Adenovirus infections in patients undergoing bone-marrow transplantation

Molecular detection and quantitative analysis of the entire spectrum of human adenoviruses by a two-reaction real-time PCR assay

Adenoviruses (AdV) can cause life-threatening infections in immunosuppressed patients. Reliable diagnostic tests are therefore of paramount importance. Apparently, any of the six AdV species (A to F), currently comprising 51 different serotypes, can play a clinically important role in patients with impaired immune response. It is imperative therefore that diagnostic assays cover the entire spectrum of these viruses. We have sequenced presumably conserved regions of the adenoviral genome in all AdV serotypes. Based on the complete sequence information of the hexon gene, we were able to develop a two-reaction real-time PCR assay covering all human adenoviruses with equally high specificity and sensitivity. The detection systems were tested using reference strains for all 51 serotypes and >1,000 clinical samples derived from peripheral blood and stool specimens from pediatric patients after allogeneic stem cell transplantation. The two-reaction assay presented permits highly specific detection and quantification of adenoviral DNA of any serotype. From the perspective of routine clinical diagnosis, the assay represents an important improvement over existing approaches by providing a sensitive and economic technique for early detection and monitoring of adenoviral infections.

Improved outcome for children with disseminated adenoviral infection following allogeneic stem cell transplantation

Adenovirus (AdV) infections are a frequent cause of morbidity and mortality following allogeneic stem cell transplantation (SCT), and disseminated infection is associated with high mortality, particularly in paediatric SCT. Here, we describe an approach to reduce mortality from adenoviraemia by combining prospective monitoring for the occurrence of adenoviraemia using a sensitive polymerase chain reaction method, early antiviral therapy and prompt withdrawal of immunosuppression. A total of 155 consecutive paediatric SCT procedures were prospectively monitored, of which 113 (73%) transplants involved donors other than matched siblings and 126 (83%) employed T-cell depletion. Adenoviraemia was detected in 26/155 (17%) transplants and developed exclusively in patients who had received T-cell-depleted grafts. Withdrawal of immunosuppression coupled with early antiviral therapy led to resolution of adenoviraemia in 19/26 (81%) patients with only five patients succumbing to disseminate AdV infection. Survival from adenoviraemia was associated with lymphocyte recovery to above 0.3x10(9)/l. Mortality was closely linked with the absence of lymphocyte recovery because of profound T-cell depletion of the graft with CD34+ magnetic-activated cell sorting. Mortality from disseminated AdV infection was 5/26 (19%) in this study, which is significantly lower than previously reported.

Localization of regions in CD46 that interact with adenovirus

A variety of pathogens use CD46, a ubiquitously expressed membrane protein that regulates complement activation, as a cellular attachment receptor. While the CD46 binding sites of several pathogens, including measles virus, Neisseria gonorrhea, and human herpesvirus 6, have been described, the region of CD46 responsible for adenovirus binding has not been determined. In this study, we used competition experiments with known CD46 ligands, CD46-specific antibodies, and a set of CD46 mutants to localize the binding domain for the group B adenovirus serotype 35 (Ad35). Our results show that Ad35 competes with measles virus for binding to CD46 but not with complement protein C3b. We further show that this interaction is a protein-protein interaction and that N glycosylations do not critically contribute to infection with Ad35 fiber-containing Ad vectors. Our data demonstrate that the native conformation of the CCP2 domain is crucial for Ad35 binding and that the substitution of amino acids at positions 130 to 135 or 152 to 156 completely abolishes the receptor function of CD46. These regions localize to the same planar face of CD46 and likely form an extended adenovirus binding surface, since no single amino acid substitution within these areas eliminates virus binding. Finally, we demonstrate that the infection with a virus possessing human group B serotype Ad11 fibers is also mediated by the CCP2 domain. This information is important to better characterize the mechanisms of the receptor recognition by adenovirus relative to other pathogens that interact with CD46, and it may help in the design of antiviral therapeutics against adenovirus serotypes that use CD46 as a primary cellular attachment receptor.

Internally controlled real-time PCR monitoring of adenovirus DNA load in serum or plasma of transplant recipients

Adenoviruses have been recognized as important pathogens in immunocompromised hosts. Particularly in pediatric allogeneic stem cell transplant recipients, the morbidity of the patients and mortality in those patients with disseminated infections have been found to increase over the last few years. Severe infections are predominantly but not exclusively caused by subgroup C adenoviruses. A multiplex real-time PCR assay using molecular beacons as probes was developed to enable monitoring of adenovirus DNA in those patients with simultaneous identification of subgroups. An internal control was coamplified in the multiplex PCR to check for the DNA isolation procedure as well as the presence of inhibitors in the clinical samples. The assay has been applied retrospectively in patient groups with different clinical outcomes of infection. In fatal cases, significantly higher adenovirus loads developed, exceeding even 10(11) copies/ml of serum or plasma. Patients with viral loads over 10(6) copies/ml appear to have an increased risk for fatal complications. This quantitative real-time PCR assay has been prospectively used clinically since 2002 to study the course of adenovirus infection. In addition, the assay provides objective start and end points of therapeutic interventions, including the clinically important evaluation of antiviral drugs.

GI complications in pediatric patients post-BMT

This retrospective study comprehensively examined hepatic and gastrointestinal complications post-bone marrow transplant (BMT) in a heterogeneous group of 132 pediatric patients that underwent 142 transplants. Hyperbilirubinemia occurred in 28% of this population with clinically evident jaundice in 16%. Acute graft-versus-host disease (GVHD) occurred in 46% of the population, with liver involvement in 39% and intestinal involvement in 60% of those with acute GVHD. Veno-occlusive disease (VOD) occurred in 18% of the population. A greater increase in hepatic transaminases was noted in GVHD and VOD than nonspecific liver injury. Serum bilirubin may help to differentiate between VOD and hepatic GVHD. Biliary sludging occurred in 20% of patients and was associated with increased morbidity. Common post transplant gastrointestinal complications included mucositis in 90%, vomiting in 85% and abdominal pain in 71%. TPN support post transplant was required in 91%. Diarrhea occurred in 67% with the most common identified etiologies reported as GVHD (27%), viral (6%), Clostridium difficile (8%) infections and unknown (28%). Typhilitis developed in 3.5%. Melena or hematochezia occurred in 11 patients (8%). However, gastrointestinal bleeding was disproportionately represented in intensive care unit admissions (5/27) and 100 day mortality (5/21). Gastrointestinal and hepatic complications represent a major cause of morbidity and mortality in pediatric BMT recipients.

Fatal adenovirus hepatitis during standard chemotherapy for childhood acute lymphoblastic leukemia

Fulminant hepatitis is a rare complication of adenoviral infection that has not previously been reported in children receiving standard chemotherapy for acute leukemia. The authors have observed fatal adenovirus hepatitis in three children receiving first-line chemotherapy for acute lymphoblastic leukemia (ALL). The patients presented 10, 17, and 8 months into therapy according to the UKALL XI (third intensification), UKALL 97/99 (maintenance), and pilot UKALL 2003 (delayed intensification II) protocols, respectively. All patients received aggressive supportive care and intravenous immunoglobulins. The second and third patients were also treated with intravenous cidofovir. Despite these measures, all three children deteriorated rapidly and died of fulminant liver failure. Although rare, adenovirus infection should be considered in the differential diagnosis of acute hepatitis in children receiving standard chemotherapy for ALL.

Incidence and outcome of adenovirus disease in transplant recipients after reduced-intensity conditioning with alemtuzumab

Adenoviruses are emerging as a major cause of infectious complications after allogeneic transplantation. We evaluated the incidence and outcome of symptomatic adenovirus infection or adenovirus disease after alemtuzumab-based reduced-intensity conditioning in 86 consecutive patients. The overall probability of adenovirus disease was 18.4% (11/86 patients). Five patients died of progressive adenovirus disease, and this was the most important infectious cause of mortality in this cohort. The probability of nonrelapse mortality was 49% in patients with adenovirus disease compared with 25.5% in those without (P=.007). The severity of lymphocytopenia and continuation of immunosuppressive therapy were the most important risk factors for progressive adenovirus disease and death. In contrast, patients who were not receiving immunosuppressive therapy or had had it reduced or withdrawn cleared the virus. We also detected a correlation between the lack of preemptive anti-cytomegalovirus (CMV) therapy for CMV reactivation and the risk of progressive adenovirus disease (P=.05). Our findings highlight the emergence of adenovirus as an important posttransplantation pathogen even after reduced-intensity conditioning and demonstrate the effect of the severity of lymphocytopenia, anti-CMV prophylaxis, and immunosuppressive therapy on the outcome of adenovirus disease.

Cidofovir for treating adenoviral hemorrhagic cystitis in hematopoietic stem cell transplant recipients

Adenovirus (AdV) infection is an important cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients. We treated 16 patients with AdV hemorrhagic cystitis (HC) following HSCT with cidofovir (CDV; 1 mg/kg/day, three times weekly for 3 weeks). Patients included 10 males and six females with a median age of 50 years (range 10-62). Two of the 16 patients were unevaluable because of early death from nonadenoviral causes. CDV therapy cleared AdV from urine in 12 of 14 patients (86%). Of 14 patients, 10 (71%) showed clinical improvements in HC. Among 14 patients, seven (50%) had avoided renal damage, the most important CDV toxicity. One patient previously treated with foscarnet for cytomegalovirus (CMV) required hemodialysis, and CDV treatment was discontinued. In another patient, CDV treatment was discontinued because of grade 2 nephrotoxicity. Four patients became positive for CMV antigenemia while being treated with CDV, and two developed herpes simplex virus (HSV) stomatitis while being treated with CDV. CDV proved effective in treating AdV HC in transplant patients. However, CDV at 1 mg/kg/day given three times weekly failed to prevent breakthrough infection with CMV and HSV in some patients.

Late hemorrhagic cystitis after reduced-intensity hematopoietic stem cell transplantation (RIST)

We reviewed medical records of 256 patients to investigate the frequency and characteristics of hemorrhagic cystitis (HC) associated with reduced-intensity stem cell transplantation (RIST) as opposed to conventional stem cell transplantation (CST); 137 patients underwent CST and 119 RIST. Diagnosis of HC was made based on two or more episodes of sterile, macroscopic hematuria with normal coagulation profiles, without any evidence of renal stones or genitourinary malignancy. Actuarial frequency of HC development in RIST group was 7.6% (9/119), which gave a cumulative annual incidence of 11.7%. In CST group, 13 of 137 patients (9.5%) developed HC, giving an estimated annual incidence of 9.7%. The probability of developing HC was similar between the two groups (P=0.77). The viral etiologies of HC, adenovirus (n=12) and BK virus (n=2), were documented in eight patients after RIST and in six after CST. HC was milder and of a shorter duration, with less blood transfusion requirements, in RIST group than in CST group. A multivariate analysis revealed that HC was associated with antiadenovirus antibody positivity in the recipients, total dose of busulfan, and chronic GVHD. Although HC following RIST is less severe than that following CST, it is still a significant problem.

Treatment of adenovirus infections in the immunocompromised host

Adenovirus infections are increasing as causes of morbidity and mortality in severely immunocompromised patients. The currently available antiviral agents, ribavirin and cidofovir, have yielded mixed results in case reports and small case series. Similar to cytomegalovirus disease, established adenovirus disease is often difficult to treat. Therapy may yield poor results, even when effective antiviral drugs are used. New strategies, including pre-emptive therapy, should be tested in prospective, clinical trials. New agents and adoptive transfer of specific T-cells to adenovirus might improve the current situation.

Pulmonary complications of solid organ and hematopoietic stem cell transplantation

The ability to successfully transplant solid organs and hematopoietic stem cells represents one of the landmark medical achievements of the twentieth century. Solid organ transplantation has emerged as the standard of care for select patients with severe vital organ dysfunction and hematopoietic stem cell transplantation has become an important treatment option for patients with a wide spectrum of nonmalignant and malignant hematologic disorders, genetic disorders, and solid tumors. Although advances in surgical techniques, immunosuppressive management, and prophylaxis and treatment of infectious diseases have made long-term survival an achievable goal, transplant recipients remain at high risk for developing a myriad of serious and often life-threatening complications. Paramount among these are pulmonary complications, which arise as a consequence of the immunosuppressed status of the recipient as well as from such factors as the initial surgical insult of organ transplantation, the chemotherapy and radiation conditioning regimens that precede hematopoietic stem cell transplantation, and alloimmune mechanisms mediating host-versus-graft and graft-versus-host responses. As the population of transplant recipients continues to grow and as their care progressively shifts from the university hospital to the community setting, knowledge of the pulmonary complications of transplantation is increasingly germane to the contemporary practice of pulmonary medicine.

ADENOVIRUS NEPHRITIS IN HEMATOPOIETIC STEM-CELL TRANSPLANTATION

BACKGROUND

Although adenovirus (ADV) infections may involve many different organs, kidney infection is seldom reported in association with hematopoietic stem-cell transplantation (HSCT).

METHODS

In the present study, the diagnosis of ADV nephritis was established by the culture isolation of adenovirus or the immunocytochemical (ICC) demonstration of the adenoviral hexon protein. The clinical description of ADV nephritis was derived from retrospective review of clinical records to identify signs, symptoms, outcomes, and associated complications. ADV nephritis was characterized as a pathologic entity by the histologic and ICC analysis of tissue from the kidney and all other major organs to establish the distribution of the virus and the associated gross and microscopic alterations.

RESULTS

ADV nephritis was diagnosed in 21 HSCT patients, in 2 by biopsy and in 19 at autopsy. Focal signs of BK nephropathy were present in only one patient. Twenty had received allogeneic marrow and one had undergone autologous transplantation. Graft-versus-host disease was a risk factor. ADV nephritis was associated with acute renal failure in 90% of the infected patients. Prodromal symptoms included fever, hematuria, and flank pain. Adenoviruria was present in 78% of the patients. Kidney infection as determined by viral antigen ICC predominantly involved the tubular epithelial cells. ADV organ tropism was striking, with sero-types from subgenus B, cluster 2, primarily responsible for cases involving predominantly the urinary system. ADV infection was a major cause of death in 17 patients.

CONCLUSIONS

ADV nephritis is a specific renal complication in HSCT patients that can be diagnosed by renal biopsy in patients with hematuria and adenoviruria.

Adenovirus infection in hospitalized immunocompetent children

This study investigated the clinical features of immunocompetent children with adenovirus infection requiring hospitalization. The files of 78 children (mean age 17 +/- 10 months) with community-acquired adenovirus infection admitted over a 2-year period were reviewed. The children were referred after 5.7 +/- 3.4 days of illness, all with fever (mean peak 39.8 +/- 0.8 degrees C). Temperature normalized after 3.5 +/- 2 days. Duration of hospitalization (mean, 7.0 +/- 3.9 days) correlated with lethargy, lung crackles, cracked lips, hypoxia, impaired liver tests, and high serum lactic dehydrogenase (LDH) concentration at admission. Serum LDH concentrations and hypoxemia predicted 70% of the variance in hospital stay. All patients recovered. Adenovirus infection may cause considerable morbidity, even in immunocompetent children. Disease severity, defined by duration of hospitalization, correlates with serum LDH concentrations and oxygen saturation at admission.

Isolation and expansion of human adenovirus–specific CD4+ and CD8+ T cells according to IFN-γ secretion for adjuvant immunotherapy

OBJECTIVE

In patients with lymphopenia following allogeneic stem cell transplantation adenovirus (ADV) infection is associated with high morbidity and mortality despite aggressive antiviral drug therapy. Virus-specific T cells seem to be essential for virus elimination. The aim of this study was to isolate and expand donor-derived human ADV-specific T lymphocytes for adoptive transfer of sufficient cell numbers to restore protective immunity after allogeneic stem cell transplantation.

MATERIALS AND METHODS

A clinical-grade strategy to generate ADV-specific T cells using the interferon-gamma (IFN-gamma) secretion assay, followed by expansion to numbers sufficient for clinical application with interleukin-2 (IL-2) and feeder cell stimulation, is described.

RESULTS

A mean number of 3.4 x 10(6) (+/-3 SD) ADV antigen-specific T lymphocytes were isolated from 0.1 to 2 x 10(9) mononuclear cells from peripheral blood (n=5) or leukapheresis products (n=6). Characterization of ADV-specific T cells after isolation revealed a mean purity of 85.1% (+/-12% SD) using antigen-specific intracellular cytokine staining. Isolated cells were expanded ex vivo for a median of 18 days (range 7-29 days; n=5) to greater than 10(8) total cells using IL-2 and autologous feeder cell stimulation. ADV-specific response to adenovirus antigen was confirmed in the generated T cell lines, using intracellular cytokine staining, IFN-gamma Elispot assay, and (3)H-thymidine uptake. Generated T-cell lines showed specific killing of ADV-infected B-LCL (n=4). Alloreactive proliferation of generated T-cell lines in mixed lymphocyte cultures was significantly reduced when compared to unmanipulated PBMCs.

CONCLUSION

Generation of adenovirus-specific T cells in a simple and rapid clinical-grade protocol was established, using IFN-gamma secretion assay with short expansion times, leading to sufficient numbers of ADV-specific T cells that can be used for adoptive immunotherapy.

A case of severe hemorrhagic cystitis following bone marrow transplantation

Hemorrhagic cystitis (HC) is a common adverse effect caused by the preparative regimens for bone marrow transplantation. Unfortunately, an effective therapy for HC has not yet been established. Here we report a case of severe HC in which the upper as well as the lower urinary tract were severely affected, resulting in right ureteral obstruction and a contracted bladder. Hyperbaric oxygen therapy was effective in suppressing the severe HC, but the cause of HC could not be identified. Five years after the bone marrow transplantation the patient underwent augmentation ileocystoplasty with ileal ureteral replacement.

Incidence and treatment of hemorrhagic cystitis in children given hematopoietic stem cell transplantation: a survey from the Italian association of pediatric hematology oncology–bone marrow transplantation group

The purpose of this multicenter study was to assess the incidence and the treatment of hemorrhagic cystitis (HC) in 1218 pediatric patients, with a mean age of 10.8 years, who underwent hematopoietic stem cell transplantation (HSCT). In all, 44 patients (3.6%) developed HC a median 23 days after HSCT. The incidence of HC was higher in allogeneic than in autologous HSCT recipients (P=0.0001). Of the 44 patients, 37 (84%) recovered from HC in a median 30 days (range 3-100); the other seven children died while still suffering from HC. Hyperbaric oxygen therapy (HOT) achieved significantly better results than prostaglandin therapy (P=0.02) in the treatment of grade II-III HC. By multivariate analysis, age <96 months and allogeneic HSCT were significantly associated with the occurrence of HC: P=0.008 and 0.013, respectively. After a median follow-up of 5.75 years, the 5-year survival of patients who did or did not develop HC was: 43 vs 52%, P=0.03, respectively. This study indicates that age and type of HSCT are factors predisposing to HC in children given HSCT and demonstrates the promising role of HOT in a conservative approach to HC treatment.

Molecular monitoring of adenovirus in peripheral blood after allogeneic bone marrow transplantation permits early diagnosis of disseminated disease

Adenovirus (AdV) infection in the course of allogeneic stem cell transplantation (SCT) is associated with high transplant-related morbidity and mortality. Disseminated AdV disease is lethal in most instances. Early detection of AdV infection and identification of patients carrying a high risk of disseminated disease therefore remain a major challenge. In view of the large number of existing AdV types, we have established real-time polymerase chain reaction (PCR) assays permitting sensitive detection and quantification of all 51 currently known human AdV serotypes. In a series of 132 consecutive pediatric patients undergoing SCT, more than 5000 samples derived from peripheral blood (PB), stool, urine, and throat were screened for adenovirus infection by PCR during the posttransplantation period. Thirty-six patients (27%) tested positive by PCR, revealing AdV types of the subgenera A, B, C, D, and F. Except for enteritis in some patients with AdV positivity in stool, detection of the virus at sites other than PB was not associated with clinical signs of virus disease, and transplant-related mortality was not significantly different from AdV-negative patients. By contrast, 82% of patients who had detectable AdV in PB died from infectious complications (P <.001). Monitoring of PB specimens by real-time PCR permitted early diagnosis of invasive AdV infection in all instances. In patients who developed disseminated AdV disease, detection of the virus in PB preceded onset of clinical symptoms by a median of more than 3 weeks. The observation of AdV in peripheral blood may therefore serve as a basis for early initiation of preemptive antiviral treatment.

Adenovirus infection in pediatric small bowel transplantation recipients

BACKGROUND

The purpose of this study was to determine the prevalence of adenoviral infection in pediatric small bowel transplantation (SBT) recipients, examine risk factors for progression to histologic disease, and examine the impact of adenovirus on outcome.

METHODS

Beginning in July 2000, all SBT recipients had viral cultures for adenovirus, cytomegalovirus (CMV), and herpes simplex virus (HSV) obtained routinely during graft biopsies. The medical records were retrospectively reviewed for frequency and site of viral culture, types and doses of immunosuppressive drugs, episodes of rejection, histology of allograft biopsies, and other infections. Adenoviral isolates were typed by polymerase chain reaction and type-specific neutralization assays.

RESULTS

All 14 SBT recipients who met enrollment criteria had evidence of adenoviral infection (intestinal graft, 13; liver graft, 1). Eight of 14 developed histologic disease with identifiable adenoviral intranuclear inclusions. In contrast, CMV enteritis was identified in only one patient, who subsequently also developed adenoviral disease. No other viruses were detected. Adenoviral cultures were first positive within 30 days of transplant in nine. Patients with histologic disease were more likely than those without to have received intensive corticosteroid therapy (P<0.007), had virus isolated from more than one site (P=0.03), and had persistent positive cultures (P<0.01).

CONCLUSIONS

Adenovirus was commonly isolated from children undergoing intestinal transplantation. Progression to disease may be associated with more intensive immunosuppressive therapy and inability to clear virus.

Acute renal failure due to adenovirus-associated obstructive uropathy and necrotizing tubulointerstitial nephritis in a bone marrow transplant recipient

Management of post-transplant complications caused by severe adenoviral infection remains a major therapeutic challenge. A 17-year-old male who had undergone bone marrow transplantation for the treatment of acute lymphoblastic leukemia developed complete anuria following hemorrhagic cystitis 34 days after the transplant procedure. The computed tomogram scan revealed bilateral hydronephrosis, indicating acute renal failure because of obstructive uropathy. The emergency procedure of percutaneous nephrostomy caused massive bleeding in the left kidney, which eventually required a nephrectomy. Adenovirus-positive severe necrotizing tubulointerstitial nephritis was the histopathological diagnosis. Post-transplant acute renal failure because of hydronephrosis, which could be complicated by adenovirus-induced renal parenchymal disease, is of great concern and may cause significant problems with interventional treatment.

Adenovirus infection in hematopoietic stem cell transplantation: effect of ganciclovir and impact on survival

Adenoviruses (ADV) are emerging as important causes of morbidity and mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). In mainly non-T-cell depleted HSCT recipients, we analyzed the incidence of ADV infection, risk factors for infection, the effect of ganciclovir administered for prevention of cytomegalovirus (CMV), and the impact of ADV infection on survival. The overall incidence of ADV, irrespective of the method of detection, was 8.5% (450/5233) and 12.3% (43/348) after the first or second allogeneic HSCT, and 6.3% (78/1219) and 6.5% (5/77) after the first or second autologous HSCT, respectively. The most frequent sites of infection and disease were stool and gastrointestinal tract, respectively. Statistically significant risk factors associated with ADV infections among allogeneic recipients included younger age, grade II to IV graft-versus-host disease, year of transplantation, and a second allogeneic HSCT. Furthermore, allogeneic patients seronegative for CMV at transplantation and seropositive allogeneic patients who did not receive ganciclovir, either at engraftment or as pre-emptive therapy on CMV reactivation, were at higher risk of developing ADV infections compared with seropositive patients who received ganciclovir (odds ratio=1.8, 95% confidence interval (CI) 1.2 to 2.8, P=.005 and odds ratio=3.4, 95% CI 2.1 to 5.55, P<.0001, respectively). The hazard of overall mortality was higher in patients who contracted ADV compared with those who did not (hazard ratio 1.5, 95% CI 1.3 to 1.7, P<.0001). This study shows that ADV infections are associated with poor transplantation outcome in T-cell repleted HSCT recipients. Ganciclovir, given for CMV prevention, may have a protective effect. Controlled treatment and prevention studies are warranted.

Adenovirus meningoencephalitis in a patient with large B-cell lymphoma

We report a case of a 58-year-old female with neuromeningeal relapse of a large B-cell lymphoma which developed a meningoencephalitis due to adenovirus (ADV). Diagnosis of suspected viral meningoencephalitis was based on computed tomography (CT) scan radiological pictures, which were atypical for CNS neoplastic infiltrations, and it was confirmed by direct immunofluorescence performed on cerebrospinal fluid. Cultural exams identified adenovirus type 7. The ADV infection resolved after treatment with total four doses of cidofovir. Unfortunately, the hematological disease progressed and the patient died 2 months later from disseminated lymphoma.

Fulminant adenovirus hepatitis following bone marrow transplantation. A case report and brief review of the literature

Adenovirus infections are frequently encountered in immunocompromised patients and transplant recipients. However, fulminant hepatic failure due to adenovirus infection as a fatal complication in bone marrow transplant recipients is extremely rare. We report a case of fulminant adenovirus hepatitis in a 21-year-old allogeneic bone marrow transplant recipient who subsequently died of the disease. The diagnosis was established by histologic and immunohistochemical examination of a liver biopsy and was confirmed by liver tissue and blood cultures.

The impact of adenovirus infection on the immunocompromised host

Adenovirus (Ad) infections in immunocompromised hosts have increased in frequency as the number of patients with transplants of bone marrow, liver, kidney, heart and other organs increase in number and survive longer. The numbers of such patients have also increased because of the emergence of the HIV epidemic. Ad infections with the 51 different serotypes recognised to date have few pathognomonic signs and symptoms, and thus require a variety of laboratory-based procedures to confirm infection. These viruses have the ability to target various organs with relative serotype specificity and can cause diverse manifestations including serious life-threatening diseases characteristic of the organs involved. Ads have cytolytic and immunoregulatory properties. The clinical dilemma remains the prompt recognition of Ad-related disease, the differentiation of Ad infection from Ad disease and the differentiation from other causative agents. Since the armamentarium of effective antiviral agents available to treat Ads is unproven by controlled trials and the virus is often not acquired de novo, it is difficult to prevent reactivation in immunodeficient hosts or new acquisition from donor organs. Timely discontinuation of immunosuppressive agents is necessary to prevent morbid outcomes. The clinical diseases, diagnostic tests, antiviral agents and biological aspects of the Ads as pathogens in immunocompromised patients are discussed in the context of this review. Some of the newer diagnostic tests are based on the well-studied molecular biology of Ads, which also have been attenuated by selective viral DNA deletions for use as vectors in numerous gene therapy trials in humans.

Adenovirus pyelonephritis in a pediatric renal transplant patient

Gross hematuria, graft pain, and rising serum creatinine are classic signs of acute rejection, obstruction, or bacterial pyelonephritis for patients with renal transplants. This presentation often prompts percutaneous renal allograft biopsy. If subsequent evaluation fails to show evidence of acute rejection, obstruction, or bacterial infection, viral etiologies should be considered. We report a 14-year-old Hispanic female with a living-related renal transplant who had gross hematuria, graft tenderness, and increased serum creatinine, but did not have evidence of acute rejection, obstruction, or bacterial pyelonephritis. To our knowledge, this is the first report of adenovirus pyelonephritis in a transplanted kidney of a pediatric patient, with isolation of adenovirus in the urine and in the allograft using immunocytochemical techniques.

The complete nucleotide sequence, genome organization, and origin of human adenovirus type 11

The complete DNA sequence and transcription map of human adenovirus type 11 are reported here. This is the first published sequence for a subgenera B human adenovirus and demonstrates a genome organization highly similar to those of other human adenoviruses. All of the genes from the early, intermediate, and late regions are present in the expected locations of the genome for a human adenovirus. The genome size is 34,794 bp in length and has a GC content of 48.9%. Sequence alignment with genomes of groups A (Ad12), C (Ad5), D (Ad17), E (Simian adenovirus 25), and F (Ad40) revealed homologies of 64, 54, 68, 75, and 52%, respectively. Detailed genomic analysis demonstrated that Ads 11 and 35 are highly conserved in all areas except the hexon hypervariable regions and fiber. Similarly, comparison of Ad11 with subgroup E SAV25 revealed poor homology between fibers but high homology in proteins encoded by all other areas of the genome. We propose an evolutionary model in which functional viruses can be reconstituted following fiber substitution from one serotype to another. According to this model either the Ad11 genome is a derivative of Ad35, from which the fiber was substituted with Ad7, or the Ad35 genome is the product of a fiber substitution from Ad21 into the Ad11 genome. This model also provides a possible explanation for the origin of group E Ads, which are evolutionarily derived from a group C fiber substitution into a group B genome.

Phase II trial of intravenous CI-1042 in patients with metastatic colorectal cancer

PURPOSE

To evaluate the antitumor activity, safety, immune response, and replication of CI-1042 (ONYX-015), an E1B 55-kd gene-deleted replication-selective adenovirus, administered intravenously to patients with metastatic colorectal cancer

PATIENTS AND METHODS

Eighteen patients with metastatic colorectal cancer for whom prior chemotherapy failed were enrolled onto an open-label, multicenter, phase II study. CI-1042 was administered intravenously at a dose of 2 x 1012 viral particles every 2 weeks. Patients were evaluated for tumor response and toxicity; in addition, blood samples were taken for adenovirus DNA and neutralizing antibody analysis.

RESULTS

Common toxicities included flu-like symptoms, nausea, and emesis. All 18 patients eventually were removed from study because of progressive disease. Seven patients were assessed as having stable disease after 2 months of treatment, whereas two patients were considered to have stable disease after 4 months. Detectable circulating CI-1042 DNA was identified in 36% of patients 72 hours after last infusion, which is suggestive of ongoing viral replication.

CONCLUSION

In this phase II study, intravenous CI-1042 was administered safely to patients with advanced colorectal cancer. Toxicity was manageable, consisting primarily of flu-like symptoms. Stable disease was experienced by seven patients for 11 to 18 weeks.

Clinical assessment of a generic DNA amplification assay for the identification of respiratory adenovirus infections

BACKGROUND

respiratory adenoviruses are common, often resulting in serious sporadic and epidemic infections and impaired immunity can dramatically increase their severity. They are now thought capable of establishing latency. Diagnosis by culture is slow while direct antigen detection by immunofluorescence lacks sensitivity. Molecular diagnosis can be both rapid and sensitive but the genetic heterogeneity of adenoviruses poses problems.

OBJECTIVES

to design a generic adenovirus nested polymerase chain amplification assay designed to be capable of detecting all respiratory adenoviruses. This was achieved through optimised thermal cycling and the development of a generic degenerate primer set targeting the adenovirus hexon gene.

STUDY DESIGN

this was a cross-sectional study on 172 respiratory specimens from hospital-based patients, and one from a general practice, in Northern Ireland. A comparison was made between the amplification assay, virus culture and immunofluorescence.

RESULTS

the nested polymerase chain reaction (nPCR) assay had a generic capacity for adenovirus detection and an analytical sensitivity of 6.4x10(2) copies/ml. Using an expanded gold standard (defined as a true positive or a true negative where a specimen was positive or negative by at least two of the study assays, respectively), PCR had a clinical sensitivity and specificity of 46/46 (100%) and 15/126 (91.3%), respectively. Patients with acute respiratory adenovirus infections were more likely to be male (chi(2), p=0.005) and to present with a fever (chi(2), p=0.02) than patients diagnosed with another respiratory virus. Co-infection was identified in 12/172 patients.

CONCLUSIONS

the nested amplification assay proved highly sensitive in both the analytical and clinical settings for the detection of respiratory adenovirus infections.

Adenovirus infection of a renal allograft

One month after renal transplantation, a 60-year-old man developed acute allograft dysfunction associated with gross hematuria and dysuria. Urinary cytological examination showed viral inclusion-bearing epithelial cells. A renal transplant biopsy specimen showed granulomatous interstitial nephritis, tubular necrosis, and ground glass-like intranuclear viral inclusion bodies in tubular cells caused by an adenovirus (ADV) infection. A reduction in baseline immunosuppressive therapy resulted in rapid normalization of allograft function and ultimately viral clearance. We report this case not only to illustrate an exceptional manifestation of an ADV infection in a renal allograft, but also to highlight the beneficial effect of reduction in immunosuppressive therapy on viral replication and clinical outcome.

Cidofovir for adenovirus infections after allogeneic hematopoietic stem cell transplantation: a survey by the Infectious Diseases Working Party of the European Group for Blood and Marrow Transplantation

Adenovirus is an important cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation and there is no established therapy. Cidofovir has in vitro efficacy against adenovirus. We performed a retrospective analysis of 45 patients treated with cidofovir for adenovirus from 10 centers. In total, 16 patients had definite adenovirus disease, 13 probable disease, and 16 asymptomatic infections. A total of 31 (69%) patients were successfully treated with cidofovir, 10 failed, and four were not evaluable owing to early death from other causes. Cidofovir therapy was successful in 10 patients with adenovirus disease, 10 patients with probable disease, and in 10 patients with asymptomatic infections. The overall survival at 28 days and 6 months after initiation of cidofovir therapy was 76 and 46%, respectively. Of the patients, 18 developed toxicity associated with cidofovir: 14 developed renal toxicity and four other types of toxicities. We conclude that cidofovir may be useful against adenovirus after allogeneic hematopoietic stem cell transplantation but additional studies are needed.

Adenovirus: an increasingly important pathogen in paediatric bone marrow transplant patients

Adenovirus is increasingly being recognised as a significant pathogen in children following bone marrow transplantation. The virus is endemic in the general paediatric population, and frequently causes severe disease in immunocompromised patients, especially children. Immune responses to adenovirus infection are not fully understood but T-cell responses appear to be important for recovery. Infections can affect a variety of organs with gastrointestinal and urinary tract diseases being the most common. When disseminated infection occurs, reported mortality rates are as high as 60%. The responses to treatment in immunocompromised patients have generally been disappointing. New molecular diagnostic techniques have meant that adenoviral infections can now be detected early, often before symptoms have developed. Clinicians now screen for adenovirus infection to allow early initiation of treatment. It is hoped that this approach, together with effective antiviral therapy, will reduce the deaths from this common virus in high-risk children.

Cytomegalovirus and adenovirus infections and diseases among 75 paediatric unrelated allogeneic bone marrow transplant recipients

Viral infections remain a major complication of allogeneic bone marrow transplantation. A population of children who underwent unrelated allogeneic bone marrow transplantation in a single centre has been followed-up for viral infections and diseases. We describe the detection of cytomegalovirus (CMV) and adenovirus among 75 children transplanted between 1989 and 2000. CMV was detected among 22 patients (29%) and adenovirus among 19 patients (25%); they were associated with clinical diseases in 10 and 8 patients, respectively. Four patients had adenovirus and CMV coinfection. The obvious risk factor for CMV infection is seropositivity of the recipient prior to transplantation. Adenovirus is detected significantly more frequently when conditioning regimen includes anti-thymocyte or anti-lymphocyte globulin. Diseases associated with adenovirus have been correlated with a significantly higher mortality rate, stressing the need for the implementation of a systematic virological survey for this virus and for the evaluation of therapeutic protocols including new molecules.

Use of polymerase chain reaction for diagnosis of disseminated adenovirus infection

We report a fatal case of disseminated adenovirus infection with fulminant hepatic failure in an 8-month-old child after peripheral blood stem cell transplantation. The virus was identified in blood, urine, respiratory aspirate and stool samples and was typed as adenovirus type 2 through PCR and sequencing of part of the hexon gene, with the use of degenerated consensus primers.

Adenovirus infections following allogeneic stem cell transplantation: incidence and outcome in relation to graft manipulation, immunosuppression, and immune recovery

Adenovirus infections occur in 5% to 21% of patients following stem cell transplantation (SCT), with an associated mortality of up to 50%. However, a lack of prospective studies has hampered further developments in the understanding and management of this infection in the posttransplantation setting. We prospectively studied the incidence and outcome of adenovirus infections after SCT using preemptive screening and a policy of reduction or withdrawal of immunosuppressive therapy if the virus was isolated. The incidence of adenovirus infection was 19.7% (15 of 76), and the virus was isolated exclusively in recipients of T-cell-depleted grafts. Patients receiving 50 or 100 mg alemtuzumab in vivo were at the greatest risk of adenovirus infection (45% probability) regardless of donor type, and this was related to the slower lymphocyte recovery. Six (40%) of the 15 adenovirus-infected patients developed adenovirus disease. Severe lymphocytopenia (less than 300/microL) at the time of first detection of adenovirus was a major risk factor for development of adenovirus disease (P =.001). In addition, failure to reduce immunosuppression (P =.04) and a positive result of adenovirus polymerase chain reaction (PCR) in blood at diagnosis (P =.01) were both associated with fatal adenovirus disease. On the basis of this study, we recommend active surveillance for adenovirus infection in T-cell-depleted SCT and withdrawal or reduction of immunosuppressive treatment, if possible, in patients with adenovirus infection. Preemptive antiviral therapy is warranted for patients with severe lymphocytopenia or positive blood PCR, and in those in whom immunosuppressive therapy cannot be reduced.

High levels of adenovirus DNA in serum correlate with fatal outcome of adenovirus infection in children after allogeneic stem-cell transplantation

An increase in the incidence of adenovirus (AdV) infection leading to death among children who have undergone allogeneic stem-cell transplantation has made it necessary to find new ways to monitor AdV infection. In this retrospective study, levels of AdV DNA in serum samples obtained from 36 transplant recipients with stool cultures positive for AdV were measured by polymerase chain reaction (PCR) semiquantitatively by analyzing serial dilutions of the DNA template. Six (86%) of 7 children who died of AdV infection, compared with only 2 (7%) of 29 other patients, had high serum levels of AdV DNA (detectable by PCR at a > or =100-fold dilution of the DNA template; P<.0001). High serum levels of AdV DNA were reached a mean of 18 days before death (range, 6-29 days). Quantification of adenoviral DNA in serum may prove to be a valuable tool to diagnose and monitor AdV infection and disease in immunocompromised children.

Infectious risks and outcomes after stem cell transplantation: are nonmyeloablative transplants changing the picture?

PURPOSE OF REVIEW

Opportunistic infections contribute to morbidity and mortality after myeloablative allogeneic stem cell transplantation. The development of nonmyeloablative or toxicity-reduced conditioning regimens for allogeneic hematopoietic stem cell transplantation might change this picture significantly. These regimens are in general highly immunosuppressive, but effects on myelopoiesis and mucosal toxicities are usually reduced compared with myeloablative hematopoietic stem cell transplantation conditioning regimens. This review summarizes the infectious risks associated with each type of hematopoietic stem cell transplantation conditioning regimen, and presents the results of early clinical studies.

RECENT FINDINGS

Although the data are preliminary, the results of recent studies suggest that nonmyeloablative conditioning regimens may decrease the risks of bacterial infections associated with mucosal damage and persistent neutropenia; however, risks for late viral and fungal infections persist during severe graft versus host disease. Results of several case reports and series emphasize that therapeutic outcomes of infections may be improved in patients who receive nonmyeloablative conditioning regimens.

SUMMARY

Infectious risks and outcomes after hematopoietic stem cell transplantation appear to be in evolution given the introduction of alternative, nonmyeloablative conditioning regimens. Although infections remain a prominent cause of transplant-related mortality, the timing and types of infections may differ. Further studies are necessary to define appropriate preventative strategies, and to determine whether patients with ongoing infections might benefit from nonmyeloablative hematopoietic stem cell transplantation.

Etiology of diarrhea in patients undergoing allogeneic bone marrow transplantation in South India

BACKGROUND

No studies so far have examined enteric infections in patients undergoing bone marrow transplantation (BMT) in developing countries where asymptomatic carriage and colonization with enteric pathogens is frequent.

METHODS

A prospective study followed 65 patients who underwent BMT in South India between 1995 and 1998. Patients were screened for enteric pathogens before transplantation, weekly during the first 4 weeks after transplantation, and during all episodes of diarrhea.

RESULTS

Enteric pathogens were found in 60% of patients before or after transplantation. Pretransplantation screening revealed asymptomatic excretion of enteric pathogens in 29% (19/65). Forty-eight percent of patients undergoing BMT developed diarrhea. Diarrhea was mainly of noninfectious origin in the first 20 days after transplantation. More than 20 days after transplantation, the major causes of diarrhea were graft-versus-host disease and infection. Parasitic infections other than Cryptosporidium did not contribute significantly to morbidity in the pre- and posttransplantation period. Rotavirus and adenoviruses were found in approximately 12% and 5% of subjects, respectively. Bacterial infections in the posttransplantation period were found to be more common in India than in developed countries. Clostridium difficile-associated diarrhea was seen in the posttransplantation period but not before transplantation. Enterotoxigenic and enterohemorrhagic Escherichia coli caused symptomatic infections in the posttransplantation period, but the association of other classes of diarrheogenic E. coli with diarrhea was doubtful.

CONCLUSIONS

There was significantly higher mortality (P<0.01) in patients with symptomatic or asymptomatic gastrointestinal infections caused by bacteria than in patients with parasitic or viral infections or without enteric infections.

Infections diagnosed in the first year after pediatric stem cell transplantation

BACKGROUND

Cumulative incidence of infections in the first year posttransplantation in adult patients has been well-described. Such description is less than complete for pediatric stem cell transplantation (SCT) patients. Further among those patients who have been infected, analysis of risk factors for infection has not been well-described for a large cohort of pediatric SCT patients.

METHODS

We conducted a retrospective cohort study of infections in the first year after SCT at Duke University Medical Center. We recorded all infections in the first year after transplantation. We determined incidences for 6 categories of infection: gram-negative rods; gram-positive cocci; yeast species; Aspergillus sp.; adenovirus; and cytomegalovirus. We determined incidences based on type of transplant and days post transplantation. We also completed bivariable and multivariable analysis of risk factors [neutropenia, graft vs. host disease (GVHD) and GVHD treatment] for infection type among those children who were infected.

RESULTS

We evaluated 510 transplants in 485 children. There were 584 infections in the first year after transplantation. During the first 30 days posttransplantation, type of transplantation did not predict incidence of infection or type of infection. After 30 days children who received unrelated cord blood transplant and matched unrelated donor transplant were at much higher risk of infection than were patients who received autologous, matched sibling or haploidentical transplant (P < 0.001). Patients who received unrelated cord blood or matched unrelated donor transplantation were at higher risk of aspergillosis (P = 0.002), candidiasis (P = 0.005) and adenovirus (P < 0.0001) but not cytomegalovirus (P = 0.18). In analysis of risk factors among those infected, patients with aspergillosis were more likely to have severe GVHD: multivariable 1 year risk ratio, 7.5; 95% confidence interval, 3.0, 18.4. Neutropenia was more strongly associated with gram-negative rod infection than any other type of infection.

CONCLUSIONS

The incidence of infection immediately after transplantation did not differ significantly by type of transplant in this pediatric population. Type of transplant predicted increased incidence of infection 30 days posttransplantation and increased incidence of infection with several organisms traditionally associated with a high mortality rate in the transplant population.

Viral causes of diarrhea

Viruses are important causes of diarrhea. In healthy adults, the main clinical manifestation is acute, self-limited gastroenteritis. Advances in molecular diagnostics have shown that epidemics of acute gastroenteritis most frequently are due to caliciviruses spread through contaminated food or through person-to-person contact. Application of similar technology is needed to make a definitive statement about the role of such candidate viruses as rotavirus, astrovirus, and adenovirus as the cause of nonepidemic acute gastroenteritis in adults. Rarely a previously healthy adult gets acute CMV colitis. CMV and EBV mainly cause diarrhea in immunocompromised patients, however. Advances in prophylaxis and treatment have reduced the frequency and severity of these diseases. Acute infantile gastroenteritis is caused by rotavirus, calcivirus, astrovirus, and adenovirus. These viral diseases of the gut are seen by the physician as routine and rare clinical problems.

Fulminant hepatic failure secondary to adenovirus following fludarabine-based chemotherapy for non-Hodgkin's lymphoma

Self-limited adenoviral infections are very common with the majority of infections resolving rapidly. Fatal complications may occur in severely immunocompromised patients. We describe a case of fulminant hepatic failure due to adenovirus in a 54-year-old man treated with fludarabine and cyclophosphamide for non-Hodgkin's lymphoma. There are no previous reports of this complication in conjunction with purine nucleoside therapy.

Fatal disseminated adenoviral infection associated with thrombotic thrombocytopenic purpura after allogeneic bone marrow transplantation

Adenoviruses are increasingly recognized as a significant cause of morbidity and mortality in immunocompromised patients. We report on a patient who, approximately 4 weeks after allogeneic stem cell transplantation, developed fever, new liver lesions and thrombotic microangiopathy. Adenovirus type 2 was isolated from blood and urine samples. Liver biopsy showed parenchymal necrosis with intranuclear viral inclusion bodies. Immunohistochemistry was positive for adenovirus. In addition, on electron microscopy the morphologic pattern was highly suggestive of adenovirus. The patient died on post-transplant day 40. The relatively early post-transplant presentation of disseminated adenoviral disease and its possible association with a TTP-like picture are rather unusual after allogeneic transplantation.

Adenoviral infection after allogeneic stem cell transplantation (SCT): report on 130 patients from a single SCT unit involved in a prospective multi center surveillance study

The incidence of adenovirus (AV) infections following SCT was determined in a prospective multicenter trial. Over 1 year, 130 consecutive patients undergoing allogeneic SCT at Essen University Hospital were included and followed for 6 months. Source of stem cells was blood in 68 cases. Fifty-eight patients had HLA-identical sibling donors. Throat swabs, urine and stool samples were screened weekly for AV antigen and DNA by ELISA and nested PCR, respectively. In 35 cases adenovirus infection was detected. There was no seasonal variation. Throat swabs were positive in 24, urine in 12, and stool in 11 cases, resulting in a cumulative risk of infection of 29%. The incidences of AV infection of the respiratory, gastrointestinal and urinary tract were 19%, 10%, and 9%, respectively, and infections were diagnosed after a median (range) interval of 44 (-2-179), 37 (-2-168), and 53 (17-153) days after transplantation. On multivariate analysis, presence of AV antibody in the donor and acute graft-versus-host disease grade IV were found to be independent risk factors for AV infection. Eleven patients had AV isolated from more than one site and five patients had probable AV disease. We were not able to identify patients in whom AV infection was the leading cause of death. The majority of patients infected with AV suffered from severe acute graft-versus-host disease often accompanied by other opportunistic infections, such as aspergillosis or CMV reactivation. Nineteen out of 36 patients who died during the observation period had AV infection. In summary, AV infection after allogeneic SCT was observed in a substantial number of patients. In addition to well-known risk factors for viral infection after SCT we were able to demonstrate that a positive AV antibody test in the donor is an important risk factor for AV infection. Further studies are needed, however, before final conclusions on the clinical sequelae of AV infection can be made and the role of preventive and therapeutic strategies toward AV infection after allogeneic SCT can be defined.

Lethal adenovirus infection in a patient who had undergone nonmyeloablative stem cell transplantation

We present a case of adenovirus (ADV) infection in a patient who had undergone nonmyeloablative stem cell transplantation (NST). A 50-year-old man with chronic myelogenous leukemia in the second chronic phase underwent NST from an HLA 2-loci-mismatched sibling. ADV hemorrhagic cystitis developed and progressed to lethal pneumonia. ADV was isolated from urine, bronchoalveolar lavage fluid, and postmortem specimens of kidney and liver. Because there are few reports of lethal pneumonia associated with ADV in Japan, we present the case and discuss the cause of and therapy for the infection.

Gastrointestinal infections in the immunocompromised host

Gastrointestinal disease is a significant cause of morbidity and mortality in the immunocompromised patient. This article focuses on the infectious gastrointestinal complications associated with the treatment of malignant disease and with solid organ transplantation but not HIV. Gastrointestinal defenses and the various mechanisms by which they are impaired are reviewed. The major pathogens and malignancies of this patient population and an approach to their diagnosis, treatment, and prevention are discussed.

Infections following hematopoietic stem cell transplantation

Numerous advances have been made in the management of infection in HSCT recipients. With increasing knowledge the authors are able to prevent several serious infections from occurring, and reduce the severity of infections once they occur. Despite these advances, several previously unrecognized pathogens have emerged and pose risks to this population. Ongoing surveillance and reporting of atypical infections are warranted. Transplant and infectious disease clinicians alike must be vigilant to the shifts in infectious syndromes as a consequence of various prophylaxis and preemptive strategies, and be ready to modify empiric strategies to meet the changing microbiologic milieu. As we increase our understanding of the HSCT process, and use the immune system rather than relying on high-dose chemotherapy, the authors are likely to reduce toxicities and improve patient outcomes.