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

Current Perspectives on the Management of Herpesvirus Infections in Solid Organ Transplant Recipients

Solid organ transplant recipients (SOTRs) are at high risk of human herpesvirus (HHV)-related morbidity and mortality due to the use of immunosuppressive therapy. We aim to increase awareness and understanding of HHV disease burden in SOTRs by providing an overview of current prevention and management strategies as described in the literature and guidelines. We discuss challenges in both prevention and treatment as well as future perspectives.

Varicella zoster virus in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the American Society of Transplantation Infectious Diseases Community of Practice review the diagnosis, prevention, and management of varicella zoster virus (VZV) in the pre- and post-transplant period. Primary varicella is an uncommon complication post-solid-organ transplant (SOT), except among pediatric transplant patients and those seronegative for VZV. As the majority of SOT recipients are seropositive for VZV, herpes zoster (HZ) occurs frequently following SOT, particularly among recipients who are older (≥65 years of age) and those receiving more intensive immunosuppression. Transplant providers should aware of the increased risk for HZ-related complications such as dissemination, organ-specific involvement, and post-herpetic neuralgia. Treatment for localized zoster is primarily given as oral regimens, but those with more complicated presentations or those at risk for dissemination should be treated initially with IV therapy. Available antiviral prophylaxis regimens and vaccination strategies for varicella and HZ among these immunosuppressed patients remain a mainstay for prevention in the pre-and post-transplant periods. Finally, we discuss important approaches to addressing post-exposure prophylaxis and infection control practices for those SOT patients with documented VZV infections.

Long-term study showed that vaccination protected paediatric renal transplant recipients from life-threatening varicella zoster virus

AIM

Renal transplant patients are particularly susceptible to highly contagious diseases due to their reduced immunity. We studied transplant recipients to gauge their varicella zoster virus (VZV) serology status over time and the outcome of any VZV infections.

METHOD

This retrospective study comprised 85 children who underwent renal transplants in Gothenburg, Sweden, from 1986 to 2014, at a mean age of eight (1-18) years. The children's medical records were reviewed and 47 had the VZV infection pre-transplant and 38 had been vaccinated pre-transplant. Clinical outcomes were available for 85 children and serology results for 72.

RESULTS

At transplantation, the VZV seropositivity rate was 50% in the vaccination group and 94% in the infection group and the antibody titres were significantly lower in the vaccination group (p = 0.031). During the median follow-up period of five years post-transplant, 28% of the vaccinated children and 97% of the infection group remained seropositive and the varicella infection affected eight children: one in the infection group and seven in the vaccination group. The herpes zoster was observed in two children in the infection group.

CONCLUSION

This study demonstrated that VZV vaccination protected from symptomatic infections to a lesser extent than natural infection, but provided effective protection from life-threatening disease.

Herpes Zoster and Immunogenicity and Safety of Zoster Vaccines in Transplant Patients: A Narrative Review of the Literature

This narrative review focuses on the herpes zoster (HZ) and its prevention in transplant patients. Varicella zoster virus (VZV) is highly contagious and distributed worldwide in humans. Primary VZV infection usually causes varicella and then establishes a lifelong latency in dorsal root ganglia. Reactivation of VZV leads to HZ and related complications such as postherpetic neuralgia. Age and decreased immunity against VZV are important risk factors for developing HZ. Transplant patients are at increased risk for developing HZ and related complications due to their immunocompromised status and the need for lifetime immunosuppression. Diagnosis of HZ in transplant patients is often clinically difficult, and VZV-specific antibodies should be determined by serologic testing to document prior exposure to VZV during their pre-transplant evaluation process. Although antiviral agents are available, vaccination should be recommended for preventing HZ in transplant patients considering their complicated condition and weak organ function. Currently, there are two licensed HZ vaccines, of which one is a live-attenuated vaccine and the other is a HZ subunit vaccine. Both vaccines have shown promising safety and efficacy in transplants patients and especially the subunit vaccine could be administered post-transplant since this vaccine does not contain any live virus. Larger studies are needed about safety and immunogenicity of HZ vaccines in transplant populations, and extra efforts are needed to increase vaccine usage according to guidelines.

Idiopathic nephrotic syndrome in children

The incidence of idiopathic nephrotic syndrome (NS) is 1·15-16·9 per 100 000 children, varying by ethnicity and region. The cause remains unknown but the pathogenesis of idiopathic NS is thought to involve immune dysregulation, systemic circulating factors, or inherited structural abnormalities of the podocyte. Genetic risk is more commonly described among children with steroid-resistant disease. The mainstay of therapy is prednisone for the vast majority of patients who are steroid responsive; however, the disease can run a frequently relapsing course, necessitating the need for alternative immunosuppressive agents. Infection and venous thromboembolism are the main complications of NS with also increased risk of acute kidney injury. Prognosis in terms of long-term kidney outcome overall is excellent for steroid-responsive disease, and steroid resistance is an important determinant of future risk of chronic or end-stage kidney disease.

Dermatological Complications After Solid Organ Transplantation

Organ transplant recipients (OTRs) are a population at high risk for cutaneous adverse events. Their early recognition and appropriate treatment is an important component of the clinical management of OTRs and should be optimally dealt with by dermatologists working in the context of a transplant dermatology clinic. Skin examination should be a standard procedure before performing organ transplantation to assess conditions which may be difficult to manage after the transplant procedure has been performed or which may represent a contraindication to transplantation, e.g., malignant melanoma. It also offers an opportunity to educate patients on skin care after organ transplantation. Skin infections can occur at any time after organ transplantation and include viral, bacterial, and fungal opportunistic infections. The risk of reactivation of latent viruses, such as varicella-zoster virus (VZV) and cytomegalovirus (CMV), is high. Bacterial infections are frequent and may be caused by unusual agents such Actinomyces, Mycobacteria, Legionella, or Nocardia. A large spectrum of fungal infections may occur, ranging from superficial (e.g., dermatophytes) to deeper and more severe ones (Alternaria, Aspergillus, Cryptococcus, Histoplasma). Drug-related idiosyncratic reactions usually occur early after the introduction of the causative drug, e.g., hypersensitivity reaction to azathioprine. On the long-term run, cutaneous effects due to cumulative drug toxicity, e.g., sebaceous hyperplasia from cyclosporine, may appear. Rare immunologically driven inflammatory reactions may occur in OTRs such as GVH or autoimmune disease. Tumors are particularly frequent. Kaposi's sarcoma, associated with persistent human herpes virus 8 (HHV8) infection, and cutaneous anaplastic large-cell lymphoma (ALCL) occur early after transplantation. Other cancers, such as nonmelanoma skin cancer (NMSCs), associated with persistent human papillomavirus (HPV) infections, malignant melanoma, Merkel cell carcinoma, or adnexal tumors, manifest later with an incidence which is much higher than observed in the general population. The incidence increases further after a first NMSC occurs.

Vaccine-Preventable Diseases Requiring Hospitalization

BACKGROUND

Plain children often have lower immunization rates than non-Plain children. Penn State Health Children's Hospital is a tertiary medical center with large nearby Plain (Amish and Mennonite) communities. We sought to describe the characteristics of children hospitalized with vaccine-preventable diseases (VPDs). We hypothesized that Amish children would have a higher risk of VPDs than non-Amish children.

METHODS

International Classification of Diseases, Ninth Revision codes were used to identify patients <18 years diagnosed with a VPD from January 1, 2005, to December 31, 2015, at Penn State Children's Hospital. Demographic information, immunization status, and outcomes were obtained from medical records. By using the number of children in our primary service area, we calculated the risk of VPD requiring hospitalization for Amish and non-Amish children. We assessed the relationship between Plain affiliation and vaccination status by using the Pearson correlation coefficient.

RESULTS

There were 215 children with 221 VPDs. Most occurred in non-Plain children: 179 of 221 (81%). Except for pneumococcal infections, VPD occurred mostly in unvaccinated or immunocompromised children, regardless of Plain affiliation. There were 15 Haemophilus influenzae type b and 5 tetanus infections that occurred in children with an unvaccinated or unknown vaccination status. The risk of a VPD requiring hospitalization was greater for Amish than for non-Plain children (risk ratio: 2.67 [95% confidence interval: 1.87-3.82]). There was a strong correlation between Plain affiliation and lack of vaccination (r = -0.63, P < .01).

CONCLUSIONS

Amish children had an increased risk of a VPD requiring hospitalization than non-Plain children. With the exception of those with pneumococcal disease, most vaccinated children hospitalized with a VPD were immunocompromised.

Use of intravenous immunoglobulin in a disseminated varicella infection in an immunocompromised child

Varicella-zoster virus infection can lead to severe illness in immunocompromised patients. Further the mortality rate of disseminated varicella infection is extremely high particularly in immunocompromised children. We report a case of disseminated varicella infection in a child with acute lymphoblastic leukemia who was receiving chemotherapy, but was initially admitted with only for acute abdominal pain. The patient rapidly developed severe complications, including acute respiratory distress syndrome, acute hepatitis, disseminated intravascular coagulation, and encephalopathy. Acyclovir is a highly potent inhibitor of varicella-zoster virus infection. However, owing to rapid disease progression, it might not be sufficient to control a disseminated varicella infection, especially in immunocompromised patients. Immunoglobulin neutralize virus invasion and suppress viremia, acting synergistically with acyclovir. In this case, early administration of acyclovir and a high-dose of immunoglobulin, combined with mechanical respiratory support, proved adequate for treatment of this severe illness.

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.

Risk of infection and prevention in pediatric patients with IBD: ESPGHAN IBD Porto Group commentary

Combined immunosuppression by immunomodulators and biological therapy has become standard in the medical management of moderate-to-severe inflammatory bowel disease (IBD) because of clearly demonstrated efficacy. Clinical studies, registries, and case reports warn of the increased risk of infections, particularly opportunistic infections; however, already in the steroid monotherapy era, patients are at risk because it is accepted that a patient should be considered immunosuppressed when receiving a daily dose of 20 mg of prednisone for 2 weeks. Prescriptions increasingly involve azathioprine, methotrexate, and various biological agents. The TREAT registry evaluated safety in >6000 adult patients, half of them treated with infliximab (IFX) for about 1.9 years. IFX-treated patients had an increased risk of infections and this was associated with disease severity and concomitant prednisone use. The REACH study, evaluating the efficacy of IFX in children with moderate-to-severe Crohn disease, refractory to immunomodulatory treatment, reports serious infections as the major adverse events and their frequency is higher with shorter treatment intervals. The combination of immunosuppressive medications is a risk factor for opportunistic infections. Exhaustive guidelines on prophylaxis, diagnosis, and management of opportunistic infections in adult patients with IBD have been published by a European Crohn's and Colitis Organization working group, including clear evidence-based statements. We have reviewed the literature on infections in pediatric IBD as well as the European Crohn's and Colitis Organization guidelines to present a commentary on infection prophylaxis for the pediatric age group.