Increasing incidence of adenovirus disease in bone marrow transplant recipients

Clinical manifestations, prognostic factors, and outcomes of adenovirus pneumonia after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Severe pneumonia is one of the most important causes of mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Adenovirus (ADV) is a significant cause of severe viral pneumonia after allo-HSCT, and we aimed to identify the clinical manifestations, prognostic factors, and outcomes of ADV pneumonia after allo-HSCT.

METHODS

Twenty-nine patients who underwent allo-HSCT at the Peking University Institute of Hematology and who experienced ADV pneumonia after allo-HSCT were enrolled in this study. The Kaplan-Meier method was used to estimate the probability of overall survival (OS). Potential prognostic factors for 100-day OS after ADV pneumonia were evaluated through univariate and multivariate Cox regression analyses.

RESULTS

The incidence rate of ADV pneumonia after allo-HSCT was approximately 0.71%. The median time from allo-HSCT to the occurrence of ADV pneumonia was 99 days (range 17-609 days). The most common clinical manifestations were fever (86.2%), cough (34.5%) and dyspnea (31.0%). The 100-day probabilities of ADV-related mortality and OS were 40.4% (95% CI 21.1%-59.7%) and 40.5% (95% CI 25.2%-64.9%), respectively. Patients with low-level ADV DNAemia had lower ADV-related mortality and better OS than did those with high-level (≥ 106 copies/ml in plasma) ADV DNAemia. According to the multivariate analysis, high-level ADV DNAemia was the only risk factor for intensive care unit admission, invasive mechanical ventilation, ADV-related mortality, and OS after ADV pneumonia.

CONCLUSIONS

We first reported the prognostic factors and confirmed the poor outcomes of patients with ADV pneumonia after allo-HSCT. Patients with high-level ADV DNAemia should receive immediate and intensive therapy.

Histologic Manifestations of Gastrointestinal Adenovirus Infection After Stem Cell Transplant

Adenovirus can cause severe disease in hematopoietic stem cell transplant (HSCT) patients. Histopathologic features of this infection in gastrointestinal biopsies and their distinction from graft-versus-host disease (GVHD) have been incompletely studied. We retrospectively identified patients with gastrointestinal adenovirus infection. H&E-stained sections were reviewed and the histologic features were recorded. The extent of immunostaining was determined using a semiquantitative scale and a maximum number of positive cells per high-power field. Information regarding the clinical course and endoscopic findings were obtained from the electronic medical records. The study group included 32 HSCT patients. Most (81%) presented with diarrhea and detectable virus in the serum. Twenty patients had multiorgan involvement in the gastrointestinal tract, mostly in the duodenum (62%) and colon (56%). Characteristic features included apoptotic epithelial cells with nuclear disarray (84%) and tufted aggregates of degenerating epithelial cells (69%), the latter of which was more commonly seen in the study population more than a control group of HSCT patients with GI involvement by GVHD. Viral inclusions were limited to the superficial epithelium in 59% of samples, and the density of viral inclusions within biopsies was variable (grade 1: 40%, grade 2: 38%, and grade 3: 22%). Following therapy, 10 patients (30%) improved and 14 (42%) had progressive disease. Patients with disease progression were often older (64 vs. 36 years, P =0.01) with higher serologic viral loads, prior history of GVHD, multifocal involvement, and increased number and density of immunoreactive nuclei. Adenovirus infection elicits a spectrum of histologic changes that can simulate or occur in combination with gastrointestinal GVHD. Patients with progressive disease are more likely to have high viral loads and more extensive infection of the gastrointestinal tract.

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.

Viral infection in hematopoietic stem cell transplantation: an International Society for Cell & Gene Therapy Stem Cell Engineering Committee review on the role of cellular therapy in prevention and treatment

Despite recent advances in the field of HSCT, viral infections remain a frequent causeof morbidity and mortality among HSCT recipients. Adoptive transfer of viral specific T cells has been successfully used both as prophylaxis and treatment of viral infections in immunocompromised HSCT recipients. Increasingly, precise risk stratification of HSCT recipients with infectious complications should incorporate not only pretransplant clinical criteria, but milestones of immune reconstitution as well. These factors can better identify those at highest risk of morbidity and mortality and identify a population of HSCT recipients in whom adoptive therapy with viral specific T cells should be considered for either prophylaxis or second line treatment early after inadequate response to first line antiviral therapy. Broadening these approaches to improve outcomes for transplant recipients in countries with limited resources is a major challenge. While the principles of risk stratification can be applied, early detection of viral reactivation as well as treatment is challenging in regions where commercial PCR assays and antiviral agents are not readily available.

Adenovirus Infection and Transplantation

Adenoviruses result in a wide array of clinical presentations, including primarily respiratory, gastrointestinal, genitourinary, or systemic infections. Although adenovirus causes mild disease limited to a single organ system in immunocompetent individuals, severe and life-threatening infections do rarely occur. Disseminated disease and severe localized disease resulting in significant morbidity and mortality have been well described in the immunocompromised populations. Although asymptomatic viremia, respiratory tract, and gastrointestinal infections are the most common disease in most transplant patients, renal transplant patients more commonly experience urinary tract infections, including hemorrhagic cystitis or nephritis. Diagnosis requires astute clinical awareness of the patient's clinical presentation that would be compatible with adenovirus combined with cultures, molecular testing, polymerase chain reaction, and tissue sampling. There is no Food and Drug Administration-approved treatment for adenovirus; however, several studies have evaluated therapeutic options including cidofovir, brincidofovir, and immunotherapy. This article will summarize our current understanding of adenovirus in the transplant population.

Mouse Adenovirus Type 1 Persistence Exacerbates Inflammation Induced by Allogeneic Bone Marrow Transplantation

Bone marrow transplantation (BMT) recipients are at risk for substantial morbidity and mortality from human adenovirus infections, often in the setting of reactivation of persistent virus. Human adenovirus persistence in mucosal lymphocytes has been described, but specific cellular reservoirs of persistence and effects of persistence on host responses to unrelated stimuli are not completely understood. We used mouse adenovirus type 1 (MAV-1) to characterize persistence of an adenovirus in its natural host and test the hypothesis that persistence increases complications of bone marrow transplantation (BMT). Following intranasal infection of C57BL/6J mice, MAV-1 DNA was detected in lung, mediastinal lymph nodes, and liver during acute infection at 7 days post infection (dpi), and at lower levels at 28 dpi that remained stable through 150 dpi. Expression of early and late viral transcripts was detected in those organs at 7 dpi but not at later time points. MAV-1 persistence was not affected by deficiency of IFN-γ. We detected no evidence of MAV-1 reactivation in vivo following allogeneic BMT of persistently infected mice. Persistent infection did not substantially affect mortality, weight loss, or pulmonary inflammation following BMT. However, T cell infiltration and increased expression of pro-inflammatory cytokines consistent with graft-versus-host disease (GVHD) were more pronounced in livers of persistently infected BMT mice than in uninfected BMT mice. These results suggest that MAV-1 persists in multiple sites without detectable evidence of ongoing replication. Our results indicate that MAV-1 persistence alters host responses to an unrelated challenge, even in the absence of detectable reactivation. Importance Long-term persistence in an infected host is an essential step in the life cycle of DNA viruses. Adenoviruses persist in their host following acute infection, but the nature of adenovirus persistence remains incompletely understood. Following intranasal infection of mice, we found that MAV-1 persists for a prolonged period in multiple organs, although we did not detect evidence of ongoing replication. Because BMT recipients are at risk for substantial morbidity and mortality from human adenovirus infections, often in the setting of reactivation of persistent virus in the recipient, we extended our findings using MAV-1 infection in a mouse model of BMT. MAV-1 persistence exacerbated GVHD-like inflammation following allogeneic BMT, even in the absence of virus reactivation. This novel finding suggests that adenovirus persistence has consequences, and it highlights the potential for a persistent adenovirus to influence host responses to unrelated challenges.

Current status of human adenovirus infection in China

BACKGROUND

Outbreaks of severe, acute hepatitis among children have recently attracted global attention. The pathogen causing the outbreak remains unknown, but there is growing evidence that it may be associated with human adenovirus (HAdV).

DATA SOURCES

A review of adenovirus-related clinical studies, epidemiological studies, etiological studies, and case reports was conducted by reviewers independently.

RESULTS

HAdV can cause a wide variety of clinical symptoms. In the Mainland of China, HAdV infection accounts for 5.8%-13% of patients with acute respiratory infections, and these infections are mainly caused by species B, C, and E of HAdV. For acute conjunctivitis, 39.8%-74.9% of sporadic cases were infected by B and D species of HAdV. Outbreaks of keratoconjunctivitis and pharyngoconjunctival fever related to HAdV infection could be found throughout the country. In pediatric patients with acute gastroenteritis, HAdV-41 was the predominant HAdV type, followed by HAdV species B and C. Several types of HAdV, including HAdV-5, HAdV-7, HAdV-1, and HAdV-2, have previously been reported as potential pathogens associated with HAdV hepatitis in immunocompromised patients. However, few HAdV-related hepatitis cases have been reported in China to date.

CONCLUSIONS

There are no systematic surveillance and clinical studies on HAdV hepatitis in China. Therefore, it is imperative to establish a nationwide HAdV virological surveillance system to collect relevant clinical, epidemiological and virological surveillance data and risk factor information as soon as possible to assess the potential risk of HAdV hepatitis among children.

Adenoviral Infections in Bone Marrow Transplanted Adult Patients: A Review of the 44 Cases Reported in the Last 25 Years

Adenoviral infections in immunocompromised individuals may be life-threatening conditions. The aim of this review is to document all the reported cases of adenoviral infection is patients having undergone bone marrow transplantation (BMT). A comprehensive literature search of the databases Pubmed, Science Direct, and Google Scholar was conducted to identify all the case reports of adenoviral infections in BMT patients. A total of 30 articles with 44 patients were included. The most common underlying condition was acute lymphocytic leukemia (23%) followed by acute myeloid leukemia (18%). The most common site of infection was disseminated (50%), followed by liver infection (8%) and hemorrhagic cystitis (8%). Cidofovir was administered in 40.9% of the cases, and death was reported in 34.4% of them. Ribavirin was administered as monotherapy in 15.9% of patients, with a mortality rate of 57.1%. We found that the antiviral drug option had no statistically significant effect on the mortality rate (p=0.242). Also, the absence of graft-versus-host disease (GVHD) was not associated with an improved outcome (p=0.523). There was, however, a statistically significant difference in the outcome based on the site of infection (p=0.005), with a higher rate of mortality in the disseminated and gastrointestinal cases. To the best of our knowledge, this is the first review documenting all the cases of adenoviral infections in BMT patients. Future randomized studies are needed to validate the results of the present study.

Viral kinetics and outcomes of adenovirus viremia following allogeneic hematopoietic cell transplantation

BACKGROUND

Adenovirus (AdV) is a serious infection following hematopoietic cell transplantation (HCT). Little is known about AdV viral kinetics and optimal threshold for initiation of pre-emptive therapy.

METHODS

Single-center retrospective study of 16 consecutive adult HCT recipients with detectable AdV identified over a 5-year period.

RESULTS

Median time to AdV reactivation after HCT was 176 days (IQR 86-408). Nine patients received cidofovir, although 14/16 had no tissue-invasive disease. Among treated patients, median duration of viremia was shorter when initiating treatment at viral loads < 10,000 copies/ml (28 vs. 52 days). All-cause mortality in this cohort was 44%. All six patients (five of which were untreated) with peak viral loads < 10,000 copies/ml survived; whereas only 30% (3/10) of patients with peak viral loads greater than this threshold survived, despite most (n = 8; 80%) of them receiving cidofovir (P = .01). Three-month survival following diagnosis of AdV viremia was significantly lower with peak viremia > 10,000 copies/ml (100 vs. 17%; P = .005).

CONCLUSION

AdV is associated with high all-cause mortality, especially for viremia > 10,000 copies/ml. Delaying therapy until viremia reaches AdV levels ≥10,000 copies/ml was associated with more protracted infection and poor outcomes. Larger studies are needed.

Post-allogeneic hematopoietic stem cell transplantation viral reactivations and viremias: a focused review on human herpesvirus-6, BK virus and adenovirus

Human cytomegalovirus and Epstein-Barr virus have been recognized as potential drivers of morbidity and mortality of patients undergoing allogeneic stem cell transplantation for years. Specific protocols for monitoring, prophylaxis and pre-emptive therapy are in place in many transplant settings. In this review, we focus on the next three most frequent viruses, human herpesvirus-6, BK virus and adenovirus, causing reactivation and/or viremia after allogeneic transplant, which are increasingly detected in patients in the post-transplant period owing to emerging techniques of molecular biology, recipients' characteristics, treatment modalities used for conditioning and factors related donors or stem cell source. Given the less frequent detection of an illness related to these viruses, there are often no specific protocols in place for the management of affected patients. While some patients develop significant morbidity (generally older), others may not need therapy at all (generally younger or children). Furthermore, some of the antiviral therapies used are potentially toxic. With the addition of increased risk of secondary infections, risk of graft failure or increased risk of graft-versus-host disease as well as the relationship with other post-transplant complications, the outcomes of patients with these viremias remain unsatisfactory and even long-term survivors experience increased morbidity.

Human Adenovirus 11 in 2 Renal Transplant Recipients: Suspected Donor-Derived Infection

BACKGROUND

Human adenovirus (HAdV) infections can lead to high mortality in solid organ transplant (SOT) recipients, with rare reports of donor-derived infection.

METHODS

Two renal transplant recipients with HAdV-11 infection who received kidneys from the same donor are described. Whole-genome sequencing (WGS) was performed.

RESULTS

WGS showed 100% nucleotide sequence identity for the 2 HAdV-11 isolates. The patients presented with distinct clinical syndromes, and both were treated with brincidofovir.

CONCLUSIONS

Donor-derived HAdV infection is presumed to be low; however, disseminated HAdV in SOT recipients can be severe, and clinicians should be aware of the clinical course and treatment options.

Broad Virus Detection and Variant Discovery in Fecal Samples of Hematopoietic Transplant Recipients Using Targeted Sequence Capture Metagenomics

Pediatric allogeneic hematopoietic stem cell transplantation (HSCT) patients often suffer from gastro-intestinal (GI) disease caused by viruses, Graft-versus-Host Disease (GVHD) or a combination of the two. Currently, the GI eukaryotic virome of HSCT recipients remains relatively understudied, which complicates the understanding of its role in GVHD pathogenicity. As decisions regarding immunosuppressive therapy in the treatment of virus infection or GVHD, respectively, can be completely contradicting, it is crucial to better understand the prevalence and relevance of viruses in the GI tract in the HSCT setting. A real time PCR panel for a set of specific viruses widely used to diagnose the most common causes of GI viral gastroenteritis is possibly insufficient to grasp the full extent of viruses present. Therefore, we applied the targeted sequence capture method ViroCap to residual fecal samples of 11 pediatric allogeneic HSCT recipients with GI symptoms and a suspicion of GVHD, to enrich for nucleic acids of viruses that are known to infect vertebrate hosts. After enrichment, NGS was applied to broadly detect viral sequences. Using ViroCap, we were able to detect viruses such as norovirus and adenovirus (ADV), that had been previously detected using clinical diagnostic PCR on the same sample. In addition, multiple, some of which clinically relevant viruses were detected, including ADV, human rhinovirus (HRV) and BK polyomavirus (BKV). Interestingly, in samples in which specific PCR testing for regular viral GI pathogens did not result in a diagnosis, the ViroCap pipeline led to the detection of viral sequences of human herpesvirus (HHV)-7, BKV, HRV, KI polyomavirus and astrovirus. The latter was an only recently described variant and showed extensive sequence mismatches with the applied real time PCR primers and would therefore not have been detected if tested. Our results indicate that target enrichment of viral nucleic acids through ViroCap leads to sensitive and broad possibly clinically relevant virus detection, including the detection of newer variants in clinical HSCT recipient samples. As such, ViroCap could be a useful detection tool clinically, but also in studying the associations between viral presence and GVHD.

Detection of adenovirus hepatitis and acute liver failure in allogeneic hematopoietic stem cell transplant patients

Human adenovirus (HAdV) is an important cause of the common cold and epidemic keratoconjunctivitis in immunocompetent individuals. In immunocompromised patients, HAdV can sometimes cause severe infection such as cystitis, gastroenteritis, pneumonia, encephalitis, hepatitis, or disseminated disease, resulting in significant morbidity and also mortality. In particular, severe cases have been reported in patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Indeed HAdV has been recognized as a pathogen that requires careful monitoring in allo-HSCT patients. While HAdV hepatitis leading to severe acute liver failure is rare, such liver failure progresses rapidly and is often fatal. Unfortunately, HAdV hepatitis has few characteristic symptoms and physical findings, which makes it difficult to promptly confirm and start treatment. We report here four cases of HAdV hepatitis after allo-HSCT and their autopsy findings.

Make Sure You Have a Safety Net: Updates in the Prevention and Management of Infectious Complications in Stem Cell Transplant Recipients

Hematopoietic stem cell transplant recipients are at increased risk of infection and immune dysregulation due to reception of cytotoxic chemotherapy; development of graft versus host disease, which necessitates treatment with immunosuppressive medications; and placement of invasive catheters. The prevention and management of infections in these vulnerable hosts is of utmost importance and a key “safety net” in stem cell transplantation. In this review, we provide updates on the prevention and management of CMV infection; invasive fungal infections; bacterial infections; Clostridium difficile infection; and EBV, HHV-6, adenovirus and BK infections. We discuss novel drugs, such as letermovir, isavuconazole, meropenem-vaborbactam and bezlotoxumab; weigh the pros and cons of using fluoroquinolone prophylaxis during neutropenia after stem cell transplantation; and provide updates on important viral infections after hematopoietic stem cell transplant (HSCT). Optimizing the prevention and management of infectious diseases by using the best available evidence will contribute to better outcomes for stem cell transplant recipients, and provide the best possible “safety net” for these immunocompromised hosts.

Brincidofovir as a Salvage Therapy in Controlling Adenoviremia in Pediatric Recipients of Hematopoietic Stem Cell Transplant

Adenovirus infection is a well-known complication in patients receiving hematopoietic stem cell transplantation (HSCT). Brincidofovir (BCV) is an orally bioavailable lipid conjugate of cidofovir, which has activity against adenoviruses. We present a review of adenovirus infections treated with BCV which were unresponsive to cidofovir initially in 4 patients and it was used upfront in one patient. Children with adenovirus infection following HSCT treated with BCV, between July 2014 and February 2018 were recognized. Five patients including 3 male and 2 female with a median age of 10 years (range, 2.2 to 10 y) were identified. The median days of adenoviremia detection was 18 days (range, 7 to 303 d) posttransplant. The median peak viral load by quantitative polymerase chain reaction was 21,38,000 copies/mL (range, 1,77,200 to 31,97,000 copies/mL). The median time from first detection of adenoviremia to become negative was 30 days (range, 15 to 113 d). The sites involved were gastrointestinal tract in all patients and 2 patients had additional respiratory tract involvement. Two patients survived and 3 patients died of sepsis. All patients responded well to BCV and no adverse effect was noticed. We saw the good safety profile and excellent antiadenoviral activity of BCV in pediatric patients receiving HSCT without the nephrotoxicity and it may have a role in preemptive therapy.

Outcomes of Human Adenovirus Infection and Disease in a Retrospective Cohort of Pediatric Hematopoietic Cell Transplant Recipients

BACKGROUND

Human adenoviruses (HAdVs) are associated with significant morbidity and death after hematopoietic cell transplantation (HCT). In this study, we sought to determine the incidence of HAdV infection among pediatric HCT recipients in the polymerase chain reaction (PCR) testing era, identify risk factors for viremia among patients undergoing HAdV surveillance, and assess the effectiveness of preemptive cidofovir.

METHODS

A single-center retrospective cohort of patients who underwent a transplant within a 10-year period was assembled. The incidence of and outcomes of patients with HAdV infection and disease were determined by PCR results and chart review. A Cox regression model was used for surveilled allogeneic HCT recipients to identify factors associated with viremia. We also used a discrete-time failure model with inverse probability treatment weights to assess the effectiveness of preemptive cidofovir for infection.

RESULTS

Among 572 HCT recipients, 76 (13.3%) had ≥1 sample that was HAdV PCR positive (3.5% of autologous HCT recipients and 19.7% of allogeneic HCT recipients). Among 191 allogeneic HCT recipients under surveillance, 58 (30.4%) had HAdV detected from any source, and 50 (26.2%) specifically had viremia. The mortality rate was higher in allogeneic HCT recipients with HAdV infection versus those without infection (25.9% vs 11.3%; P = .01). Factors associated with infection included an age of 6 to 12 years, an absolute lymphocyte count of <200 cells/μL, recent prednisone exposure, and recent bacteremia. Preemptive cidofovir was not associated with a reduced risk of infection progression (odds ratio, 0.96 [95% confidence interval, 0.30-3.05]).

CONCLUSIONS

HAdV infection is common and associated with an increased rate of death after allogeneic HCT. Using prediction models that incorporate factors associated with HAdV might help target surveillance. Preemptive cidofovir therapy was not protective in a subset of HAdV-positive patients. Larger observational or randomized investigations are necessary, because the utility of surveillance requires effective preemptive therapies.

Outcomes of human adenovirus infection and disease in a retrospective cohort of pediatric solid organ transplant recipients

Information about HAdV infection in SOT recipients is limited. We aimed to describe HAdV infection epidemiology and outcomes in a single-center retrospective cohort during the era of PCR availability. SOT recipients transplanted at the CHOP 2004-2013 were followed up for 180 days post-transplant. HAdV infection was defined as a positive HAdV PCR from a clinical specimen. HAdV disease was defined by organ-specific radiologic and/or laboratory abnormalities. No HAdV surveillance protocols were employed during the study period; testing was solely per clinician discretion. Progression of HAdV infection was defined as HAdV disease or ≥1-log viral load increase since a corresponding site's first positive specimen. Of the assembled 425 SOT recipients, 227 (52.6%) had ≥1 HAdV PCR. Twenty-four (10.6%) had ≥1 HAdV-positive PCR. HAdV-positive subjects were younger than uninfected subjects (2.0 years vs 6.5, P = 0.001). Infection incidence rates were highest in liver recipients (15.3%), followed by heart (8.6%), kidney (8.3%), and lung (4.2%). Four subjects (16.7%) met HAdV disease criteria at virus detection. Five subjects (20.8%) had progression of HAdV infection. All-cause mortality rates in positive and negative subjects were 0% and 3.9%, respectively. HAdV infection was infrequently detected in SOT recipients. Over one-third of HAdV-positive patients met disease criteria at detection or had infection progression, but none died. This low all-cause mortality raises questions about benefits of HAdV surveillance. Larger multicenter studies are needed to assess incidence variance by center and comparative effectiveness of therapeutic interventions.

Association between adenovirus viral load and mortality in pediatric allo-HCT recipients: the multinational AdVance study

This multivariable analysis from the AdVance multicenter observational study assessed adenovirus (AdV) viremia peak, duration, and overall AdV viral burden-measured as time-averaged area under the viremia curve over 16 weeks (AAUC_0-16)-as predictors of all-cause mortality in pediatric allo-HCT recipients with AdV viremia. In the 6 months following allo-HCT, 241 patients had AdV viremia ≥ 1000 copies/ml. Among these, 18% (43/241) died within 6 months of first AdV ≥ 1000 copies/ml. Measures of AdV viral peak, duration, and overall burden of infection consistently correlate with all-cause mortality. In multivariable analyses, controlling for lymphocyte recovery, patients with AdV AAUC_0-16 in the highest quartile had a hazard ratio of 11.1 versus the lowest quartile (confidence interval 5.3-23.6); for peak AdV viremia, the hazard ratio was 2.2 for the highest versus lowest quartile. Both the peak level and duration of AdV viremia were correlated with short-term mortality, independent of other known risk factors for AdV-related mortality, such as lymphocyte recovery. AdV AAUC_0-16, which assesses both peak and duration of AdV viremia, is highly correlated with mortality under the current standard of care. New therapeutic agents that decrease AdV AAUC_0-16 have the potential of reducing mortality in this at-risk patient population.

Impacts and Challenges of Advanced Diagnostic Assays for Transplant Infectious Diseases

The advanced technologies described in this chapter should allow for full inventories to be made of bacterial genes, their time- and place-dependent expression, and the resulting proteins as well as their outcome metabolites. The evolution of these molecular technologies will continue, not only in the microbial pathogens but also in the context of host-pathogen interactions targeting human genomics and transcriptomics. Their performance characteristics and limitations must be clearly understood by both laboratory personnel and clinicians to ensure proper utilization and interpretation.

EBV-PTLD, Adenovirus, and CMV in Pediatric Allogeneic Transplants With Alemtuzumab as Part of Pretransplant Conditioning: A Retrospective Single Center Study

The risk of viral infections and reactivation occurring in the setting of pediatric allogeneic hematopoietic stem cell transplantation is a concern in the pediatric patient, especially with the use of Alemtuzumab (Campath) as a conditioning agent. The purpose of this study was to determine the incidence of Epstein-Barr virus posttransplant lymphoproliferative disorder (EBV-PTLD), cytomegalovirus (CMV), and adenovirus among pediatric recipients of alemtuzumab at our institution. We found that EBV-PTLD occurred in 2.1% of transplants (1 matched unrelated donor [MUD] recipient), CMV reactivation occurred in 12.5% of transplants (4 MUD and 2 matched related donor [MRD] recipients) with disseminated CMV in 2.1% of cases (1 MRD recipient), and adenovirus infection occurred in 8.3% of the total transplants (2 MUD and 2 MRD recipients). Alemtuzumab continues to be used as a method of graft-versus-host disease and graft failure prevention among pediatric recipients of hematopoietic stem cell transplantation and seems to be safer than previously reported. At our institution, alemtuzumab has not increased the risk for EBV-PTLD, CMV infection, or adenovirus.

Discovery of small molecule inhibitors of adenovirus by disrupting E3-19K/HLA-A2 interactions

The binding of the adenovirus (Ad) protein E3-19K with the human leukocyte antigen (HLA) plays an important role in Ad infections, which is the causative agent of a series of gastrointestinal, respiratory and ocular diseases. The objective of this research is to evaluate the essential interactions between E3-19K and HLA-A2 using the X-ray crystal structure of the E3-19K/HLA-A2 complex, and to identify small molecules that could potentially disrupt their binding. Computational methods, including molecular dynamic simulations, MM/GBSA calculations, and computational solvent mapping, were implemented to determine potential binding site(s) for small molecules. The previous experimentally determined hot spot residues, Q54 and E177 in HLA-A2, were also predicted to be the dominant residues for binding to E3-19K by our theoretical calculations. Several other residues were also found to play pivotal roles for the binding of E3-19K with HLA-A2. Residues adjacent to E177, including Q54 and several other residues theoretically predicted to be crucial in HLA-A2 were selected as a potential binding pocket to perform virtual screening with 1200 compounds from the Prestwick library. Seven hits were validated by surface plasmon resonance (SPR) as binders to HLA-A2 as a first step in identifying molecules that can perturb its association with the Ad E3-19K protein.

Disseminated adenovirus infection after allogeneic stem cell transplant and the potential role of brincidofovir - Case series and 10 year experience of management in an adult transplant cohort

BACKGROUND

Adenovirus infection is a recognized complication following haematopoietic stem cell transplantation. We present a review of our experience of these infections in our transplant cohort over 10 years including 3 patients treated with the novel antiviral brincidofovir.

OBJECTIVES

We aimed to describe the presentation, response to treatment and outcomes of adult stem cell transplant patients with disseminated adenovirus infection.

STUDY DESIGN

All adult cases of disseminated adenovirus infection following haematopoietic stem cell transplant in our unit between 2005 and 2015 were identified. Transplant details and data on timing of diagnosis, course of infection, viral co-infection and treatment were collected.

RESULTS

Of 733 patients transplanted, 10 patients had disseminated infection, including 4 male and 6 female patients with median age of 36.5 (range 19-59) years. 6/10 received an allograft from an unrelated donor. Median post-transplant time to detection of viraemia was 67days (range 20-1140days). Median peak viral load was 3133 copies/ml (352-11,000,000) in survivors received cidofovir alone, one cidofovir then brincidofovir and two brincidofovir alone. 8/10 p and 1,580,000 copies/ml (41,999-3,000.000) in those who died. Five patientsatients had a decrease in viral load following antivirals and/or reduction in immunosuppression including all on brincidofovir. Three died on treatment.

CONCLUSIONS

Disseminated adenovirus infection is uncommon in adult transplant patients and uncertainties remain surrounding effective treatment. In our cohort, brincidofovir has shown promise in treatment of adenoviral infection. However, randomized controlled studies are required to confirm this impression.

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.

Adenovirus

Adenoviruses are a highly prevalent infection that can cause a range of clinical syndromes in immunocompromised patients, ranging from localized disease of the respiratory tract, gastrointestinal tract, or urinary tract to disseminated disease. Adenovirus infections may develop in this unique population as the result of primary infection or reactivation of latent virus. Disease can be potentially progressive with high rates of mortality in patients with pneumonia and disseminated disease. Fortunately, cidofovir and its lipid ester, brincidofovir, appear to be effective for the treatment of adenovirus, although neither is specifically approved for this indication. Adenovirus should always be considered when immunocompromised patients present with any clinical syndrome that could be compatible with adenoviral infection. Once disease is suspected, cultures or molecular testing of appropriate specimens should be obtained and blood should be sent for adenovirus polymerase chain reaction (PCR) whenever adenovirus is suspected. Monitoring of quantitative viral loads in blood is helpful in predicting response to therapy with a significant drop (>1 log) associated with a higher probability of clinical response.

Genitourinary Tract Infections

Similarly to the general population, genitourinary tract infections are common conditions in theimmunocompromised host. They can be furthermore divided into infections of the urinary tract and genital tract infections. Transplant recipients are more likely to have infections of the urinary tract infections while persons with human immunodeficiency virus (HIV) are at higher risk for the second group of infections, especially sexually transmitted infections (STIs). Manifestations of these diseases can be associated with more complications and can be more severe. We provide an overview of manifestations, diagnosis, and management of these disorders.

Brincidofovir for Asymptomatic Adenovirus Viremia in Pediatric and Adult Allogeneic Hematopoietic Cell Transplant Recipients: A Randomized Placebo-Controlled Phase II Trial

Adenovirus infection in immunocompromised patients contributes to significant morbidity and mortality, especially after allogeneic hematopoietic cell transplantation (HCT). Brincidofovir (BCV, CMX001) is an orally bioavailable lipid conjugate of cidofovir that has in vitro activity against adenoviruses and other double-stranded DNA viruses. This randomized placebo-controlled phase II trial evaluated pre-emptive treatment with BCV for the prevention of adenovirus disease in pediatric and adult allogeneic HCT recipients with asymptomatic adenovirus viremia. Allogeneic HCT recipients with adenovirus viremia were randomized 1:1:1 to receive oral BCV 100 mg (2 mg/kg if <50 kg) twice weekly (BIW), BCV 200 mg (4 mg/kg if <50 kg) once weekly (QW), or placebo for 6 to 12 weeks, followed by 4 weeks of post-treatment follow-up. For randomization, subjects were stratified by screening absolute lymphocyte count (<300 cells/mm³ versus ≥300 cells/mm³). Assignment to BCV or placebo was double blinded; dose frequency was unblinded. The primary endpoint was the proportion of subjects experiencing treatment failure, defined as either progression to probable or definitive adenovirus disease or confirmed increasing adenovirus viremia (≥1 log₁₀ copies/mL) during randomized therapy. Between June 2011 and December 2012, 48 subjects were randomized to the BCV BIW (n = 14), BCV QW (n = 16), or placebo (n = 18) groups. The proportion of subjects with treatment failure in the BCV BIW group was 21% (odds ratio, .53; 95% confidence interval [CI], .11 to 2.71; P = .45), 38% (odds ratio, 1.23; 95% CI, .30 to 5.05, P = .779) in the BCV QW group, and 33% in the placebo group. All-cause mortality was lower in the BCV BIW (14%) and BCV QW groups (31%) relative to the placebo group (39%), but these differences were not statistically significant. After 1 week of therapy, 8 of 12 subjects (67%) randomized to BCV BIW had undetectable adenovirus viremia (<100 copies/mL), compared with 4 of 14 subjects (29%) randomized to BCV QW and 5 of 15 subjects (33%) randomized to placebo. In a post hoc analysis of subjects with viremia ≥1000 copies/mL at baseline, 6 of 7 BCV BIW subjects (86%) achieved undetectable viremia compared with 2 of 8 placebo subjects (25%; P = .04). Early treatment discontinuation because of adverse events was more common in subjects treated with BCV than with placebo. Diarrhea was the most common event in all groups (57% BCV BIW, 38% BCV QW, 28% placebo), but it led to treatment discontinuation in only 1 subject receiving BCV QW. Events diagnosed as acute graft-versus-host disease, primarily of the gastrointestinal tract, were more frequent in the BCV BIW group (50%) than in the BCV QW (25%) and placebo (17%) groups. There was no evidence of myelotoxicity or nephrotoxicity in BCV-treated subjects. The results of this trial confirm the antiviral activity of BCV against adenoviruses. Further investigation is ongoing to define the optimal treatment strategy for HCT recipients with serious adenovirus infection and disease.

Humanized Mice Reproduce Acute and Persistent Human Adenovirus Infection

Severe human adenovirus (HAdV) infections are an increasing threat for immunosuppressed individuals, particularly those who have received stem cell transplants. It has been previously hypothesized that severe infections might be due to reactivation of a persistent infection, but this hypothesis has been difficult to test owing to the lack of a permissive in vivo model of HAdV infection. Here we established a humanized mouse model that reproduces features of acute and persistent HAdV infection. In this model, acute infection correlated with high mortality, weight loss, liver pathology, and expression of viral proteins in several organs. In contrast, persistent infection was asymptomatic and led to establishment of HAdV-specific adaptive immunity and expression of early viral genes exclusively in the bone marrow. These findings validate the use of humanized mice to study acute and persistent HAdV infection and strongly suggest the presence of cellular reservoirs in the bone marrow.

Structure of the Adenovirus Type 4 (Species E) E3-19K/HLA-A2 Complex Reveals Species-Specific Features in MHC Class I Recognition

Adenoviruses (Ads) subvert MHC class I Ag presentation and impair host anti-Ad cellular activities. Specifically, the Ad-encoded E3-19K immunomodulatory protein targets MHC class I molecules for retention within the endoplasmic reticulum of infected cells. We report the x-ray crystal structure of the Ad type 4 (Ad4) E3-19K of species E bound to HLA-A2 at 2.64-Å resolution. Structural analysis shows that Ad4 E3-19K adopts a tertiary fold that is shared only with Ad2 E3-19K of species C. A comparative analysis of the Ad4 E3-19K/HLA-A2 structure with our x-ray structure of Ad2 E3-19K/HLA-A2 identifies species-specific features in HLA-A2 recognition. Our analysis also reveals common binding characteristics that explain the promiscuous, and yet high-affinity, association of E3-19K proteins with HLA-A and HLA-B molecules. We also provide structural insights into why E3-19K proteins do not associate with HLA-C molecules. Overall, our study provides new information about how E3-19K proteins selectively engage with MHC class I to abrogate Ag presentation and counteract activation of CD8(+) T cells. The significance of MHC class I Ag presentation for controlling viral infections, as well as the threats of viral infections in immunocompromised patients, underline our efforts to characterize viral immunoevasins, such as E3-19K.

Prolonged outbreak of adenovirus A31 in allogeneic stem cell transplant recipients

BACKGROUND

An outbreak of human adenovirus (HAdV) A31 occurred from December 2011 to March 2012 at the Center for Allogeneic Stem Cell Transplantation (CAST), Karolinska University Hospital in Sweden. We analyzed the outbreak, the routes of transmission, and report the medical consequences.

METHODS

The medical records of all patients admitted to CAST during the outbreak period were studied. Phylogenetic analysis of the patient HAdV strains was performed by sequencing the hexon gene and the more variable E3 gene.

RESULTS

We identified 9 cases of HAdV A31. Hygiene measures were implemented, but transmission continued for 2 months. All 9 patients had been admitted to the ward, but 2 had no connection in time to other known HAdV A31 cases. DNA sequencing of the patient strains strongly suggested nosocomial transmission. Transplantation was postponed and then cancelled in 1 patient, and 5 patients were treated with cidofovir because of high levels of viremia. In 7 patients, concomitant graft-versus-host disease (GVHD) grade II-V complicated the clinical picture, as it was difficult to distinguish symptoms of GVHD from those of HAdV infection.

CONCLUSION

An outbreak of HAdV in HSCT recipients can be difficult to control. Although none of the patients had severe disease, the medical consequences were significant. It is possible that unidentified cases with mild symptoms may have caused continuous transmission at the unit. Regular testing of all patients several weeks beyond the last case identified may be an important measure to control transmission.

Fulminant adenovirus hepatitis after hematopoietic stem cell transplant: Retrospective real-time PCR analysis for adenovirus DNA in two cases

BACKGROUND

Viral infection is one of the major causes of mortality in patients undergoing hematopoietic stem cell transplant (HSCT). Systemic infection of adenovirus (AdV) has emerged as a not uncommon viral infection with significant morbidity and mortality as with cytomegalovirus and Epstein-Barr virus infection. Routine surveillance for these viruses has become a clinical practice and subsequent preemptive therapy improves patients' outcomes; however, the effectiveness of preemptive therapy for AdV has not been fully investigated in patients with a lethal form of AdV infection.

METHODS

Sequential AdV loads were retrospectively analyzed in children with fulminant AdV hepatitis after HSCT.

RESULTS

The AdV DNA became detectable (1 × 10(4) copies/mL) as early as 2 weeks after HSCT. These levels reached >1 × 10(8) copies/mL at the onset of fulminant hepatitis. However, we determined that γ-glutamyltransferase levels were elevated to >100 IU/L at least 2 weeks before the diagnosis of hepatitis.

CONCLUSIONS

Our observation raises the possibility that elevated γ-glutamyltransferase could be a sentinel marker for AdV hepatitis, which prompts elaborated monitoring of AdV load and targeted treatment.

Prostaglandin E2 Production and T Cell Function in Mouse Adenovirus Type 1 Infection following Allogeneic Bone Marrow Transplantation

Adenovirus infections are important complications of bone marrow transplantation (BMT). We demonstrate delayed clearance of mouse adenovirus type 1 (MAV-1) from lungs of mice following allogeneic BMT. Virus-induced prostaglandin E₂ (PGE₂) production was greater in BMT mice than in untransplanted controls, but BMT using PGE₂-deficient donors or recipients failed to improve viral clearance, and treatment of untransplanted mice with the PGE₂ analog misoprostol did not affect virus clearance. Lymphocyte recruitment to the lungs was not significantly affected by BMT. Intracellular cytokine staining of lung lymphocytes demonstrated impaired production of INF-γ and granzyme B by cells from BMT mice, and production of IFN-γ, IL-2, IL-4, and IL-17 following ex vivo stimulation was impaired in lymphocytes obtained from lungs of BMT mice. Viral clearance was not delayed in untransplanted INF-γ-deficient mice, suggesting that delayed viral clearance in BMT mice was not a direct consequence of impaired IFN-γ production. However, lung viral loads were higher in untransplanted CD8-deficient mice than in controls, suggesting that delayed MAV-1 clearance in BMT mice is due to defective CD8 T cell function. We did not detect significant induction of IFN-β expression in lungs of BMT mice or untransplanted controls, and viral clearance was not delayed in untransplanted type I IFN-unresponsive mice. We conclude that PGE₂ overproduction in BMT mice is not directly responsible for delayed viral clearance. PGE₂-independent effects on CD8 T cell function likely contribute to the inability of BMT mice to clear MAV-1 from the lungs.

A Rare Case of Hemorrhagic Cystitis in Allogeneic Hematopoietic Stem Cell Transplant Patient

Post bone marrow transplant patients are susceptible to atypical infections, especially viral pathogens. The risk increases many folds in cases of allogeneic transplantation, which also receive GVHD prophylaxis. Viral pathogens like cytomegalovirus and herpes are the common ones encountered during follow-up period. However, in recent times there have been reports of a variety of disease manifestations of rare viruses like polyoma virus and adenovirus. These viral infections may play a crucial role in morbidity and mortality in immunocompromised patients. We hereby elaborate the follow-up course of a 36-year-old post allogeneic transplant patient of acute myeloid leukemia who developed adenovirus related haemorrhagic cystitis. Treatment with oral ribavirin lead to dramatic improvement in symptomatology within a week. This cases re-emphasizes the fact that after ruling out the commoner pathogens, it's of utmost importance to strongly consider the atypical pathogens in such cases.

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.

The effects of intestinal tract bacterial diversity on mortality following allogeneic hematopoietic stem cell transplantation

Highly diverse bacterial populations inhabit the gastrointestinal tract and modulate host inflammation and promote immune tolerance. In allogeneic hematopoietic stem cell transplantation (allo-HSCT), the gastrointestinal mucosa is damaged, and colonizing bacteria are impacted, leading to an impaired intestinal microbiota with reduced diversity. We examined the impact of intestinal diversity on subsequent mortality outcomes following transplantation. Fecal specimens were collected from 80 recipients of allo-HSCT at the time of stem cell engraftment. Bacterial 16S rRNA gene sequences were characterized, and microbial diversity was estimated using the inverse Simpson index. Subjects were classified into high, intermediate, and low diversity groups and assessed for differences in outcomes. Mortality outcomes were significantly worse in patients with lower intestinal diversity; overall survival at 3 years was 36%, 60%, and 67% for low, intermediate, and high diversity groups, respectively (P = .019, log-rank test). Low diversity showed a strong effect on mortality after multivariate adjustment for other clinical predictors (transplant related mortality: adjusted hazard ratio, 5.25; P = .014). In conclusion, the diversity of the intestinal microbiota at engraftment is an independent predictor of mortality in allo-HSCT recipients. These results indicate that the intestinal microbiota may be an important factor in the success or failure in allo-HSCT.

Adenovirus: current epidemiology and emerging approaches to prevention and treatment

Infections caused by adenoviruses are associated with significant morbidity and mortality in both hematopoietic stem cell and solid organ transplant recipients. The risk seems to be highest in allogeneic hematopoietic stem cell transplant recipients as well as heart, lung and small-bowel transplant recipients. Management of these infections may be difficult and includes reduction of immunosuppression whenever possible combined sometimes with antiviral therapy (mainly cidofovir). The currently available antiviral therapy is limited by the need for intravenous administration, potentially significant renal and hematologic toxicities. New emerging therapies such as brincidofovir and transfusion of adenovirus-specific T-lymphocytes may increase the available armamentarium for these potentially life-threatening infections.

Mesenchymal stromal cell therapy is associated with increased adenovirus-associated but not cytomegalovirus-associated mortality in children with severe acute graft-versus-host disease

Beneficial effects of mesenchymal stromal cells (MSCs) in patients with severe steroid-refractory acute graft-versus-host disease (aGvHD) have been reported. However, controversy exists about the effect of MSCs on virus-specific T cells. We evaluated 56 patients with grade II-IV aGvHD who responded to steroids (n = 21) or were steroid refractory receiving either MSCs (n = 22) or other second-line therapy (n = 13). Although the overall incidence of cytomegalovirus (CMV), Epstein-Barr virus, and human adenovirus (HAdV) infections was not significantly increased, HAdV infection was associated with decreased survival in children treated with MSCs. Thus, we investigated in vitro the effects of MSCs on virus-specific T cells. Both CMV-specific and, to a lesser extent, HAdV-specific T-cell activation and proliferation were negatively affected by MSCs either after induction of a response in peripheral blood mononuclear cells (PBMCs) or after restimulation of virus-specific T-cell lines. In patient-derived PBMCs, CMV-specific proliferative responses were greatly decreased on first-line treatment of aGvHD with systemic steroids and slowly recovered after MSC administration and tapering of steroids. HAdV-specific T-cell proliferation could not be detected. In contrast, the proportion of CMV- and HAdV-specific effector T cells, measured as interferon-γ-secreting cells, remained stable or increased after treatment with MSCs. In conclusion, although in vitro experimental conditions indicated a negative impact of MSCs on CMV- and HAdV-specific T-cell responses, no solid evidence was obtained to support such an effect of MSCs on T-cell responses in vivo. Still, the susceptibility of steroid-refractory severe aGvHD patients to viral reactivation warrants critical viral monitoring during randomized controlled trials on second-line treatment including MSCs.

Advances in the management of viral infections

Viral infections are common in cancer patients. The risk and severity of infection are influenced by patient, disease, treatment, and viral factors. Severe viral infections are more likely to occur in treatment regimens that are more immunosuppressive. Historically, the most frequent severe infections have been due to herpesviruses, but more recently, other pathogens, especially community respiratory and hepatitis viruses, have received increasing attention as major viral pathogens in cancer patients. Because of the new diagnostic assays and the introduction of better therapeutic options, knowledge of viral infections is important in optimizing antineoplastic therapies.

Adenovirus pneumonia presenting with nodular shadows on chest X-ray in two unrelated allogeneic bone marrow transplant recipients

Adenoviruses are increasingly recognized as important pathogens following allogeneic stem cell transplantation. We herein report two cases of disseminated adenovirus infection that presented with nodular shadows on chest X-ray after allogeneic bone marrow transplantation from unrelated donors. Both patients died of respiratory failure. Autopsies revealed adenovirus infection of multiple organs. Adenovirus infection should be suspected when nodular lung lesions of unknown origin appear in allogeneic stem cell transplant recipients.

Diagnosis and treatment of viral diseases in recipients of allogeneic hematopoietic stem cell transplantation

Viral infections are important causes of morbidity and mortality after allogeneic stem cell hematopoietic transplantation (allo-HSCT). Although most viral infections present with asymptomatic or subclinical manifestations, viruses may result in fatal complications in severe immunocompromised recipients. Reactivation of latent viruses, such as herpesviruses, is frequent during the immunosuppression that occurs with allo-HSCT. Viruses acquired from community, such as the respiratory and gastrointestinal viruses, are also important pathogens of post-transplant viral diseases. Currently, molecular diagnostic methods have replaced or supplemented traditional methods, such as viral culture and antigen detection, in diagnosis of viral infections. The utilization of polymerase chain reaction facilitates the early diagnosis. In view of lacking efficacious agents for treatment of viral diseases, prevention of viral infections is extremely valuable. Application of prophylactic strategies including preemptive therapy reduces viral infections and diseases. Adoptive cellular therapy for restoring virus-specific immunity is a promising method in the treatment of viral diseases.

Management of adenovirus in children after allogeneic hematopoietic stem cell transplantation

Adenovirus (ADV) can cause significant morbidity and mortality in children following haematopoietic stem cell transplantation (HSCT), with an incidence of up to 27% and notable associated morbidity and mortality. T-cell depleted grafts and severe lymphopenia are major risk factors for the development of adenovirus disease after HSCT. Current antiviral treatments are at best virostatic and may have significant side effects. Adoptive transfer of donor-derived virus-specific T cells has been shown to be an effective strategy for the prevention and treatment of ADV infection after HSCT. Here we review progress in the field and present a pathway for the management of adenovirus in the posttransplant setting.

Fulminant hepatitis due to human adenovirus

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.

Adenoviral infections in adult allogeneic hematopoietic SCT recipients: a single center experience

Disseminated adenoviral infection (AI) is associated with profound immunosuppression and poor outcome after allogeneic hematopoietic SCT (allo-HSCT). A better understanding of AI in allo-HSCT recipients can serve as a basis to develop more effective management strategies. We evaluated all adult patients who received allo-HSCT at MD Anderson Cancer Center between 1999 and 2008. Among the 2879 allo-HSCT patients, 73 (2.5%) were diagnosed with AI. Enteritis (26%) and pneumonia (24%) were the most common clinical manifestations; pneumonia was the most common cause of adenovirus-associated death. A multivariable Bayesian logistic regression showed that when the joint effects of all covariates were accounted for, cord blood transplant, absolute lymphocyte count (ALC) ≤ 200/mm(3) and male gender were associated with a higher probability of disseminated AI. The OS was significantly worse for patients with AI that was disseminated rather than localized (median of 5 months vs median of 28 months, P<0.001) and for patients with ALC ≤ 200/mm(3) (P<0.001). Disseminated AI, in patients who received allo-HSCT, is a significant cause of morbidity and mortality. Strategies for early diagnosis and intervention are essential, especially for high-risk patients.

[Adenovirus infections in immunocompromised patients]

Human adenoviruses function as genetic models and vectors for gene therapy. Upper respiratory, gastrointestinal or ocular infections usually have mild course without any major complication in immunocompetent individuals. However, reactivation from latency in immunocompromised patients may lead to death. Depending on the underlying diseases, different adenovirus serotypes damage different organs. In children with severe combined immunodeficiency syndrome, serotypes of species A and C induce lung, liver or bladder inflammation. Paediatric hematopoietic stem cell transplantation is frequently followed by serotype 31-induced pneumonia, enteritis, cystitis. B serotypes can destroy transplanted organs. In AIDS patients, D and novel F serotypes cause enteritis. Recombinants of B serotypes induce urinary tract infections. Progression of lymphomas, tumours, and systemic lupus erythematosus might be facilitated by immunosuppressive effects of adenoviruses. As far as the diagnostic work-up of adenoviruses, detection of viral DNA and virus copy number is predictive, while serology testing is quite unreliable. For treatment, cidofovir derivates, ribavirin, ganciclovir, vidarabine and microRNA have been used.

Adenovirus viremia and disease: comparison of T cell-depleted and conventional hematopoietic stem cell transplantation recipients from a single institution

Adenovirus (ADV) is an important cause of viral mortality in hematopoietic stem cell transplantation (HSCT). Recipients of T cell-depleted (TCD) HSCT are at increased risk for viral infections. We compared the rates and outcomes of ADV viremia and disease between TCD and conventional (CONV) HSCT at our institution. This was an observational study of 624 adult and pediatric recipients of myeloablative HSCT at Memorial Sloan-Kettering Cancer Center between January 1, 2006, and March 11, 2011. Viral cultures and ADV PCR were ordered as clinically indicated. ADV viremia by quantitative PCR assay was defined as 1 or more positive values ≥1,000 copies/mL or 2 or more consecutive positive values. Competing-risk regression analyses were used to identify predictors for ADV viremia. ADV viremia at 1 year after HSCT occurred in 8% of TCD HSCT recipients and in 4.0% of CONV HSCT recipients (P = .041). Among the TCD recipients, ADV viremia was seen in 15% of children, compared with 5% of adults (P = .008). Young age (hazard ratio [HR], 3.0; P < .001) and acute graft-versus-host disease (GVHD) (HR, 3.2; P = .001) were identified as risk factors for ADV viremia. ADV viremia was predictive of mortality (HR, 6.0; P < .001). ADV disease developed in 3.5% of TCD HSCT recipients and in 0.4% of CONV HSCT recipients (P = .022), with an attributable mortality of 27%. Among TCD HSCY recipients, grade II to IV GVHD was a risk factor for ADV disease (HR, 13; P < .001), but age was not. More than 90% of the cases of ADV disease involved a viral load of ≥10,000 copies/mL. Rates of ADV disease were 10-fold greater in TCD HSCT recipients compared with CONV HSCT recipients, predominantly in patients who developed acute GVHD. The benefit of preemptive therapy for an ADV viral load ≥10,000 copies/mL for preventing ADV disease in TCD HSCT recipients should be evaluated in prospective clinical trials.