Adenovirus-associated hemorrhagic cystitis in a pediatric renal transplant recipient

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.

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

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

Virus-specific T cells in pediatric renal transplantation

After pediatric kidney transplantation, immunosuppressive therapy causes an increased risk of severe viral complications, especially from cytomegalovirus (CMV), BK polyomavirus (BKPyV) or Epstein-Barr virus (EBV), and less frequent from adenovirus (ADV). However, suitable predictive markers for the individual outcome of viral infections are missing and the therapeutic management remains a challenge to the success of pediatric kidney transplantation. Virus-specific T cells are known for controlling viral replication and there is growing evidence that virus-specific T cells may serve as a prognostic marker to identify patients at risk for viral complications. This review provides an overview of the usability of virus-specific T cells for improving diagnostic and therapeutic management of viral infections with reference to the necessity of antiviral prophylaxis, timing of pre-emptive therapy, and dosing of immunosuppressive medication after pediatric kidney transplantation. Several studies demonstrated that high levels of virus-specific T cells are associated with decrease of virus load and favorable outcome, whereas lack of virus-specific T cells coincided with virus-induced complications. Accordingly, the additional monitoring of virus-specific T cells aims to personalize the management of antiviral therapy, identify overimmunosuppression, and avoid unnecessary therapeutic interventions. Prospective randomized trials in pediatric kidney recipients comparing standard antiviral and immunosuppressive regimens with T cell-guided therapeutic interventions are needed, before monitoring of virus-specific T cells is implemented in the routine care of pediatric kidney graft recipients.

Prospective Assessment of Adenovirus Infection in Pediatric Kidney Transplant Recipients

BACKGROUND

Adenovirus infection is associated with graft dysfunction and graft loss in pediatric cardiac, lung, and liver transplants in prior retrospective studies, but data in pediatric kidney transplant recipients is limited.

METHODS

We conducted a prospective single-center cohort study of 75 consecutive pediatric kidney transplant recipients who underwent monthly screening for adenovirus viremia and symptom assessment for 2 years posttransplant.

RESULTS

Adenovirus viremia was detected in 11 (14.7%) patients at a median onset of 173 days (interquartile range, 109-310 days) posttransplant, 6 (8%) had asymptomatic viremia, and 5 (6.7%) had symptomatic disease (2 with hematuria and 3 with an acute febrile respiratory illness). Viremic patients did not differ from nonviremic patients in age, immunosuppression management, or cytomegalovirus or Epstein-Barr virus serostatus, but were more likely to develop cytomegalovirus viremia during the first 2 years posttransplant. No patient had an increase in creatinine from baseline during the time of adenovirus viremia. In a Cox proportional hazards regression, subclinical adenovirus viremia was not associated with a faster time to a 30% decline in estimated glomerular filtration rate.

CONCLUSIONS

Adenovirus infection is common among pediatric kidney transplant recipients and frequently causes symptomatic disease; however, symptoms are often mild and are not associated with a decline in graft function. Routine monitoring for adenovirus viremia in pediatric kidney transplant recipients may not be warranted.

Adenovirus: Epidemiology, Global Spread of Novel Serotypes, and Advances in Treatment and Prevention

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

[Hemorrhagic cystitis due to adenovirus in a renal transplant recipient: the first reported case in black Africa in a setting of a very beginning of a kidney transplantation program and review of the literature]

Viral infections are an important complication of transplantation. Polyomavirus are the commonest viruses that infect the renal allograft. Herpes virus nephropathy has also been described. In the past 15 years, adenovirus nephritis has emerged as a potentially life-threatening disease in renal transplant patients in developed countries. Most of the papers devoted to adenovirus nephritis are reported cases. The fate of such patients in resources-limited countries is not known. Herein, we describe the clinical, biological and prognostic findings of a black African transplanted patient with adenoviral hemorrhagic cystitis. This case is the very first of its kind reported in black Africa in a setting of a start of a renal transplantation pilot project. The patient is a 54-year-old man admitted at the nephrology service for gross haematuria and fever occurred 1 month after kidney transplantation. The diagnosis of adenoviral hemorrhagic cystitis has been suspected because the patient has displayed recurrent conjunctivitis and gastroenteritis well before transplantation, which was then confirmed by the real-time polymerase chain reaction performed on the blood. Conservatory measures associated with immunosuppression reduction have permitted the discontinuation of haematuria. This case has been discussed in regard of the epidemiology, the diagnosis, the treatment, the evolution and the prognosis of the adenoviral infection in the renal transplant patient. A review of the literature has been performed subsequently.

Respiratory viral infections in hematopoietic stem cell and solid organ transplant recipients

Respiratory viral infections (RVIs) are common causes of mild illness in immunocompetent children and adults with rare occurrences of significant morbidity or mortality. Complications are more common in the very young, very old, and those with underlying lung diseases. However, RVIs are increasingly recognized as a cause of morbidity and mortality in recipients of hematopoietic stem cell transplants (HSCT) and solid organ transplants (SOTs). Diagnostic techniques for respiratory syncytial virus (RSV), parainfluenza, influenza, and adenovirus have been clinically available for decades, and these infections are known to cause serious disease in transplant recipients. Modern molecular technology has now made it possible to detect other RVIs including human metapneumovirus, coronavirus, and bocavirus, and the role of these viruses in causing serious disease in transplant recipients is still being worked out. This article reviews the current information regarding epidemiology, pathogenesis, clinical presentation, diagnosis, and treatment of these infections, as well as the aspects of clinical significance of RVIs unique to HSCT or SOT.

Infection and chronic allograft dysfunction

With the advent of more potent immunosuppressive regimens, the incidence of acute rejection following renal transplantation has declined sharply in recent years. In spite of this, long-term graft outcomes remain suboptimal because of relentless attrition by cumulated insults to the allograft. As acute rejection rates have declined, other causes of graft injury and loss have recently emerged. Among these, infectious diseases remain a persistent threat and can be associated with allograft dysfunction. This group includes nephropathy due to polyoma (BK) virus infection, cytomegalovirus disease, and bacterial infection (the latter most commonly arising from the urinary tract). Rarer infectious causes of chronic allograft dysfunction include cryoglobulinemia associated with hepatitis C, Epstein-Barr virus-associated posttransplant lymphoproliferative disease, and direct cytotoxicity from adenoviral infection or parvovirus B19.

Hematuria due to adenoviral infection in bone marrow transplant recipients

Late-onset hemorrhagic cystitis (HC) caused by adenovirus (AdV) infection is a common complication in hematopoietic stem cell transplantation (HSCT) recipients. However, limited information exists regarding adenovirus-associated HC. We report a retrospective study of 84 hematopoietic stem cell transplant recipients that evaluated the incidence and risk factors for AdV-induced HC. The development of HC was strongly related to adenoviral infection (P = .004). Among 13 patients who developed late-onset HC, AdVs were identified as a causative agent in 10 cases. AdV preferentially affected younger (P = .013) and male patients. Affected subjects had been transplanted for either malignant (7/10) or nonmalignant disorders (3/10). Most cases of AdV-hematuria were self-limited single or recurrent mild hemorrhagic episodes (P = .000), occurring at a median of 41 days after transplantation and lasting an average of 4 days. Viral load in patients with AdV-induced HC was similar to infected subjects who did not develop HC (2.5 × 10(3) vs 3.4 × 10(3) copies/mL). We HC occurring before 200 days was associated with a greater risk of a fatal outcome (P = .002) but occurrence of AdV infection did not affect a patient's survival. Our study confirmed the suggestion that non-AdV coinfections may worsen the course of AdV-HC.

Treatment strategies to minimize or prevent chronic allograft dysfunction in pediatric renal transplant recipients: an overview

Long-term allograft survival poses a major problem in pediatric renal transplantation, with allograft nephropathy being the principal cause of graft failure after the first post-transplant year. The mechanisms of nephron loss resulting in graft dysfunction are multiple, comprising both immunologic factors such as acute and chronic antibody- or T-cell-mediated rejection and non-immunologic components. The latter include peri-transplant injuries and renovascular lesions (renal artery stenosis, thrombosis) as well as cardiovascular risk factors such as arterial hypertension and hyperlipidemia. Another relevant issue leading to progressive nephron loss and declining kidney transplant function is acute and chronic nephrotoxicity induced by the calcineurin inhibitors (CNIs) ciclosporin (cyclosporine microemulsion) and tacrolimus. Furthermore, the presence of an abnormal lower urinary tract as well as bacterial (recurrent pyelonephritis) and viral (cytomegalovirus [CMV], polyomavirus [BK virus; BKV]) infections are crucial factors involved in the incidence of chronic allograft dysfunction and graft failure. Renovascular lesions and lower urinary tract obstruction are typical indicators for surgical intervention. The aim of treatment in pediatric patients with renal failure secondary to a dysfunctional lower urinary tract is to create a sterile, continent, and nonrefluxive reservoir. Surgical techniques such as bladder augmentation and the introduction of intermittent catheterization and anticholinergic therapy have significantly improved graft outcome. Arterial hypertension, another factor responsible for graft function deterioration in pediatric renal transplant recipients, is controlled preferably by the use of angiotensin converting enzyme (ACE) inhibitors or angiotensin II receptor antagonists, which are known to possess nephroprotective properties in addition to their potent antihypertensive effects. Although treatment of subclinical rejection with augmented immunosuppression has been associated with better graft survival, an increase of the immunosuppressive level to avoid subclinical rejection should be weighed against the risk of infection. The majority of viral infections affecting kidney allografts are caused by CMV and BKV. Antiviral CMV prophylaxis or pre-emptive therapy with ganciclovir has been shown to have beneficial effects in the pediatric renal transplant population. Treatment of BKV-induced nephropathy is based on reduction of the immunosuppressant therapy, although specific antiviral agents such as cidofovir and leflunomide are known to inhibit BKV. However, cidofovir itself is nephrotoxic and should therefore be administered cautiously to pediatric renal transplant patients. Since CNIs are likewise known for their nephrotoxic effects, especially with long-term use, alteration of the immunosuppressant regimen is necessary in case of deteriorating graft function due to CNI-induced histopathologic changes. Complete CNI avoidance seems inappropriate because, in this situation in pediatric renal transplant recipients, other relatively potent immunosuppressant agents such as lymphocyte-depleting antibodies, which are frequently accompanied by a higher incidence of infections, are needed for rejection prophylaxis. CNI withdrawal and switching of the immunosuppressant regimen from CNI therapy to sirolimus may be an option for some pediatric renal transplant patients with less advanced graft function deterioration. Nevertheless, potential adverse events such as aggravation of proteinuria, hyperlipidemia, myelosuppression, and hypergonadotropic hypogonadism have to be considered, and controlled studies are lacking. At present, an immunosuppressant maintenance therapy composed of low-dose tacrolimus or ciclosporin (CNI minimization) and mycophenolate mofetil with low-dose corticosteroids appears to be the most promising strategy to adopt in pediatric renal transplant recipients at low or normal immunologic risk.

Hemorrhagic cystitis secondary to adenovirus infection in a kidney transplant recipient: case report

Increasingly potent immunosuppressive agents have reduced the incidence of rejection of transplanted organs while increasing patient susceptibility to opportunistic infections and cancer. Adenoviruses are increasingly recognized as contributors to morbidity and mortality in stem cell and solid-organ transplant recipients. Clinical findings range from asymptomatic viremia to respiratory and gastrointestinal disease, hemorrhagic cystitis, and severe disseminated illness. We describe the first case in Chile of hemorrhagic adenovirus cystitis after renal transplantation in an adult.

Disseminated adenovirus infection in renal transplant recipients: the role of cidofovir and intravenous immunoglobulin

Disseminated adenovirus (ADV) infection in solid organ transplant patients is associated with high mortality. Limited studies have shown benefit from using cidofovir (CDV), as well as intravenous immunoglobulin (IVIG). In this study, we report 2 renal transplant patients who presented with fever and pulmonary infiltrates. Both patients continued to worsen despite antibiotic therapy. Bronchoalveolar lavage viral culture and serum polymerase chain reaction (PCR) were positive for ADV. Patients were treated with CDV, IVIG, and reduction in immunosuppression. A progressive decline in serum ADV DNA by PCR correlated with clinical improvement and pulmonary infiltrates improved. Both patients recovered. Allograft function was preserved although reversible acute kidney injury was observed in both patients. To the best of our knowledge, this is the first successful use of CDV and IVIG in renal transplant patients with disseminated ADV infection.