Immunity to diphtheria and tetanus in a young population on a dialysis regimen or with a renal transplant

Vaccination in adult liver transplantation candidates and recipients

In patients with chronic liver disease and liver transplant recipients, cirrhosis-associated immune dysfunction syndrome and immunosuppressant drug regimens required to prevent graft rejection lead to a high risk of severe infections, associated with acute liver decompensation, graft loss and increased mortality. In addition to maintain their global health status, vaccination represents a major preventive measure against specific infectious risks of particular concern in this population, such as invasive pneumococcal diseases, influenza or viral hepatitis A and B. However, immunization in this setting raises several issues: i) recommended vaccination schedules rely on sparse immunogenicity data without clinical efficacy and effectiveness trials designed for this specific population; ii) dynamics of immunosuppression makes timing of immunization challenging; iii) live attenuated vaccines are contraindicated after transplantation; and iv) vaccines tolerance is poorly known in cirrhotic patients. This review outlines the rational for vaccination in adult liver transplant candidates and recipients and available data regarding immunization in this specific population.

Immunization of Solid Organ Transplant Candidates and Recipients: A 2018 Update

This article discusses the recommended vaccines used before and after solid organ transplant period, including data regarding vaccine safety and efficacy and travel-related vaccines. Vaccination is an important part of the preparation for solid organ transplantation, because vaccine-preventable diseases contribute to the morbidity and mortality of these patients. A pretransplantation protocol should be encouraged in every transplant center. The main goal of vaccination is to provide seroprotection before transplantation, because iatrogenically immunosuppressed patients posttransplant have a lower seroresponse to vaccines.

Vaccination titres pre- and post-transplant in paediatric renal transplant recipients and the impact of immunosuppressive therapy

BACKGROUND

Avoidance of vaccine-preventable infections in paediatric renal allograft recipients is of utmost importance. However, the development and maintenance of protective vaccination titres may be impaired in this patient population owing to their need for immunosuppressive medication.

METHODS

In the framework of the Cooperative European Paediatric Renal Transplant Initiative (CERTAIN), we therefore performed a multi-centre, multi-national study and analysed vaccination titres pre- and post-transplant in 155 patients with serial titre measurements in comparison with published data in healthy children.

RESULTS

The percentage of patients with positive vaccination titres before renal transplantation (RTx) was low, especially for diphtheria (38.5%, control 75%) and pertussis (21.3%, control 96.3%). As few as 58.1% of patients had a hepatitis B antibody (HBsAb) titre >100 IU/L before RTx. 38.1% of patients showed a vaccination titre loss post-transplant. Patients with an HBsAb titre between 10 and 100 IU/L before RTx experienced a significantly (p < 0.05) more frequent hepatitis B vaccination titre loss post-transplant than patients with an HBsAb titre >100 IU/L. The revaccination rate post-transplant was low and revaccination failed to induce positive titres in a considerable number of patients (27.3 to 83.3%). Treatment with rituximab was associated with a significantly increased risk of a vaccination titre loss post-transplant (odds ratio 4.26, p = 0.033).

CONCLUSIONS

These data show a low percentage of patients with positive vaccination titres pre-transplant, a low revaccination rate post-transplant with limited antibody response, and a high rate of vaccination titre losses.

Does vaccination in solid-organ transplant recipients result in adverse immunologic sequelae? A systematic review and meta-analysis

BACKGROUND

Clinical guidelines recommend vaccinations for solid-organ transplant recipients. However, concern exists that vaccination may stimulate adverse alloimmune responses.

METHODS

We systematically reviewed the published literature regarding this aspect of vaccine safety. Electronic databases were searched for interventional and observational studies assessing de novo donor-specific antibodies (DSA) and rejection episodes after vaccination against infectious pathogens. Graft loss was also assessed. A meta-analysis was conducted for prospective, controlled studies. PRISMA reporting guidelines were followed.

RESULTS

Ninety studies (15,645 vaccinated patients and 42,924 control patients) were included. Twelve studies included control groups. The incidence of de novo DSA (14 studies) was 23 of 1,244 patients (1.85%) at 21 to 94 days. The incidence of rejection (83 studies) was 107 episodes in 5,116 patients (2.1%) at 0.7 to 6 months. Meta-analysis of prospective controlled studies (n = 8) showed no increased rejection risk with vaccination compared with no vaccination (RR 1.12, 95% CI 0.75 to 1.70). This finding was supported by data from 3 registry analyses.

CONCLUSIONS

Although the current evidence lacks high-quality, controlled studies, the currently available data provide reassurance that clinicians should recommend appropriate vaccination for their transplant patients as the risk of de novo DSA and rejection is relatively low.

Vaccinations in children on immunosuppressive medications for renal disease

Renal diseases are often treated with immunosuppressive medications, placing patients at risk of infections, some of which are vaccine-preventable. However, in such patients vaccinations may be delayed or disregarded due to complications of the underlying disease process and challenges in its management. The decision to administer vaccines to immunosuppressed children is a risk-benefit balance as such children may have a qualitatively diminished immunological response or develop diseases caused by the vaccine pathogen. Vaccination may cause a flare-up of disease activity or provocation of graft rejection in renal transplant recipients. Moreover, it cannot be assumed that a given antibody level provides the same protection in immunosupressed children as in healthy ones. We have evaluated the safety and efficacy of licensed vaccines in children on immunosuppressive therapy and in renal transplant recipients. The limited evidence available suggests that vaccines are most effective if given early, ideally before the requirement for immunosuppressive therapy, which may require administration of accelerated vaccine courses. Once treatment with immunosuppressive drugs is started, inactivated vaccines are usually considered to be safe when the disease is quiescent, but supplemental doses may be required. In the majority of cases, live vaccines are to be avoided. All vaccines are generally contraindicated within 3-6 months of a renal transplant.

Travel vaccination recommendations and endemic infection risks in solid organ transplantation recipients

BACKGROUND

Solid organ transplant (SOT) recipients are often heavily immunosuppressed and consequently at risk of serious illness from vaccine preventable viral and bacterial infections or with endemic fungal and parasitic infections. We review the literature to provide guidance regarding the timing and appropriateness of vaccination and pathogen avoidance related to the immunological status of SOT recipients.

METHODS

A PUBMED search ([Vaccination OR vaccine] AND/OR ["specific vaccine"] AND/OR [immunology OR immune response OR cytokine OR T lymphocyte] AND transplant was performed. A review of the literature was performed in order to develop recommendations on vaccination for SOT recipients travelling to high-risk destinations.

RESULTS

Whilst immunological failure of vaccination in SOT is primarily the result of impaired B-cell responses, the role of T-cells in vaccine failure and success remains unknown. Vaccination should be initiated at least 4 weeks prior to SOT or more than 6 months post-SOT. Avoidance of live vaccination is generally recommended, although some live vaccines may be considered in the specific situations (e.g. yellow fever). The practicing physician requires a detailed understanding of region-specific endemic pathogen risks.

CONCLUSIONS

We provide a vaccination and endemic pathogen guide for physicians and travel clinics involved in the care of SOT recipients. In addition, recommendations based on timing of anticipated immunological recovery and available evidence regarding vaccine immunogenicity in SOT recipients are provided to help guide pre-travel consultations.

Vaccine administration in children with chronic kidney disease

Pediatric patients with severe chronic kidney disease (CKD) on conservative treatment, on dialysis, and those with renal transplantation are at a higher risk for infectious diseases as the result of impaired immune responses against infectious agents. Infections in these patients can have drastic consequences for disease morbidity and mortality. Immunization is a crucial preventive strategy for disease management in this pediatric population. However, vaccination coverage among children with CKD remains low due to safety concerns and doubts about vaccine immunogenicity and efficacy. In this study, we reviewed why children with CKD are at higher risk of infections, the importance of vaccinations among these children, barriers to vaccinations, and recommend the best vaccination schedules. Overall, vaccines have acceptable immunogenicity, efficacy, and safety profiles in children with CKD. However, in some cases, the protective antibody levels induced by vaccines and the benefits and risks of booster vaccine doses must be individually managed. Furthermore, close contacts and household members of these children should complete age-appropriate vaccination schedules to increase the child's indirect protection.

Vaccination of the immunocompromised child

The development of vaccination is a major achievement in modern medicine. However, children treated with immunosuppression may not at all, or only in part, receive routine immunization due to uncertainty of its risks and effect. There is a substantial lack of pediatric studies concerning the efficacy and safety of vaccination in this patient group. Experience from similar adult groups and children with HIV infection can be used as a model for other disease categories. With increasing knowledge of the immunologic basis of vaccination and how immunosuppressive drugs interfere with the immune system, improved vaccines could be tailored, and adequate, individualized guidelines issued.

Serologic vaccination response after solid organ transplantation: a systematic review

BACKGROUND

Infectious diseases after solid organ transplantation (SOT) are one of the major complications in transplantation medicine. Vaccination-based prevention is desirable, but data on the response to active vaccination after SOT are conflicting.

METHODS

In this systematic review, we identify the serologic response rate of SOT recipients to post-transplantation vaccination against tetanus, diphtheria, polio, hepatitis A and B, influenza, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitides, tick-borne encephalitis, rabies, varicella, mumps, measles, and rubella.

RESULTS

Of the 2478 papers initially identified, 72 were included in the final review. The most important findings are that (1) most clinical trials conducted and published over more than 30 years have all been small and highly heterogeneous regarding trial design, patient cohorts selected, patient inclusion criteria, dosing and vaccination schemes, follow up periods and outcomes assessed, (2) the individual vaccines investigated have been studied predominately only in one group of SOT recipients, i.e. tetanus, diphtheria and polio in RTX recipients, hepatitis A exclusively in adult LTX recipients and mumps, measles and rubella in paediatric LTX recipients, (3) SOT recipients mount an immune response which is for most vaccines lower than in healthy controls. The degree to which this response is impaired varies with the type of vaccine, age and organ transplanted and (4) for some vaccines antibodies decline rapidly.

CONCLUSION

Vaccine-based prevention of infectious diseases is far from satisfactory in SOT recipients. Despite the large number of vaccination studies preformed over the past decades, knowledge on vaccination response is still limited. Even though the protection, which can be achieved in SOT recipients through vaccination, appears encouraging on the basis of available data, current vaccination guidelines and recommendations for post-SOT recipients remain poorly supported by evidence. There is an urgent need to conduct appropriately powered vaccination trials in well-defined SOT recipient cohorts.

Immunizations in children with chronic kidney disease

Children with chronic kidney disease (CKD) are at increased risk for vaccine-preventable diseases. These patients may have a reduced response to and/or reduced duration of antibody after immunization and therefore monitoring of antibody levels or titers is indicated for some vaccines. In addition, pediatric CKD patients require immunizations not routinely provided to healthy children. Unfortunately, studies in pediatric CKD patients, including those on dialysis and awaiting kidney transplantation, have demonstrated sub-optimal immunization rates. In order to minimize the risk for vaccine-preventable disease in pediatric CKD patients, it is imperative that all who care for these patients remain abreast of the recommended childhood immunization schedule, as well as alterations to this schedule required for children with CKD, including end-stage kidney disease. This article reviews recent changes to the recommended childhood immunization schedule and alterations and additions to this schedule recommended for children with CKD. Where available, data on antibody response to immunizations in children with CKD are presented.

Immunization issues before and after solid organ transplantation in children

Solid-organ transplant recipients are at risk from various infectious diseases, many of which can be prevented by immunizations that could reduce morbidity and mortality. However, it is not uncommon for children requiring transplantation to have received inadequate or no immunizations pre-transplant. Every effort should be made to immunize transplant candidates early in the course of their disease according to recommended schedules prior to transplantation. It is also important to immunize their household contacts and healthcare workers. In this review, we summarize the major immunization issues for children undergoing transplantation, the data currently available on immunization safety and efficacy, and suggest immunization practices to reduce vaccine-preventable disease. There is a real need for a standardized approach to the administration and evaluation of immunizations in this group of patients.

Immunization in children with chronic renal failure: a practical approach

The prevention of systemic viral and bacterial infections by effective vaccination represents an essential task of pediatric nephrologists caring for children with chronic renal failure (CRF) undergoing renal transplantation (RTPL) with life-long immunosuppression. This review addresses three issues: risk of vaccine-preventable diseases, safety, immunogenicity, and clinical efficacy of available vaccines, and implementation of immunization guidelines. Infections (including vaccine-preventable infections) represent the leading cause of morbidity and mortality in children on dialysis and after RTPL. Vaccination in children with CRF and after RTPL is safe and does not cause reactivation of an immune-related renal disease or rejection after RTPL. Children with CRF generally produce protective serum antibodies to primary vaccinations with killed or component vaccines and live virus vaccines; some children on dialysis and after RTPL may not respond optimally, requiring repeated vaccination. Proof of vaccine efficacy is absence of disease, which can only be confirmed in large cohort studies. A few observational studies provide evidence that vaccination has contributed significantly, at least in the western hemisphere, to the low prevalence of vaccine-preventable diseases among children with CRF. Close cooperation between the local pediatrician/practitioner and the pediatric nephrologist is essential for successful implementation of the vaccination schedule.

Immunization of children after solid organ transplantation

The array of immunizations commonly used in childhood has risen in an attempt to prevent many of the potentially serious infections of infancy and childhood. In this article, the authors provide rational guidelines for vaccination of these children. The authors briefly review the susceptibilities caused by immunosuppression in these patients, discuss the problems with various immunizations, and make individual recommendations regarding the use of each vaccine. Most recommendations are based on inferences from populations that may not be directly comparable to the transplantation population (patients with HIV or cancer or patients who have undergone bone marrow transplant), from case reports, and from small series of patients. The best recommendations ultimately must await the results of controlled trials of immunization.

Vaccinations for adult solid-organ transplant recipients: current recommendations and protocols

Recipients of solid-organ transplantation are at risk of severe infections due to their life-long immunosuppression. Despite emerging evidence that vaccinations are safe and effective among immunosuppressed patients, most vaccines are still underutilized in these patients. The efficacy, safety, and protocols of several vaccines in this patient population are poorly understood. Timing of vaccination appears to be critical because response to vaccinations is decreased in patients with end-stage organ disease and in the first 6 months after transplantation. For these reasons, the primary immunizations should be given before transplantation, as early as possible during the course of disease. Vaccination strategy should include vaccination of household contacts and health care workers at transplant centers unless contraindicated. No conclusive data are available on the use of immunoadjuvants and screening for protective titers. Most vaccines appear to be safe in solid-organ transplantation recipients, but live vaccines should be avoided until further studies are available. The risk of rejection appears minimal. Recommended vaccines include pneumovax, hepatitis A and B, influenza, and tetanus-diphtheria. We outline specific protocols and recommendations in this particular patient population. Specific contraindications exist for other vaccines, such as yellow fever, oral polio vaccine, bacillus Calmette-Guerin, and vaccinia. We conclude that solid-organ recipients will benefit from consistent immunization practices. Further studies are recommended to improve established protocols in this patient population.

[Vaccinations and solid-organ transplantation: review and recommendations]

Pediatric solid-organ transplant recipients are at high risk for various infectious diseases. Many children are not fully vaccinated before transplantation. To reduce the risk of morbidity and mortality from vaccine-preventable disease, physicians treating pediatric solid-organ transplant recipients should monitor the immunization status of these patients. Consensus on the most appropriate immunization schedule for solid-organ transplant recipients is lacking. Therefore, we provide a review of the currently available data on immunization safety and efficacy and describe strategies to avoid vaccine-preventable diseases in pediatric solid-organ transplant recipients.

Immunisations in solid-organ transplant recipients

Solid-organ transplant recipients are at increased risk of various infectious diseases, some of which are vaccine preventable mmunisations are among the most efficient interventions available. Solid-organ tranplant recipients would greatly benefit from effective immunisations, provided the recommendations are based on a careful risk-benefit analysis in which the effectiveness of the vaccine is weighed against possible adverse reactions, including graft rejection. In this review, we summarise the data from studies on relevant immunisations in solid-organ transplant recipients. The major issues are the immunogenicity and safety of immunisations, the factors associated with poor immune response, and recommendations for immunisation schemes.

Management of the pediatric liver transplant patient

1. In pretransplant management, the prevention and treatment of malnutrition is essential for pediatric patients as malnutrition is associated with both increased pre- and posttransplant mortality. 2. Technical complications, particularly hepatic artery thrombosis, after pediatric liver transplantation are relatively common given the small size of the majority of the recipients. Early recognition is essential to reduce the associated increased risk for both patient and graft loss. 3. Immunosuppression regimens in children should aim to begin weaning of steroids within the first year after transplant because of their detrimental impact on growth. 4. Long-term immunosuppression strategies must focus on avoiding the risks of long-term immunosuppression, particularly nephrotoxicity, neurotoxicity, de novo malignancy, and late infections. 5. EBV-associated PTLD is a special problem for young pediatric liver recipients. Strategies for prevention and preemptive management are essential. 6. Noncompliance in teens is a particular problem and is associated not only with graft dysfunction, but also with graft loss and patient death. Recognizing teens at risk and providing intervention strategies require a multi-disciplinary approach.

Liver transplantation. The pediatric challenge

Successful liver transplantation in a child is often a hard-won victory, requiring all the combined expertise of a dedicated pediatric transplant team. This article outlines the considerable challenges still facing pediatric liver transplant physicians and surgeons. In looking to the future, where should priorities lie to enhance the success already achieved? First, solutions to the donor shortage must be sought aggressively by increasing the use of from split-liver transplants, judicious application of living-donor programs, and increasing the donation rate, perhaps by innovative means. The major immunologic barriers, to successful xenotransplantation make it unlikely that this option will be tenable in the near future. Second, current immunosuppression is nonspecific, toxic, and unable to be individually adjusted to the patient's immune response. The goal of achieving donor-specific tolerance will require new consideration of induction protocols. Developing a clinically applicable method to measure the recipient's immunoreactivity is of paramount importance, for future studies of new immunosuppressive strategies and to address the immediate concern of long-term over-immunosuppression. The inclusion of pediatric patients in new protocols will require the ongoing insistence of pediatric transplant investigators. Third, the current immunosuppressive drugs have a long-term morbidity and mortality of their own. These long-term effects are particularly important in children who may well have decades of exposure to these therapies. There is now some understanding of their long-term renal toxicity and the risk of malignancy. New drugs may obviate renal toxicity, whereas the risk of malignancy is inherent in any nonspecific immunosuppressive regimen. Although progress is being made in preventing and recognizing PTLD, this entity remains an important ongoing concern. The global effect of long-term immunosuppression on the child's growth, development, and intellectual potential is unknown. Of particular concern is the potential for neurotoxicity from the calcineurin inhibitors. Fourth, recurrent disease and new diseases, perhaps potentiated by immunosuppressive drugs, must be considered. Already the recurrence of autoimmune disease and cryptogenic cirrhosis have been documented in pediatric patients. Now, a new lesion, a nonspecific hepatitis, sometimes with positive autoimmune markers, that may progress to cirrhosis has been recognized. It is not known whether this entity is an unusual form of rejection, an unrecognized viral infection, or a response to immunosuppressive drugs themselves. Finally, pediatric transplant recipients, like any other children, must be protected and nourished physically and mentally if they are to fulfill their potential. After liver transplantation the child's growth, intellectual functioning, and psychologic adaptation may all require special attention from parents, teachers, and physicians alike. There is limited understanding of how the enormous physical intervention of a liver transplantation affects a child's cognitive and psychologic function as the child progresses through life. The persons caring for these children have the difficult responsibility of providing services to evaluate these essential measures of children's health over the long term and to intervene if necessary. Part of the transplant physician's our duty to protect and advocate for children is to fight for equal access to health care. In most of the developing world, economic pressures make it impossible to consider liver transplantation a health care priority. In the United States and in other countries with the medical infrastructure to support liver transplantation, however, health care professionals must strive to be sure that the policies governing candidacy for transplantation and allocation of organs are applied justly and uniformly to all children whose lives are threatened by liver disease. In the current regulatory climate that increasingly takes medical decisions out of the hands of physicians, pediatricians must be even more prepared to protect the unique and often complicated needs of children both before and after transplantation. Only in this way can the challenges of the present and the future be met.

Vaccine recommendations for patients on chronic dialysis. The Advisory Committee on Immunization Practices and the American Academy of Pediatrics

Pediatric patients on dialysis should receive all the vaccines currently recommended by the ACIP and the AAP for healthy children, except the oral polio vaccine (34, 35). Adult patients should receive the hepatitis B vaccine series, pneumococcal vaccine, yearly influenza vaccinations, tetanus-diphtheria toxoids, and varicella vaccine, if they are susceptible (33, 48, 69). Vaccines are well tolerated by these patients (33), but higher doses and/or additional boosters may be required periodically to adequately protect dialysis patients from vaccine-preventable diseases (33, 36, 37, 82, 83). Following vaccination, antibody concentrations for hepatitis B vaccine should be measured annually and booster doses administered when antibody concentrations fall below protective levels (33, 38). Although both children and adults on dialysis may show an impaired and/or delayed immunologic response to certain antigens, particularly hepatitis B virus and S. pneumoniae, appropriate immunizations can significantly reduce the risk of serious complications from vaccine-preventable diseases (11, 84). Because the protection these vaccines provide may be incomplete or transient, infection control strategies at hospitals and other health care facilities should be implemented simultaneously. Health care providers are encouraged to assess each patients need for vaccinations individually and formulate immunization strategies early in the course of progressive renal disease, ideally before the patient requires dialysis.

Immunity to poliomyelitis, diphtheria and tetanus in pediatric patients before and after renal or liver transplantation

Few studies have considered the safety, efficacy and appropriateness of vaccinations in pediatric patients before and after solid organ transplantation. The aim of this study was to evaluate the immune status after primary vaccination to diphtheria, tetanus and poliomyelitis in pediatric patients before and after hepatic transplantation and to poliomyelitis in pediatric patients before and after renal transplantation. All the patients had received a complete primary immunization schedule for diphtheria and tetanus and poliomyelitis. Immunity to the three polioviruses was evaluated in 56 patients with renal transplant, 27 on chronic dialysis and 33 controls and in 39 patients with hepatic transplant, 25 with chronic hepatic failure and their 36 controls. Immunity to diphtheria and tetanus was evaluated in 52 liver transplant patients, 29 children with chronic hepatic failure and 54 healthy children. Renal transplant patients were less protected and had lower antibody geometric mean titers than healthy controls for polioviruses 1 and 2. Whereas, protection in the children liver transplant patients was similar to that in their controls. Patients with chronic hepatic failure had higher antibody geometric mean titers to diphtheria and polioviruses 1 and 3 than their control group. Immunosuppression after transplantation has a negative influence on the immune status after primary vaccination in children with renal transplant. Whereas children with chronic hepatic failure have higher antibodies than a normal population. When possible, it could be advisable to individualize immunization schedules in patients at high risk.

Duration of immunity to diphtheria and tetanus in young kidney transplant patients

A considerable proportion of patients with renal transplant, evaluated many years after transplant, lack protective diphtheria antibody levels, despite primary immunization, but maintain immunity to tetanus. These patients respond to a diphtheria and tetanus booster but the duration of the response is uncertain. This study was undertaken to assess if protective antibodies evoked by primary immunization are lost quickly after transplantation, and whether the extent of the immune response to a booster influences the persistence of protective antibodies. We studied 15 patients (group 1) immediately after renal transplant and 35 patients with renal transplant for 6 +/- 4 yr who received a diphtheria and tetanus booster (group 2). Six patients (40%) of group 1 lost protective diphtheria antibodies a median time of 6.5 months after transplant. Thirty-three patients of group 2 responded to the booster with normal diphtheria antibody titers (> 1 IU/mL) in 22 cases and with low titers in 11. Four of the latter lacked immunity to diphtheria at 12 months follow-up. All patients with normal immunity maintained protective levels of diphtheria antibodies. The low responders had a creatinine clearance of 50 +/- 20 mL/min/1.73 m2. Tetanus immunity was maintained in almost all patients of both groups. In conclusion, renal transplant patients had an accelerated loss of diphtheria antibodies in the early post-transplant period. Response to a diphtheria booster identified a group at particular risk, namely the low responders, who may require frequent booster doses. This group had significantly poorer renal function than the normal responders.