Fatal adenovirus hepatitis during maintenance therapy for childhood acute lymphoblastic leukemia

Dissemination and genome characterization of a human adenovirus F41 in a patient with B-Cell lymphoma

Adenovirus (HAdV) F41 is a common cause of gastroenteritis and has rarely been reported associated with disseminated disease. In this report, an adult patient with a history of ulcerative colitis, cryptogenic cirrhosis, stage III adenocarcinoma, high-grade diffuse large B-cell lymphoma on chemotherapy was diagnosed with disseminated adenovirus infection. HAdV DNA was quantified in stool, plasma, and urine with viral loads of 7, 4, and 3 log10 copies/mL, respectively. The patient's course was rapidly progressive and he passed away 2 days after initiation of antiviral therapy. The patient's infecting virus was characterized as HAdV-F41 by whole genome sequencing.

Lipid nanoparticle-encapsulated, chemically modified anti-adenoviral siRNAs inhibit hepatic adenovirus infection in immunosuppressed Syrian hamsters

RNA interference has demonstrated its potential as an antiviral therapy for treatment of human adenovirus (hAd) infections. The only existing viral vector-based system for delivery of anti-adenoviral artificial microRNAs available for in vivo use, however, has proven to be inefficient in therapeutic applications. In this study, we investigated the potential of stabilized small interfering RNA (siRNA) encapsulated in lipid nanoparticles (LNPs) for treatment of hepatic hAd serotype 5 (hAd5) infection in an hAd infection model using immunosuppressed Syrian hamsters. The siRNA sipTP_mod directed against the adenoviral pre-terminal protein (pTP) and containing 2'-O-methyl modifications as well as phosphorothioate linkages effectively inhibited hAd5 infection in vitro. In light of this success, sipTP_mod was encapsulated in LNPs containing the cationic lipid XL-10, which enables hepatocyte-specific siRNA transfer, and injected intravenously into hAd5-infected immunosuppressed Syrian hamsters. This resulted in a significant reduction of liver hAd5 titers, a trend toward reduced liver injury and inflammation, and reduction of viral titers in the blood and spleen compared with hAd5-infected animals that received a non-silencing siRNA. These effects were demonstrated in animals infected with low and moderate doses of hAd5. These data demonstrate that hepatic hAd5 infection can be successfully treated with anti-adenoviral sipTP_mod encapsulated in LNPs.

Acute Hepatitis of Unknown Etiology Among Young Children: Research Agenda by the ESPGHAN Hepatology Committee

In April 2022, an increased incidence of acute hepatitis cases of unknown etiology among previously healthy children across the United Kingdom was described. Since, more than 270 cases from the United Kingdom and hundreds more from all across the world have been reported. The majority of affected children were younger than 6 years of age. The clinical presentation was nonspecific with diarrhea and vomiting usually preceding the appearance of jaundice, abdominal pain, nausea, and malaise. Approximately 5% have required liver transplantation. An infectious etiology has been considered likely given the epidemiological and clinical features of the reported cases. Between 50 and 60% of the children tested were diagnosed with adenovirus infection although a clear etiological connection has still to be demonstrated. No link with SARS-CoV-2 infection and COVID-19 vaccine was found. What is not clear to date is whether the high number of acute hepatitis cases reported is related to a true increase in incidence or heightened awareness following on from the initial reports from the United Kingdom. The Hepatology Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) developed a paper on the current outbreak of acute hepatitis of unknown etiology recognizing its importance and the need of approaching the current situation with a scientifically rigorous approach. The aims of the article are to summarize the current knowledge and to identify the most pertinent issues regarding the diagnosis and management of this condition and the research questions raised.

Genomic analyses of human adenoviruses unravel novel recombinant genotypes associated with severe infections in pediatric patients

Human adenoviruses (HAdVs) are highly contagious pathogens of clinical importance, especially among the pediatric population. Studies on comparative viral genomic analysis of cases associated with severe and mild infections due to HAdV are limited. Using whole-genome sequencing (WGS), we investigated whether there were any differences between circulating HAdV strains associated with severe infections (meningitis, sepsis, convulsion, sudden infant death syndrome, death, and hospitalization) and mild clinical presentations in pediatric patients hospitalized between the years 1998 and 2017 in a tertiary care hospital group in Bern, Switzerland covering a population base of approx. 2 million inhabitants. The HAdV species implicated in causing severe infections in this study included HAdV species C genotypes (HAdV1, HAdV2, and HAdV5). Clustering of the HAdV whole-genome sequences of the severe and mild cases did not show any differences except for one sample (isolated from a patient presenting with sepsis, meningitis, and hospitalization) that formed its own cluster with HAdV species C genotypes. This isolate showed intertypic recombination events involving four genotypes, had the highest homology to HAdV89 at complete genome level, but possessed the fiber gene of HAdV1, thereby representing a novel genotype of HAdV species C. The incidence of potential recombination events was higher in severe cases than in mild cases. Our findings confirm that recombination among HAdVs is important for molecular evolution and emergence of new strains. Therefore, further research on HAdVs, particularly among susceptible groups, is needed and continuous surveillance is required for public health preparedness including outbreak investigations.

Adenovirus vector-attributed hepatotoxicity blocks clinical application in gene therapy

Adenoviruses (Ads), common self-limiting pathogens in humans and animals, usually cause conjunctivitis, mild upper respiratory tract infection or gastroenteritis in humans and hepatotoxicity syndrome in chickens and dogs, posing great threats to public health and livestock husbandry. Artificially modified Ads, which wipe out virulence-determining genes, are the most frequently used viral vectors in gene therapy, and some Ad vector (AdV)-related medicines and vaccines have been licensed and applied. Inherent liver tropism enables AdVs to specifically deliver drugs/genes to the liver; however, AdVs are closely associated with acute hepatotoxicity in immunocompromised individuals, and the side effects of AdVs, which stimulate a strong inflammatory reaction in the liver and cause acute hepatotoxicity, have largely limited clinical application. Therefore, this review systematically elucidates the intimate relationship between AdVs and hepatotoxicity in terms of virus and host and precisely illustrates the accumulated understanding in this field over the past decades. This review demonstrates the liver tropism of AdVs and molecular mechanism of AdV-induced hepatotoxicity and looks at the studies on AdV-mediated animal hepatotoxicity, which will undoubtedly deepen the understanding of AdV-caused liver injury and be of benefit in the further safe development of AdVs.

Systemic viral infection in children receiving chemotherapy for acute leukemia

Systemic viral diseases frequently occur in allogeneic hematopoietic stem cell transplantation, but data in children receiving chemotherapy for acute leukemia are scarce. We therefore collected and analyzed the published data on symptomatic infection from cytomegalovirus, herpes simplex virus, varicella zoster virus, parvovirus B19, or adenovirus in pediatric acute leukemia. Reports on 68 children were identified, of whom 16 patients have died from the infection. Further studies have to (1) evaluate the true incidence of these infections in pediatric acute leukemia, (2) their impact on outcome, and (3) whether a subpopulation of patients could benefit from screening and prophylactic strategies.

Epidemiology of Human Adenoviruses: A 20-Year Retrospective Observational Study in Hospitalized Patients in Bern, Switzerland

BACKGROUND

Human adenovirus (HAdV) is an important pathogen seen in clinical practice. Long-term studies may help better understand epidemiological trends and changes in circulating genotypes over time.

PURPOSE

Using a large biobank of samples from hospitalized, adenovirus-positive patients over a 20-year period, we aimed to analyze long-term epidemiological trends and genotypic relatedness among circulating HAdV strains.

METHODS

Based on samples from hospitalized patients confirmed to be HAdV positive in Bern, Switzerland, from 1998 to 2017, and on their associated demographic and clinical data, we identified epidemiological trends and risk factors associated with HAdV infection. HAdV genotyping was performed by PCR amplification and sequencing of the hypervariable hexon gene. The obtained sequences were phylogenetically compared with sequences from international HAdV strains.

RESULTS

HAdV was identified in 1302 samples tested. Cases of HAdV infection were reported throughout the years with no clear seasonality. Upper respiratory tract samples, conjunctivitis swabs, and stool had the highest positivity rate (56.2%, 18.7%, and 14.2% of the cases, respectively). HAdV infection was highest among children ≤4 years old. Increased number of HAdV cases were observed in years 2009 (n = 110) and 2010 (n =112). HAdV8 was the predominant genotype among patients older than 20 years, and was mostly associated with ophthalmic infection. Predominant genotypes among children ≤4 years old were HAdV1, HAdV2, and HAdV3, which were mostly associated with respiratory tract infections. Recurring peaks of increased HAdV cases were evidenced every 4 years among children ≤4 years old.

CONCLUSION

Our study gives novel insights on long-term epidemiological trends and phylogenetic relatedness among circulating HAdV strains in Switzerland, country in which little data on HAdV prevalence and diversity was so far available.

The Role of Emerging and Neglected Viruses in the Etiology of Hepatitis

PURPOSE OF REVIEW

In this review, we present the overview of emerging and neglected viruses associated with liver involvement.

RECENT FINDINGS

Hepatitis E virus (HEV) emerged in the last two decades, causing hepatitis in many parts of the world. Moreover, liver involvement was also described in some emerging arboviral infections. Many reports showed dengue-associated liver injury; however, chikungunya, West Nile, tick-borne encephalitis, and Zika virus are rarely associated with clinically manifest liver disease. In addition, some neglected highly prevalent viruses such as adenoviruses and parvovirus B19 are capable of causing hepatitis in specific population groups. Anelloviruses (torque teno virus/torque teno mini virus/torque teno midi virus, SEN virus), human bocavirus, pegiviruses, and lymphocytic choriomeningitis virus have shown a little potential for causing hepatitis, but their role in the etiology of liver disease remains to be determined. In addition to the well-known hepatotropic viruses, many emerging and neglected viruses have been associated with liver diseases. The number of emerging zoonotic viruses has been increasingly recognized. While zoonotic potential of HEV is well documented, the recent identification of new hepatitis-related animal viruses such as HEV strains from rabbits and camels, non-primate hepaciviruses in domestic dogs and horses, as well as equine and porcine pegivirus highlights the possible zoonotic transmission in the context of "One Health." However, zoonotic potential and hepatotropism of animal hepatitis viruses remain to be determined.

The Repertoire of Adenovirus in Human Disease: The Innocuous to the Deadly

Adenoviridae is a family of double-stranded DNA viruses that are a significant cause of upper respiratory tract infections in children and adults. Less commonly, the adenovirus family can cause a variety of gastrointestinal, ophthalmologic, genitourinary, and neurologic diseases. Most adenovirus infections are self-limited in the immunocompetent host and are treated with supportive measures. Fatal infections can occur in immunocompromised patients and less frequently in the healthy. Adenoviral vectors are being studied for novel biomedical applications including gene therapy and immunization. In this review we will focus on the spectrum of adenoviral infections in humans.

Case report: a fatal case of disseminated adenovirus infection in a non-transplant adult haematology patient

BACKGROUND

We report a fatal case of disseminated adenovirus infection in a non-transplant haematology adult patient with chronic lymphocytic leukaemia who had completed combination chemoimmunotherapy a few months before developing respiratory symptoms. In such non-transplant patients, monitoring for adenovirus in the blood is not routine. However, with adenoviruses, when there is a more peripheral (i.e. non-blood) site of infection such as the chest, serial adenovirus monitoring in blood for the duration of that illness may be warranted.

CASE PRESENTATION

This case started with an initial bacterial chest infection that responded to treatment, followed by an adenovirus pneumonitis that disseminated to his blood a week later with levels of up to 92 million adenovirus DNA copies/ml. Despite prompt treatment with cidofovir, his respiratory function continued to deteriorate over the next two weeks and he was moved to intensive care. Intravenous immunoglobulin and ribavirin were subsequently added to his treatment. However, he died soon after this with a final adenovirus load of 20 million copies/ml in his blood.

CONCLUSIONS

We recommend that even in non-transplant haematology patients, where such patients present with an acute respiratory adenovirus infection, teams should consider checking the blood for adenovirus to check for signs of disseminated infection. The earlier this can be tested, the earlier treatment can be initiated (if adenovirus positive), which may produce more successful clinical outcomes.

Adenovirus Hepatitis: Clinicopathologic Analysis of 12 Consecutive Cases From a Single Institution

Adenoviruses are common pathogens that usually cause self-limited infections. However, in the immunocompromised host they can cause severe infections involving multiple organs including the liver. A search of the pathology database at Stanford University Medical Center (1995 to 2016) identified 12 cases of adenovirus hepatitis including biopsy and autopsy specimens. There were 8 pediatric patients, 7 of which had received orthotropic liver transplants and 1 of which was receiving chemotherapy for lymphoblastic leukemia. There were 4 adult patients, of which 1 was actively receiving chemotherapy for chronic lymphocytic leukemia and 2 had undergone hematopoietic stem cell transplantation for hematologic malignancies. One patient had lymphoplasmacytic lymphoma and had received chemotherapy over a year prior but was not receiving therapy at the time he contracted adenovirus hepatitis. In all cases, histologic sections showed nonzonal coagulative hepatocyte necrosis and characteristic intranuclear inclusions. Hepatocyte necrosis ranged from spotty to massive. The majority of cases (7/12; 58%) had no associated inflammation. If present, inflammation was focal and lymphohistiocytic. In 1 case, findings were focal within the liver, requiring an image-guided biopsy. This patient underwent a simultaneous nontargeted liver biopsy that lacked histologic evidence of adenovirus. Among the pediatric patients, 63% (5/8) died secondary to organ failure, while there was 100% (4/4) mortality in the adult population.

Fatal systemic adenoviral infection superimposed on pulmonary mucormycosis in a child with acute leukemia: A case report

BACKGROUND

Although adenovirus (ADV) infection usually causes self-limiting respiratory disorders in immune competent children; severe and systemic ADV infection in children undergoing chemotherapy for leukemia has been continuously reported. Nevertheless, there has been no consensus on risk factors and treatment strategies for severe ADV infection in children undergoing chemotherapy.

CASE SUMMARY

We report a case of a 15-year-old boy with a fatal systemic ADV infection. He had received reinduction chemotherapy for relapsed acute lymphoblastic leukemia under continuing antifungal therapy for previously diagnosed fungal pneumonia. He complained of fever and right shoulder pain 4 days after completing the reinduction chemotherapy. In spite of appropriate antibiotic and antifungal therapy, pneumonia was aggravated and gross hematuria was accompanied. A multiplex polymerase chain reaction test for respiratory viruses was positive for ADV in a blood sample, and a urine culture was positive for ADV. He received oral ribavirin, intravenous immunoglobulin, and intravenous cidofovir therapy; however, he eventually died. Relapsed leukemia, concurrent fungal pneumonia, and delayed cidofovir administration were considered the cause of the grave outcome in this patient.

CONCLUSION

ADV may cause severe infections not only in allogeneic hematopoietic cell transplant recipients, but also in patients undergoing chemotherapy for acute leukemia. The risk factors for severe ADV infection in patients undergoing chemotherapy should be determined in the future studies, and early antiviral therapy should be administered to immune compromised patients with systemic ADV infection.

Progress in Treatment of Viral Infections in Children with Acute Lymphoblastic Leukemia

In children, the most commonly encountered type of leukemia is acute lymphoblastic leukemia (ALL). An important source of morbidity and mortality in ALL are viral infections. Even though allogeneic transplantations, which are often applied also in ALL, carry a recognized risk for viral infections, there are multiple factors that make ALL patients susceptible to viral infections. The presence of those factors has an influence in the type and severity of infections. Currently available treatment options do not guarantee a positive outcome for every case of viral infection in ALL, without significant side effects. Side effects can have very serious consequences for the ALL patients, which include nephrotoxicity. For this reason a number of strategies for personalized intervention have been already clinically tested, and experimental approaches are being developed. Adoptive immunotherapy, which entails administration of ex vivo grown immune cells to a patient, is a promising approach in general, and for transplant recipients in particular. The ex vivo grown cells are aimed to strengthen the immune response to the virus that has been identified in the patients' blood and tissue samples. Even though many patients with weakened immune system can benefit from progress in novel approaches, a viral infection still poses a very significant risk for many patients. Therefore, preventive measures and supportive care are very important for ALL patients.

Viral and Cellular Genomes Activate Distinct DNA Damage Responses

In response to cellular genome breaks, MRE11/RAD50/NBS1 (MRN) activates a global ATM DNA damage response (DDR) that prevents cellular replication. Here, we show that MRN-ATM also has critical functions in defending the cell against DNA viruses. We reveal temporally distinct responses to adenovirus genomes: a critical MRN-ATM DDR that must be inactivated by E1B-55K/E4-ORF3 viral oncoproteins and a global MRN-independent ATM DDR to viral nuclear domains that does not impact viral replication. We show that MRN binds to adenovirus genomes and activates a localized ATM response that specifically prevents viral DNA replication. In contrast to chromosomal breaks, ATM activation is not amplified by H2AX across megabases of chromatin to induce global signaling and replicative arrest. Thus, γH2AX foci discriminate "self" and "non-self" genomes and determine whether a localized anti-viral or global ATM response is appropriate. This provides an elegant mechanism to neutralize viral genomes without jeopardizing cellular viability.

Adenovirus necrotizing hepatitis complicating atypical teratoid rhabdoid tumor

Adenovirus-induced fulminant hepatitis is rare. It has been reported in children with primary immunodeficiency, following transplantation or while receiving chemotherapy for hematological malignancy. We present the case of an infant recovering from chemotherapy for atypical teratoid rhabdoid tumor (ATRT) in whom a diagnosis of hepatic necrosis due to adenovirus was made.

Enhanced suppression of adenovirus replication by triple combination of anti-adenoviral siRNAs, soluble adenovirus receptor trap sCAR-Fc and cidofovir

Adenoviruses (Ad) generally induce mild self-limiting respiratory or intestinal infections but can also cause serious disease with fatal outcomes in immunosuppressed patients. Antiviral drug therapy is an important treatment for adenoviral infections but its efficiency is limited. Recently, we have shown that gene silencing by RNA interference (RNAi) is a promising new approach to inhibit adenoviral infection. In the present in vitro study, we examined whether the efficiency of an RNAi-based anti-adenoviral therapy can be further increased by combination with a virus receptor trap sCAR-Fc and with the antiviral drug cidofovir. Initially, three siRNAs, siE1A_4, siIVa2_2 and Pol-si2, targeting the adenoviral E1A, IVa2 and DNA polymerase mRNAs, respectively, were used for gene silencing. Replication of the Ad was inhibited in a dose dependent manner by each siRNA, but the efficiency of inhibition differed (Pol-si2>siIVa2_2>siE1A_4). Double or triple combinations of the siRNAs compared with single siRNAs did not result in a measurably higher suppression of Ad replication. Combination of the siRNAs (alone or mixes of two or three siRNAs) with sCAR-Fc markedly increased the suppression of adenoviral replication compared to the same siRNA treatment without sCAR-Fc. Moreover, the triple combination of a mix of all three siRNAs, sCAR-Fc and cidofovir was about 23-fold more efficient than the combination of siRNAs mix/sCAR-Fc and about 95-fold more efficient than the siRNA mix alone. These data demonstrate that co-treatment of cells with sCAR-Fc and cidofovir is suitable to increase the efficiency of anti-adenoviral siRNAs.

Successful Treatment of Disseminated Adenovirus Infection in an Infant With Acute Lymphoblastic Leukemia

Systemic adenovirus infection in the immunocompromised host is often fatal and therapeutic options are limited. We report an infant with acute lymphoblastic leukemia who developed disseminated adenovirus infection while lymphopenic during maintenance chemotherapy 6 months following a bout of adenoviral diarrhea. His serum adenoviral load peaked at 35 million copies/mL and was associated with pancytopenia and hepatic injury. Treatment with cidofovir was effective although associated with mild renal injury. The patient recovered fully and completed chemotherapy for infant acute lymphoblastic leukemia.

Expression of an engineered soluble coxsackievirus and adenovirus receptor by a dimeric AAV9 vector inhibits adenovirus infection in mice

Immunosuppressed (IS) patients, such as recipients of hematopoietic stem cell transplantation, occasionally develop severe and fatal adenovirus (Ad) infections. Here, we analyzed the potential of a virus receptor trap based on a soluble coxsackievirus and Ad receptor (sCAR) for inhibition of Ad infection. In vitro, a dimeric fusion protein, sCAR-Fc, consisting of the extracellular domain of CAR and the Fc portion of human IgG1 and a monomeric sCAR lacking the Fc domain, were expressed in cell culture. More sCAR was secreted into the cell culture supernatant than sCAR-Fc, but it had lower Ad neutralization activity than sCAR-Fc. Further investigations showed that sCAR-Fc reduced the Ad infection by a 100-fold and Ad-induced cytotoxicity by ~20-fold. Not only was Ad infection inhibited by sCAR-Fc applied prior to infection, it also inhibited infection when used to treat ongoing Ad infection. In vivo, sCAR-Fc was delivered to IS mice by an AAV9 vector, resulting in persistent and high (>40 μg ml(-1)) sCAR-Fc serum levels. The sCAR-Fc serum concentration was sufficient to significantly inhibit hepatic and cardiac wild-type Ad5 infection. Treatment with sCAR-Fc did not induce side effects. Thus, sCAR-Fc virus receptor trap may be a promising novel therapeutic for treatment of Ad infections.

Adenovirus infections in immunocompetent and immunocompromised patients

Human adenoviruses (HAdVs) are an important cause of infections in both immunocompetent and immunocompromised individuals, and they continue to provide clinical challenges pertaining to diagnostics and treatment. The growing number of HAdV types identified by genomic analysis, as well as the improved understanding of the sites of viral persistence and reactivation, requires continuous adaptions of diagnostic approaches to facilitate timely detection and monitoring of HAdV infections. In view of the clinical relevance of life-threatening HAdV diseases in the immunocompromised setting, there is an urgent need for highly effective treatment modalities lacking major side effects. The present review summarizes the recent progress in the understanding and management of HAdV infections.

A prospective multicenter study of microbiologically defined infections in pediatric cancer patients with fever and neutropenia: Swiss Pediatric Oncology Group 2003 fever and neutropenia study

BACKGROUND

Fever and neutropenia (FN) often complicate anticancer treatment and can be caused by potentially fatal infections. Knowledge of pathogen distribution is paramount for optimal patient management.

METHODS

Microbiologically defined infections (MDI) in pediatric cancer patients presenting with FN by nonmyeloablative chemotherapy enrolled in a prospective multicenter study were analyzed. Effectiveness of empiric antibiotic therapy in FN episodes with bacteremia was assessed taking into consideration recently published treatment guidelines for pediatric patients with FN.

RESULTS

MDI were identified in a minority (22%) of pediatric cancer patients with FN. In patients with, compared with patients without MDI, fever [median, 5 (interquartile range: 3-8) vs. 2 (interquartile range: 1-3) days, P < 0.001] and hospitalization [10 (6-14) vs. 5 (3-8) days, P < 0.001] lasted longer, transfer to the intensive care unit was more likely [13 of 95 (14%) vs. 7 of 346 (2.0%), P < 0.001], and antibiotics were given longer [10 (7-14) vs. 5 (4-7) days, P < 0.001]. Empiric antibiotic therapy in FN episodes with bacteremia was highly effective if not only intrinsic and reported antimicrobial susceptibilities were considered but also the purposeful omission of coverage for coagulase-negative staphylococci and enterococci was taken into account [81% (95% confidence interval: 68-90) vs. 96.6% (95% confidence interval: 87-99.4), P = 0.004].

CONCLUSIONS

MDI were identified in a minority of FN episodes but they significantly affected management and the clinical course of pediatric cancer patients. Compliance with published guidelines was associated with effectiveness of empiric antibiotic therapy in FN episodes with bacteremia.

Exploring the association of hemoglobin level and adverse events in children with cancer presenting with fever in neutropenia

Background

In children and adolescents with fever in neutropenia (FN) during chemotherapy for cancer, hemoglobin ≥90 g/L at presentation with FN had been associated with adverse events (AE). This analysis explored three hypothetical pathophysiological mechanisms potentially explaining this counterintuitive finding, and further analyzed the statistical association between hemoglobin and AE.

Methods

Two of 8 centers, reporting on 311 of 421 FN episodes in 138 of 215 patients participated in this retrospective analysis based on prospectively collected data from three databases (SPOG 2003 FN, transfusion and hematology laboratories). Associations with AE were analyzed using mixed logistic regression.

Results

Hemoglobin was ≥90 g/L in 141 (45%) of 311 FN episodes, specifically in 59/103 (57%) episodes with AE, and in 82/208 (39%) without (OR, 2.3; 99%CI, 1.1–4.9; P = 0.004). In FN with AE, hemoglobin was bimodally distributed with a dip around 85 g/L. There were no significant interactions for center, age and sex. In multivariate mixed logistic regression, AE was significantly and independently associated with leukopenia (leukocytes <0.3 G/L; OR, 3.3; 99%CI, 1.1–99; P = 0.004), dehydration (hemoglobin_Presentation/hemoglobin_{8–72 hours} ≥1.10 in untransfused patients; OR, 3.5; 99%CI, 1.1–11.4; P = 0.006) and non-moderate anemia (difference from 85 g/L; 1.6 per 10 g/L; 1.0–2.6; P = 0.005), but not with recent transfusion of packed red blood cells (pRBC), very recent transfusion of pRBC or platelets, or with hemoglobin ≥90 g/L as such.

Conclusions

Non-moderate anemia and dehydration were significantly and relevantly associated with the risk of AE in children with cancer and FN. These results need validation in prospective cohorts before clinical implementation.

Pediatric sepsis: important considerations for diagnosing and managing severe infections in infants, children, and adolescents

Sepsis is the leading cause of death in children worldwide. Although the diagnosis and management of sepsis in infants and children is largely influenced by studies done in adults, there are important considerations relevant for pediatrics. This article highlights pediatric-specific issues related to the definition of sepsis and its epidemiology and management. We review how the capacity of the immune system to respond to infection develops over early life. We also bring attention to primary immune deficiencies that should be considered in children recurrently infected with specific types of organisms. The management of pediatric sepsis must be tailored to the child’s age and immune capacity, and to the site, severity, and source of the infection. It is important for clinicians to be aware of infection-related syndromes that primarily affect children. Although children in developed countries are more likely to survive severe infections than adults, many survivors have chronic health impairments.

Diagnosis and treatment of adenovirus infection in immunocompromised patients

In immunocompromised patients, human adenovirus (HAdV) infections can cause life-threatening multiorgan disease. This review summarizes the incidence and risk factors of invasive human adenovirus infections in immunocompromised patients as well as the recently developed standards for diagnostic methods and strategies according to the predominant risk factors in adults and children. Recommendations for preemptive and therapeutic treatment strategies and the outcome in different risk groups are presented. Novel therapeutic approaches including CMX001, a new orally bioavailable lipid conjugate of cidofovir and the transfer of adenovirus-specific donor T cells in the context of allogeneic stem cell transplantation are discussed.

Fulminant hepatitis due to human adenovirus. Infection. 2014;42:105-111. [PMID: 23979854 DOI: 10.1007/s15010-013-0527-7]

PURPOSE

To describe the demographics, clinical manifestations, treatment and outcomes of patients with human adenovirus (HAdV) hepatitis.

METHODS

A case of fulminant HAdV hepatitis in a patient with chronic lymphocytic leukemia receiving rituximab and fludarabine is described. We conducted a comprehensive review of the English-language literature through May, 2012 in search of definite cases of HAdV hepatitis.

RESULTS

Eighty-nine cases were reviewed. Forty-three (48 %) were liver transplant recipients, 19 (21 %) were bone marrow transplant recipients, 11 (12 %) had received chemotherapy, five (6 %) had severe combined immunodeficiency, four (4 %) were HIV infected, two had heart transplantation, and two were kidney transplant recipients. Ninety percent (46/51) of patients presented within 6 months following transplantation. Fever was the most common initial symptom. Abdominal CT scan revealed hypodense lesions in eight of nine patients. Diagnosis was made by liver biopsy in 43 (48 %), and on autopsy in 46 (52 %). The HAdV was isolated at other sites in 54 cases. Only 24 of 89 patients (27 %) survived: 16 whose immunosuppression was reduced, six with liver re-transplantation, and two who received cidofovir and intravenous immunoglobulin.

CONCLUSION

HAdV hepatitis can manifest as a fulminant illness in immunocompromised hosts. Definitive diagnosis requires liver biopsy. Early consideration of a viral etiology, reduction in immunosuppression, and liver transplantation can be potentially life-saving.

Successful response to cidofovir of adenovirus hepatitis during chemotherapy in a child with hepatoblastoma

BACKGROUND

Adenoviral infections are endemic in the pediatric population. Most of these infections are mild and self-limited in immunocompetent individuals. Although in profoundly immunocompromised hosts after solid organ or stem cell transplantation, adenovirus may cause fulminant hepatitis or other life-threatening infections, this is a rare complication in patients receiving standard chemotherapy.

OBSERVATION

We report a case of severe adenovirus hepatitis in a 7-month-old child receiving induction chemotherapy for hepatoblastoma who fully recovered after treatment with cidofovir.

CONCLUSIONS

To our knowledge, this is the first report documenting recovering of severe adenoviral hepatitis in a nontransplanted immunocompromised host.

First-day step-down to oral outpatient treatment versus continued standard treatment in children with cancer and low-risk fever in neutropenia. A randomized controlled trial within the multicenter SPOG 2003 FN study

BACKGROUND

The standard treatment of fever in chemotherapy-induced neutropenia (FN) includes emergency hospitalization and empirical intravenous antimicrobial therapy. This study determined if first-day step-down to oral outpatient treatment is not inferior to continued standard regarding safety and efficacy in children with low-risk FN.

PROCEDURE

In a randomized controlled non-blinded multicenter study, pediatric patients with FN after non-myeloablative chemotherapy were reassessed after 8-22 hours of inpatient intravenous antimicrobial therapy. Low-risk patients were randomized to first-day step-down to experimental (outpatient, oral amoxicillin plus ciprofloxacin) versus continued standard treatment. Exact non-inferiority tests were used for safety (no serious medical complication; non-inferiority margin of difference, 3.5%) and efficacy (resolution of infection without recurrence, no modification of antimicrobial therapy, no adverse event; 10%).

RESULTS

In 93 (26%) of 355 potentially eligible FN episodes low-risk criteria were fulfilled, and 62 were randomized, 28 to experimental (1 lost to follow-up) and 34 to standard treatment. In intention-to-treat analyses, non-inferiority was not proven for safety [27 of 27 (100%) vs. 33 of 34 (97%; 1 death) episodes; 95% upper confidence border, 6.7%; P = 0.11], but non-inferiority was proven for efficacy [23 of 27 (85%) vs. 26 of 34 (76%) episodes; 95% upper confidence border, 9.4%; P = 0.045]. Per-protocol analyses confirmed these results.

CONCLUSIONS

In children with low-risk FN, the efficacy of first-day step-down to oral antimicrobial therapy with amoxicillin and ciprofloxacin in an outpatient setting was non-inferior to continued hospitalization and intravenous antimicrobial therapy. The safety of this procedure, however, was not assessable with sufficient power.

Serious medical complications in children with cancer and fever in chemotherapy-induced neutropenia: results of the prospective multicenter SPOG 2003 FN study

BACKGROUND

Fever and chemotherapy-induced neutropenia (FN) is the most frequent potentially lethal complication of therapy in children with cancer. This study aimed to describe serious medical complications (SMC) in children with FN regarding incidence, clinical spectrum, and associated characteristics.

PROCEDURE

Pediatric patients presenting with FN induced by non-myeloablative chemotherapy were observed in a prospective multicenter study. SMC was defined as potentially life-threatening complication (PLTC), transfer to the pediatric intensive care unit (PICU), or death.

RESULTS

A total of 443 FN episodes were reported from 8 centers. Of these, 411 episodes were reported from 4 centers recruiting consecutively and without bias regarding the risk of complications. They were used for calculation of proportions. An SMC was reported in 23 episodes [5.6%; 95% confidence interval (CI): 3.7-8.1], usually defined by more than one criterion. These were PLTC in 13 episodes, PICU in 22, and death in 3 (mortality, 0.7%; 95% CI: 0.2-2.1). Both a delayed onset of SMC (14 of 23 episodes, 61%) and a biphasic clinical course (11 of 23, 48%) were frequently observed. In a multivariate logistic regression analysis, 4 characteristics were significantly and independently associated with the risk of SMC: diagnosis of acute myeloid leukemia, interval since chemotherapy ≤7 days, severely reduced general condition, and hemoglobin ≥9.0 g/dl at presentation.

CONCLUSIONS

In children with FN, SMC were rare, and mortality was very low. Those with SMC often had a delayed onset and biphasic clinical course with secondary deterioration.

Predicting bacteremia in children with cancer and fever in chemotherapy-induced neutropenia: results of the prospective multicenter SPOG 2003 FN study

STUDY AIM

To develop a score predicting the risk of bacteremia in cancer patients with fever and neutropenia (FN), and to evaluate its performance.

METHODS

Pediatric patients with cancer presenting with FN induced by nonmyeloablative chemotherapy were observed in a prospective multicenter study. A score predicting the risk of bacteremia was developed from a multivariate mixed logistic regression model. Its cross-validated predictive performance was compared with that of published risk prediction rules.

RESULTS

Bacteremia was reported in 67 (16%) of 423 FN episodes. In 34 episodes (8%), bacteremia became known only after reassessment after 8 to 24 hours of inpatient management. Predicting bacteremia at reassessment was better than prediction at presentation with FN. A differential leukocyte count did not increase the predictive performance. The reassessment score predicting future bacteremia in 390 episodes without known bacteremia used the following 4 variables: hemoglobin ≥ 90 g/L at presentation (weight 3), platelet count <50 G/L (3), shaking chills (5), and other need for inpatient treatment or observation according to the treating physician (3). Applying a threshold ≥ 3, the score--simplified into a low-risk checklist--predicted bacteremia with 100% sensitivity, with 54 episodes (13%) classified as low-risk, and a specificity of 15%.

CONCLUSIONS

This reassessment score, simplified into a low-risk checklist of 4 routinely accessible characteristics, identifies pediatric patients with FN at risk for bacteremia. It has the potential to contribute to the reduction of use of antimicrobials in, and to shorten the length of hospital stays of pediatric patients with cancer and FN.

Predicting Adverse Events in Children With Fever and Chemotherapy-Induced Neutropenia: The Prospective Multicenter SPOG 2003 FN Study

Purpose

To develop a score predicting the risk of adverse events (AEs) in pediatric patients with cancer who experience fever and neutropenia (FN) and to evaluate its performance.

Patients and Methods

Pediatric patients with cancer presenting with FN induced by nonmyeloablative chemotherapy were observed in a prospective multicenter study. A score predicting the risk of future AEs (ie, serious medical complication, microbiologically defined infection, radiologically confirmed pneumonia) was developed from a multivariate mixed logistic regression model. Its cross-validated predictive performance was compared with that of published risk prediction rules.

Results

An AE was reported in 122 (29%) of 423 FN episodes. In 57 episodes (13%), the first AE was known only after reassessment after 8 to 24 hours of inpatient management. Predicting AE at reassessment was better than prediction at presentation with FN. A differential leukocyte count did not increase the predictive performance. The score predicting future AE in 358 episodes without known AE at reassessment used the following four variables: preceding chemotherapy more intensive than acute lymphoblastic leukemia maintenance (weight = 4), hemoglobin ≥ 90 g/L (weight = 5), leukocyte count less than 0.3 G/L (weight = 3), and platelet count less than 50 G/L (weight = 3). A score (sum of weights) ≥ 9 predicted future AEs. The cross-validated performance of this score exceeded the performance of published risk prediction rules. At an overall sensitivity of 92%, 35% of the episodes were classified as low risk, with a specificity of 45% and a negative predictive value of 93%.

Conclusion

This score, based on four routinely accessible characteristics, accurately identifies pediatric patients with cancer with FN at risk for AEs after reassessment.

Coagulation factors determine tumor transduction in vivo

A critical obstacle for efficient gene therapy and virotherapy of cancer with adenoviral vectors and oncolytic adenoviruses is to target tumor cells in vivo. Recent reports indicate that, contrary to the natural airborne infection of epithelial cells with adenovirus type 5 mediated by coxsackievirus B and adenovirus receptor (CAR) and integrins, blood-borne adenovirus infects hepatocytes mainly through an indirect pathway that involves blood coagulation factors. In this report we have studied whether adenovirus also infects tumor cells in vivo by this pathway. In vitro and in vivo analyses show that vitamin K-dependent coagulation zymogens mediate tumor transduction and that the elimination of these factors abrogates tumor transduction. This finding imposes new challenges to retarget adenoviruses in vivo.

Designing adenoviral vectors for tumor-specific targeting

Adenovirus provides an attractive candidate tool to destroy tumor cells. However, to fulfill the expectations, selective targeting of tumor cells is mandatory. This chapter reviews critical aspects in the design of tumor-targeted adenovirus vectors and oncolytic adenoviruses. The review focuses on genetic modifications of capsid and regulatory genes that can enhance the therapeutic index of these agents after systemic administration. Selectivity will be considered at different levels: biodistribution selectivity of the injected virus particles, transductional selectivity defined as cell receptor interactions and trafficking that lead to virus gene expression, transcriptional selectivity by means of tumor-selective promoters, and mutation-rescue selectivity to achieve selective replication. Proper assays to analyze selectivity at these different levels are discussed. Finally, mutations and transgenes that can enhance the potency and efficacy of tumor-targeted adenoviruses from virocentric or immunocentric points of view will be presented.

Fiber shaft-chimeric adenovirus vectors lacking the KKTK motif efficiently infect liver cells in vivo

The molecular mechanisms governing the infectivity of adenovirus (Ad) toward specific cell and tissue types in vivo remain poorly understood. The direct Ad binding to hepatic heparan sulfate proteoglycans via the KKTK motif within the fiber shaft domain was suggested to be the major mechanism of Ad liver cell infection in vivo. Here, we describe the generation and in vitro and in vivo infectivity studies of Ad5-based vectors possessing long Ad31- or Ad41-derived fiber shaft domains, which lack the KKTK motif. We found that all the critical early steps of Ad infection, including attachment to the cellular receptor, internalization, and virus genome transfer into the nucleus, occurred with similar levels of efficiency for fiber shaft-chimeric vectors and unmodified Ad5. Upon intravenous delivery into mice, fiber shaft-chimeric vectors accumulated in liver tissue, transduced liver cells, and induced the production of proinflammatory cytokines (tumor necrosis factor alpha and interleukin-6) and the chemokine monocyte chemoattractant protein 1 at levels indistinguishable from those observed for Ad5. Thus, our data provide evidence that the Ad5 fiber shaft amino acid sequence does not play any substantial role in determining adenovirus infectivity toward hepatic cells in vivo. The data obtained contribute to improving our understanding of the molecular mechanisms determining Ad infectivity and biodistribution in vivo and may aid in designing novel Ad-based vectors for gene therapy applications.