Routine immunizations in adult renal transplant recipients

Evidence for Immunity against Tetanus, Diphtheria, and Pertussis through Natural Infection or Vaccination in Adult Solid Organ Transplant Recipients: A Systematic Review

(1) Background: We aim to systematically review the current evidence on immunity against tetanus, diphtheria, and pertussis in adult solid organ transplantation (SOT) recipients, either through natural infection or vaccination. (2) Methods: This systematic review was conducted per PRISMA guidelines. We assessed the risk of bias using the Cochrane RoB 2 and ROBINS-I and summarized the findings narratively due to the heterogeneity of the studies. (3) Results: Of the 315 screened articles, 11 were included. Tetanus immunity varied between 55% and 86%, diphtheria immunity from 23% to 75%, and pertussis immunity was between 46% and 82%. Post-vaccination immunity showed variation across the studies, with some indicating reductions and others no change, with antibody responses influenced by transplanted organs, gender, age, and immunosuppressive regimens. The single randomized study exhibited a low risk of bias, while of the ten non-randomized studies, six showed moderate and four serious risks of bias, necessitating cautious interpretation of results. (4) Conclusions: SOT recipients exhibit considerable immunity against tetanus and diphtheria at transplantation, but this immunity decreases over time. Although vaccination can enhance this immunity, the response may be suboptimal, and the increased antibody levels may not persist, underscoring the need for tailored vaccination strategies in this vulnerable population.

Vaccination in Chronic Liver Disease: An Update

Patients with chronic liver disease (CLD) with or without cirrhosis remain at risk of developing hepatic decompensation when infected with viral or bacterial pathogens. The Advisory Committee on Immunization Practices (ACIP) currently recommends vaccination in CLD against hepatitis A virus (HAV), hepatitis B virus (HBV), influenza, pneumococcus, herpes zoster, tetanus, diphtheria, pertussis, and SARS-CoV-2. Inactivated vaccines are preferred over live attenuated ones, especially in transplant recipients where live vaccines are contraindicated. As the severity of the liver disease progresses, vaccine efficacy declines, and therefore, vaccines should be ideally administered early in the disease course for optimal immune response. Despite the strong recommendations, overall vaccination coverage in CLD remains poor; however, it is encouraging to note that in recent years coverage against influenza and pneumococcus has shown some improvement. Inadequate access to healthcare, lack of information on vaccine safety, poor financial reimbursement for healthcare providers, and vaccine misinformation are often responsible for low immunization rates. This review summarizes the impact of vaccine-preventable illness in those with CLD, updated vaccine guidelines, seroconversion rates in the vaccinated, and barriers faced by healthcare professionals in immunizing those with liver disease.

Immunizations in Chronic Kidney Disease and Kidney Transplantation

Purpose of Review

Infection is a significant cause of morbidity and mortality in both patients with chronic kidney disease (CKD) and in recipients of a kidney transplant (KT). We review the current data in patients with CKD, on dialysis, and in KT recipients to provide further guidance for clinicians regarding vaccine optimization in this patient population.

Recent Findings

This patient population remains under-vaccinated and thus more vulnerable to vaccine-preventable illness. Despite diminished responses to immunization in this population, significant protection is generally achieved.

Summary

Vaccines are an important preventative tool and offer protection against infection. In the setting of suboptimal and waning immunity in this patient population, future studies are indicated to determine optimal vaccination regimens.

Serostatus following polio-containing vaccination before and after liver transplantation

BACKGROUND

The strategy to eradicate polio is based on preventing infection by immunizing all children until the world is polio-free. However, data regarding efficacy of polio-containing vaccination in immunocompromised patients such as LT recipients are limited.

METHODS

We conducted an observational study at the largest pediatric transplant center in Japan from January 2011 to January 2015. LT recipients were enrolled after transplantation, and those who had completed the Japanese polio vaccination program were eligible for the study. Patients' demographics were collected from their medical records. Antibody titers against poliovirus serotypes 1-3 were measured using the neutralization test at the routine follow-up visits after enrollment. Factors associated with seropositivity against each type of poliovirus were evaluated.

RESULTS

Sixty-four patients who had received the complete polio vaccination series were enrolled in the study. Of these, 37 patients had received all series of polio-containing vaccination before LT. Median age of the patients was 75 months. Their underlying diseases included the following: 40 (63%) with cholestatic liver diseases and 11 (17%) with metabolic disorders. After a median interval of 43 months after LT, seropositivity rates against poliovirus 1, 2, and 3 were 93.8% (60/64), 92.2% (59/64), and 54.7% (35/64), respectively. Among 32 patients who had received only oral polio vaccine (OPV), seropositivity against poliovirus 3 was particularly low (25.0%). No factors associated with seropositivity against each type of poliovirus were identified.

CONCLUSIONS

In the LT recipients, seropositivity for poliovirus 3 was low, suggesting a need for additional inactivated polio-containing vaccination after LT, especially for patients who had received only OPV.

Vaccinations in pediatric kidney transplant recipients

Pediatric kidney transplant (KT) candidates should be fully immunized according to routine childhood schedules using age-appropriate guidelines. Unfortunately, vaccination rates in KT candidates remain suboptimal. With the exception of influenza vaccine, vaccination after transplantation should be delayed 3-6 months to maximize immunogenicity. While most vaccinations in the KT recipient are administered by primary care physicians, there are specific schedule alterations in the cases of influenza, hepatitis B, pneumococcal, and meningococcal vaccinations; consequently, these vaccines are usually administered by transplant physicians. This article will focus on those deviations from the normal vaccine schedule important in the care of pediatric KT recipients. The article will also review human papillomavirus vaccine due to its special importance in cancer prevention. Live vaccines are generally contraindicated in KT recipients. However, we present a brief review of live vaccines in organ transplant recipients, as there is evidence that certain live virus vaccines may be safe and effective in select groups. Lastly, we review vaccination of pediatric KT recipients prior to international travel.

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.

Seroprevalence of antibodies against the three serotypes of poliovirus and IPV vaccine response in adult solid organ transplant candidates

OBJECTIVES

To assess the prevalence of protective antibody titers to polioviruses in adults candidates for solid organ transplant (SOT), and to assess the immunogenic response to inactivated polio vaccine in this population.

METHODS

The study included SOT candidates referred to Immunization Reference Centre of Evandro Chagas National Institute of Infectious Diseases from March 2013 to January 2016. It was conducted in 2 phases. The first one, a cross-sectional seroprevalence study, followed by an uncontrolled analysis of vaccine response among patients without protective antibody titers at baseline. Antibody titers to poliomyelitis were determined by microneutralization assay.

RESULTS

Among 206 SOT candidates included, 156 (76%) had protective antibody titers to all poliovirus serotypes (95% CI: 70-81%). Proven history of oral vaccination in childhood was not associated with higher seroprevalence of protective antibody. In 97% of individuals without protective antibody titers at baseline, there was adequate vaccine response with one dose of inactivated polio vaccine.

CONCLUSIONS

A relevant proportion of adult candidates for SOT does not have protective titers of antibodies to one or more poliovirus serotype. One dose of inactivated vaccine elicited protective antibody titers in 97% of these subjects and should be routinely prescribed prior to SOT.

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.

Seronegativity to polio viruses among previously immunized adult candidates to solid organ transplantation

In the current effort to eliminate polio from the world, it is important to recognize and vaccinate susceptible groups, especially immunocompromised patients living in countries where attenuated polio vaccine is still used. In this report, we describe the frequency of protective antibodies in a small sample of adult SOT candidates in whom previous vaccination could be ascertained. Patients included in this report were selected among the participants of an ongoing prospective study carried out at the Reference Center for Special Immunobiologicals of the Evandro Chagas National Institute of Infectious Diseases in Rio de Janeiro, Brazil. Among the first 100 patients enrolled in this study, only seven adult SOT candidates had proven polio vaccination at childhood. Three of these seven patients (43%) had no protective antibody titers to one or more poliovirus subtype before solid organ transplant. Proven childhood vaccination against polio does not reliably provide lifelong protective antibody titers for adult SOT candidates and should not be used as a criterion to analyze the need for vaccination in this population.

Immunization and Organ Transplantation

With the rapid pace of immunologic research, it is more important than ever for readers to understand rational immunodiagnosis, immunopro-phylaxis, and immunotherapy. This column is intended to help you ensure proper immunologic drug use in your practice.

Enteroviruses and Parechoviruses

Infections with enteroviruses and human parechoviruses are highly prevalent, particularly in neonates, where they may cause substantial morbidity and mortality. Individuals with B-cell-related immunodeficiencies are at risk for severe enteroviral infections, usually a chronic and fatal meningoencephalitis. In transplant recipients and patients with malignancy, enterovirus infections typically involve the respiratory tract, but cases of severe, disseminated infection have been described. The mainstay of diagnosis for enterovirus and human parechovirus infections involves the use of molecular diagnostic techniques. However, routine nucleic acid-detection methods for enteroviruses will not detect human parechoviruses. Laboratory diagnosis of these viral infections is important in determining a patient's prognosis and guiding clinical management.

Vaccination strategies in patients with solid organ transplant: evidences and future perspectives

Solid organ transplant recipients need emphases on immunization that result in certainly decrease the risk of vaccine preventable diseases. Organ transplant candidate should complete the recommended full vaccination schedule as early as possible during the courses of underlying disease because the patients with end stage liver or renal disease have reduced immune response to vaccine. Furthermore, live attenuated vaccines are generally contraindicated after transplantation. This review summarizes current information and the evidences regarding the efficacy and safety of immunization in adult solid organ transplant candidates and recipients.

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.

A cross-sectional study of tetanus and diphtheria antibody concentrations post vaccination among lung transplant patients compared with healthy individuals

BACKGROUND

Lung transplant (LuTx) patients are routinely immunized against tetanus and diphtheria. However, few studies have been done to measure serologic immunity in the transplant population.

OBJECTIVES

The primary objective of this study was to compare tetanus and diphtheria antibody concentrations in LuTx vs. healthy subjects.

METHODS

Serum was used from an available sample of 111 total individuals (n = 36 healthy; n = 75 LuTx). Tetanus and diphtheria antibody concentrations were measured using an enzyme-linked immunosorbant assay method.

RESULTS

A statistically significant difference in both tetanus and diphtheria antibody concentrations was found between the groups. The median concentration of tetanus antibody was higher for healthy individuals compared with the LuTx group (3.2 IU/mL [1.2-5.2 interquartile range {IQR}] vs. 1.3 IU/mL [0.4-2.6 IQR], respectively; P = 0.0001). No difference in time was found since the last tetanus-diphtheria vaccine or tetanus-diphtheria-pertussis vaccine dose between the groups (healthy 76.5 months [16-114 IQR] vs. LuTx 74.5 months [45-118 IQR]; P = 0.44).

CONCLUSIONS

Tetanus and diphtheria immunizations are recommended for LuTx patients to reduce the risk of infection. Because the LuTx group has lower antibody concentrations, further studies should investigate the possible need for more frequent tetanus and diphtheria boosters.

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.

A decade of infliximab: The Austrian evidence based consensus on the safe use of infliximab in inflammatory bowel disease

Infliximab (IFX) has tremendously enriched the therapy of inflammatory bowel diseases (IBD) and other immune mediated diseases. Although the efficacy of IFX was undoubtedly proven during the last decade numerous publications have also caused various safety concerns. To summarize the immense information concerning adverse events and safety issues the Austrian Society of Gastroenterology and Hepatology launched this evidence based consensus on the safe use of IFX which covers the following topics: infusion reactions and immunogenicity, skin reactions, opportunistic infections (including tuberculosis), non-opportunistic infections (bacterial and viral), vaccination, neurological complications, hepatotoxicity, congestive heart failure, haematological side effects, intestinal strictures, stenosis and bowel obstruction (SSO), concomitant medication, malignancy and lymphoma, IFX in the elderly and the young, mortality, fertility, pregnancy and breast feeding. To make the vast amount of information practicable for routine application the consensus was finally condensed into a checklist for a safe use of IFX which consists of two parts: issues to be addressed prior to anti-TNF therapy and issues to be addressed during maintenance. Both parts are further divided into obligatory and facultative items.

Maintenance immunosuppressive therapy with everolimus preserves humoral immune responses

While the guidelines for vaccination in renal transplant recipients recommend the use of pneumococcal polysaccharide (PPS) and tetanus toxoid (TT), their efficacy in immunocompromised renal transplant recipients is not known. Here we tested the effect of everolimus on immune responses after vaccination by measuring the capacity of 36 stable renal transplant recipients to mount cellular and humoral responses after vaccination. Twelve patients in each treatment arm received immunosuppressive therapy consisting of prednisolone (P) plus cyclosporine (CsA), mycophenolate sodium (MPA), or everolimus. Patients were vaccinated with the T-cell-dependent antigens immunocyanin and TT, and the T-cell-independent PPS. Treatment with CsA partially inhibited and MPA completely abolished the capacity to mount a primary humoral response, whereas everolimus left this largely intact. Recall responses were inhibited by MPA only. All drug combinations inhibited cellular responses against TT. In patients treated with MPA, B-cell numbers were severely reduced. Thus, combined with P, treatment with MPA completely disturbed primary and secondary humoral responses. Everolimus or CsA allowed the boosting of T-cell-dependent and -independent secondary humoral responses. Treatment with everolimus allowed a primary response.

[Recommendations before travelling for renal transplant patients]

Travel is now a reasonable objective of CKD patients after renal transplantation. However, immunosuppressive treatment makes them particularly susceptible to infections and may interfere with vaccinations and other drugs. Travel in countries with low health level should be strongly discouraged in the first six months after transplantation or following an acute event. Otherwise, specific consultations should be arranged to prepare the patient as soon as possible. Vaccinations should be started early before departure. Specific immunisations include vaccines against hepatitis A, typhoid, meningococcus and rabies in some cases. Living vaccines are formally contra-indicated. Particular attention should be paid for protection against insects because this is the only effective measure against diseases. In the case of malaria, it should be complemented by adapted chemoprophylaxis that should be started 15 days before the departure date. Advice on hygiene measures should be clarified because this can prevent numerous infections, especially of the digestive tract. Advice on the management of diarrhoea is essential, especially in terms of preventing dehydration. Finally, advice about transport and physical risks, especially those related to sun exposure, should also be addressed.

Vaccination of the solid organ transplant recipient

Active immunization is the most important way to protect immunocompromised patients from vaccine-preventable infectious diseases. Although live vaccines are contraindicated for most immunocompromised patients, many inactivated or conjugate vaccines are safe and generally recommended. Some vaccines are known to be of suboptimal immunogenicity in transplant recipients. As a consequence, this may be associated with an impaired ability to mount protective immunity. Nevertheless, even partial protection has been shown to confer significant benefit to this vulnerable patient group. To increase efficacy in generating protective immunity, patients should complete the full complement of recommended vaccinations early in the course of disease before transplantation. This review summarizes the general recommendations for vaccinations of adult transplant recipients and candidates including special considerations for household contacts and health care workers.

Immune responsiveness and protective immunity after transplantation

The growing success of solid organ transplantation poses unique challenges for the implementation of effective immunization strategies. Although live attenuated vaccines have proven benefits for the general population, immunosuppressed patients are at risk for unique complications such as infection from the vaccine because of lack of both clearance and containment of a live attenuated virus. Moreover, while vaccination strategies using killed organisms or purified peptides are believed to be safe for immunosuppressed patients, they may have reduced efficacy in this population. The current lack of knowledge of the basic safety and efficacy of vaccination strategies in the immunosuppressed has limited the development of guidelines regarding vaccination in this population. Recent fears of influenza pandemics and potential attacks by weaponized pathogens such as smallpox heighten the need for increased knowledge. Herein, we review the current understanding of the effects of immunosuppressants on the immune system and the ability of the suppressed immune system to respond to vaccination. This review highlights the need for systematic, longitudinal studies in both humans and nonhuman primates to understand better the defects in innate and adaptive immunity in transplant recipients, thereby aiding the development of strategies to vaccinate these individuals.

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.

The use of vaccines in adult patients with renal disease

In patients with renal disease, infection remains among the most common causes of morbidity and mortality. Alterations in the function of the immune system, as well as unique exposures of this patient population, account for the increased risk. Vaccination is an invaluable tool in preventing many infectious diseases. Unfortunately, responsiveness to vaccination in patients with renal disease can be diminished. In the present review, we examine the available evidence on the use of vaccinations in adult patients at different stages of chronic kidney disease. We address efficacy, clinical outcomes, and potential costs of individual vaccinations and provide our recommendations based on the literature reviewed. We also identify areas in which additional research is needed.

Immunization of pediatric solid-organ transplantation candidates: immunizations in transplant candidates

Many children who receive solid-organ transplants have not completed their primary immunizations prior to transplantation. This leaves pediatric transplant recipients susceptible to the vaccine preventable illness of childhood, which if acquired post-transplantation are associated with increased rates of complications, hospitalization, graft rejection and mortality. The administration of vaccines to transplant candidates earlier and more rapidly than in the healthy child will improve vaccination rates among transplant recipients while not compromising immunogenicity. The recommended vaccines and vaccine schedule are discussed in detail.

Efficacy of pneumococcal immunization in patients with renal disease--what is the data?

BACKGROUND/AIMS

There is an increased incidence of invasive pneumococcal disease in patients with renal allografts, chronic renal insufficiency (CRI), or nephrotic syndrome (NS). Routine pneumococcal immunization (PI) has been recommended for these patients, but the efficacy of PI in this population is not well established.

METHODS

A review was done of studies that reported the immunologic response, efficacy, or safety of PI in patients with renal allografts, CRI, or NS.

RESULTS

On review of 26 published studies of PI in this population, all studies demonstrated a serologic response by the majority of patients to at least some pneumococcal serotypes. Use of steroids did not alter this response. In the studies with a greater than 6-month follow-up, declining antibody titers were consistently reported, and this decline was usually more rapid than in healthy controls. However, because the studies of the efficacy of PI in this population involve small numbers of patients and are not controlled, the significance of this decline in titers is not known. The incidence of serious adverse reactions to PI is very low.

CONCLUSION

Pending more data, patients with renal transplants, CRI, or NS should continue to be offered PI.

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.

Infectious disease prophylaxis in renal transplant patients: a survey of US transplant centers

Definitive approaches to most infectious diseases following renal transplantation have not been established, leading to different approaches at different transplant centers. To study the extent of these differences, we conducted a survey of the practices surrounding specific infectious diseases at US renal transplant centers. A survey containing 103 questions covering viral, bacterial, mycobacterial and protozoal infections was developed. Surveys were sent to program directors at all U.S. renal transplant centers. Responses were received from 147 of 245 (60%) transplant centers and were proportionately represented all centers with respect to program size and geographical location. Pre-transplant donor and recipient screening for hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV) and cytomegalovirus (CMV) is uniform, but great discrepancy exists in the testing for other agents. HCV seropositive donors are used in 49% of centers. HIV seropositivity remains a contraindication to transplantation, although 13% of centers indicated they have experience with such patients. Post-transplant, there is wide variety in approach to CMV and Pneumocystis carinii (PCP) prophylaxis. Similarly divergent practices affect post-transplant vaccinations, with 54% of centers routinely vaccinating all patients according to customary guidelines in non-transplant populations. In contrast, 22% of centers indicated they do not recommend vaccination in any patients. We believe an appreciation of the differences in approaches to post-transplant infectious complications may encourage individual centers to analyse the results of their own practices. Such analysis may assist in the design of studies to answer widespread and important questions regarding the care of patients following renal transplantation.

Assessment of cytomegalovirus infections using neopterin and a new immunoblot

Human cytomegalovirus (HCMV) infections are a major cause of morbidity and mortality in immunocompromised patients despite advances in diagnostic tests and antiviral therapies. The underlying study investigates the diagnostic value of the immune marker neopterin and a recently developed HCMV-specific western blot to detect HCMV infections and to differentiate them into either syndromes or diseases. The mean period of observation was 1428 days. Thirteen HCMV diseases and nine syndromes were diagnosed retrospectively. The first appearance of clinical signs or symptoms was always associated with a marked increase of serum and urine neopterin. The HCMV-specific IgM response followed in the mean 9 days later. Median values and the course of the neopterin levels were significantly higher during the HCMV diseases. In addition, the strength of the humoral immune response was related to the severity of the HCMV infection. Patients with HCMV diseases developed antibodies against a higher number of epitopes. The anti-HCMV IgM response persisted in more than 80% of the patients for longer than 3 years. In conclusion, combining the HCMV-specific western blot and neopterin permit detection of the immune response against HCMV, reflect the severity of the infection and might guide the anti-viral therapy.

Prophylactic measures in the solid-organ recipient before transplantation

Pretransplant screening affords an important opportunity to detect and treat preexisting active infection in the solid-organ transplant recipient. In this article, pretransplant strategies for preventing infections after solid-organ transplantation are reviewed. In addition to the search for active preexisting infection in the transplant candidate, immunization remains a cornerstone of preventive practice. Because there is a suboptimal response to vaccinations in patients who are receiving immunosuppressive therapy, as well as in patients with end-stage organ dysfunction, standard immunization of the transplant candidate should be updated as early as possible in the course of the illness, including pneumococcal, influenza, and hepatitis B vaccines. Liver transplant candidates should receive hepatitis A vaccine, and children should receive Haemophilus influenzae type B conjugate vaccine. All nonimmune pretransplant patients should be considered candidates for the varicella vaccine. The management of special risk groups is discussed in detail.

Vaccines for transplant recipients

Immune dysregulation and immunosuppression regimens impact on the ability of transplant recipients to respond to immunizations. The distinct challenges of immunizations to benefit stem cell transplant recipients and solid organ transplant recipients are discussed separately. Recommended vaccines for stem cell transplant recipients and solid organ transplant candidates are suggested. New approaches to consider to enhance immune responses of transplant recipients are discussed.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.

Rapid decline of antibodies after hepatitis A immunization in liver and renal transplant recipients

BACKGROUND

Hepatitis A vaccine is safe and achieves good seroconversion rates in liver (LTX) and renal (RTX) transplant recipients.

METHODS

A study was performed to determine the anti-hepatitis A virus (HAV) antibody decline in LTX and RTX patients, and in healthy controls who have been immunized with two doses of hepatitis A vaccine.

RESULTS

LTX and RTX patients had a satisfactory seroconversion rate after complete immunisation. However, 2 years later they had experienced a much more rapid antibody decline than controls, and only 59% of LTX and 26% of RTX seroconverters showed titres above the cut-off level defined as protective.

CONCLUSIONS

Patients on immunosuppressive therapy may not be adequately protected against hepatitis A a few years after vaccination and alternative vaccination schemes may have to be considered.

Influenza vaccination does not promote cellular or humoral activation among heart transplant recipients

BACKGROUND

The impact of influenza vaccination on in vitro parameters of cellular and humoral immunity, anti-viral titers, and clinical outcome was evaluated among cardiac transplant recipients.

METHODS

Blood was collected from 29 patients before and 3-4 weeks after influenza vaccination and tested for phenotypic changes in lymphoid subpopulations and generation of antibodies against the allograft and vaccine.

RESULTS

Vaccination did not change the percentage of lymphoid subpopulations and did not induce generation of anti-HLA alloantibodies. Anti-vaccine response was detected in 12 of 29 patients and did not correlate with rejection history, length of graft survival, or immunosuppressive therapy. Vaccination did not change the frequency of rejection. Flu-like symptoms were reported in one patient but not confirmed microbiologically.

CONCLUSION

Despite the small number of patients in the study, influenza vaccination did not induce undesirable side effects, such as graft rejection or allo-sensitization. Generation of a positive anti-vaccine response was lower among the transplant recipients than healthy volunteers (41% vs. 80%). Clinical efficacy of the vaccine among the responders was not evaluated.

Immunization of renal transplant recipients with pneumococcal polysaccharide vaccine

BACKGROUND

Streptococcus pneumoniae, a common pathogen leading to pneumonia, is a cause of morbidity and mortality in immunosuppressed patients. Vaccination against this agent can be recommended for immunosuppressed patients, including those with chronic renal failure, nephrotic syndrome and renal transplant recipients; however, a diminished immune response and loss of protective antibodies have been observed.

PATIENTS AND METHODS

In our prospective study, the efficacy and side effects of polyvalent pneumococcal vaccination were investigated in renal transplant recipients. A total of 21 patients (6 female, 15 male) with well-functioning renal allografts, who had transplant surgery at least 2 months before, were included in the study. The patients were stratified according to the immunosuppressive protocol and 8 received double, while 13 received triple, immunosuppressive agents. After obtaining basal serum samples, all cases were vaccinated with the 0.5 mL intramuscular administration of polyvalent polysaccharide pneumococcal vaccine (Pneumo 23 Pasteur Merieux, lot No: K 1131).

RESULTS

Following a mean of 6 wk in all patients and also a mean of 12 wk in 12 patients, serum samples were again obtained to measure pneumococcal antibodies. Antibody titers following 6 and 12 wk of vaccination were significantly higher, as compared with basal values in all patients, except one. These titers did not show any statistically significant difference between double and triple therapies. There was no significant difference between the 12th and 6th wk postvaccination antibody titers. No systemic or local adverse effects were observed.

CONCLUSION

Pneumococcal vaccination is safe and effective in patients with well-functioning renal allografts, at least in the short term. This vaccination policy may be useful for preventing invasive pneumococcal disease in immunosuppressed patients.