Response to varicella immunization in pediatric liver transplant recipients

Low post-transplant measles and varicella titers among pediatric liver transplant recipients: A 10-year single-center study

BACKGROUND

Vaccine preventable illnesses are important sources of morbidity, mortality, and increased healthcare costs in pediatric LT recipients. Our aim was to measure the seroprevalence of antibodies to measles and VZV in this population.

METHODS

We conducted a retrospective chart review of 44 patients who received LT before age 18 at UCLA Mattel Children's Hospital from January 2008 to December 2017.

RESULTS

Median age at transplantation was 2.5 years (IQR 1.2-7.7). Post-transplant measles antibodies were present in 17 of 37 patients (46%); risk factors for seronegativity included younger age at transplant (p = .02) and greater time from transplant to testing (p = .04). Post-transplant VZV antibodies were present in 17 of 39 patients (44%); risk factors for seronegativity included greater time from transplant to testing (p = .04). 6 of 16 patients (38%) who tested positive for pre-transplant VZV antibodies tested negative after transplantation. Fourteen of 20 patients (70%) with at least 1 documented dose of the MMR vaccine tested positive for post-transplant measles antibodies. Ten of 20 of patients (50%) with at least 1 documented dose of the VZV vaccine tested positive for post-transplant VZV antibodies. We also describe 10 patients who received post-transplant measles and VZV vaccines without documented complications.

CONCLUSIONS

Our study suggests that pediatric LT patients are at greater risk of contracting measles and VZV despite vaccination status, and that prevalence of measles and VZV antibodies decreases as time from transplantation increases. This should weigh into the institutional risk-benefit assessment when deciding whether or not to administer LAVs to these patients.

Long-Term Varicella Zoster Virus Immunity in Paediatric Liver Transplant Patients Can Be Achieved by Booster Vaccinations—A Single-Centre, Retrospective, Observational Analysis

Varicella is one of the most common vaccine-preventable infections after paediatric solid organ transplantation; thus, vaccination offers simple and cheap protection. However, children with liver disease often progress to liver transplantation (LT) before they reach the recommended vaccination age. As a live vaccine, varicella zoster virus (VZV) vaccination after transplantation is controversial; however, many case series demonstrate that vaccination may be safe and effective in paediatric liver transplant recipients. Only limited data exists describing long-term vaccination response in such immunocompromised patients. We investigated retrospectively vaccination response in paediatric patients before and after transplantation and describe long-term immunity over ten years, including the influence of booster-vaccinations. In this retrospective, single-centre study, 458 LT recipients were analysed between September 2004 and June 2021. Of these, 53 were re-transplantations. Patients with no available vaccination records and with a history of post-transplant lymphoproliferative disease, after hematopoietic stem cell transplantation and clinical chickenpox were excluded from this analysis (n = 198). In total, data on 207 children with a median annual follow-up of 6.2 years was available: 95 patients (45.9%) were unvaccinated prior to LT. Compared to healthy children, the response to vaccination, measured by seroconversion, is weaker in children with liver disease: almost 70% after one vaccination and 93% after two vaccinations. One year after transplantation, the mean titres and the number of children with protective antibody levels (VZV IgG ≥ 50 IU/L) decreased from 77.5% to 41.3%. Neither diagnosis, gender, nor age were predictors of vaccination response. Booster-vaccination was recommended for children after seroreversion using annual titre measurements and led to a significant increase in mean titre and number of protected children. Response to vaccination shows no difference from monotherapy with a calcineurin inhibitor to intensified immunosuppression by adding prednisolone or mycophenolate mofetil. Children with liver disease show weaker seroconversion rates to VZV vaccination compared to healthy children. Therefore, VZV-naïve children should receive basic immunization with two vaccine doses as well as those vaccinated only once before transplantation. An average of 2–3 vaccine doses are required in order to achieve a long-term seroconversion and protective antibody levels in 95% of children.

Immunogenicity of varicella zoster vaccine in pediatric liver transplantation

BACKGROUND

Pediatric liver transplant (LT) candidates often miss complete varicella-zoster virus (VZV) vaccination before LT. We aimed to evaluate the immunogenicity of two doses of VZV vaccines in pediatric LT candidates younger than 2 years and persistence of its immunogenicity after LT.

METHODS

Patients aged 9-24 months were enrolled before LT. The first dose of VZV vaccine was given at 9 months, and the second dose was given at between 1 to 3 months later, and at least 4 weeks before LT. Varicella-zoster IgG (VZG) was used to detect immunoglobulin G antibodies to VZV and was reported as a test value (TV). A test value ≥ 0.9 was considered as seropositive. TV was measured at enrollment, 1 month after the first and the second dose of VZV vaccine, before LT, and 3 and 6 months after LT.

RESULTS

Fourteen children were enrolled in this prospective cohort study. The median age at the first and the second dose of VZV vaccine was 11.5 months (IQR 9-12) and 13 months (IQR 12-33), respectively. The seroconversion rate was 66.7% (8/12) and 70% (7/10) after the first and second VZV vaccine doses, respectively. Seven of nine patients who underwent LT had two doses of VZV vaccine. Six patients were seropositive before LT, which persisted at 3 to 6 months after LT. Of two patients who received only one dose, TV was not detected after LT.

CONCLUSIONS

The two doses of VZV vaccine appeared to be more immunogenic than one dose in pediatric LT candidates aged less than 2 years.

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.

Vaccines in pediatric transplant recipients-Past, present, and future

Infections significantly impact outcomes for solid organ and hematopoietic stem cell transplantation in children. Vaccine-preventable diseases contribute to morbidity and mortality in both early and late posttransplant time periods. Several infectious diseases and transplantation societies have published recommendations and guidelines that address immunization in adult and pediatric transplant recipients. In many cases, pediatric-specific studies are limited in size or quality, leading to recommendations being based on adult data or mixed adult-pediatric studies. We therefore review the current state of evidence for selected immunizations in pediatric transplant recipients and highlight areas for future investigation. Specific attention is given to studies that enrolled only children.

Immunization practices among pediatric transplant hepatologists

Vaccination of pediatric liver transplant candidates and recipients represents an opportunity to decrease infectious complications following transplant. Although vaccine recommendations exist, studies have shown that many transplant candidates and recipients are under-immunized. The goals of this study were to assess among pediatric transplant hepatologists: (i) current immunization practices before and after transplantation, (ii) involvement of an ID physician in the transplant evaluation, and (iii) perceptions about vaccine safety and barriers to immunization. An 80-item e-mail survey of pediatric transplant hepatologists at centers in the United States and Canada participating in the SPLIT consortium was conducted from December 2014 to March 2015. The overall response rate was 80% (73/91), representing 97% (32/33) of SPLIT centers. Fifty percent of programs routinely involved an ID physician in the transplant evaluation. Administration of palivizumab was routinely considered by 48% of hepatologists pre-transplant and by 41% post-transplant. Live vaccines were recommended by 26% of hepatologists after transplant. About 10% of hepatologists reported concern that live vaccines after transplant could induce rejection. There is wide variation in immunization practices among transplant hepatologists. Specific evidence-based protocols are needed to guide immunization practices in transplant candidates and recipients.

Serostatus following live attenuated vaccination administered before pediatric liver transplantation

After liver transplantation (LT), live attenuated vaccines (LAVs) are generally contraindicated. LAVs are recommended before LT for patients ≥ 6 months of age. However, the evidence supporting this practice is limited. Patients were enrolled before and after LT. Clinical data for patients were obtained from medical records. Serum antibody titers were evaluated at the time of enrollment and prospectively. Serum antibody titers were measured with a hemagglutination inhibition test for measles and rubella and with an enzyme-linked immunosorbent assay for varicella and mumps. Univariate and multivariate analyses were performed to investigate the factors that affect the serostatus. Serological analyses of 49 patients immunized before LT (median age, 45 months; male, 35%) were performed. Underlying diseases were biliary atresia (n = 27; 55%), metabolic diseases (n = 13; 27%), fulminant hepatic failure (n = 5; 10%), and others (n = 4; 8%). The seropositivity rate after each vaccine was 46.9% (measles), 89.4% (rubella), 67.5% (varicella), and 48.8% (mumps). Factors independently associated with seronegativity were a vaccination age < 12 months for measles (P = .002), a lower body weight for varicella (P = 0.01), and underlying diseases other than biliary atresia for mumps (P = .004). No serious adverse event was observed during the study period. The immunogenicity of LAVs before LT was high for rubella but low for the others. Before LT, further vaccination strategies are needed for patients. In addition, serological follow-up may be indicated for patients with factors associated with seronegativity.

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 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.

Health maintenance in the inflammatory bowel disease patient

Gastroenterologists are in a unique position to make very positive differences in the lives of their IBD patients. We understand that IBD patients do not receive preventive services at the same rate as general medical patients. Because these individuals are at increased risk for complications from preventable diseases, we have a valuable opportunity to protect this population (Table 1). Establishing a close working relationship with PCPs can facilitate delivering quality care, but it is important to note that some of these patients rely solely on their GI clinician for the majority of their care. In such a vulnerable population, it is important to be aggressive with vaccine recommendations, monitoring for depression, tobacco cessation, and in performing the appropriate cancer screening examinations. As professional societies and health care system increase their focus on quality measures, incorporating these important issues into routine practice will ultimately result in addressing quality standards; perhaps more important, it should provide our patients with the best individual care possible.

Aciclovir and varicella-zoster-immunoglobulin in solid-organ transplant recipients

Clear recommendations for the management of acute varicella-zoster virus (VZV) infections for cases of significant exposure and the use of prophylactic drugs after solid-organ transplantation are missing due to the lack of evidence by prospective studies. Heterogeneity in patient groups, patient numbers, age groups, immunosuppressive regimens, timing, and dosage of aciclovir and/or varicella-zoster immunoglobulin (VZIG), pre-transplant vaccination or VZV wild-type infection and inconsistency of data make comparability of different studies impossible. Although the benefit of aciclovir and/or VZIG is uncertain in immunosuppressed children, prospective controlled double-blind studies are not feasible for ethical considerations as fatal cases with disseminating varicella disease are well known in these patient groups despite the use of aciclovir and/or VZIG, whereas severe side-effects of these drugs are rare. However, a reporting bias is likely as mainly severe or fatal cases might have been predominantly published or cases of successfully used aciclovir and/or VZIG in mild cases or in cases of breakthrough infections after vaccination. As neither VZIG prophylaxis nor treatment with intravenous aciclovir offers complete protection against severe VZV infection to immunosuppressed pediatric solid-organ transplant recipients, high priority should be given to vaccination against VZV prior to transplantation, and, most importantly, in their close contact persons. Clinical observations suggest that only assessment of humoral immunity together with cellular immunity may allow predication about protection in exposed patients.

A practical guide to vaccinating the inflammatory bowel disease patient

The increasing use of corticosteroids, immune modulators, and biologics as a mainstay of therapy in certain Crohn's disease and ulcerative colitis patients have placed these inflammatory bowel disease (IBD) patients at increased risk for a variety of infections, many of which are preventable by prior vaccination. This article provides a review of the issues surrounding immunizations in the IBD patient and a practical guide for clinicians regarding the appropriate vaccinations to administer both before and during immunosuppressive therapy.

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.

Sustainability of humoral responses to varicella vaccine in pediatric transplant recipients following a pretransplantation immunization strategy

Varicella infections pose serious challenges for organ transplant recipients. To determine the safety and immunogenicity of the OMVV and determine the maintenance of OMVV responses in transplanted subjects at varying periods of immunosuppression within the first two yr following transplantation. Eligible subjects given a two-dose OMVV pretransplantation were monitored for AE. Antibody levels were assessed at baseline, six wk post-OMVV, pretransplantation and up to 24 months post-transplantation. Seroprotection was defined as >or=5 gpEU. Twenty-one seronegative children were vaccinated. Following 42 doses, no vaccine-related serious AE occurred. Mab_titer were 17.8 (5.7-910.2) and 183.5 EU (18.8-8116.4) at six and 12 wk, respectively (p < 0.0001). Fourteen (66.7%) participants were transplanted at a median of 16 months (1.5-56) following OMVV and had Mab_titer of 27.2 EU (9.0-236.2) just prior to transplantation. Of 11 who had post-transplantation serology, seroprotection was sustained at three, six and 12 months post-transplantation in 10/11, 12/12 and 8/10 subjects. In five of six subjects with two-yr follow-up, antibody levels remained seroprotective. No breakthrough varicella infections occurred. The receipt of OMVV prior to transplantation induced humoral responses which persisted in the early months following transplantation and up to two yr post-transplantation and was not associated with any serious adverse consequences.

Effective and safe immunizations with live-attenuated vaccines for children after living donor liver transplantation

Immunizations using live-attenuated vaccines are not recommended for post-liver transplant children due to its theoretical risks. However, they will encounter vaccine-preventable viral diseases upon returning to real-life situations. We performed a total of 70 immunizations with four individual live-attenuated vaccines to 18 pediatric post-living donor liver transplant (LDLT) recipients who fulfilled a clinical criteria including humoral and cell-mediated immunity. The seroconversion rates at the first dose for measles (strain AIK-C), rubella (strain TO-336), varicella (strain Oka), and mumps (strains Hoshino) were 100% (15/15), 100% (15/15), 82% (9/11), and 82% (9/11), respectively. During observed period (-5 years 11 months), a few cases with waning immunity (antibodies were once produced but the levels fell over time) were seen except after rubella immunization. Clinical diseases after seroconversion or definite serious adverse effects due to immunization were not observed. Immunizations using selected live-attenuated vaccines were safe and effective for post-LDLT children who were not severely immunosuppressed.

Safety of live-virus vaccines for children with immune deficiency

PURPOSE

Conduct an integrative literature review to evaluate the safety and effectiveness of live-virus vaccines, namely, the measles, mumps, rubella, and varicella vaccines, in children who are immune compromised by exogenous medication either posttransplant or while undergoing maintenance chemotherapy for leukemia.

DATA SOURCES

Medline, MedlinePlus, EBSCO, PubMed, MD Consult, CINAHL, Clinical Pharmacology, ERIC, Biomedical Reference Collection-Basic, Health Source-Consumer Edition, Health Source-Nursing/Academic Edition, Ovid, CANCERLIT, and the Cochrane Library Online.

CONCLUSIONS

Because measles infection has a low incidence rate in the United States, it may be advisable not to vaccinate children who are immunocompromised and risk side effects of the vaccine. In contrast to measles infection, varicella has a higher incidence rate and poses a more imminent threat to those who are immunocompromised. Children who are immunosuppressed can receive the varicella vaccination; however, they should have regular titers drawn to confirm adequate protection against the disease and should receive boosters as deemed appropriate.

IMPLICATIONS FOR PRACTICE

The number of solid organ transplant recipients is steadily increasing with more than 600,000 solid organ transplantations worldwide since the first renal transplant in 1954. The steadily increasing numbers of pediatric patients surviving transplantation, coupled with increased life expectancy, accelerate the need for nurse practitioners to understand the management of these delicate patients following release from the transplant unit.

Patients with inflammatory bowel disease are at risk for vaccine-preventable illnesses

BACKGROUND

Patients with chronic, immune-mediated conditions such as inflammatory bowel disease (IBD) are often treated with long-term immunosuppressive therapies, potentially increasing their risk of developing an infection. Empiric data suggest that vaccines are underutilized in immunocompromised patients, despite published guidelines recommending their use. We aimed to assess exposure risk and immunization status among patients receiving care in an IBD specialty clinic.

METHODS

Patients completed a self-administered, pretested, structured questionnaire during a routine visit for the management of IBD. Survey questions related to medical and immunization histories, and exposures to known risk factors for influenza, pneumococcus, viral hepatitis, and varicella. Additionally, in a subgroup of patients who agreed to donate a sample of blood, immune status to hepatitis A (HAV), hepatitis B (HBV), and varicella was determined.

RESULTS

Two hundred four patients were asked to participate in the study; 169 completed surveys and comprised the study population. Mean age was 35 yr (range 13-75 yr). One hundred forty-six respondents (86%) reported current or prior use of immunosuppressive medications. Only 45% of respondents recalled tetanus immunization within the past 10 yr, 41 (28%) reported regularly receiving flu shots, and 13 (9%) reported having received pneumococcal vaccine. The most common reasons for nonimmunization with influenza included lack of awareness (49%) and concern for side effects (18%). Responses indicated that 75 (44%) patients were at risk for HBV but only 47 (28%) had been vaccinated against the infection; of patients with previous HBV vaccination, only three of nine (33%) had measurable antibodies against hepatitis B surface antigen.

CONCLUSIONS

Immunization against selected vaccine-preventable illnesses was uncommon in patients with IBD, despite the presence of significant risk factors. Efforts to improve immunization status among patients with IBD and other chronic, immune-mediated conditions are needed.

Viral infections affecting the skin in organ transplant recipients: epidemiology and current management strategies

Viral skin infections are common findings in organ transplant recipients. The most important etiological agents are the group of human herpesviruses (HHV), human papillomaviruses (HPV), and molluscum contagiosum virus. HHV that are important in this group of patients are herpes simplex virus (HSV) types 1 and 2, varicella-zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), HHV-6 and -7, and HHV-8, which causes Kaposi sarcoma (KS). HSV infections are characterized by their ability to establish latency and then reactivate at a later date. The most common manifestations of HSV infection in organ transplant recipients are mucocutaneous lesions of the oropharynx or genital regions. Treatment is usually with acyclovir, valaciclovir, or famciclovir. Acyclovir resistance may arise although the majority of acyclovir-resistant strains have been isolated from AIDS patients and not organ transplant recipients. In such cases, alternatives such as foscarnet, cidofovir, or trifluridine may have to be considered. VZV causes chickenpox as well as herpes zoster. In organ transplant recipients, recurrent herpes zoster can occur. Acute chickenpox in organ transplant patients should be treated with intravenous acyclovir. CMV infection occurs in 20-60% of all transplant recipients. Cutaneous manifestations, which include nonspecific macular rashes, ulcers, purpuric eruptions, and vesiculobullous lesions, are seen in 10-20% of patients with systemic infection and signify a poor prognosis. The present gold standard for treatment is ganciclovir, but newer drugs such as valganciclovir appear promising. EBV is responsible for some cases of post-transplant lymphoproliferative disorder, which represents the greatest risk of serious EBV disease in transplant recipients. HHV-6 and HHV-7 are two relatively newly discovered viruses and, at present, the body of information concerning these two agents is still fairly limited. KS is caused by HHV-8, which is the most recently discovered lymphotrophic HHV. Iatrogenic KS is seen in solid-organ transplant recipients, with a prevalence of 0.5-5% depending on the patient's country of origin. HPV is ubiquitous, and organ transplant recipients may never totally clear HPV infections, which are the most frequently recurring infections in renal transplant recipients. HPV infection in transplant recipients is important because of its link to the development of certain skin cancers, in particular, squamous cell carcinoma. Regular surveillance, sun avoidance, and patient education are important aspects of the management strategy.

Safety and immunogenicity of varicella-zoster virus vaccine in pediatric liver and intestine transplant recipients

Primary varicella-zoster virus (VZV) infections following organ transplantation may cause significant morbidity. We examined the safety and immunogenicity of Varivax after transplantation as a potential prophylactic tool. Pediatric liver and intestine transplant recipients without history of chickenpox received one dose of Varivax. VZV humoral and cellular immunity were assessed before and > or =12 weeks after vaccination. Adverse events (AE) and management of exposure to wild type VZV were monitored. Sixteen VZV-naïve subjects, 13-76 months of age, at 257-2045 days after transplantation were immunized. Five children developed mild local AE of short duration. Four subjects developed fever and four developed non-injection site rashes, three of whom received acyclovir. Liver enzymes did not increase during the month after vaccination. Eighty-seven percent and 86% of children developed humoral and cellular immunity, respectively. There were five reported exposures to varicella in four children, none of which resulted in chickenpox. One subject received VZV-immunoglobulin and another subject with liver enzyme elevations after exposure received acyclovir; all remained asymptomatic. Varivax was safe and immunogenic in pediatric liver and intestine transplant recipients. Larger studies are needed to establish the efficacy and role of varicella vaccination after transplantation.

Specific autologous cytotoxic T lymphocytes for chronic varicella in a liver transplanted child

Infections by herpesviruses may have severe complications in liver transplant patients. Although prophylactic varicella zoster virus vaccination is strongly recommended and widely applied, severe infection may still occur. We report the case of systemic chronic varicella, which developed in a liver allograft recipient, unresponsive to antiviral drug treatment, successfully treated by varicella zooster-specific CTL. Graft failure ensued, likely, because of massive cytolysis of infected hepatocytes. The patient, who was re-transplanted in the absence of signs of varicella zooster reactivation, is now well and disease free 3 yr after second liver transplant.

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.

Chicken pox after pediatric liver transplantation

Previous case series have reported serious complications of chicken pox (CP) after pediatric liver transplantation (PLT), mainly due to visceral dissemination. The goal of our study was to determine the incidence, risk factors, and outcomes of CP after PLT. A case-control study of all CP infections in pediatric transplant recipients followed at our center from September 1993 to April 2004 was performed. Data were collected before and after infection and at the same time points in age-, gender-, and transplant year-matched controls. Potential risk factors prior to CP and adverse outcomes after infection were compared between cases and controls. Twenty (6.2%) developed CP at a median of 1.8 yr (0.6-4.8) after PLT. All CP infections were cutaneous, with no evidence of organ involvement. Twelve were hospitalized: 9 only to receive intravenous acyclovir and 3 stayed > or =2 weeks for other complications. Risk factors were not statistically different among cases and controls. Of the outcomes analyzed, cases were significantly more likely to develop non-CP infections within one year of CP than controls (Hazard Ratio = 12.6, 95% confidence interval = 3.1-51.7; P < 0.001). These infections were often bacterial and occurred long after CP infection. In conclusion, CP is uncommon after PLT and has a low likelihood of organ dissemination. No risk factors were identified. Some cases required prolonged hospitalizations. Close monitoring for the development of late bacterial infections is warranted.

[Immunisation against varicella]

Two vaccines against varicella are now being licensed in France, both deriving from the Oka strain. Seroconversion has been obtained in almost 100% of the cases after one dose in toddlers and children, and two doses in adolescents and adults. Efficacy has been mainly established from the US experience, where a universal immunisation programme of children aged > 12 months with a catch-up for susceptible adolescents and adults was begun in 1995. The incidence of varicella has decreased by about 85% over all age groups. The safety of the vaccine is good, and most adverse events are represented by fever, reactions at the injection site and varicella-like rashes. For the time being, France has adopted restrictive recommendations for the use of this vaccine because of uncertainties with respect to the duration of protection, a shift of the disease towards older age and the potential increase of the incidence of herpes-zoster.

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.

Health Status Ten Years After Pediatric Liver Transplantation—Looking Beyond The Graft

BACKGROUND

Little is known about long-term health after pediatric orthotopic liver transplantation (OLT). This study aimed to characterize the health status of recipients 10 years after OLT, with an emphasis on transplant-related morbidity and quality of life.

METHODS

We performed a retrospective database review of 32 children who underwent OLT before October 1992 at one center and were alive after 10 years. Outcome measures were assessed 10 years after OLT. Cantril's self-anchoring scale was used for global quality of life assessment.

RESULTS

Synthetic liver function at 10 years was preserved in all patients. The annual rate of episodes of acute rejection dropped markedly after the first year (1.4 at year 1 to 0.19 rejections/patient/year at year 10). Histologically confirmed chronic rejection developed in eight (25%) patients. At 10 years, long-term complications included mild to severe chronic renal failure (77%), mild chronic anemia (59%), and hypertension (25%). Significant growth retardation (z-score < -2), hyperlipidemia, and diabetes were uncommon. Infection requiring hospitalization occurred in 81% of the patients, with varicella zoster virus as the most common pathogen. Epstein-Barr virus-related malignancies affected 22% of patients. Ten-year survivors perceived quality of life as very good. Self-reporting of drug nonadherence by seven (22%) adolescents may have contributed to development of late onset rejection in this subgroup. Conclusions. Children who are 10-year survivors of OLT have excellent graft function and, despite chronic extrahepatic morbidities, a self-reported high quality of life.

[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.

Pediatric Liver Transplantation

Pediatric liver transplantation is a fast-growing and challenging field. Healthcare providers must stay informed of advancements in the management of liver transplant candidates and recipients. The goal of this paper is to provide nurses who care for pediatric liver transplant candidates and recipients with a review of the basic medical management of these patients, from the preoperative evaluation to postoperative care.

Recent advances in pediatric liver transplantation

Pediatric liver transplantation has matured into a well-established, highly successful treatment for advanced pediatric liver disease. Recent 1-year success rates range from 85% to 95%. This unprecedented achievement is the result of careful selection criteria and optimal timing of transplantation, technical advances in surgical technique, and improved treatment following transplant. This report highlights many recent published findings representing advances that have led to current successful approaches.