Approach to infection and disease due to adenoviruses in solid organ transplantation

In vitro assessment of the anti-adenoviral activity of artemisinin and its derivatives

Adenoviral infections, particularly in children, remain a significant public health issue with no approved targeted treatments. Artemisinin and its derivatives, well-known for their use in malaria treatment, have shown antiviral activities in recent studies. However, their efficacy against human adenovirus (HAdV) remains unexplored. This study aimed to assess the activity of artemisinin and its derivatives against HAdV infection in vitro using cell lines and primary cells. Our data revealed that artemisinin exhibited dose-dependent anti-HAdV activity with no apparent cytotoxicity over a wide concentration range. Mechanistically, artemisinin did not affect viral attachment or entry into target cells, nor the viral genome entry into cell nucleus. Instead, it inhibited HAdV through suppression of viral DNA replication. Comparative analysis with its derivatives, artesunate and artemisone, showed distinct cytotoxicity and anti-adenoviral profiles, with artemisone showing superior efficacy and lower toxicity. Further validation using a primary airway epithelial cell model confirmed the anti-adenoviral activity of both artemisinin and artemisone against different virus strains. Together, our findings suggest that artemisinin and its derivatives may be promising candidates for anti-HAdV treatment.

Approach for defining human adenovirus infection and disease for central review adjudication in clinical studies

BACKGROUND

Pediatric allogeneic hematopoietic cell transplant (allo-HCT) recipients are at risk for morbidity and mortality from human adenovirus (HAdV). HAdV can be detected in an asymptomatic state, referred to as infection or with signs or symptoms of illness, referred to as disease. Standardized case definitions are needed to distinguish infection from disease and allow for consistent reporting in both observational cohort studies and therapeutic clinical trials.

METHODS

A working group of experts in virology, transplant infectious disease, and HCT was assembled to develop HAdV infection and disease definitions with the degree of certainty (i.e., possible, probable, and proven). Definitions were further refined through an iterative process and independently applied by two central review committees (CRCs) to 20 pediatric allo-HCT recipients with at least one HAdV-positive PCR.

RESULTS

Initial HAdV infection and disease definitions were developed and updated through an iterative process after reviewing clinical and virological details for 81 subjects with at least one positive HAdV PCR detected in a clinical specimen. Independent application of final definitions to 20 HAdV positive allo-HCT recipients by two CRCs yielded similar number of HAdV infection or disease events but with variation of degree of certainty for some events.

CONCLUSIONS

Application of definitions by a CRC for a study of HAdV infection and disease is feasible and can provide consistency in the assignment of outcomes. Definitions need further refinement to improve reproducibility and to provide guidance on determining clinical improvement or worsening after initial diagnosis of HAdV infection or disease.

A quick algorithmic review on management of viral infectious diseases in pediatric solid organ transplant recipients

Pediatric solid organ transplant is a life-saving procedure for children with end-stage organ failure. Viral infections are a common complication following pediatric solid organ transplantation (SOT), which can lead to increased morbidity and mortality. Pediatric solid organ transplant recipients are at an increased risk of viral infections due to their immunosuppressed state. The most commonly encountered viruses include cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV), varicella-zoster virus (VZV), adenoviruses, and BK polyomavirus. Prevention strategies include vaccination prior to transplantation, post-transplant prophylaxis with antiviral agents, and preemptive therapy. Treatment options vary depending on the virus and may include antiviral therapy and sometimes immunosuppression modification. This review provides a Quick Algorithmic overview of prevention and treatment strategies for viral infectious diseases in pediatric solid organ transplant recipient.

Adenovirus-Associated Acute Interstitial Nephritis With Graft Survival and Novel Follow-Up Biopsy Findings Including Karyomegaly: A Case Series

Adenoviral infections in post-transplant patients have been described in multiple organ systems, most classically the lung, liver, and alimentary tract. In the genitourinary tract, hemorrhagic cystitis is most frequently observed. Clinically apparent renal involvement with adenovirus is rare, and adenovirus-associated interstitial nephritis (AAIN) is an uncommon cause of renal allograft failure. Here, we present three cases of AAIN in patients who, after prompt diagnosis and treatment adjustment, experienced a return of allograft function. All patients were on standard triple therapy with tacrolimus levels within the target range at the time of biopsy. None of the patients had respiratory symptoms, and despite diarrhea, colon biopsies were negative. Only case one had positive adenovirus serology (IgG only) and case three had positive urine; two patients had leukopenia without neutropenia. Renal biopsies showed a characteristic granulomatous tubulocentric mixed lymphocytic and neutrophilic infiltrate. Adenovirus immunohistochemistry (IHC) showed strong staining in the tubular epithelium (nuclear and cytoplasmic) while staining for polyomavirus was negative. A follow-up biopsy two months after the diagnosis of AAIN in one patient revealed persistent cytopathic effects with negative adenoviral IHC staining while a biopsy at one year in another patient showed glomerular and tubulointerstitial scarring. AAIN is an uncommon but important etiology to consider in cases of acute renal allograft dysfunction. Although the presenting symptoms for AAIN are nonspecific, hematuria is frequently noted. Adenovirus IHC should be considered in cases with granulomatous inflammation associated with necrosis and mixed inflammatory infiltrate. As demonstrated in this single-institution case series, prompt diagnosis can result in the preservation of the renal allograft. Lasting cytopathic effects after adenoviral infection should also be considered in patients with a history, or potential history, of AAIN.

A Nomogram Based on Comorbidities and Infection Location to Predict 30 Days Mortality of Immunocompromised Patients in ICU: A Retrospective Cohort Study

Background

The existing comorbidity indexes, like Charlson Comorbidity Index (CCI) and the Elixhauser Comorbidity Index (ECI), do not take infection factors into account for critically ill patients with immunocompromise, bringing about a decrease of prediction accuracy. Therefore, we attempted to incorporate infection location into the analysis to construct a rapid comorbidity scoring system independent of laboratory tests.

Methods

Data were extracted from the Multiparameter Intelligent Monitoring in Intensive Care III database. A total of 3904 critically ill patients with immunocompromise admitted to ICU were enrolled and assigned into training or validation sets according to the date of ICU admission. The predictive nomogram was constructed in the training set based on logistic regression analysis and then undergone validation in the validation set in comparison with SOFA, CCI and ECI.

Results

Factors eligible for the nomogram included patient’s age, gender, ethnicity, underlying disease of immunocompromise like metastatic cancer and leukemia, possible infection on admission including pulmonary infection, urinary tract infection and blood infection, and one comorbidity, coagulopathy. The nomogram we developed exhibited better discrimination than SOFA, CCI and ECI with an area under the receiver operating characteristic curve (AUC) of 0.739 (95% CI 0.707–0.771) and 0.746 (95% CI 0.713–0.779) in the training and validation sets, respectively. Combining the nomogram and SOFA could bring a new prediction model with a superior predictive effect in both sets (training set AUC = 0.803 95% CI 0.777–0.828, validation set AUC = 0.818 95% CI 0.783–0.854). The calibration curve exhibited coherence between the nomogram and ideal observation for two cohorts (p>0.05). Decision curve analysis revealed the clinical usefulness of the nomogram in both sets.

Conclusion

We established a nomogram that could provide an accurate assessment of 30 days ICU mortality in critically ill patients with immunocompromise, which can be employed to evaluate the short-term prognosis of those patients and bring more clinical benefits without dependence on laboratory tests.

Adenovirus: Epidemiology, Global Spread of Novel Types, and Approach to Treatment

Adenoviruses (AdVs) are DNA viruses that typically cause mild infections involving the upper or lower respiratory tract, gastrointestinal tract, or conjunctiva. Rare manifestations of AdV infections include hemorrhagic cystitis, hepatitis, hemorrhagic colitis, pancreatitis, nephritis, or meningoencephalitis. AdV infections are more common in young children, due to lack of humoral immunity. Epidemics of AdV infection may occur in healthy children or adults in closed or crowded settings (particularly military recruits). The vast majority of cases are self-limited. However, the clinical spectrum is broad and fatalities may occur. Dissemination is more likely in patients with impaired immunity (e.g., organ transplant recipients, human immunodeficiency virus infection). Fatality rates for untreated severe AdV pneumonia or disseminated disease may exceed 50%. More than 100 genotypes and 52 serotypes of AdV have been identified and classified into seven species designated HAdV-A through -G. Different types display different tissue tropisms that correlate with clinical manifestations of infection. The predominant types circulating at a given time differ among countries or regions, and change over time. Transmission of novel strains between countries or across continents and replacement of dominant viruses by new strains may occur. Treatment of AdV infections is controversial, as prospective, randomized therapeutic trials have not been done. Cidofovir has been the drug of choice for severe AdV infections, but not all patients require treatment. Live oral vaccines are highly efficacious in reducing the risk of respiratory AdV infection and are in routine use in the military in the United States but currently are not available to civilians.

Viral Enteritis in Solid-Organ Transplantation

Solid organ transplant recipients are at increased risk for infections due to chronic immunosuppression. Diarrhea is a commonly encountered problem post transplantation, with infectious causes of diarrhea being a frequent complication. Viral infections/enteritides in solid organ transplant recipients often result from frequently encountered pathogens in this population such as cytomegalovirus, adenovirus, and norovirus. However, several emerging viral pathogens are increasingly being recognized as more sensitive diagnostic techniques become available. Treatment is often limited to supportive care and reduction in immunosuppression, though antiviral therapies mayplay a role in the treatment in certain diseases. Viral enteritis is an important entity that contributes to morbidity and mortality in transplant recipients.

Potential Diagnostic and Prognostic Biomarkers for Adenovirus Respiratory Infection in Children and Young Adults

Human Adenoviruses (HAdV) are known to be potentially associated with strong inflammatory responses and morbidity in pediatric patients. Although most of the primary infections are self-limiting, the severity of clinical presentation, the elevation of the white blood cell count and inflammatory markers often mimic a bacterial infection and lead to an inappropriate use of antibiotics. In infections caused by HAdV, rapid antigen detection kits are advisable but not employed routinely; costs and feasibility of rapid syndromic molecular diagnosis may limit its use in the in-hospital setting; lymphocyte cultures and two-sampled serology are time consuming and impractical when considering the use of antibiotics. In this review, we aim to describe the principal diagnostic tools and the immune response in HAdV infections and evaluate whether markers based on the response of the host may help early recognition of HAdV and avoid inappropriate antimicrobial prescriptions in acute airway infections.

Renal allograft function in kidney transplant recipients infected with SARS-CoV 2: An academic single center experience

BACKGROUND

Kidney transplant recipients are a unique cohort in regard to SARS-CoV 2 susceptibility and clinical course, owing to their immunosuppressed state and propensity for kidney injury. The primary purpose of this study is to ascertain if, in kidney transplant recipients, SARS-CoV 2 infection impacts long term renal allograft function.

METHODS

This retrospective, single-center study reviewed 53 kidney transplant recipients with a positive SARS-CoV-2 PCR at NMH from January 1, 2020 to June 30, 2020.

RESULTS

Change in eGFR from baseline kidney function prior to infection to 90 days after the first positive SARS-CoV 2 test was +1.76%, -17.5% and -23.16% the mild, moderate and severe disease groups respectively. There was a significant decline in kidney function in the moderate and severe disease cohorts as compared to the mild disease cohort, with respective p values of p = 0.0002 and p = 0.021. Relative to the mild disease cohort, the moderate and severe disease cohorts also demonstrated significantly increased risk of developing AKI (66%, 85%), both with p values of P = 0.0001.

CONCLUSIONS

Clinically severe SARS-CoV 2 infection is associated with greater risk of acute kidney injury and greater decline in renal allograft function at 90 days post infection, compared to mild disease.

Epstein-Barr Virus and Human Adenovirus Viremia in Renal Tumors Is Associated with Histological Features of Malignancy

Background: There is growing evidence that viral infections may impact the risk and clinical course of malignancies, including solid tumors. The aim of this study was to assess the possible association of selected chronic/latent viral infections with the clinical course of renal cell carcinoma (RCC). Methods: In this prospective study we enrolled 27 patients undergoing partial or radical nephrectomy due to the histologically confirmed RCC and followed them up for one year post-operation. Isolation of the nucleic acids was performed using the NucleoSpin Tissue Kit (Macherey-Nagel, Düren, Germany) from tumor tissue and using the EZ1 Virus Mini Kit v2.0 from plasma. The number of viral copies of human adenovirus (ADV), herpes simplex virus HSV-1 and HSV-2, Epstein-Barr virus (EBV), cytomegalovirus (CMV), BK virus (BKV) and John Cunningham virus (JCV) in the tissue and plasma was assessed with real-time PCR. Results: Viral infections were diagnosed in ten patients (37.0%), including three ADV cases (11.1%) and eight EBV cases (29.6%). Infected patients tended to be significantly older (71.3 vs. 57.6 years, p < 0.05), more commonly presented with chronic renal disease (OR 2.4, p < 0.05), diabetes (OR 4.2, p < 0.05) and overweight (OR 2.0, p < 0.05). Regarding oncological data, infected patients were found to have a higher rate of high-grade cancers (OR 5.0, p < 0.05) and a higher rate of papillary RCCs (OR 8.3, p < 0.05). Status of viral infections had no influence on the clinical cancer stage, surgical procedure or survival. Conclusions: EBV and ADV infections are common in renal cancer patients and increase the risk of high-grade RCC presence. While there is no significant impact on short term survival, further studies are needed to assess the relevance of these findings in a long run.

Brincidofovir: understanding its unique profile and potential role against adenovirus and other viral infections

Brincidofovir (BCV) is a lipid conjugate of cidofovir with good oral bioavailability, enabling optimal intracellular levels of the active drug. Lower rates of nephrotoxicity and myelotoxicity make it a favorable alternative. Despite a greater safety profile among pediatric hematopoietic cell transplant recipients, the oral formulation has been associated with increased gastrointestinal toxicity in adult hematopoietic cell transplant recipients. Oral BCV continues to be developed as a countermeasure against smallpox, while a potentially safer intravenous preparation has been out licensed to another company. BCV has demonstrated great in vitro potency against double-stranded DNA viruses, especially adenovirus. Because of its importance for immunocompromised patients, this review aims to evaluate BCV's clinical and safety profile to support its continued development.

Epidemiology and Outcomes of Early-Onset and Late-Onset Adenovirus Infections in Kidney Transplant Recipients

Objective

Adenovirus (ADV) infection after kidney transplantation (KT) causes significant morbidity. Patient characteristics and outcomes of ADV infection in KT recipients were investigated.

Method

All adult KT recipients with ADV infection between January 2015 and June 2019 were included. ADV infection/disease was defined as detection of ADV DNA in clinical specimens/plus symptoms. Clinical and laboratory findings, treatments, and outcomes were assessed.

Results

Adenovirus infection was diagnosed in 24 of 751 (3.2%) KT recipients. Twenty (83%) were male with a median age of 47 years (interquartile range [IQR], 36–58). Fifteen (63%) underwent deceased donor KT, and 13 (54%) received induction therapy. Twenty-one (88%) and 4 (17%) patients developed hemorrhagic cystitis and disseminated disease, respectively. There were equal distributions of early-onset (EOI) (≤3 months) and late-onset (LOI) (>3 months) infections. Patients who were diagnosed with EOI had lower median absolute lymphocyte counts compared with those with LOI (735/mm³ [IQR, 543–1123] vs 1122/mm³ [IQR, 784–1344], P = .04). All achieved resolution after reduction of their immunosuppression regimen and 13 (54%) received cidofovir therapy. Eighteen (75%) developed allograft dysfunction, of which 67% were transient. One (4%) underwent nephrectomy for allograft failure and 1 (4%) died (non-ADV–related). Patients with EOI were more likely to receive cidofovir therapy (75% vs 33%, P = .04) and develop other opportunistic infections (75% vs 8%, P < .001).

Conclusions

Adenovirus infection after KT typically involves a genitourinary system and transiently impairs an allograft function. Those who developed early infection tend to have more lymphopenia, coinfection, and receive antiviral therapy.