Varicella vaccination in pediatric kidney transplant candidates

2013 IDSA clinical practice guideline for vaccination of the immunocompromised host

An international panel of experts prepared an evidenced-based guideline for vaccination of immunocompromised adults and children. These guidelines are intended for use by primary care and subspecialty providers who care for immunocompromised patients. Evidence was often limited. Areas that warrant future investigation are highlighted.

Reduced varicella-zoster-virus (VZV)-specific lymphocytes and IgG antibody avidity in solid organ transplant recipients

BACKGROUND

Varicella-zoster-virus (VZV) infection may cause significant morbidity and mortality in immunocompromised patients. So far, only IgG-anti-VZV antibody concentrations were used to estimate immunity against VZV, but the antibody binding strength (avidity) together with VZV-specific cellular responses have not been evaluated in solid organ transplant (SOT) recipients.

METHODS

Thus, we assessed the humoral and cellular immune responses to two doses of the VZV vaccine (vacc) and wild-type VZV infection (wt) in 23 kidney (KTx) and 19 liver transplant (LTx) recipients including children and adults compared to 48 healthy controls (HC) for measurement of IgG-anti-VZV relative avidity index (RAI) and frequency of VZV-specific peripheral blood mononuclear cells (PBMCs) in vaccinated individuals using an adapted ELISA and IFN-gamma ELISPOT, respectively.

RESULTS

KTx(wt) (median RAI 72.3%) or LTx(wt) (79.2%) and KTx(vacc) (91.0%) or LTx(vacc) (72.5%) showed lower avidities compared to HC(wt) (84.5%) and HC(vacc) (94.0%), respectively, despite equally distributed IgG-anti-VZV concentrations. RAI>60% (high avidity) was detected in all HC, but only in 69.0% of SOT patients. KTx(vacc) (median 64 spot forming units SFU/500,000 PBMCs) and LTx(vacc) (67 SFU) had significantly lower VZV-specific cellular responses compared to HC(vacc) (268 SFU).

CONCLUSIONS

The diminished cellular reactivity to VZV has to be considered in SOT patients receiving immunosuppressive treatments when evaluating immunity against VZV. IgG antibody avidity and VZV-specific cellular responses may serve as additional markers to evaluate immunity against VZV in SOT recipients. The role of wild-type exposures and endogenous VZV re-activation on long-term immunity in SOT patients has to be awaited to establish recommendations for vaccine spacing in these patients, considering immunogenicity and safety aspects.

Varicella zoster virus (VZV) and herpes simplex virus (HSV) in solid organ transplant patients

Varicella zoster virus (VZV) and the two herpes simplex viruses (HSV) are human α-herpesviruses that establish life-long latency in neural ganglia after initial primary infection. In the solid organ transplant (SOT) population, manifestations of VZV or HSV may be seen in up to 70% of recipients if no prophylaxis is used, some of them life and organ threatening. While there are effective vaccines to prevent VZV primary infection and reactivation in immunocompetent adults, these vaccines are contraindicated after SOT because they are live-virus vaccines. For HSV, prevention has focused primarily on antiviral strategies because the immunologic correlates of protection and control are different from VZV, making vaccine development more challenging. Current antiviral therapy remains effective for the majority of clinical VZV and HSV infections.

Varicella-zoster immunization in pediatric liver transplant recipients: safe and immunogenic

Varicella can have a severe course in immunosuppressed patients. Although prevention is fundamental, live-attenuated varicella-zoster (VZV) vaccine is not currently recommended in transplant recipients. Our aims were to (1) evaluate VZV immunity in pediatric liver transplant (LT) recipients; (2) immunize (two doses) seronegative patients post-LT; (3) monitor vaccine safety, (4) assess B and T cell vaccine responses. All patients followed at the Swiss National Pediatric LT Center were approached and 77/79 (97.5%) were enrolled (median age 7.8 years). Vaccine safety was monitored by standardized diary cards and phone calls. VZV-specific serology and CD4(+) T cells were assessed before and after immunization. Thirty-nine patients (51.1%) were seronegative including 14 children immunized pre-LT. Thirty-six of 39 seronegative patients were immunized post-LT (median 3.0 years post LT). Local (54.8%) and systemic (64.5%) reactions were mild and transient. The frequency of VZV-specific CD4(+) T cells and antibody titers increased significantly (respectively from 0.085% to 0.16%, p = 0.04 and 21.0 to 1134.5 IU/L, p < 0.001). All children reached seroprotective titers and 31/32 (97%) patients assessed remained seroprotected at follow-up (median 1.7 years). No breakthrough disease was reported during follow-up (median 4.1 years). Thereby, VZV vaccine appears to be safe, immunogenic and provide protection against disease in pediatric LT patients.

An update on immunizations before and after transplantation in the pediatric solid organ transplant recipient

Vaccination offers a unique opportunity to decrease the burden of infectious complications following solid organ transplantation. In this paper we review the current guidelines for routine immunizations before and after solid organ transplantation, including the recent updates and changes to recommendations for certain vaccines. We also address the issue of waning immunity in solid organ transplant recipients and discuss the current data on vaccinating this patient population with live vaccines after transplantation.

Nonneoplastic mucocutaneous lesions in organ transplant recipients

Nonneoplastic mucocutaneous lesions are frequent in organ transplant recipients. Many of them are caused by a direct toxicity of immunosuppressive drugs, in particular glucocorticoids and cyclosporine. The effects of these agents are dose- and time-dependent. Glucocorticoids can cause acne, Cushingoid appearance, irregular purpuric areas, friable skin, and wide and violaceous stripes. Cyclosporine can cause hypertrichosis, pilosebaceous lesions, and gum hypertrophy. Patients with esthetic changes may show poor adherence to treatment with these immunosuppressive agents that may lead to progressive graft dysfunction. Apart from this direct toxicity, vigorous immunosuppression may render the transplant recipients more susceptible to mucocutaneous infections. Fungal infection, viral warts, and bacterial folliculitis are the most frequent types of mucocutaneous infection. Some fungal infections, such as oral candidiasis and pityriasis versicolor, are relatively trivial, but other mycotic infections can cause severe or disfigurating lesions. Among viral infections, warts and condylomata caused by human papilloma virus are frequent and may favor the development of nonmelanoma skin cancer. Bacterial infections are usually trivial in the early period after transplantation, being represented almost exclusively by folliculitis. However, subcutaneous infections may cause a necrotizing fasciculitis which is a life-threatening disorder, usually sustained by polymicrobial pathogens.

Post-transplant infections: An ounce of prevention

Infections are the leading cause of hospitalization in transplant recipients. The increased risk of new onset diabetes after transplantation, cardiovascular disease, post-transplant lymphoproliferative disorders adversely affects allograft outcomes. Risk is determined by epidemiologic exposure, immunosuppressive therapy and prophylaxis. The predictable sequence of appearance of infections helps in making management decisions. High likelihood of infections with unusual and multiple organisms necessitates aggressive use of imaging techniques and invasive procedures. Serologic tests depend upon antibody response and are unreliable. Nucleic acid based assays are sensitive, rapid, and allow detection of subclinical infection and assessment of response to therapy. Preventive steps include screening of donors and recipients and vaccination. All indicated vaccines should be administered before transplantation. Inactivated vaccines can be administered after transplantation but produce weak and transient antibody response. Boosters may be required once antibody titers wane. Post-transplant chemoprophylaxis includes cotrimoxazole for preventing urinary tract infections, pneumocystis and Nocardia infections; ganciclovir, valganciclovir, or acyclovir for cytomegalovirus related complications in at-risk recipients; and lamivudine for prevention of progressive liver disease in HBsAg positive recipients. Viral load monitoring and pre-emptive treatment is used for BK virus infection. Infection with new organisms has recently been reported, mostly due to inadvertent transmission via the donor organ.

Varicella vaccination in pediatric kidney and liver transplantation

Reports about efficacy and safety of live-virus attenuated vaccines in patients before and after transplantation are mainly based on small patient numbers, making general recommendations for this patient population difficult. Children and adults as well as their close relatives and contact persons should be preferably immune to VZV before solid organ transplantation to avoid VZV-associated complications, thus making VZV vaccination necessary in susceptible individuals. The following literature review focused on efficacy and safety of VZV vaccination in pediatric kidney and liver transplant recipients. Review of literature also revealed that in all pediatric transplant candidates, humoral and cellular immunity against VZV should be consistently monitored to assess waning immunity under immunosuppressive treatment. This approach is desirable to estimate the risk of severe varicella disease after exposure in these patients.

Efficacy and safety of measles, mumps, rubella and varicella live viral vaccines in transplant recipients receiving immunosuppressive drugs

BACKGROUND

This review was designed to summarize published data on the efficacy and safety of live viral vaccines for measles, mumps, rubella, or varicella in post-transplant patients currently on immunosuppression.

DATA SOURCES

Medline, EMBASE and Evidence Based Medicine Reviews were searched from 1966 to November 2007 for case reports or studies describing the efficacy and/or safety of live attenuated measles, mumps, rubella, or varicella vaccine in children on immunosuppression following solid organ, bone marrow or stem cell transplantation.

RESULTS

The review identified 6 case series and 2 case reports describing 114 solid organ transplant recipients and one case series describing 27 bone marrow transplant recipients who had received a combined total of 206 doses of live varicella, measles, mumps, or rubella vaccine while on immunosuppression. Post-immunization titers were in the immune range in 109 of the 171 situations where they were measured following a single dose of vaccine (64%) and in 15 of 22 situations following 2 doses (68%). There were no major safety concerns in this small sample.

CONCLUSION

There are insufficient published data to derive evidence-based guidelines for use of live viral vaccines in transplant recipients on immunosuppression but preliminary data on efficacy and safety suggest that the use of these live viral vaccines in transplant recipients still on immunosuppression could be a reasonable strategy.

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.

Recurrent pancreatitis after renal transplantation in a child

A five-yr-old girl, who was a renal transplant recipient, presented with nausea, vomiting, epigastric discomfort, papules, and vesicles on her body. She was diagnosed with acute pancreatitis and varicella zoster infection because her serum amylase and lipase levels were positive. Fourteen months later, she was readmitted with nausea, vomiting, and epigastric pain similar to the previous symptoms and was diagnosed with acute pancreatitis. This case report indicates that acute pancreatitis can be one of a number of complications following pediatric renal transplantation and can recur because of various causes.

Avaliação da suscetibilidade à varicela no paciente pediátrico portador de insuficiência renal crônica

OBJETIVO: Avaliar a suscetibilidade natural à varicela de crianças e adolescentes portadores de insuficiência renal crônica (IRC). MÉTODOS: Estudo transversal de 83 pacientes com idade acima de 18 meses e inferior a 18 anos, durante 2000 e 2001, com ritmo de filtração glomerular (RFG) abaixo de 70mL/min/1,73m², portando cartão vacinal preconizado pela Fundação Nacional de Saúde e que não receberam nenhuma dose da vacina específica. Do total, três pacientes (3/83) foram excluídos, por terem recebido doses da vacina por meio de órgãos não governamentais. A sorologia foi realizada pelo método Enzyme-Linked Immuno Sorbent Assay, considerando-se títulos sorológicos protetores acima de 100mUA/mL. RESULTADOS: Os pacientes renais crônicos tinham idade mediana de 11 anos, 66% eram masculinos, 60% procedentes do próprio município de São Paulo, com RFG médio de 33,6mL/min/1,73m². O diagnóstico clínico de varicela por profissional médico ocorreu em 39 pacientes; destes, 10% se mostraram soronegativos. Dos 80 pacientes restantes, 21 (26%) apresentaram títulos não protetores para varicela. A prevalência de suscetibilidade em menores de seis anos foi 7,93 (IC95%=3,29-19,12) vezes superior à de maiores de seis anos. CONCLUSÕES: Houve diminuição da suscetibilidade à varicela com a idade. Pacientes abaixo de seis anos foram cerca de oito vezes mais suscetíveis à varicela que os renais crônicos com idade mais avançada e duas vezes mais suscetíveis do que a população pediátrica brasileira de mesma idade.

Kidney transplantation in children and adolescents

Worldwide, specific pediatric allocation schemes successfully try to minimize waiting time for children with end-stage renal disease (ESRD). The article is a review of current issues in pediatric kidney transplantation. The procedure is the treatment of choice for children and adolescents with ESRD, with 1- and 3-year graft survival rates of 95% and 90% and recipient survival after 5 and 10 years of 95% and 90%. Preoperative surgery is often necessary to minimize negative effects of congenital anomalies. No minimum age exists for pediatric transplantation, but most often the recipient body weight is ideally above 10 to 15 kg. Technical concepts should include extravesical anastomosis, stenting of the ureter, and potentially intraperitoneal placement of the graft. Immunosuppression has constantly improved. The aim is a tailored regimen to reduce side effects and improve compliance, which necessitates intense counseling of the child and the parents prior to, during, and after transplantation as many adolescents lose their graft due to noncompliance. Intense follow-up must also exclude infections, especially with herpes and polyoma viruses. For the future, age matching may be only one promising concept to improve results. As only a small number of children require the procedure in each country, multinational studies should be initiated to optimize outcomes in children and adolescents.

Live virus immunization after orthotopic liver transplantation

Viral infection is a recognized and potentially serious complication in children following solid organ transplantation. The risks of viral infection are particularly important for infants who may not have completed standard childhood immunizations at the time of transplantation and are therefore at risk for otherwise preventable infections. The general practice of withholding live virus immunization from transplant recipients has been questioned and several small studies have looked at MMR and/or Varivax administration in children following transplantation. This retrospective study analyzes the response to primary MMR and varicella immunization in selected pediatric liver transplant recipients in the largest such study to date. Nineteen of 26 children (73%) developed serologic immunity for measles following MMR (although 18 required multiple doses). Similarly, varicella immunization resulted in seroconversion in 20 of 31 children (64.5%; seven required multiple doses). Only minor adverse effects reported in the general population were observed. Live virus immunization with MMR and Varivax was safe and immunogenic in this selected population of liver transplant recipients.

Cutaneous adverse reactions following anti-infective vaccinations

Although widely administered, anti-infective vaccinations are rarely responsible for cutaneous adverse effects. In this context, hepatitis B and bacillus Calmette-Guerin vaccines are the most frequently incriminated products. Cutaneous adverse effects are less frequently encountered following administration of vaccines against varicella, diphtheria/tetanus/pertussis (primary and booster doses), measles, poliomyelitis, rubella, pneumococcus, tick-borne encephalitis, smallpox, Meningococcus and influenza. The adverse effects can occur at the site of or at a distance from the injection. The patho-mechanisms of local adverse cutaneous reactions include predominantly nonspecific lymphoid or granulomatous reactions. Allergic reactions to the vaccine strain, adjuvants, conservatives or other components are less frequently involved in local vaccine adverse effects. Systemic reactions are mainly mediated by immediate type or immune complex-related allergic reactions to toxoid-, ovalbumin-, gelatin- or pneumococcal-containing vaccines. Systemic reactions are sometimes related to a specific vaccine strain. Other cutaneous reactions may also occur through unknown patho-mechanisms. No vaccine type or strain is specifically associated with a particular type of cutaneous adverse effect. This article presents seven case reports of cutaneous adverse effects following anti-infective vaccination then reviews the relevant literature on this subject.

Loss of antibodies to measles and varicella following solid organ transplantation in children

The objective of this study was to determine if loss of antibodies to measles and to varicella occurs in pediatric solid organ transplant recipients. Antibodies were measured in eight hepatic, four cardiac, and six renal transplant patients who had antibodies to measles prior to transplantation, and in six hepatic, five cardiac, and seven renal transplant patients who had antibodies to varicella prior to transplantation. Within 6 months of the transplant, loss of antibodies occurred in four of 18 patients who were seropositive for measles prior to transplantation (22.2%) and in two of 18 patients who were seropositive for varicella prior to transplantation (11.1%). In conclusion, serology for measles and varicella should be considered annually following solid organ transplantation so that appropriate advice can be given to patients who have seroreverted.

Seroprevalence of antibodies against varicella-zoster virus and response to the varicella vaccine in pediatric renal transplant patients

The severity of varicella-zoster virus (VZV) in immunocompromised children, especially in those receiving renal transplants, is well known. However, the use of live attenuated virus vaccine in this population is controversial. This study aimed to: (i) assess the immunization status of pediatric renal transplant recipients at our center; (ii) determine the anti-VZV antibody titers in such patients; (iii) evaluate the response to VZV vaccine in seronegative children and in those who present low antibody titers (defined as <500 mAU/mL). Vaccinated children were monitored for adverse effects for 8 wk after vaccination. Fifty patients with a mean age of 13.7 yr (range, 3-17 yr) were enrolled. In 49, blood samples were collected and antibodies were screened using ELISA. Seropositivity to VZV was found in 43 (88%), and antibody titers were >/=500 mAU/mL in 37 (75.5%). Of the 12 children who were eligible for vaccination and had antibody titers <500 mAU/mL, one developed varicella before vaccination, two did not meet the inclusion criteria, and three parents refused the vaccination. In the six vaccinated children, there were no adverse reactions to the vaccine, and four (66.6%) responded with anti-VZV titers >/=500 mAU/mL 6-8 wk after vaccination. In conclusion, after renal transplantation, varicella vaccine is safe with a 66% rate of conversion to high antibody titers.

A review of the varicella vaccine in immunocompromised individuals

BACKGROUND

Individuals with underlying cell-mediated immunodeficiency disorders are at high risk of developing severe, life-threatening illness associated with varicella-zoster virus infection. A live-attenuated varicella vaccine is recommended for routine childhood immunisation in some countries. In healthy children, the vaccine is efficacious and safe but because immunocompromised individuals may be unable to limit replication of live-attenuated vaccine viruses, the varicella vaccine is not recommended for them and there are few exceptions.

OBJECTIVES

The purpose of this paper is to review the published studies addressing the use of the varicella vaccine in people with cell-mediated immunodeficiency disorders.

METHODS

A computerised search on the PubMed database was used to collect the relevant papers published up to March 2003.

RESULTS

The varicella vaccine has been extensively studied in susceptible children with acute lymphoblastic leukaemia in remission, but studies involving individuals with other immunodeficiency disorders are scarce. Some of the current recommendations are based on very few and small studies with short follow-up. Immunocompromised individuals should be given the varicella vaccine only with complete knowledge of their clinical and immunological conditions and after considering the risks of natural infection and vaccination.

A longitudinal study of children who received renal transplants 10-20 years ago

BACKGROUND

We have previously reported on our 10-year experience of renal transplantation in children in the cyclosporine era, that is, from December 1981 until December 1991. In this paper, we report on the same children observed for another 10 years.

METHODS

Of 53 children who received a renal transplant between 1981 and 1991, 47 survived and were observed for 10 to 20 years. Immunosuppression consisted of cyclosporine, prednisolone, and azathioprine. Yearly clinical examinations were performed.

RESULTS

Overall, actual patient survival is 91%, 89%, and 89%, and actual graft survival 85%, 77%, and 66% at 1, 5, and 10 years, respectively. No patients have died during the last 10 years. Twenty-six grafts were lost over 20 years. Thirteen of those were lost during the present follow-up (10-20 years): 11 in chronic rejection and 2 because of development of renal cell carcinoma. No other malignancies were noted. Mean glomerular filtration rate decreased from 58+/-19 at 1 year (n=42) to 44+/-16 mL/min/1.73 m2 body surface area at 10 (n=33) years. Hypertension was treated in 46%, 40%, and 66% of the children at 1, 5, and 10 years, respectively; two of them showed left ventricular hypertrophy 10 years after transplant. Minor cataracts without visual disturbance were found in 45% of patients. All children except three with mental retardation are, or have been, attending normal day care or normal school.

CONCLUSION

Social integration is good, and severe complications are scarce, even when renal transplantation occurred at a very young age.

[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.