Herpes simplex virus in solid organ transplantation

Risk of herpes simplex virus infection in solid organ transplant recipients: A population-based cross-sectional study

BACKGROUND

Herpes simplex virus (HSV) is an opportunistic infection antigen in solid organ transplant (SOT) recipients. However, this phenomenon has received limited attention from epidemiologists. Our study aims to determine the HSV infection risk in SOT recipients.

METHODS

This was a nationwide population-based cross-sectional study based on the National Health Insurance Research Database from 2002 to 2015. We used propensity score matching to avoid selection bias and analyzed the association between HSV infection and SOT recipients with multiple logistic regression analysis.

RESULTS

At a 3-year follow-up, SOT recipients had a higher risk of developing HSV, with an adjusted odds ratio (aOR) of 3.28 (95% confidence interval (CI), 2.51-4.29). Moreover, at 6-month, 1-year, and 2-year follow-ups, SOT recipients also had an increased risk of HSV than general patients with aORs of 3.85 (95% CI, 2.29-6.49), 4.27 (95% CI, 2.86-6.36), and 3.73 (95% CI, 2.74-5.08), respectively. In the subgroup analysis, lung transplant recipients (aOR = 8.01; 95% CI, 2.39-26.88) exhibited a significantly higher chance of HSV among SOT recipients, followed by kidney transplant recipients (aOR = 3.33; 95% CI, 2.11-5.25) and liver transplant recipients (aOR = 3.15; 95% CI, 2.28-4.34).

CONCLUSION

HSV can develop at any time after organ transplantation. SOT recipients had a higher risk of HSV infection than the general population at 6 months, 1 year, 2 years, and 3 years after transplantation, with the highest chance at 1 year after. In addition, the patients who underwent lung transplantion were at higher risk for HSV infection than liver or kidney transplant recipients.

Modulatory immune responses in fungal infection associated with organ transplant - advancements, management, and challenges

Organ transplantation stands as a pivotal achievement in modern medicine, offering hope to individuals with end-stage organ diseases. Advancements in immunology led to improved organ transplant survival through the development of immunosuppressants, but this heightened susceptibility to fungal infections with nonspecific symptoms in recipients. This review aims to establish an intricate balance between immune responses and fungal infections in organ transplant recipients. It explores the fundamental immune mechanisms, recent advances in immune response dynamics, and strategies for immune modulation, encompassing responses to fungal infections, immunomodulatory approaches, diagnostics, treatment challenges, and management. Early diagnosis of fungal infections in transplant patients is emphasized with the understanding that innate immune responses could potentially reduce immunosuppression and promise efficient and safe immuno-modulating treatments. Advances in fungal research and genetic influences on immune-fungal interactions are underscored, as well as the potential of single-cell technologies integrated with machine learning for biomarker discovery. This review provides a snapshot of the complex interplay between immune responses and fungal infections in organ transplantation and underscores key research directions.

Prediction of herpes virus infections after solid organ transplantation: a prospective study of immune function

Introduction

Herpes virus infections are a major concern after solid organ transplantation and linked to the immune function of the recipient. We aimed to determine the incidence of positive herpes virus (cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus type 1/2 (HSV-1/2), and varicella zoster virus (VZV)) PCR tests during the first year post-transplantation and assess whether a model including immune function pre-transplantation and three months post-transplantation could predict a subsequent positive herpes virus PCR.

Methods

All participants were preemptively screened for CMV, and EBV IgG-negative participants were screened for EBV during the first year post-transplantation. Herpes virus PCR tests for all included herpes viruses (CMV, EBV, HSV-1/2, and VZV) were retrieved from the Danish Microbiology database containing nationwide PCR results from both hospitals and outpatient clinics. Immune function was assessed by whole blood stimulation with A) LPS, B) R848, C) Poly I:C, and D) a blank control. Cytokine concentrations (TNF-α, IL-1β, IL-6, IL-8, IL-10, IL-12p40, IL-17A, IFN-α, and IFN-γ) were measured using Luminex.

Results

We included 123 liver (54%), kidney (26%), and lung (20%) transplant recipients. The cumulative incidence of positive herpes virus PCR tests was 36.6% (95% CI: 28.1-45.1) during the first year post-transplantation. The final prediction model included recipient age, type of transplantation, CMV serostatus, and change in Poly I:C-induced IL-12p40 from pre-transplantation to three months post-transplantation. The prediction model had an AUC of 77% (95% CI: 61-92). Risk scores were extracted from the prediction model, and the participants were divided into three risk groups. Participants with a risk score <5 (28% of the cohort), 5-10 (45% of the cohort), and >10 (27% of the cohort) had a cumulative incidence of having a positive herpes virus PCR test at 5.8%, 25%, and 73%, respectively (p < 0.001).

Conclusion

In conclusion, the incidence of positive herpes virus PCR tests was high, and a risk model including immune function allowed the prediction of positive herpes virus PCR and may be used to identify recipients at higher risk.

Hypertrophic Perianal Herpes Mimicking Squamous Cell Cancer: A Case Report and a Review of the Literature

Clinical practice frequently involves the discovery of perineal lesions. The human papillomavirus, molluscum contagiosum, and herpes simplex virus are to blame for the majority of these anogenital lesions. In the majority of cases, these lesions may be identified by their distinctive appearance. It is challenging to make a clinical diagnosis in immunocompromised people since these lesions might be large and have uncommon appearances. Verrucous perianal herpes is a rare type of herpes that resembles squamous cell carcinoma in gross appearance. We present a case of a 71-year-old man on azathioprine, an immunosuppressive drug for autoimmune pancreatitis, who developed a perianal lesion resembling squamous cell carcinoma. Excisional biopsy revealed a benign ulcerative lesion with herpetic inclusions. The patient received antiviral treatment, and the perianal wound completely healed. He developed a similar lesion in the perineum at one year follow up, which was successfully treated with oral and topical antivirals.

Cytomegalovirus and other herpesviruses after hematopoietic cell and solid organ transplantation: From antiviral drugs to virus-specific T cells

Herpesviruses can either cause primary infection or may get reactivated after both hematopoietic cell and solid organ transplantations. In general, viral infections increase post-transplant morbidity and mortality. Prophylactic, preemptive, or therapeutically administered antiviral drugs may be associated with serious side effects and may induce viral resistance. Virus-specific T cells represent a valuable addition to antiviral treatment, with high rates of response and minimal side effects. Even low numbers of virus-specific T cells manufactured by direct selection methods can reconstitute virus-specific immunity after transplantation and control viral replication. Virus-specific T cells belong to the advanced therapy medicinal products, and their production is regulated by appropriate legislation; also, strict safety regulations are required to minimize their side effects.

EYE DISEASE IN KIDNEY TRANSPLANTATION: CLINICAL CHALLENGES IN A UNIQUE PATIENT POPULATION

Eye disease is common among kidney transplant recipients and their management is challenging. Chronic kidney disease is associated with ocular complications, both independently and in the context of various systemic disorders. In addition, chronic immunosuppression predisposes kidney transplant recipients to an array of long-term ocular issues. This may be broadly categorized into infections, malignancies, and other immunosuppression-specific side effects. The interdependence of kidney disease, transplant pharmacotherapy and ocular health therefore requires a multispecialty approach. Although the kidney transplant population has grown along with the burden of associated oculopathies, systematic guidelines targeting this patient group are lacking. This evidenced-based narrative review summarizes the pertinent issues that may present in the ophthalmic and optometric clinical settings, with emphasis on collaborative management and directions for future research.

Alemtuzumab in Renal Retransplantation - Transplant Outcomes and Associated Infections

Renal retransplant patients have decreased graft survival compared with primary renal transplant patients. Alemtuzumab induction is often used at the time of retransplant; however, the literature surrounding alemtuzumab induction in renal retransplant patients is limited. In this single-center, retrospective, observational study, we aimed to determine the 1-year incidence of infections and transplant outcomes in renal retransplant patients who received alemtuzumab induction. Thirty-four patients who received alemtuzumab met inclusion criteria and were included in the final analysis. Twenty-two (64.7%) of these patients acquired infections. Of these, 7 patients (31.8%) acquired infections that resulted in hospitalization or intravenous antibiotics. The most common infections were urinary tract infections (n = 10; 29.4%), cytomegalovirus DNAemia (n = 7; 20.6%), and BK virus (n = 6; 17.6%). The use of steroid maintenance therapy after alemtuzumab induction did not increase the number of infections compared with patients with a steroid-free interval after alemtuzumab induction. The number of patients who developed de novo donor-specific antibodies (DSA) was 11 (32.4%) with only 1 of these patients having DSA before retransplantation. The incidence of acute cellular rejection was 2.9% (n = 1). There was no graft loss, and patient survival was 97% (n = 33). There were no significant differences in infection rate or DSA development between alemtuzumab and the other induction agents, antithymocyte globulin and basiliximab, among retransplanted patients. Alemtuzumab induction in renal retransplant patients resulted in similar bacterial and viral infection rates as previously reported in the literature and did not negatively impact graft and patient survival.

Routine testing for herpes simplex virus in bronchoalveolar lavage specimens is unwarranted

Herpes simplex virus (HSV) infections of the lung are rare, but HSV is occasionally detected in bronchoalveolar lavage (BAL) specimens. We assessed whether routinely performing HSV PCR tests in BAL specimens is warranted. HSV was detected in 7% (52/722) of BALs. In 47% of HSV-positive patients a typical respiratory virus or pathologic microorganism was identified. Oral HSV reactivation was identified in 27%; however, anti-HSV therapy was initiated in just three patients following the positive HSV test. Patients undergoing BAL for transplant surveillance received anti-HSV prophylaxis more often than those with acute respiratory failure, but both groups did not differ significantly in terms of patient outcome or co-infections. No patient was diagnosed with HSV pneumonia. These findings suggest that positive HSV PCR results in BAL specimens most commonly represents contamination from oral HSV reactivation, and that HSV PCR should be ordered selectively, rather than routinely, as part of a test panel.

Beyond Cytomegalovirus and Epstein-Barr Virus: a Review of Viruses Composing the Blood Virome of Solid Organ Transplant and Hematopoietic Stem Cell Transplant Recipients

Viral primary infections and reactivations are common complications in patients after solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) and are associated with high morbidity and mortality. Among these patients, viral infections are frequently associated with viremia. Beyond the usual well-known viruses that are part of the routine clinical management of transplant recipients, numerous other viral signatures or genomes can be identified in the blood of these patients. The identification of novel viral species and variants by metagenomic next-generation sequencing has opened up a new field of investigation and new paradigms. Thus, there is a need to thoroughly describe the state of knowledge in this field with a review of all viral infections that should be scrutinized in high-risk populations. Here, we review the eukaryotic DNA and RNA viruses identified in blood, plasma, or serum samples of pediatric and adult SOT/HSCT recipients and the prevalence of their detection, with a particular focus on recently identified viruses and those for which their potential association with disease remains to be investigated, such as members of the Polyomaviridae, Anelloviridae, Flaviviridae, and Astroviridae families. Current knowledge of the clinical significance of these viral infections with associated viremia among transplant recipients is also discussed. To ensure a comprehensive description in these two populations, individuals described as healthy (mostly blood donors) are considered for comparative purposes. The list of viruses that should be on the clinicians' radar is certainly incomplete and will expand, but the challenge is to identify those of possible clinical significance.

Post liver transplant recurrent and de novo viral infections

Survival following liver transplantation has changed dramatically owing to improvement in surgical techniques, peri-operative care and optimal immunosuppressive therapy. Post-Liver transplant (LT) de novo or recurrent viral infection continues to cause major allograft dysfunction, leading to poor graft and patient survival in untreated patients. Availability of highly effective antiviral drugs has significantly improved post-LT survival. Patients transplanted for chronic hepatitis B infection should receive life-long nucleos(t)ide analogues, with or without HBIg for effective viral control. Patients with chronic hepatitis C should be commenced on directly acting antiviral (DAA) drugs prior to transplantation. DAA therapy for post-LT recurrent hepatitis C infection is associated with close to 100% sustained virological response (SVR), irrespective of genotype. De novo chronic Hepatitis E infection is an increasingly recognised cause of allograft dysfunction in LT recipients. Untreated chronic HEV infection of the graft may lead to liver fibrosis and allograft failure. CMV and EBV can reactivate leading to systemic illness following liver transplantation. With COVID-19 pandemic, post-transplant patients are at risk of SARS-Co-V2 infection. Majority of the LT recipients require hospitalization, and the mortality in this population is around 20%. Early recognition of allograft dysfunction and identification of viral aetiology is essential in the management of post-LT de novo or recurrent infections. Optimising immunosuppression is an important step in reducing the severity of allograft damage in the treatment of post-transplant viral infections. Viral clearance or control can be achieved by early initiation of high potency antiviral therapy.

Infection prophylaxis and management of viral infection

Viral infections are associated with significant morbidity and mortality in lung transplant recipients. Importantly, several viral infections have been associated with the development of chronic lung allograft dysfunction (CLAD). Community-acquired respiratory viruses (CARV) such as influenza and respiratory syncytial virus (RSV), are frequently associated with acute and chronic rejection. Cytomegalovirus (CMV) remains a significant burden in regards to morbidity and mortality in lung transplant recipients. Epstein-Barr virus (EBV) is mostly involved with the development of post-transplant lymphoproliferative disorder (PTLD), a lymphoid proliferation that occurs in the setting of immunosuppression. On the other hand, the development of direct acting antivirals for hepatitis C virus (HCV) is changing the use of HCV-positive organs in transplantation. In this article we will focus on reviewing common viral infections that have a significant impact on lung transplant recipients looking at epidemiology, prevention and potential treatment.

Varicella Zoster Virus Vasculopathy

Varicella zoster virus (VZV) is a ubiquitous, exclusively human alphaherpesvirus that produces varicella then becomes latent in ganglionic neurons. In elderly and immunocompromised individuals, VZV reactivates and typically produces herpes zoster. Studies of patients with VZV vasculopathy have identified key clinical, imaging, and laboratory features to assist in diagnosis and treatment. Complementary studies have further expanded the spectrum of VZV vasculopathy to include the extracranial circulation and identified mechanisms contributing to its pathogenesis. Given our increasing aging population and recognition that VZV reactivation manifesting as zoster is a risk factor for stroke and myocardial infarction, recognition of VZV as a potential cause of vascular disease with or without associated zoster rash is essential to decrease associated morbidity and mortality because VZV vasculopathy can be treated with antiviral therapy.

Unusual oral presentation of HSV-1 lesions in an adult liver transplant recipient

Herpes Simplex Virus (HSV) hepatitis in liver transplant patients is a rarely reported infective complication of HSV with severe consequences, often leading to fulminant hepatitis if left untreated. The clinical signs are often atypical, leading to under-reporting in the literature and potential delays in treatment. Our case report describes such atypical mucocutaneous lesions in a liver transplant recipient. We highlight the need for further reports, especially those with images, in order to aid the diagnosis of HSV infection, and to allow prompt treatment to prevent complications such as HSV hepatitis.

Management of Infection in Patients With Kidney Transplant

With the pervasive nature of chronic kidney disease, kidney transplantation is likely to continue to increase in the coming years. There are many infectious risks related to kidney transplant, including reactivation of latent infections, surgical complications, infectious risks related to immunosuppression, and nosocomial and community-acquired infections. These are described classically via timeline with early infections (first month), middle (1 to 6 months), and late (after 6 months). Kidney transplant patients may suffer from infections secondary to a vast array of organisms, including bacteria, fungi, and viruses. Certain infections, particularly viral infections such as cytomegalovirus, Epstein-Barr virus, and BK virus, may portend acute and chronic implications of the infection and its subsequent impact on graft function. Critical care physicians and nephrologists caring for patients with a renal transplant must understand the broad array of possible infections, atypical presentations, and nuanced implications for appropriate evaluation and subsequent therapy, combined with the need for possible prophylaxis and/or suppression. Multidisciplinary teams, including transplant physicians and infectious diseases physicians, are encouraged strongly.

Oral shedding of HSV-1 and EBV and oral manifestations in paediatric chronic kidney disease patients and renal transplant recipients

OBJECTIVE

Previous research demonstrated that salivary shedding of HSV-1 and EBV occurs often in adult renal transplant recipients, but there is a lack of studies on the presence of them in the saliva of paediatric population. Therefore, the objective of this study is to describe oral characteristics and to compare the shedding profile of HSV-1 and EBV in the saliva of children with renal transplant to that of chronic kidney disease patients and controls.

METHODS

This is a cross-sectional study involving 100 children, being 25 renal transplant recipients, 25 chronic kidney disease patients and 50 healthy children. Demographic and oral clinical characteristics were assessed. Saliva samples were collected and submitted to screening for EBV and HSV-1 by using nested polymerase chain reaction technique. Fisher's exact, Pearson's chi-square and Kruskal-Wallis tests were used for statistical analysis at a significance level of 5%.

RESULTS

Oral shedding of HSV-1 (28%) and EBV (60%) were significantly higher in renal transplant recipients compared to the other groups. Single vesicles in the oral mucosa were statistically associated with the presence of HSV-1 (p = .035). In children with chronic kidney disease, there was a higher prevalence of pale oral mucosa (32%) and enamel hypoplasia (40%) compared to paediatric renal transplant recipients and controls. Dental calculus (36%), candidiasis (8%), drug-induced gingival overgrowth (16%), mouth blisters (8%), xerostomia (12%) and salivary gland enlargement (20%) were more common in paediatric renal transplant recipients.

CONCLUSIONS

Therefore, it can be concluded that salivary shedding of HSV-1 and EBV in paediatric patients was more often found in renal transplant recipients than in the renal failure and control children. Transplanted recipients showed more oral manifestations than renal failure and control children did.

"For your eyes only": ophthalmic complications following lung transplantation

Ophthalmic complications in the lung transplant population are a little-known entity. It includes a spectrum of diseases ranging from infections such as cytomegalovirus (CMV) retinitis, herpetic keratitis, Pseudallescheria boydii to non-infectious complications such as posterior subcapsular cataracts (PSCs), cyclosporine retinopathy, and post-transplant lymphoproliferative disorder (PTLD). These diseases can be attributed to high levels of immunosuppression, advanced age, and drug-specific side effects. Underlying comorbidities such as diabetes mellitus may also play a role in the pathogenesis. Patients can present with varied symptoms such as blurry vision, floaters or eye pain. Prompt diagnosis often requires a high index of suspicion. With increasing numbers of transplants being performed worldwide, it is imperative for the pulmonologist and transplant physician to recognize these often subtle symptoms. Any visual symptom should trigger an ophthalmological evaluation in order to manage these complications; some of which pose the risk of systemic dissemination and significant morbidity. The following article provides an in-depth review of the common presenting symptoms, treatments and recent advances related to common ophthalmic complications following lung transplantation. While this article focuses on the lung transplant sub-population, the authors would like to point out that some of these complications are shared by other solid-organ transplants as well, by virtue of their shared immunosuppressive therapies.

Antiviral efficacy of the helicase-primase inhibitor amenamevir in murine models of severe herpesvirus infection

Existing treatments have limited efficacy against severe infection associated with herpes simplex virus (HSV) and herpes zoster virus (VZV), particularly in immunocompromized patients and those with multidermatomal infection. This issue, along with issues regarding drug resistance, support the need for improved therapeutic options. To investigate the antiviral effect of amenamevir, a VZV and HSV helicase-primase inhibitor, in severe infection conditions, mouse models of severe HSV-1 infection were developed by immunosuppression or multidermatomal infection. Mice with cyclosporin-induced immunosuppression and HSV-1 infection via inoculation of a dorsolateral area of skin were orally treated with amenamevir (10-100 mg/kg/day) for different durations (2-5 days). Immunosuppressed mice maintained high skin HSV-1 titers in the absence of treatment. Amenamevir successfully reduced HSV-1 titers at all tested doses in immunosuppressed mice, but required a longer treatment period to avoid a rebound in viral titers due to immunosuppression. To compare the efficacy of amenamevir and valacyclovir, a murine model of multidermatomal HSV-1 infection was generated by scarifying the dorsolateral area of skin in a line and inoculating broadly with HSV-1. The mice were treated with amenamevir or valacyclovir starting on Day 3, 4, or 5 post-infection for 5 days. Although both drugs similarly reduced disease scores when treatment was started on Day 3, amenamevir also reduced disease severity when treatment was initiated on Day 4, whereas valacyclovir did not. Amenamevir was not affected by the host's immune status in terms of effective oral doses and was more efficacious in treating severe cutaneous infection even when treatment initiation was delayed.

Active-site mTOR inhibitors augment HSV1-dICP0 infection in cancer cells via dysregulated eIF4E/4E-BP axis

Herpes Simplex Virus 1 (HSV1) is amongst the most clinically advanced oncolytic virus platforms. However, efficient and sustained viral replication within tumours is limiting. Rapamycin can stimulate HSV1 replication in cancer cells, but active-site dual mTORC1 and mTORC2 (mammalian target of rapamycin complex 1 and 2) inhibitors (asTORi) were shown to suppress the virus in normal cells. Surprisingly, using the infected cell protein 0 (ICP0)-deleted HSV1 (HSV1-dICP0), we found that asTORi markedly augment infection in cancer cells and a mouse mammary cancer xenograft. Mechanistically, asTORi repressed mRNA translation in normal cells, resulting in defective antiviral response but also inhibition of HSV1-dICP0 replication. asTORi also reduced antiviral response in cancer cells, however in contrast to normal cells, transformed cells and cells transduced to elevate the expression of eukaryotic initiation factor 4E (eIF4E) or to silence the repressors eIF4E binding proteins (4E-BPs), selectively maintained HSV1-dICP0 protein synthesis during asTORi treatment, ultimately supporting increased viral replication. Our data show that altered eIF4E/4E-BPs expression can act to promote HSV1-dICP0 infection under prolonged mTOR inhibition. Thus, pharmacoviral combination of asTORi and HSV1 can target cancer cells displaying dysregulated eIF4E/4E-BPs axis.

Dysregulated mRNA translation occurs frequently in tumours due to elevated eIF4E expression or a hyperactive mTOR complex 1 (mTORC1) signaling pathway that results in the inactivation of the eIF4E binding proteins (4E-BPs). Targeting the mTORC1/4E-BPs/eIF4E axis is a promising strategy in cancer therapies and for preventing resistance to treatment. Enhanced mTORC1 activity also drives innate immune responses by modulating protein expression of antiviral genes. It was previously shown that the mTORC1 inhibitor rapamycin limits antiviral responses and promotes replication of oncolytic viruses within tumour tissues. Active-site dual mTORC1 and mTORC2 inhibitors (asTORi) have been developed for superior mTOR inhibition and anti-cancer potency but have not been studied in the context of oncolytic viral infection. We show here that prolonged treatment with asTORi strongly augments infection of HSV1-dICP0 in cancer cells, but not in normal cells, an effect modulated via eIF4E/4E-BP expression. Thus, cancer cells with dysregulated translation could be amenable to the pharmacoviral combination of HSV1 and asTORi treatment.

Anti-infective chemoprophylaxis after solid-organ transplantation

INTRODUCTION

Solid organ transplant (SOT) recipients are at high risk of opportunistic infections due to bacterial, viral, fungal, and parasitic pathogens. Anti-infective prophylaxis is a time-tested proven strategy for the prevention of these infections after SOT. Areas covered: The current recommendations for the prevention of surgical site infections, herpes simplex, cytomegalovirus, invasive fungal infections, and selected parasitic diseases are highlighted. Recent peer-reviewed publications on the prevention of infection after SOT were reviewed and their significance was discussed in the context of the current recommendations for preventing infectious complications. Expert commentary: The authors comment on the current approaches to infection prevention in transplant recipients, and discuss how these recommendations are implemented in their clinical practice. Notable findings published during the past year were highlighted, and their clinical significance was interpreted in the context of current recommendations. The evolution of diagnostic and immunologic assays was emphasized, with focus on their potential role in optimizing the current antimicrobial approaches to infection prevention after SOT.

Respiratory Viruses and Other Relevant Viral Infections in the Lung Transplant Recipient

As advances occur in surgical technique, postoperative care, and immunosuppressive therapy, the rate of mortality in the early postoperative period following lung transplantation continues to decline. With the improvements in immediate and early posttransplant mortality, infections and their sequel as well as rejection and chronic allograft dysfunction are increasingly a major cause of posttransplant mortality. This chapter will focus on infections by respiratory viruses and other viral infections relevant to lung transplantation, including data regarding the link between viral infections and allograft dysfunction.

α Herpes Virus Infections Among Renal Transplant Recipients

The α herpes viruses HSV-1, HSV-2, and VZV often reactivate in the setting of immune suppression after solid organ transplantation. Oral or genital mucocutaneous disease is the most common clinical manifestation of HSV disease while VZV manifests as varicella (or chickenpox) or reactivation herpes zoster, characterized by a diffuse rash, or a painful unilateral vesicular eruption in a dermatomal distribution, respectively. The diagnosis of HSV and VZV is primarily based on history and clinical presentation, although diagnostic tests may be necessary for atypical presentations of disease. Treatment usually involves oral or intravenous antiviral therapy, depending on severity of illness.

Preventive Strategies Against Cytomegalovirus and Incidence of α-Herpesvirus Infections in Solid Organ Transplant Recipients: A Nationwide Cohort Study

We assessed the impact of antiviral preventive strategies on the incidence of herpes simplex virus (HSV) and varicella-zoster virus (VZV) infections in a nationwide cohort of transplant recipients. Risk factors for the development of HSV or VZV infection were assessed by Cox proportional hazards regression. We included 2781 patients (56% kidney, 20% liver, 10% lung, 7.3% heart, 6.7% others). Overall, 1264 (45%) patients received antiviral prophylaxis (ganciclovir or valganciclovir, n = 1145; acyclovir or valacyclovir, n = 138). Incidence of HSV and VZV infections was 28.9 and 12.1 cases, respectively, per 1000 person-years. Incidence of HSV and VZV infections at 1 year after transplant was 4.6% (95% confidence interval [CI] 3.5-5.8) in patients receiving antiviral prophylaxis versus 12.3% (95% CI 10.7-14) in patients without prophylaxis; this was observed particularly for HSV infections (3% [95% CI 2.2-4] versus 9.8% [95% CI 8.4-11.4], respectively). A lower rate of HSV and VZV infections was also seen in donor or recipient cytomegalovirus-positive patients receiving ganciclovir or valganciclovir prophylaxis compared with a preemptive approach. Female sex (hazard ratio [HR] 1.663, p = 0.001), HSV seropositivity (HR 5.198, p < 0.001), previous episodes of rejection (HR 1.95, p = 0.004), and use of a preemptive approach (HR 2.841, p = 0.017) were significantly associated with a higher risk of HSV infection. Although HSV and VZV infections were common after transplantation, antiviral prophylaxis significantly reduced symptomatic HSV infections.

Infection in Organ Transplantation

The prevention, diagnosis, and management of infectious disease in transplantation are major contributors to improved outcomes in organ transplantation. The risk of serious infections in organ recipients is determined by interactions between the patient's epidemiological exposures and net state of immune suppression. In organ recipients, there is a significant incidence of drug toxicity and a propensity for drug interactions with immunosuppressive agents used to maintain graft function. Thus, every effort must be made to establish specific microbiologic diagnoses to optimize therapy. A timeline can be created to develop a differential diagnosis of infection in transplantation based on common patterns of infectious exposures, immunosuppressive management, and antimicrobial prophylaxis. Application of quantitative molecular microbial assays and advanced antimicrobial therapies have advanced care. Pathogen-specific immunity, genetic polymorphisms in immune responses, and dynamic interactions between the microbiome and the risk of infection are beginning to be explored. The role of infection in the stimulation of alloimmune responses awaits further definition. Major hurdles include the shifting worldwide epidemiology of infections, increasing antimicrobial resistance, suboptimal assays for the microbiologic screening of organ donors, and virus-associated malignancies. Transplant infectious disease remains a key to the clinical and scientific investigation of organ transplantation.

Varicella zoster virus vasculopathy: The expanding clinical spectrum and pathogenesis

Varicella zoster virus (VZV) is a ubiquitous, human alphaherpesvirus that produces varicella on primary infection then becomes latent in ganglionic neurons along the entire neuraxis. In elderly and immunocompromised individuals, VZV reactivates and travels along nerve fibers peripherally resulting in zoster. However, VZV can also spread centrally and infect cerebral and extracranial arteries (VZV vasculopathy) to produce transient ischemic attacks, stroke, aneurysm, sinus thrombosis and giant cell arteritis, as well as granulomatous aortitis. The mechanisms of virus-induced pathological vascular remodeling are not fully elucidated; however, recent studies suggest that inflammation and dysregulation of programmed death ligand-1 play a significant role.

Hemorrhagic Herpes Simplex Virus Type 1 Nephritis: An Unusual Cause of Acute Allograft Dysfunction

Interstitial nephritis due to viruses is well-described after solid organ transplantation. Viruses implicated include cytomegalovirus; BK polyomavirus; Epstein-Barr virus; and, less commonly, adenovirus. We describe a rare case of hemorrhagic allograft nephritis due to herpes simplex virus type 1 at 10 days after living donor kidney transplantation. The patient had a favorable outcome with intravenous acyclovir and reduction of immunosuppression.

Treatment of alpha and beta herpesvirus infections in solid organ transplant recipients

INTRODUCTION

Human herpesviruses frequently cause infections in solid organ transplant (SOT) recipients. Areas covered: We provide an overview of the clinical impact of alpha and beta herpesviruses and highlight the mechanisms of action, pharmacokinetics, clinical indications, and adverse effects of antiviral drugs for the management of herpes simplex virus, varicella zoster virus and cytomegalovirus. We comprehensively evaluated key clinical trials that led to drug approval, and served as the foundation for management guidelines. We further provide an update on investigational antiviral agents for alpha and beta herpesvirus infections after SOT. Expert commentary: The therapeutic armamentarium for herpes infections is limited by the emergence of drug resistance. There have been major efforts for discovery of new drugs against these viruses, but the results of early-phase clinical trials have been less than encouraging. We believe, however, that more antiviral drug options are needed given the adverse side effects associated with current antiviral agents, and the emergence of drug-resistant virus populations in SOT recipients. Likewise, optimized use and strategies are needed for existing and novel antiviral drugs against alpha and beta-herpesviruses in SOT recipients.

Central nervous system syndromes in solid organ transplant recipients

Solid organ transplant recipients have a high incidence of central nervous system (CNS) complications, including both focal and diffuse neurologic deficits. In the immunocompromised host, the initial clinical evaluation must focus on both life-threatening CNS infections and vascular or anatomic lesions. The clinical signs and symptoms of CNS processes are modified by the immunosuppression required to prevent graft rejection. In this population, these etiologies often coexist with drug toxicities and metabolic abnormalities that complicate the development of a specific approach to clinical management. This review assesses the multiple risk factors for CNS processes in solid organ transplant recipients and establishes a timeline to assist in the evaluation and management of these complex patients.