concern in KTRs. HHV-8, PVB19, WNV, JCV, H1N1 influenza virus A, HEV, and GB virus were the main other emerging viruses. Excluding HHV8, newly discovered viruses have been infrequently linked to clinical diseases in KTRs. Nonetheless, pathogenicity can emerge long after the discovery of the causative agent, as has been the case for BKV. Overall, antiviral treatments are very limited, and reducing immunosuppressive therapy remains the cornerstone of management.

Poor seroprotection but allosensitization after adjuvanted pandemic influenza H1N1 vaccine in kidney transplant recipients

BACKGROUND

Seasonal and pandemic influenza virus infections in renal transplant patients are associated with poor outcomes. During the pandemic of 2009-2010, the AS03-adjuvanted monovalent H1N1 influenza vaccine was recommended for transplant recipients, although its immunogenicity in this population was unknown. We sought to determine the safety and immunogenicity of an adjuvant-containing vaccine against pandemic influenza A H1N1 2009 (pH1N1) administered to kidney transplant recipients.

METHODS

We prospectively enrolled 124 adult kidney transplant recipients in the fall of 2009 at two transplant centers. Cohort 1 (n = 42) was assessed before and after pH1N1 immunization, while Cohort 2 (n = 82) was only assessed post immunization. Humoral response was measured by the hemagglutination inhibition assay. Vaccine safety was assessed by adverse event reporting, graft function, and human leukocyte antigen (HLA) alloantibody measurements.

RESULTS

Cohort 1 had a low rate of baseline seroprotection to pH1N1 (7%) and a low rate of seroprotection after immunization (31%). No patient <6 months post transplant (n = 5) achieved seroprotection. Seroprotection rate was greater in patients receiving double as compared with triple immunosuppression (80% vs. 24%, P = 0.01). In Cohort 2, post-immunization seroprotection was 35%. In both cohorts, no confirmed cases of pH1N1 infection occurred. No difference was seen in estimated glomerular filtration rate before (54.3 mL/min/1.73 m(2) ) and after (53.8 mL/min/1.73 m(2) ) immunization, and no acute rejections had occurred after immunization at last follow-up. In Cohort 1, 11.9% of patients developed new anti-HLA antibodies.

CONCLUSION

An adjuvant-containing vaccine to pH1N1 provided poor seroprotection in renal transplant recipients. Receiving triple immunosuppression was associated with a poor seroresponse. Vaccination appeared safe, but some patients developed new anti-HLA antibodies post vaccination. Alternative strategies to improve vaccine responses are necessary.